Next Article in Journal
Workers of Apis mellifera Reared in Small-Cell Combs Show Higher Activity of the Proteolytic System in Hemolymph than Workers Reared in Standard-Cell Combs in Laboratory Cage Tests
Next Article in Special Issue
Dietary Malondialdehyde Damage to the Growth Performance and Digestive Function of Hybrid Grouper (Epinephelus fuscoguttatus× E. lanceolatu♂)
Previous Article in Journal
Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome
Previous Article in Special Issue
Behaviour in Slower-Growing Broilers and Free-Range Access on Organic Farms in Sweden
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Valorization of Food Waste as Animal Feed: A Step towards Sustainable Food Waste Management and Circular Bioeconomy

Department of Bio Engineering, National Institute of Technology Agartala, Jirania 799046, India
Department of Applied Biology, University of Science and Technology Meghalaya, Baridua 793101, India
Department of Food Engineering and Technology, Central Institute of Technology Kokrajhar, Kokrajhar 783370, India
Department of Food Technology, Karpagam Academy of Higher Education (Deemed to Be University), Coimbatore 641021, India
Department of Food Science, Fu Jen Catholic University, New Taipei City 242062, Taiwan
Authors to whom correspondence should be addressed.
Animals 2023, 13(8), 1366;
Submission received: 2 March 2023 / Revised: 5 April 2023 / Accepted: 14 April 2023 / Published: 16 April 2023
(This article belongs to the Special Issue Animal Health, Welfare and Sustainability of Organic Production)



Simple Summary

Have you ever thrown away food that you didn’t eat? Most people do this all around the world but throwing away food can actually harm the environment. One way to reduce this harm is by turning the food scraps into animal feed. This not only helps the environment but also makes livestock production cheaper. Different technologies have been developed to make a safe and healthy animal feed from food waste. This helps us to get rid of waste by giving animals a new source of protein and recycling the discarded food waste. This article talks about how to turn food waste into animal food and its advantages. However, it is important to make sure the feed is of high quality and safe for the animals. It is also important to do research and development to make even better food-waste-based animal feed by reducing production costs and waste disposal, thereby making things better for both the animals and the environment. Overall, using food waste as animal food is a good waste management idea that provides food security and preserves the environment. So, next time when you have some leftover food, remember that it could be turned into something useful instead of being thrown away.


The growing population and healthy food demands have led to a rise in food waste generation, causing severe environmental and economic impacts. However, food waste (FW) can be converted into sustainable animal feed, reducing waste disposal and providing an alternative protein source for animals. The utilization of FW as animal feed presents a solution that not only tackles challenges pertaining to FW management and food security but also lessens the demand for the development of traditional feed, which is an endeavour that is both resource and environmentally intensive in nature. Moreover, this approach can also contribute to the circular economy by creating a closed-loop system that reduces the use of natural resources and minimizes environmental pollution. Therefore, this review discusses the characteristics and types of FW, as well as advanced treatment methods that can be used to recycle FW into high-quality animal feed and its limitations, as well as the benefits and drawbacks of using FW as animal feed. Finally, the review concludes that utilization of FW as animal feed can provide a sustainable solution for FW management, food security, preserving resources, reducing environmental impacts, and contributing to the circular bioeconomy.

1. Introduction

Food waste (FW) is described as the loss of food that occurs at the end of the food chain. This loss of food results in a loss of resources such as labour, water, energy, and land that were used in production, as well as losses for retailers and customers [1]. Exorbitant amounts of food are wasted worldwide as a result of differences in food production, transportation, and consumption [2]. Compounding issues include the ongoing creation of garbage and the concurrent migration of people from rural to urban areas. Because of the variety in generation patterns, chemical and physical characteristics, as well as underlying challenges and differences in assessing their growing volume, managing food loss and waste is a huge task [3]. By 2050, researchers estimate that 68% of the world’s population will reside in urban areas, leaving only 30% of the population to produce the vast quantities of fruits, vegetables, and animal products needed by urban dwellers [4]. The features and composition of wasted food in various studies have also been summarized in the process of evaluating the policies and treatment alternatives in light of their significance in choosing the best prevention policies and treatment approaches [5]. Whereas the latter has been explored in terms of the recovery (reuses and recycle) and disposal of the FW hierarchy, the former has been illustrated via an analysis of the policies and regulation systems that have been enacted [6]. This has been utilized to gain understanding of the motivations guiding initiatives to handle FW sustainably [7]. “Circular economy” and “bioeconomy” are concepts on the cutting edge of change. According to the Circular Economy Action Plan [8], “circular economy” is defined as the long-term conservation of product value, materials, and resources in the economy with reduced waste generation. FW, in particular, is an important aspect of the circular economy and should be considered at various levels throughout the value chain. Food that is excreted and digested ends up as organic waste, energy recovery, or landfill disposal. Reduction of food loss and waste is a serious challenge in India, which needs to feed its rapidly growing population (1.7 billion by 2050) [9]. In order to alleviate the environmental burden that is caused by FW, alternative methods are required to repurpose FW into uses with a higher value [10,11]. This will minimize the impact that FW has on the environment and promote the long-term sustainability of our system of obtaining food [12]. The utilization of FW as an alternative source of animal feed contains a significant amount of promise for the purpose of overcoming the existing precarious situation, which is characterized by excessive costs and an inadequate supply of livestock feed [13,14]. This review discusses a complete explanation of the FWs and types, nutritive attributes of FWs, meat quality and animal growth, energy consumed to produce animal feed, types of FWs for animal feed, and the methods of converting FWs into animal feed, as well as the limitations of this process and the benefits and drawbacks of using FWs as animal feed.

2. Food Waste and Types

Depending on its nature and origin, FW can be categorized in a variety of ways. On the basis of their primary natural resource, FW can be classified as either plant or animal derived [15]. Similarly, FW may be classed as raw or uncooked FW, cooked FW, or semi-cooked FW, depending on the cooking method. Food is transported from the producer to the customer via a variety of routes during the production process, and waste is created at each of these levels. Agriculture is the first link in the food chain. As a result, growers are regarded as the main producers. At the secondary level of the human food chain, warehouses and businesses such as flour mills and food preservation mills can be thought of as primary distributors [16]. Due to the fact that they create processed food ingredients, they might also be considered secondary producers [17]. Markets, hotels, and restaurants are categorized as secondary and direct distributors at the third level of the human food chain [18]. Customers (also known as consumers) represent the apex of the food chain. Based on this human food chain, FW can be classified as follows: (i) agro FWs—that comes from farmers, (ii) industrial FWs—generated by wholesalers, (iii) market FWs—fresh and uncooked food made by secondary distributors, (iv) hotel and restaurant FWs—additionally generated by secondary distributors in the form of cooked products, and (v) domestic FWs—generated by customers. FW is divided into three types based on its physical state: solid FWs, semisolid FWs, and liquid FWs. Figure 1 depicts the overall classification of FWs.

3. Nutritive Attributes of FWs

The nutritional value of FW or loss per day has been estimated to be approximately 1200–1500 food calories [19]. Carbohydrates make up around 30 to 60% of FWs, whereas proteins range from 5 to 10%, and fats make up 10 to 40% [20]. The nutrients that are present in foods that are discarded are lost when those items are wasted. The generation of FW, measured in grammes per person per day, can be broken down into the following categories: cooked food (56%), vegetables (18%), fruits (16%), dairy (3%), and cereals (4%) [21]. Most food waste is a good source of nutrients for animals to eat. Therefore, FWs can be used as an alternative to feed for animals. It is thought that 1 tonne of dry FW could be used instead of the same amount of maize grain to meet an animal’s protein needs [22]. FW can be used instead of maize, which is a main feed source and has 8 to 10 percent protein [23]. Organic waste is being composted with the help of insects, which is a new trend. Insects are also being used as animal food because they are more nutritious than other foods. The fact that a mature larva of the black soldier fly Hermetiaillucens has 40 to 45% protein in biomass and up to 35 percent fat by dry weight demonstrates its usefulness as animal feed [24]. A study on H. illucens demonstrated that the fly can ingest a variety of organic wastes, including poultry feed, pig liver, pig manure, kitchen trash, vegetables and fruits, and rendered fish, with kitchen waste exhibiting the highest fly biomass output [24].The concentration of bioactive chemicals and polyphenols in food waste peel, pomace, and seeds is double that of the edible component used in animal feed production. The chemicals found in FW have anti-cancer, anti-bacterial, anti-oxidative, and immune-stimulant properties in vertebrates, as well as being linked to a lower prevalence of cardiovascular disease [25].FW has dyes such as carotenoids from tomato peel and carrot pomace, anthocyanin from banana bracts, and betalains from beetroot pulp. These dyes have anti-oxidant activities that can be used to protect living systems from oxidative damage by removing oxygen free radicals and making foods more stable by preventing lipid peroxidation in animals [25].

4. Food Waste in Animal Feed Production

Three times as much food is wasted as is produced each year (or 1.3 billion tonnes) [26]. “Food waste” is commonly used to describe the phenomenon of food spoilage in the last phases of the food supply chain, including retail and final consumption. “Food loss” is the term used when food is wasted during the production, post-harvest, and processing phases of the food supply chain. As one of the most underutilized resources, micronutrients in food are lost at an alarming rate due to FW. ”Food waste” is the term for wasting ideal nutrients meant for human consumption, which normally have good nutritional value. From the early and intermediate stages of the food supply chain, losses in impoverished nations substantially outweigh the FW that occurs in retail and ultimate consumption, it may be concluded that the bulk of food spoilage occurs during manufacture, transit, and warehousing [27]. Despite the importance of decreasing FW, the circular economy, which sees waste as a valuable resource, calls for the reintroduction of food scraps into the food supply chain [28].
Scientists from around the country (Table 1) are largely working on reintroducing food waste and surplus vegetables and fruits into the food chain as animal feed [29]. Instead of feed grains or protein sources, livestock ranchers have historically fed their animal’s food scraps [30]. Farmers can increase their earnings by utilizing food scraps to lower the cost of animal feed. Another key advantage is the reduction of environmental difficulties caused by the decomposition of such wastes. The use of industrial FW as animal feed comes with a number of drawbacks in addition to the benefits that were discussed before. These drawbacks include a lack of safety, an unpredictable nutrient profile, and expensive production costs. Because they include a high percentage of water, food scraps are more likely to deteriorate during the collection, transportation, and storage processes. As a consequence of this, the quality of animal feed that is manufactured from FW suffers during the processes of garbage collection, transportation, and storage [31]. In addition, commercial FW (namely waste from the food service and retail sectors) varies in both quantity and homogeneity and its nutritional make-up is inconsistent [32]. Manufacturers of recycled animal feed have addressed these challenges with innovative thinking and now successfully recycle FW into animal feed at a relatively low cost [33].
Particle solids from the waste solids separation process can be used in animal feed. These items can be used to dry or pellet FW for sale as animal feed. Animal feed has long been used and will continue to be utilized in the production of meat and poultry. Animal feed frequently contains blood, feathers, and bones that have been processed into a meal. Leftover meat that is deemed unfit for human eating is either sold to rendering enterprises or sent directly to them in order to prepare animal and pet meals [53]. The use of these resources benefits both the environment and the economy. This is due to the way they are marketed in comparison with other fats, vegetable oils, and proteins.
It has been common practice for many years to incorporate food scraps and other forms of trash into the diets of animals, particularly those that are kept on farms [54]. According to the FAO, around 30 percent of all of the world’s cow feed is comprised of waste or leftovers from the production and processing of food goods [55]. However, a sizeable amount of freshly produced food might be better suited for use as animal feed rather than being disposed of in landfills, where it would add to the greenhouse effect by releasing methane [56]. Landfills are one of the most significant contributors to the problem [57].This would be the environmentally preferable alternative. Reusing nutrients for feed through more circular systems can also assist to reduce the significant environmental impacts of growing feed crops, such as the consumption of land, energy, and water, while simultaneously improving food security by reducing FW and increasing food production [58]. Despite its apparent simplicity, returning FW into the food chain presents numerous obstacles. The ideal feed option for livestock must always be available and affordable. The pros and cons of reintroducing this waste into the food supply chain, as well as the environmental consequences, must also be considered [59]. Converting “waste into development potential” can be an effective strategy for preserving sustainability in the livestock industry [60].
According to Moult et al. [61], people think about environmental effects other than greenhouse gas emissions when they think about the possibility of using food waste as animal feed. Retailers’ choices regarding the handling of food waste are heavily influenced by considerations of their effect on the environment. Greenhouse gas (GHG) production, water consumption, and contamination of water, air, and soil systems are all examples [62]. Any way of getting rid of food waste will have a different carbon footprint depending on what kind of food is being thrown away and how it is thrown away. The average amount of methane captured by landfills around the world is 20% (landfills with no gas collection equipment) [63]. Due to the rules stated above in the UK, some of these ways to get rid of food are fictional, such as turning it into raw meat or feeding it to animals. However, they are still included in the list of GHG emissions so that the full picture can be seen.
During the manufacturing process, food waste can be generated from products that are damaged or of poor value that are abandoned in the field. Damage to the food while it is being transported, deterioration or contamination with bacteria while it is being stored, and losses while it is being processed all contribute to the wastage of food [64]. Food is thrown away in the retail system as a result of handling-related damage, a dearth of cold storage, and inadequate inventory management. Overbuying, improper storing, excessive preparation, improper portioning or heating, and inadequate reading of product labels are the primary causes of food waste produced by individual consumers [65]. An increased risk of infection occurs in a cyclical food system due to the retention and accumulation of microbial pathogens.

5. Methods of Converting FWs into Animal Feed

A range of processing processes are used to increase the nutritional content, digestibility, feeding efficiency, removal of toxins, pathogen sanitation, removal of non-edible components, feasibility for long-term storage, transportability, and marketability of FW [66]. FWs converting to a value-added product, such as animal feed, can enhance food efficiency by lowering the cost of animal feed, resulting in higher profitability for farmers and decreased environmental consequences caused by FW disposal [67]. Processing foods by changing their physical (and seldom chemical) qualities is a crucial stage in any such conversion process to improve feed quality, stable feed in the animal diet, and decrease loss during feeding [68]. The methods for processing FW concentrate primarily on feed conversion efficiency, higher feed intake, and cattle health, with decreased digestive diseases. Several processing techniques, including dehydration and/or drying, pelleting, extrusion, fermentation, silage production, etc., can be utilized to convert food scraps into animal feed. In order to transform a certain type of FW into an acceptable animal feed, these processing technologies are either combined or used independently. Conversion of FWs into animal feed by each producer is shown in Figure 2.

5.1. Solar Drying

The Gorgan University of Agricultural Sciences and Natural Resources in Iran developed and produced a waste dryer with a 25 kg capacity [69]. Figure 3 depicts the device’s major components. According to Bulgakov et al. [70] a vibrating dryer for FWs was simulated. Their theoretical studies have revealed that this form of drier is able to minimize humidity as a guarantee. Song et al. [71] also created a food waste dryer. If water is evaporated by the drier, the drying rate will be 19.65 percent, and if a mixture of water and other substances is dried, the rate will be 3.85 percent. In order to create animal feed, Rahmani et al. [69] studied the energy and exergy of semi-industrial FW drying equipment. The amount of energy that is being used, as well as the amount of lost exergy and the rate at which the potential is being improved, grows as the temperature rises [69]. The amount of energy needed to make feed from FW is 18.30 MJ/kg, which is 1.8 MJ/kg less than the amount of energy needed to make feed from corn [69]. Producing animal feed from FW is a viable option because it requires less resources and costs less money compared with other feed sources [69].

5.2. Spray Drying

Spray drying is one of the simplest ways to extend the shelf life of liquid extracts and improve the organoleptic features of products by converting extracts into a stable dry powder (Figure 4). With spray drying, liquid feeds (extracts) are atomized into the drying chamber, then the resulting droplets pass through a hot-air (or sometimes nitrogen) stream to evaporate [72]. The evaporation of water takes place at a faster pace when the droplets themselves are smaller since this increases the surface-to-mass ratio. Because of the speed and intensity with which this procedure is carried out, there is very little heat damage caused to sensitive material.
Several studies have employed microencapsulation by spray drying to create anthocyanin concentrates from sources such as grapes, cranberries, Roselle black carrots, hibiscus extracts, blueberry by-products, blackcurrants, bayberry juice, and many more [73,74]. An enormous amount of waste and by-products are produced during the processing of the plants used in the food, beverage, cosmetic, and pharmaceutical industries [75]. Peels, husks, unused plant components (seeds, roots, and broken leaves), and oil seed cakes are a few examples of plant by-products. Some non-plant businesses, such asthe fish and meat sectors, also produce waste and by-products. According to the FAO, without retail and consumer generated waste, 13.7% of all food is discharged as by-products and waste [76]. On the other hand, Gustavsson et al. [77] found that a third of the weight of all the food produced globally is regarded as waste. According to Red Corn et al. [78], over a quarter of all edible food is wasted. The phrases most frequently used to define losses during production, post-harvesting, and processing are “food wastes”, “food losses”, and “waste of plant origin”. Numbers are inconsistent and widely variable due to reporting differences; however, anywhere between 6% and 25% of the total amount of food produced is thrown away as waste [79]. One of the key objectives for sustainable development is the reduction and reuse of FW. Several sectors suffer large financial losses as a result of underutilizing by-products. Additionally, producers typically have to cover the cost of waste transportation and disposal [80].

5.3. Dehydration

For the management of home FW and pre-treatment using dehydration of FW segregated at source, the study’s methodology involved the use of a cutting-edge household garbage dryer. In this study, a novel approach for the separation and dehydration of FW separated at source is presented together with the methodology and findings of the first pilot-scale demonstration [81].The sanitary dehydration of FW at the source resulted in a large mass reduction, approximately 70% w/w, due to the removal of moisture content throughout the drying process, while the energy requirements remained economically acceptable [82].The created biomass’s low water content avoids biological decomposition, limits odour emissions, and so minimizes the frequency with which residential trash must be collected. Additionally, dry biomass is considerably easier to handle than wet FW. Moreover, the waste can be used in environmentally friendly and alternative methods to create high-value goods such as compost, bioethanol, biogas, animal feed, and thermal energy [83]. This is demonstrated by the waste’s evaluated physicochemical properties. Table 2 lists certain FWs and their basic processing techniques for the production of animal feed.

5.4. Freeze Drying

High-quality fruits and vegetables that have been dehydrated are frequently processed via freeze-drying. During freeze-drying protection, the water solid-state, low temperatures, and moisture sublimation processes preserve the fundamental structure and shape of the products, which also have a low bulk density, high porosity, and a stronger rehydration.
To remove the unfrozen solvent from a liquid formulation solvent, a desorption process must be used after the solvent has been extracted, frozen, and subjected to low pressure to cause the solvents to sublimate [105]. As a result, the process of drying can be broken down into two stages: sublimation (also known as primary drying) and desorption (also known as secondary drying). This is because both stages involve two processes that are equally as significant: freezing, in which almost all of the solvent is transformed into a solid that is frozen, and drying, in which the mixture almost completely gets rid of all of the solvent (frozen or unfrozen) [106].
In the process of freeze-drying, the food is first frozen, which consolidates it. The size and development of ice crystals depend on the freezing rate; sluggish freezing results in larger or smaller ice particles [107]. Only high-value foods such as coffee, ingredients for ready-to-eat meals (fruits and vegetables or meat and fish), and aromatic herbs are typically freeze-dried in the food industry. The solid waste produced during lengthy human-crewed space trips has been extensively handled by the MEADOW processor freeze-drying solid waste [108]. The two main drying techniques investigated were freeze-drying and vacuum-drying. A Peltier condenser collects wastewater vapour in either mode or transforms it back into relatively pure water. The dried waste product has less water activity than what is necessary for bacteria to continue their metabolic activity. The treated waste must be contained and kept in a way that prevents water from being reabsorbed for it to be stable. Many studies have shown that freeze-drying is an effective method for minimizing FWs [109]. However, they argued that freeze-drying was an inappropriate way to dispose of garbage due to its high cost. Yet, the unique circumstances will aid in minimizing waste for animal feed [110].

5.5. Microwave Drying

Processing agricultural crops after harvest effectively uses microwave drying. The drying sector can benefit greatly from three main factors: its speed, low energy usage, and good product quality [111]. The development of new technologies has made it possible to monitor and manage an increased number of parameters during the drying process. These characteristics include temperature, weight, power, aroma, and others. According to Bai et al. [112], the increased relative humidity of convection air may be a significant component that slows drying while preserving the quality of the products’ interior or exterior surfaces. The volatile compounds that are continuously released from the material being dried during microwave drying are transported by convection air. The moisture transport equation, whose driving force depends on the concentration difference, is comparable to the diffusion model for volatile chemicals [113]. There is very little research on using high humidity throughout the drying process [114]. Moreover, these works solely used natural, sun, and convective drying processes; microwave drying was not used. Microwave drying, which could be a valuable technique for processes such as drying vegetables and fruits in closed packages, requires research on the impact of high humidity on the drying rate as well as the product quality [115]. In this study, an effort is made to track and manage the convective air’s humidity in an effort to solve the issue. For this, a novel microwave drying technology was created. The system included three subsystems: a one-way air flow control system for removing the gaseous moisture, a thermostatic microwave heating system with online mass weighting, and a humidity measuring system [116]. Since waste foods are simple to obtain and have highly volatile chemicals, they were chosen as the drying samples. For the objective of changing the relative humidity surrounding the samples, various plans were made. Analysis and discussion were conducted on the connections between relative humidity and drying speed as well as between relative humidity and product quality [117]. The findings will be used to support the claim that high humidity improves the quality of the produced products.

5.6. Silage

Agriculture has undergone significant changes since the 1960s, with a focus on using science to produce crops, increased mechanization, and larger livestock farms [118]. With better animal diet and genetics, there was an increase in output per head of livestock. Between 1975 and 2000, the production of silage dry matter (DM) increased across the majority of European nations [119]. A decrease in hay output and an increase in the size of animal farms over that time period both contributed to this in part. In contrast, hay production increased substantially in the US during the same time period, with crops such aslucerne being cultivated expressly for that purpose [120]. The US had a similar pattern.
Farmers can employ grains and other commercial feeds, conserve seasonally surplus grass or other fodder crops, or a combination of these methods to manage seasonal feed shortages. Before to the 1960s, fodder was primarily stored as hay, typically gathered at a mature growth stage and vulnerable to weather uncertainties throughout the lengthy intervals between cutting and harvest [119]. This definition of silage refers to the collection and storage of fermented materials such as fermented whole-crop cereals, fermented crop by-products, and moist grass for use as livestock feed. Crop production, engineering, chemistry and biochemistry, microbiology, and animal nutrition are a few of the scientific and technological fields that are involved in the conservation process [121]. Because of this, the successful production of silage necessitates an understanding of the critical physical, chemical, and biological elements affecting the entire conservation process, among which oxygen and water are the most crucial, at least in terms of nutrient losses. Silage plays two crucial roles in the nutrition of livestock: (i) it serves as a preserved source of digestible nutrients in diets for high-producing animals to maintain optimal rumen function and lowers the risk of diseases such as rumen acidosis and displaced abomasa; and (ii) it serves as a supplemental feed to be used when the rate of pasture growth is insufficient in relation to animal needs, such as in the winter and during dry spells [122,123].

6. Meat Quality and Animal Growth

The proportion of FW that was employed in meals (the replacement rate) ranged from 10% all the way up to 100% in the various feeding experiments that were conducted [124]. Responses in terms of animal weight increase and/or feed use efficiency vary based on the animal species and physiological stage, as well as the length of the feeding trial, the type of FW, and the substitution rate [125]. A number of studies found no difference when comparing diets with substitution with diets without substitution [126,127,128]. On the other hand, other studies found that diets with substitution caused poultry [129] and pigs [130] to gain less weight. The findings of various investigations were compiled by Guo et al. [131], who found that pigs with a substitution rate of 50% had a growth rate that was 13% slower.
The quality of meat has been studied by comparing diets with and without food waste [132]. For instance, Katajajuuri et al. (1998) [133] discovered that pork from animals given heat-treated FW was comparable in flavour and quality with meat from pigs fed a maize–soy diet, as rated by a panel of volunteers. Giamouri et al. [134] revealed that, through blind tasting, panellists preferred the softness of lean meat from pigs fed a diet of liquid food waste over that of animals fed a regular diet. Using linear mixed models to examine the impacts of the inclusion of FW in pig diets, with the original data gathered from many studies, Giamouri et al. [135] found that feeding FW had no impact on 16 of 18 pork quality measures (e.g., juiciness, dressing percentage, meat colour, fat-free lean percentage, flavour, overall palatability, etc.). The discovered effects of two criteria (monounsaturated fats and marbling) were “weak and did not detrimentally affect pork quality or value”. The researchers concluded that including food waste into diets resulted in pork of comparable quality with that generated by animals fed normal diets [135].

7. Energy Consumed to Produce Animal Feed

Corn is one of the most commonly utilized products for animal feed. To determine the energy (Equation(1)) required for manufacturing animal feed from corn, it is necessary to compute all the energy entering the farm per kg of corn. Livestock production rises by an average of 2.46% each year [136], whereas the demand will rise owing to population expansion. Many sources (fossil energy, water, and land) are utilized to generate livestock, poultry, and aquatic feed, but the energy required for maize production in Iran comprises machinery, human labour, seeds, fertilizers, chemicals, and water. According to Banacian and Zangench [137], each kg of corn requires an average of 7.24 MJ of energy to grow. Similarly, Rahmani et al. [69] assumed that transporting maize to the feed mill consumed 0.4 MJ per kg of corn energy. Furthermore, the energy required for the conversion of corn-to corn guten feed has been calculated to be 12.46 MJ/Kg. Eventually, the production of each kg of livestock feed is calculated to be 20.10 MJ per kg.
E U C M = E U I F + E U T R + E U P R
where E U C M is the energy consumed to produce animal feed, EUIF is the total energy input to the farm, E U T R is the energy consumption for transportation, and E U P R is the total energy consumption for processing.

8. Types of FWs to Animal Feeds

A wide variety of domestic animals receive their nutrition from a variety of food scraps and waste products of the food industry. The total digestible nutrients (TDN) indicates the total amount of a meal or diet’s fat, protein, and carbohydrates that are digestible. Energy that can be digested is directly linked to TDN. The TDN is beneficial for cattle cow diets that are mainly foragebased. TDN values frequently underestimate the worth of giving concentrate in comparison to forage. Conversion and processing of food wastes not only prevents waste putrefaction but also helps to conserve abandoned food resources and transform them into economically viable goods [13]. Conversion and processing of FWs avoid putrefaction of wastes. Table 3 outlines several types of FW and the various species of animals that can benefit from its consumption as feed.

8.1. Poultry Feed

Poultry is an important component of livestock. Chickens are in such high demand because they are robust animals that mature very quickly in the majority of the world’s regions. Many people throughout the world rely heavily on chicken meat and eggs as a source of protein, as seen by the 25.2 million metric tons (MMTs) of chicken produced in the US alone in 2017 and the expected 83.9 MMTs of broiler output globally in 2018. By 2050, it is anticipated that worldwide meat production willincrease by 66% and that of industrialized nations will increase by 78% [161].
In broiler and layer diets, it is crucial to maintain a balance of nutrients including energy, crude protein, and crude fibre. Analyzing the nutrient makeup of chicken diets is necessary. A well-designed diet based on the nutritional needs of the animal and nutrient analyses of the feed ingredients may boost the animals’ feed conversion ratio. According to numerous studies, when compared with a conventional maize and soy diet, broilers fed food waste consisting of trash from various foods supply chain segments at different percentages performed noticeably similarly. The manufacturing and processing industry produces meat meal, cornflake leftovers, carrot top hay, and dried tomato pomace. Broiler feed has been successfully formulated from bakery trash. Truong et al. [56] discovered that 56-day-old broilers fed only corn/soy had no significant variations in body weights or feed conversion ratios when dried bakery goods up to 10% was added. Additionally, Siddiqui et al. [162] discovered that when compared with 42-day-old broilers fed only corn/soy, the addition of up to 30% dried bakery waste did not significantly alter body weight, feed conversion ratio, or feed intake. When broilers were given beef meal at 65 and 80 g/kg feed in a corn/soy-based diet, they had equivalent daily weight gain, daily feed intake, and feed conversion ratio to birds fed with a full corn/soy diet [163].

8.2. Fish Feed

Fish meal is the most valuable commodity in fish farming. Soybean hull, barley, corn, wheat, and other by-products can be used to replace more expensive feed ingredients [164]. Utilizing the by-products of industries that process mangoes allows for the production of freshwater fishes such ascarp and rohu. Fish wastes, including bones, heads, and intestines, as well as FWs such asgroundnut cake, palm kernel cake, wheat bran, rice bran, maize bran, and calf blood, can be used in fish feed production. FW fish feed is generally composed of fruit wastes such as peels with some fruit flesh from pineapple, watermelon, cantaloupe, blackberry, banana, and apple, as well as vegetable wastes such aslettuce, spinach, and so on. Fish feed consists of cereals such as rice bran, soybean meal, rice grain, and spaghetti. The fish feed that was prepared consisted of 60 to 70 percent animal by-products (beef, pork, and chicken) and 30 to 40 percent fish (salmon, etc.) [165]. Carrots have been utilized with mixed results as a source of natural colours. The cichlid fish (Cichlasomaseverum) receives 50 mg/kg of total pigments from a diet comprising carrots, resulting in the fish’s colour [139]. There was an increase in pigmentation in prawns given 10 percent frozen carrot tips. Organic wastes suchspent grain from breweries, palm kernel cake, and groundnut cake are used to make more fish meals. Garlic peel has been reported to have immunostimulant properties in aquaculture and to protect African catfish Clariasgariepinus from illness [166]. It also boosted resistance to infection by Aeromonashydrophila [167].

8.3. Cattle Feed

Large volumes of crop-based biomass produced by contemporary agri-food systems are unsuited for direct human consumption but may be used to feed animals for the production of meat, milk, and eggs. Fundamental problems with satisfying the increasing demand for food availability and justice, as well as the urgent need to reduce the impact of food on climate change, environmental degradation, and unsustainable resource exploitation are at the core of the problem [168]. Strategies that encourage circularity and increase the agri-food systems’ potential for regeneration are crucial in this situation. Indigestible, unpleasant, or unwanted biomass (IUUB), which is often unsuited for direct human consumption, is the principal way that biomass materials escape the food supply chain [169]. These materials frequently still contain high levels of proteins, carbs, and other macro-and micronutrients. Due to farm animals’ natural capacity to digest a range of biomass, these nutrients may be recycled by feeding cattle [170]. Consequently, increasing food production while reducing the strain on resources, the environment, and the climate may be accomplished by maximizing the use of IUUB materials through livestock feeding [171]. FWs or discards from different points in the food supply chains that are often not suitable for human consumption. Over the globe, a staggering 1140 MMTs of agricultural wastes and 600 metric tons (MTs) of industrial by-products are frequently utilized as feedstuffs [172]. Yet, there are still enormous quantities of undiscovered resources available for up-cycling using livestock. This is especially true for FWs/discards, which are now estimated to be between 1300 and 1600 MTs globally and 2500 MTs are expected to rise in the future decades [173] the effectiveness of ensiling to preserve leftover fruits and vegetables. On dairy farms, ensiling is a routinely utilized microbiological technique that serves the specific aim of preserving recently harvested feed crops (around 35%) for lengthy storage and feeding [174].
The most effective method is probably using animal feed since it converts FW into food that is high in protein while using very little infrastructure. The World Wildlife Fund (WWF) estimates that by-products from food production and processing make approximately 30% of the feed given to animals globally. Manufacturers and grocery stores supply the vast bulk of the 10% of extra food in the US that is delivered to feed animals [175,176]. Yet, 14.7 MTs of food waste remain that could be utilized as animal feed [177]. The majority of this is disposed of in landfills, which emit methane. Using waste alternatives might assist in preventing further land conversion for producing feed crops according to the WWF, which claims that all food waste to feed component manufacture had a beneficial influence on land usage.

8.4. Swine Feed

Swine may integrate dietary fatty acids into meat [178]. Georganas et al. [178] conducted a trial in which pigs were fed only boiled restaurant garbage (26.59% CP, 7.33% total lipids) without any additional food in comparison with a control group that was fed a typical diet (20.21% CP, 15.67% total lipids). Dried ripe banana peels can make up to 20% of the food of developing pigs and 30% of the diet of rabbits [25]. Pigs are mostly fed scraps from kitchens, such as uneaten food and vegetable peels, in addition to other readily available crops and the by-products of agricultural production. Pigs can be directly fed the scraps of fruit and vegetable products that are discarded at marketplaces. The majority of studies on the effect of feeding pigs waste food has been conducted with animals weighing between 50 and 250 pounds [179]. Pigs that are finished off on food scraps often reach a weight of at least 400 pounds before being slaughtered. Intake estimates range from approximately 8 to 10 lb (asfed) per pig per day for pigs weighing less than 100 to 200 lb or more for pigs weighing more than 250 lb [180]. Domesticated pig production in India is mostly reliant on unprocessed agricultural and household waste for the fulfilment of pig diets, whereas the cost of feeding contributes to around 80% of the total expense associated with pork production across the globe [181].

9. Safety Policies

Untreated FW may contain pathogens that cause disease. This was demonstrated by the 2001 outbreak of foot-and-mouth disease in the United Kingdom, which was caused by feeding uncooked food waste to pigs. In the same year, the United Kingdom government prohibited the use of FW in animal feeding, and one year later, the European Union issued a similar prohibition. The prohibition does not apply to FWs that contain no meat, fish, or other animal products [182]. These wastes, however, are limited to specific manufacturing by-products and account for a small proportion of EU food wastes. Appropriate heat treatments can make recovered feeds safe for animals by deactivating potentially harmful bacteria and/or viruses that may be present in these types of feeds; we believe that heat-treated waste should be exempt from the ban. Heat treatments can include prolonged heating to temperatures above 70 °C for more than 30 min in order to ensure the safety of the feed produced. Furthermore, when offering leftover human food to animals, disease issues become less important because human food specifications are generally more stringent than animal feed specifications. Furthermore, heat treatment would alleviate problems that arise after waste generation. Unfortunately, current EU bans restrict recycling FW as animal feed, allowing only 3 million tons of manufacturing food losses to be recovered as animal feed out of the 102.5 million tons of FW produced in the EU each year [183].

10. Conclusions and Future Perspectives

All across the world, people often throw away a wide variety of food items. Due to the fact that it includes a lot of nutrients, FW can have a number of negative consequences for the environment if it is not properly disposed of or handled. These include, but are not limited to, greenhouse gas emissions, eutrophication, and acidification. Converting food scraps into useful animal feed is a viable solution that can help reduce environmental damage. Though it is normal practice to use leftovers from human meals to feed livestock, scientifically authorized production methods and certified quality feed production are essential for healthy livestock production in all regions. Diverse technologies have been developed for the safe conversion of FW into various dry and liquid livestock feeds. Animal feed made from FW not only replaces commercial feed but also cuts the cost of livestock production. Turning FW into animal feed is one way that can contribute to the creation of a circular economy as well as the achievement of sustainable development. Nevertheless, certification and quality control require a complete characterization of the many forms of FW both before and after the process of conversion into feed. There is an immediate demand for research and development in technology that can convert wasted food into animal feeds that are healthier and more economically viable as well as other useful products. The techniques that are being developed will make it possible to generate data that will be essential in enabling the commercial inclusion of animal feeds that are derived from waste materials to end users. The incorporation of low-cost FW-derived items into animal diets will, in the future, provide the opportunity to reduce production expenses, which account for a significant portion of overall poultry and swine production costs. These expenses account for the opportunity to reduce production costs. Those active in the business world could have a significant incentive to become involved with the practice of using FW as animal feed if they are guaranteed that the practice is safe and of high quality. Last but not least, recycling food scraps for use in animal feed has the potential to improve both food safety and environmental conditions.
Future research must address multiple crucial issues. First, systematic sample collection and comprehensive nutrient analysis are required to provide more accurate information on the complete nutrient profile of pre-treatment food waste and, more importantly, post-treatment feed products in terms of concentration, variability, and bioavailability of key nutrients. This information is crucial for the incorporation of feeds derived from food waste into the precision feeding routine of modern animal production systems. Second, a quantitative assessment is required to link feed grain replacement with resource and environmental benefits throughout the entire food system, including major resource indices such as land, water, energy, fertilizer, and other agricultural inputs and environmental parameters such as soil erosion, nitrogen losses, and greenhouse gas emissions. The scientific and policymaking communities, as well as the public and private sectors, would all benefit from the new understanding provided by this information. The development of effective interventions to support and promote the adoption of food waste recovery for animal feeding also requires input and feedback from stakeholders, such as feed suppliers, livestock producers, food waste emitters, and consumers. The re-feed strategy’s full range of costs and benefits, as well as any potential broader impacts, must be examined in-depth in economic analyses in order to provide the fundamental framework required for the creation of sound, successful, and path-altering policies.

Author Contributions

Conceptualization, K.S. and B.S.I.; methodology, P.C.N., A.O. and S.D.; software, A.O. and M.S.; validation, P.K.N. and B.S.I.; formal analysis, P.C.N. and S.D.; investigation, P.C.N. and S.D.; resources, M.S., K.S., P.K.N. and B.S.I.; data curation, A.O., P.C.N. and S.D.; writing—original draft preparation, P.C.N., M.S. and S.D.; writing—review and editing, M.S., P.K.N., K.S. and B.S.I.; visualization, M.S., K.S. and B.S.I.; supervision, K.S. and B.S.I.; project administration, K.S. and B.S.I.; funding acquisition, K.S. and B.S.I. All authors have read and agreed to the published version of the manuscript.


This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are included in the article.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Ishangulyyev, R.; Kim, S.; Lee, S.H. Understanding food loss and waste—Why are we losing and wasting food? Foods 2019, 8, 297. [Google Scholar] [CrossRef]
  2. Li, M.; Jia, N.; Lenzen, M.; Malik, A.; Wei, L.; Jin, Y.; Raubenheimer, D. Global food-miles account for nearly 20% of total food-systems emissions. Nat. Food 2022, 3, 445–453. [Google Scholar] [CrossRef]
  3. Hoang, A.T.; Varbanov, P.S.; Nižetić, S.; Sirohi, R.; Pandey, A.; Luque, R.; Ng, K.H. Perspective review on Municipal Solid Waste-to-energy route: Characteristics, management strategy, and role in circular economy. J. Clean. Prod. 2022, 359, 131897. [Google Scholar] [CrossRef]
  4. Elechi, J.O.G.; Nwiyi, I.U.; Adamu, C.S. Global food system transformation for resilience. In Food Systems Resilience; Intech open: London, UK, 2022; p. 21. [Google Scholar]
  5. Granato, D.; Carocho, M.; Barros, L.; Zabetakis, I.; Mocan, A.; Tsoupras, A.; Cruz, A.G.; Pimentel, T.C. Implementation of Sustainable Development Goals in the dairy sector: Perspectives on the use of agro-industrial side-streams to design functional foods. Trends Food Sci. Technol. 2022, 124, 128–139. [Google Scholar] [CrossRef]
  6. Bertocci, F.; Mannino, G. Can agri-food waste be a sustainable alternative in aquaculture? A bibliometric and meta-analytic study on growth performance, innate immune system, and antioxidant defenses. Foods 2022, 11, 1861. [Google Scholar] [CrossRef]
  7. Sarker, A.; Ghosh, M.K.; Islam, T.; Bilal, M.; Nandi, R.; Raihan, M.L.; Hossain, M.N.; Rana, J.; Barman, S.K.; Kim, J.-E. Sustainable Food Waste Recycling for the Circular Economy in Developing Countries, with Special Reference to Bangladesh. Sustainability 2022, 14, 12035. [Google Scholar] [CrossRef]
  8. Directorate-General for Research and Innovation (European Commission). A Sustainable Bioeconomy for Europe: Strengthening the Connection between Economy, Society and the Environment. 2018. Available online: (accessed on 25 February 2020).
  9. Murillo-Roos, M.; Uribe-Lorío, L.; Fuentes-Schweizer, P.; Vidaurre-Barahona, D.; Brenes-Guillén, L.; Jiménez, I.; Arguedas, T.; Liao, W.; Uribe, L. Biogas production and microbial communities of mesophilic and thermophilic anaerobic co-digestion of animal manures and food wastes in Costa Rica. Energies 2022, 15, 3252. [Google Scholar] [CrossRef]
  10. Visco, A.; Scolaro, C.; Facchin, M.; Brahimi, S.; Belhamdi, H.; Gatto, V.; Beghetto, V. Agri-food wastes for bioplastics: European prospective on possible applications in their second life for a circular economy. Polymers 2022, 14, 2752. [Google Scholar] [CrossRef] [PubMed]
  11. Alagappan, S.; Hoffman, L.C.; Mantilla, S.M.O.; Mikkelsen, D.; James, P.; Yarger, O.; Cozzolino, D. Near Infrared Spectroscopy as a Traceability Tool to Monitor Black Soldier Fly Larvae (Hermetia illucens) Intended as Animal Feed. Appl. Sci. 2022, 12, 8168. [Google Scholar] [CrossRef]
  12. Lu, S.; Taethaisong, N.; Meethip, W.; Surakhunthod, J.; Sinpru, B.; Sroichak, T.; Archa, P.; Thongpea, S.; Paengkoum, S.; Purba, R.A.P. Nutritional composition of black soldier fly larvae (Hermetia illucens L.) and its potential uses as alternative protein sources in animal diets: A review. Insects 2022, 13, 831. [Google Scholar] [CrossRef]
  13. Mangindaan, D.; Kaburuan, E.R.; Meindrawan, B. Black Soldier Fly Larvae (Hermetia illucens) for Biodiesel and/or Animal Feed as a Solution for Waste-Food-Energy Nexus: Bibliometric Analysis. Sustainability 2022, 14, 13993. [Google Scholar] [CrossRef]
  14. Abeliotis, K.; Lasaridi, K. Food Waste Prevention: Reduction, Reuse, and Recycling. Resources 2022, 12, 3. [Google Scholar] [CrossRef]
  15. Shurson, G.C. “What a waste”—Can we improve sustainability of food animal production systems by recycling food waste streams into animal feed in an era of health, climate, and economic crises? Sustainability 2020, 12, 7071. [Google Scholar] [CrossRef]
  16. Bartali, E.H.; Boutfirass, M.; Yigezu, Y.A.; Niane, A.A.; Boughlala, M.; Belmakki, M.; Halila, H. Estimates of Food Losses and Wastes at Each Node of the Wheat Value Chain in Morocco: Implications on Food and Energy Security, Natural Resources, and Greenhouse Gas Emissions. Sustainability 2022, 14, 16561. [Google Scholar] [CrossRef]
  17. Nath, P.C.; Nandi, N.B.; Tiwari, A.; Das, J.; Roy, B. Applications of nanotechnology in food sensing and food packaging. In Nanotechnology Applications for Food Safety and Quality Monitoring; Elsevier: Amsterdam, The Netherlands, 2023; pp. 321–340. [Google Scholar]
  18. Sharma, R.; Kannan, D.; Darbari, J.D.; Jha, P. Analysis of Collaborative Sustainable Practices in multi-tier food supply chain using integrated TISM-Fuzzy MICMAC model: A supply chain practice view. J. Clean. Prod. 2022, 354, 131271. [Google Scholar] [CrossRef]
  19. Conrad, Z.; Blackstone, N.T. Identifying the links between consumer food waste, nutrition, and environmental sustainability: A narrative review. Nutr. Rev. 2021, 79, 301–314. [Google Scholar] [CrossRef]
  20. Brennan, A.; Browne, S. Food waste and nutrition quality in the context of public health: A scoping review. Int. J. Environ. Res. Public Health 2021, 18, 5379. [Google Scholar] [CrossRef]
  21. Schanes, K.; Dobernig, K.; Gözet, B. Food waste matters—A systematic review of household food waste practices and their policy implications. J. Clean. Prod. 2018, 182, 978–991. [Google Scholar] [CrossRef]
  22. Wu, G.; Bazer, F.W.; Cross, H.R. Land-based production of animal protein: Impacts, efficiency, and sustainability. Ann. N. Y. Acad. Sci. 2014, 1328, 18–28. [Google Scholar] [CrossRef]
  23. Esteban, J.; Ladero, M. Food waste as a source of value-added chemicals and materials: A biorefinery perspective. Int. J. Food Sci. Technol. 2018, 53, 1095–1108. [Google Scholar] [CrossRef]
  24. Miranda, C.D.; Cammack, J.A.; Tomberlin, J.K. Life-history traits of the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), reared on three manure types. Animals 2019, 9, 281. [Google Scholar] [CrossRef]
  25. Wadhwa, M.; Bakshi, M. Utilization of fruit and vegetable wastes as livestock feed and as substrates for generation of other value-added products. Rap Publ. 2013, 4, 67. [Google Scholar]
  26. Koul, B.; Yakoob, M.; Shah, M.P. Agricultural waste management strategies for environmental sustainability. Environ. Res. 2022, 206, 112285. [Google Scholar] [CrossRef] [PubMed]
  27. Diaconeasa, Z.; Iuhas, C.I.; Ayvaz, H.; Mortas, M.; Farcaş, A.; Mihai, M.; Danciu, C.; Stanilă, A. Anthocyanins from Agro-Industrial Food Waste: Geographical Approach and Methods of Recovery—A Review. Plants 2023, 12, 74. [Google Scholar] [CrossRef]
  28. Hoehn, D.; Vázquez-Rowe, I.; Kahhat, R.; Margallo, M.; Laso, J.; Fernández-Ríos, A.; Ruiz-Salmón, I.; Aldaco, R. A critical review on food loss and waste quantification approaches: Is there a need to develop alternatives beyond the currently widespread pathways? Resour. Conserv. Recycl. 2023, 188, 106671. [Google Scholar] [CrossRef]
  29. Edwards, F. Food Waste Activism in Australia. In Food Resistance Movements: Journeying through Alternative Food Networks; Springer: Berlin/Heidelberg, Germany, 2023; pp. 29–48. [Google Scholar]
  30. Castrica, M.; Rebucci, R.; Giromini, C.; Tretola, M.; Cattaneo, D.; Baldi, A. Total phenolic content and antioxidant capacity of agri-food waste and by-products. Ital. J. Anim. Sci. 2019, 18, 336–341. [Google Scholar] [CrossRef]
  31. Messner, R.; Johnson, H.; Richards, C. From surplus-to-waste: A study of systemic overproduction, surplus and food waste in horticultural supply chains. J. Clean. Prod. 2021, 278, 123952. [Google Scholar] [CrossRef]
  32. Gonçalves, M.L.M.; Maximo, G.J. Circular Economy in the Food Chain: Production, Processing and Waste Management. Circ. Econ. Sustain. 2022, 1–19. [Google Scholar] [CrossRef]
  33. Liu, C.; Mao, C.; Bunditsakulchai, P.; Sasaki, S.; Hotta, Y. Food waste in Bangkok: Current situation, trends and key challenges. Resour. Conserv. Recycl. 2020, 157, 104779. [Google Scholar] [CrossRef]
  34. Ramakrishna, V.; Subrahmanyam, C.N.; Bhanuchand, S.; Rao, B.S.; Kumar, A.A. Municipal solid waste quantification, characterization and management in Mylavaram. IOSR J. Mech. Civ. Eng. 2016, 13, 77–87. [Google Scholar] [CrossRef]
  35. Sahoo, A.; Dwivedi, A.; Madheshiya, P.; Kumar, U.; Sharma, R.K.; Tiwari, S. Insights into the management of food waste in developing countries: With special reference to India. Res. Sq. 2022. [Google Scholar] [CrossRef]
  36. Arcadis, N.J.A. National Food Waste Baseline: Final Assessment Report; Australian Government National Environmental Science Program: Amsterdam, The Netherlands, 2019.
  37. Zhang, H.; Liu, G.; Xue, L.; Zuo, J.; Chen, T.; Vuppaladadiyam, A.; Duan, H.J. Anaerobic digestion based waste-to-energy technologies can halve the climate impact of China’s fast-growing food waste by 2040. J. Clean. Prod. 2020, 277, 123490. [Google Scholar] [CrossRef]
  38. Diana, R.; Martianto, D.; Baliwati, Y.F.; Sukandar, D.; Hendriadi, A. Household Food Waste Policy: A Literature Review. J. Environ. Health 2022, 14, 218–228. [Google Scholar] [CrossRef]
  39. Vetter-Gindele, J.; Braun, A.; Warth, G.; Bui, T.T.Q.; Bachofer, F.; Eltrop, L.J. Assessment of household solid waste generation and composition by building type in Da Nang, Vietnam. Resources 2019, 8, 171. [Google Scholar] [CrossRef]
  40. Alsabbagh, M.J.C. Mitigation of CO2e emissions from the municipal solid waste sector in the Kingdom of Bahrain. Climate 2019, 7, 100. [Google Scholar] [CrossRef]
  41. Karthik, L.; Kumar, G.; Keswani, T.; Bhattacharyya, A.; Chandar, S.S.; Bhaskara Rao, K.J. Protease inhibitors from marine actinobacteria as a potential source for antimalarial compound. PLoS ONE 2014, 9, e90972. [Google Scholar] [CrossRef]
  42. Furbeck, R. The Invisible Meat Microcosmos-Investigations of Processed Meats’ Specific Spoilage Organisms. Ph.D. Thesis, University of Nebraska-Lincoln, Lincoln, NE, USA, 2022. [Google Scholar]
  43. Baseline, S.S.F. Food Loss & Waste Index in Kingdom of Saudi Arabia; Saudi Grains Organization: Riyadh, Saudi Arabia, 2019.
  44. Lourenco, C.E.; Porpino, G.; Araujo, C.M.L.; Vieira, L.M.; Matzembacher, D.E. We need to talk about infrequent high volume household food waste: A theory of planned behaviour perspective. Sustain. Prod. Consum. 2022, 33, 38–48. [Google Scholar] [CrossRef]
  45. Leverenz, D.; Schneider, F.; Schmidt, T.; Hafner, G.; Nevárez, Z.; Kranert, M.J. Food waste generation in Germany in the scope of European legal requirements for monitoring and reporting. Sustainability 2021, 13, 6616. [Google Scholar] [CrossRef]
  46. Kasza, G.; Dorkó, A.; Kunszabó, A.; Szakos, D.J. Quantification of household food waste in Hungary: A replication study using the FUSIONS methodology. Sustainability 2020, 12, 3069. [Google Scholar] [CrossRef]
  47. Giordano, C.; Alboni, F.; Falasconi, L.J. Quantities, determinants, and awareness of households’ food waste in Italy: A comparison between diary and questionnaires quantities. Sustainability 2019, 11, 3381. [Google Scholar] [CrossRef]
  48. Van Dooren, C. Synthesis Report on Food Waste in Dutch Households in 2019; The Netherlands Nutrition Centre Foundation: The Hague, The Netherlands, 2019; Volume 202019. [Google Scholar]
  49. de Araujo, G.; Lourenço, C.; de Araújo, C.; Bastos, A. Intercâmbio Brasil-União Europeia Sobre Desperdício de Alimentos: Relatório Final. 2018. Available online: (accessed on 3 March 2023).
  50. Orhorhoro, E.K.; Ebunilo, P.O.; Sadjere, E.G. Determination and quantification of household solid waste generation for planning suitable sustainable waste management in Nigeria. Int. J. Emerg. Eng. Res. Technol. 2017, 5, 1–9. [Google Scholar]
  51. Ramukhwatho, F.R. An Assessment of the Household Food Wastage in a Developing Country: A Case Study of Five Areas in the City of Tshwane Metropolitan Municipality, Gauteng Province, South Africa. Ph.D. Thesis, University of South Africa, Pretoria, South Africa, 2016. [Google Scholar]
  52. Caldeira, C.; Barco, H.; De Laurentiis, V.; Sala, S. Review of Studies on Food Waste Accounting at Member State Level; Publications Office of the European Union: Luxembourg, 2019.
  53. Pinotti, L.; Manoni, M.; Fumagalli, F.; Rovere, N.; Luciano, A.; Ottoboni, M.; Ferrari, L.; Cheli, F.; Djuragic, O. Reduce, reuse, recycle for food waste: A second life for fresh-cut leafy salad crops in animal diets. Animals 2020, 10, 1082. [Google Scholar] [CrossRef] [PubMed]
  54. Rajeh, C.; Saoud, I.P.; Kharroubi, S.; Naalbandian, S.; Abiad, M.G. Food loss and food waste recovery as animal feed: A systematic review. J. Mater. Cycles Waste Manag. 2021, 23, 1–17. [Google Scholar] [CrossRef]
  55. Rohini, C.; Geetha, P.; Vijayalakshmi, R.; Mini, M.; Pasupathi, E. Global effects of food waste. J. Pharmacogn. Phytochem. 2020, 9, 690–699. [Google Scholar]
  56. Truong, L.; Morash, D.; Liu, Y.; King, A. Food waste in animal feed with a focus on use for broilers. Int. J. Recycl. Org. Waste Agric. 2019, 8, 417–429. [Google Scholar] [CrossRef]
  57. Pinto, J.; Boavida-Dias, R.; Matos, H.A.; Azevedo, J. Analysis of the food loss and waste valorisation of animal by-products from the retail sector. Sustainability 2022, 14, 2830. [Google Scholar] [CrossRef]
  58. Gadisa, B.; Taffa, G. Assessment of beef cattle production, slaughtering and marketing practice in Haramaya University, Ethiopia. World 2019, 3, 26–31. [Google Scholar]
  59. Patsios, S.I.; Dedousi, A.; Sossidou, E.Ν.; Zdragas, A. Sustainable animal feed protein through the cultivation of Yarrowia lipolytica on agro-industrial wastes and by-products. Sustainability 2020, 12, 1398. [Google Scholar] [CrossRef]
  60. Pinotti, L.; Luciano, A.; Ottoboni, M.; Manoni, M.; Ferrari, L.; Marchis, D.; Tretola, M. Recycling food leftovers in feed as opportunity to increase the sustainability of livestock production. J. Clean. Prod. 2021, 294, 126290. [Google Scholar] [CrossRef]
  61. Moult, J.; Allan, S.; Hewitt, C.; Berners-Lee, M. Greenhouse gas emissions of food waste disposal options for UK retailers. Food Policy 2018, 77, 50–58. [Google Scholar] [CrossRef]
  62. Mora, C.; Spirandelli, D.; Franklin, E.C.; Lynham, J.; Kantar, M.B.; Miles, W.; Smith, C.Z.; Freel, K.; Moy, J.; Louis, L. Broad threat to humanity from cumulative climate hazards intensified by greenhouse gas emissions. Nat. Clim. Change 2018, 8, 1062–1071. [Google Scholar] [CrossRef]
  63. Wang, Y.; Levis, J.W.; Barlaz, M.A. Life-Cycle Assessment of a regulatory compliant US municipal solid waste landfill. Environ. Sci. Technol. 2021, 55, 13583–13592. [Google Scholar] [CrossRef] [PubMed]
  64. Erickson, M.C. MicrobiologicalAssociated Vegetables, with Nuts, Fruits, Issues and Grains. In Food Microbiology: Fundamentals and Frontiers; ASM Press: Washington, DC, USA, 2020; p. 179. [Google Scholar]
  65. Bunditsakulchai, P.; Liu, C.J. Integrated strategies for household food waste reduction in Bangkok. Sustainability 2021, 13, 7651. [Google Scholar] [CrossRef]
  66. Bhatia, L.; Jha, H.; Sarkar, T.; Sarangi, P.K. Food Waste Utilization for Reducing Carbon Footprints towards Sustainable and Cleaner Environment: A Review. Int. J. Environ. Res. Public Health 2023, 20, 2318. [Google Scholar] [CrossRef] [PubMed]
  67. Afreen, M.; Ucak, I. Fish processing wastes used as feed ingredient for animal feed and aquaculture feed. J. Surv. Fish. Sci. 2023, 6, 55–64. [Google Scholar] [CrossRef]
  68. Peng, X.; Jiang, Y.; Chen, Z.; Osman, A.I.; Farghali, M.; Rooney, D.W.; Yap, P.-S. Recycling municipal, agricultural and industrial waste into energy, fertilizers, food and construction materials, and economic feasibility: A review. Environ. Chem. Lett. 2023, 21, 765–801. [Google Scholar] [CrossRef]
  69. Rahmani, M.; Azadbakht, M.; Dastar, B.; Esmaeilzadeh, E. Production of animal feed from food waste or corn? Analyses of energy and exergy. Bioresour. Technol. Rep. 2022, 20, 101213. [Google Scholar] [CrossRef]
  70. Bulgakov, V.; Sevostianov, I.; Kaletnik, G.; Babyn, I.; Ivanovs, S.; Holovach, I.; Ihnatiev, Y. Theoretical studies of the vibration process of the dryer for waste of food. Rural Sustain. Res. 2020, 44, 32–45. [Google Scholar] [CrossRef]
  71. Song, D.B.; Lim, K.H.; Jung, D.H.; Yoon, J.H. Analysis of drying characteristics and cost of high-capacity vacuum-drying food waste disposal system using steam. J. Biosyst. Eng. 2020, 45, 126–132. [Google Scholar] [CrossRef]
  72. Filková, I.; Mujumdar, A.S. Industrial spray drying systems. In Handbook of Industrial Drying; CRC Press: Boca Raton, FL, USA, 2020; pp. 263–307. [Google Scholar]
  73. Koç, M.; Elmas, F.; Baysan, U.; Nadeem, H.Ş.; Ertekin, F.K. Spray Drying for Production of Food Colors from Natural Sources. In Handbook on Spray Drying Applications for Food Industries; CRC Press: Boca Raton, FL, USA, 2019; pp. 132–179. [Google Scholar]
  74. López-Pedrouso, M.; Bursać Kovačević, D.; Oliveira, D.; Putnik, P.; Moure, A.; Lorenzo, J.M.; Domínguez, H.; Franco, D. In vitro and in vivo Antioxidant Activity of Anthocyanins. In Anthocyanins—Aantioxidant Properties, Sources and Health Benefits; Lorenzo, J.M., Barba, F.J., Munekata, P., Eds.; Nova Science Publishers, Inc.: New York, NY, USA, 2020; pp. 169–204. [Google Scholar]
  75. Osorio, L.L.D.R.; Flórez-López, E.; Grande-Tovar, C.D.J.M. The potential of selected agri-food loss and waste to contribute to a circular economy: Applications in the food, cosmetic and pharmaceutical industries. Molecules 2021, 26, 515. [Google Scholar] [CrossRef] [PubMed]
  76. Despoudi, S.; Bucatariu, C.; Otles, S.; Kartal, C. Food waste management, valorization, and sustainability in the food industry. In Food Waste Recovery; Elsevier: Amsterdam, The Netherlands, 2021; pp. 3–19. [Google Scholar]
  77. Betz, A.; Buchli, J.; Göbel, C.; Müller, C.J. Food waste in the Swiss food service industry—Magnitude and potential for reduction. Waste Manag. 2015, 35, 218–226. [Google Scholar] [CrossRef]
  78. RedCorn, R.; Fatemi, S.; Engelberth, A.S. Comparing end-use potential for industrial food-waste sources. Engineering 2018, 4, 371–380. [Google Scholar] [CrossRef]
  79. Goodman-Smith, F.; Mirosa, M.; Skeaff, S.J. A mixed-methods study of retail food waste in New Zealand. Food Policy 2020, 92, 101845. [Google Scholar] [CrossRef]
  80. Abdel-Shafy, H.I.; Mansour, M.S.J.E.j.o.p. Solid waste issue: Sources, composition, disposal, recycling, and valorization. Egypt. J. Pet. 2018, 27, 1275–1290. [Google Scholar] [CrossRef]
  81. Tiwari, S.K.; Bystrzejewski, M.; De Adhikari, A.; Huczko, A.; Wang, N.J. Methods for the conversion of biomass waste into value-added carbon nanomaterials: Recent progress and applications. Prog. Energy Combust. Sci. 2022, 92, 101023. [Google Scholar] [CrossRef]
  82. Sotiropoulos, A.; Malamis, D.; Loizidou, M.J. Dehydration of domestic food waste at source as an alternative approach for food waste management. Waste Biomass Valorization 2015, 6, 167–176. [Google Scholar] [CrossRef]
  83. Yaashikaa, P.; Kumar, P.S.; Saravanan, A.; Varjani, S.; Ramamurthy, R. Bioconversion of municipal solid waste into bio-based products: A review on valorisation and sustainable approach for circular bioeconomy. Sci. Total Environ. 2020, 748, 141312. [Google Scholar] [CrossRef]
  84. Onyeaka, H.; Anumudu, C.K.; Okpe, C.; Okafor, A.; Ihenetu, F.; Miri, T.; Odeyemi, O.A.; Anyogu, A. Single Cell Protein for Foods and Feeds: A Review of Trends. Open Microbiol. J. 2022, 16, e187428582206160. [Google Scholar] [CrossRef]
  85. Türker, M.; Selimoğlu, S.M.; Taşpınar-Demir, H. Waste (water) to feed protein: Effluent characteristics, protein recovery, and single-cell protein production from food industry waste streams. Clean Energy Resour. Recovery 2022, 2, 201–244. [Google Scholar]
  86. Carrillo-Nieves, D.; Alanís, M.J.R.; de la Cruz Quiroz, R.; Ruiz, H.A.; Iqbal, H.M.; Parra-Saldívar, R. Current status and future trends of bioethanol production from agro-industrial wastes in Mexico. Renew. Sustain. Energy Rev. 2019, 102, 63–74. [Google Scholar] [CrossRef]
  87. Georganas, A.; Giamouri, E.; Pappas, A.C.; Papadomichelakis, G.; Fortatos, S.; Manios, T.; Lasaridi, K.; Fegeros, K.; Tsiplakou, E.; Zervas, G. Redefining the Future of Catering Waste Application in Animal Diets. A Review on the Minimization of Potential Hazards in Catering Waste Prior to Application in Animal Diets. Anim. Feed Sci. Technol. 2022, 289, 115334. [Google Scholar] [CrossRef]
  88. Gao, S.; Bao, J.; Li, R.; Liu, X.; Wu, C. Drivers and reduction solutions of food waste in the Chinese food service business. Sustain. Prod. Consum. 2021, 26, 78–88. [Google Scholar] [CrossRef]
  89. Zhao, Y.; Yu, S.; Zhao, H.; Li, L.; Li, Y.; Tu, Y.; Jiang, L.; Zhao, G. Lipidomic profiling using GC and LC-MS/MS revealed the improved milk quality and lipid composition in dairy cows supplemented with citrus peel extract. Food Res. Int. 2022, 161, 111767. [Google Scholar] [CrossRef] [PubMed]
  90. Zhao, Y.; Yu, S.; Zhang, S.; Li, Y.; Tu, Y.; Liu, M.; Jiang, L. Microbiome-Metabolomics Insights into the Milk of Lactating Dairy Cows to Reveal the Health-Promoting Effects of Dietary Citrus Peel Extracts on the Mammary Metabolism. Foods 2022, 11, 4119. [Google Scholar] [CrossRef]
  91. Hoka, A.I.; Gicheru, M.; Otieno, S. Effect of cow parity and calf characteristics on milk production and reproduction of friesian dairy cows. Exp. Anim. 2019, 9. [Google Scholar] [CrossRef]
  92. Suri, S.; Singh, A.; Nema, P.K. Current applications of citrus fruit processing waste: A scientific outlook. Appl. Food Res. 2022, 2, 100050. [Google Scholar] [CrossRef]
  93. Ogana, G.; Abang, F.; Carew, S. Effect of Cocoa Husk Meal Based Diets on the Growth Performance and Nutrient Digestibility of Weaned Rabbits. Am. Res. J. Humanit. Soc. Sci. 2020, 3, 1–9. [Google Scholar]
  94. Hassan, F.A.; Shalaby, A.G.; Elkassas, N.E.M.; El-Medany, S.A.; Hamdi Rabie, A.; Mahrose, K.; Abd El-Aziz, A.; Bassiony, S. Efficacy of ascorbic acid and different sources of orange peel on growth performance, gene expression, anti-oxidant status and microbial activity of growing rabbits under hot conditions. Anim. Biotechnol. 2022, 1–12. [Google Scholar] [CrossRef]
  95. Ahmad, F.; Tauqir, N.; Faraz, A.; Asghar, I.; Wadood, F.; Tahir, M.; Mujahid, M. Performance of Lactating Sahiwal Cows Fed Corn Stovers Ensiled with Molasses, Urea and Lime Solution. Iran. J. Appl. Anim. Sci. 2021, 11, 59–66. [Google Scholar]
  96. Hifizah, A. Horticultural Harvest Waste as an Alternative Feed with Anti-Methanogenic Properties for Ruminants: In Vitro Evaluation. Ph.D. Thesis, University of Western Australia, Perth, Australia, 2019. [Google Scholar]
  97. Wang, H.; Xu, J.; Sheng, L. Study on the comprehensive utilization of city kitchen waste as a resource in China. Energy 2019, 173, 263–277. [Google Scholar] [CrossRef]
  98. Banožić, M.; Vladić, J.; Banjari, I.; Velić, D.; Aladić, K.; Jokić, S. Spray Drying as a Method of Choice for Obtaining High Quality Products from Food Wastes–A Review. Food Rev. Int. 2021, 1–33. [Google Scholar] [CrossRef]
  99. Farias, N.N.P.; Freitas, E.R.; Nepomuceno, R.C.; Gomes, H.M.; Souza, D.H.; de Oliveira Costa, M.K.; da Costa, H.S.; Fernandes, D.R.; Araújo, L.R.S.; do Nascimento, G.A.J. Ethanolic extract of mango seed in broiler feed: Effect on productive performance, segments of the digestive tract and blood parameters. Anim. Feed Sci. Technol. 2021, 279, 114999. [Google Scholar] [CrossRef]
  100. Admasu, S.; Wondifraw, Z.; Gash, M. Effects of replacing maize with boiled mango (Mangifera indica) seed kernel on feed intake, body weight gain and feed conversion ratio of Cobb 500 Broiler Chicken. Poult. Fish. Wildl. Sci. 2020, 8, 211. [Google Scholar] [CrossRef]
  101. Brancoli, P.; Bolton, K.; Eriksson, M. Environmental impacts of waste management and valorisation pathways for surplus bread in Sweden. Waste Manag. 2020, 117, 136–145. [Google Scholar] [CrossRef] [PubMed]
  102. Janmaat, K.R.; Ban, S.D.; Boesch, C. Chimpanzees use long-term spatial memory to monitor large fruit trees and remember feeding experiences across seasons. Anim. Behav. 2013, 86, 1183–1205. [Google Scholar] [CrossRef]
  103. Difonzo, G.; Troilo, M.; Squeo, G.; Pasqualone, A.; Caponio, F. Functional compounds from olive pomace to obtain high-added value foods—A review. J. Sci. Food Agric. 2021, 101, 15–26. [Google Scholar] [CrossRef]
  104. Tropea, A.; Potortì, A.G.; Lo Turco, V.; Russo, E.; Vadalà, R.; Rando, R.; Di Bella, G. Aquafeed production from fermented fish waste and lemon peel. Fermentation 2021, 7, 272. [Google Scholar] [CrossRef]
  105. Qian, L.; Zhang, H. Controlled freezing and freeze drying: A versatile route for porous and micro-/nano-structured materials. J. Chem. Technol. Biotechnol. 2011, 86, 172–184. [Google Scholar] [CrossRef]
  106. Assegehegn, G.; Brito-de la Fuente, E.; Franco, J.M.; Gallegos, C. The importance of understanding the freezing step and its impact on freeze-drying process performance. J. Pharm. Sci. 2019, 108, 1378–1395. [Google Scholar] [CrossRef]
  107. Korolev, A.; Leisner, T.J.A.C. Review of experimental studies of secondary ice production. Atmos. Chem. Phys. 2020, 20, 11767–11797. [Google Scholar] [CrossRef]
  108. Khalida, A.; Arumugam, V.; Abdullah, L.C.; Abd, L. Dehydrated Food Waste for Composting: An Overview. Sci. Technol 2022, 30, 2933–2960. [Google Scholar] [CrossRef]
  109. Wheeler, R.R., Jr.; Hadley, N.M.; Dahl, R.W.; Williams, T.W.; Zavala, D.B., Jr.; Akse, J.R.; Fisher, J.W. Microwave enhanced freeze drying of solid waste. SAE Trans. 2007, 116, 510–537. [Google Scholar]
  110. Nayak, A.; Bhushan, B.J. An overview of the recent trends on the waste valorization techniques for food wastes. J. Environ. Manag. 2019, 233, 352–370. [Google Scholar] [CrossRef] [PubMed]
  111. Karam, M.C.; Petit, J.; Zimmer, D.; Djantou, E.B.; Scher, J. Effects of drying and grinding in production of fruit and vegetable powders: A review. J. Food Eng. 2016, 188, 32–49. [Google Scholar] [CrossRef]
  112. Bai, Y.; Rahman, M.S.; Perera, C.O.; Smith, B.; Melton, L.D. Structural changes in apple rings during convection air-drying with controlled temperature and humidity. J. Agric. Food Chem. 2002, 50, 3179–3185. [Google Scholar] [CrossRef]
  113. Yadav, A.K.; Singh, S.V. Osmotic dehydration of fruits and vegetables: A review. J. Food Sci. Technol. 2014, 51, 1654–1673. [Google Scholar] [CrossRef]
  114. Pu, H.; Li, Z.; Hui, J.; Raghavan, G.V. Effect of relative humidity on microwave drying of carrot. J. Food Eng. 2016, 190, 167–175. [Google Scholar] [CrossRef]
  115. Calín-Sánchez, Á.; Lipan, L.; Cano-Lamadrid, M.; Kharaghani, A.; Masztalerz, K.; Carbonell-Barrachina, Á.A.; Figiel, A. Comparison of traditional and novel drying techniques and its effect on quality of fruits, vegetables and aromatic herbs. Foods 2020, 9, 1261. [Google Scholar] [CrossRef]
  116. Monteiro, R.L.; Link, J.V.; Tribuzi, G.; Carciofi, B.A.; Laurindo, J.B. Microwave vacuum drying and multi-flash drying of pumpkin slices. J. Food Eng. 2018, 232, 1–10. [Google Scholar] [CrossRef]
  117. Jödicke, K.; Arendt, S.; Hofacker, W.; Speckle, W.J.D.T. The influence of process parameters on the quality of dried agricultural products determined using the cumulated thermal load. Dry. Technol. 2019, 38, 321–332. [Google Scholar] [CrossRef]
  118. Stanton, R.; Morrissey, C.A.; Clark, R.G.J. Analysis of trends and agricultural drivers of farmland bird declines in North America: A review. Ecosyst. Environ. 2018, 254, 244–254. [Google Scholar] [CrossRef]
  119. Wilkinson, J.; Rinne, M.J.G.; Science, F. Highlights of progress in silage conservation and future perspectives. Grass Forage Sci. 2018, 73, 40–52. [Google Scholar] [CrossRef]
  120. MacLaren, C.; Storkey, J.; Menegat, A.; Metcalfe, H.; Dehnen-Schmutz, K. An ecological future for weed science to sustain crop production and the environment. A review. Agron. Sustain. Dev. 2020, 40, 24. [Google Scholar] [CrossRef]
  121. Henderson, N. Silage additives. Anim. Feed. Sci. Technol. 1993, 45, 35–56. [Google Scholar]
  122. Wilkanowska, A.; Kokoszyński, D. Effect of diet and physical activity of farm animals on their health and reproductive performance. In Handbook of Fertility; Elsevier: Amsterdam, The Netherlands, 2015; pp. 159–171. [Google Scholar]
  123. Shinde, A.; Mahanta, S.K. Nutrition of small ruminants on grazing lands in dry zones of India. Range Manag. Agrofor. 2020, 41, 1–14. [Google Scholar]
  124. Makokha, M.P.; Muliro, P.S.; Ngoda, P.N.; Ghemoh, C.J.; Xavier, C.; Tanga, C.M. Nutritional quality of meat from hen fed diet with full-fat black soldier fly (Hermetia illucens) larvae meal as a substitute to fish meal. J. Funct. Foods 2023, 101, 105430. [Google Scholar] [CrossRef]
  125. He, Y.; Li, J.; Wang, F.; Na, W.; Tan, Z. Dynamic Changes in the Gut Microbiota and Metabolites during the Growth of Hainan Wenchang Chickens. Animals 2023, 13, 348. [Google Scholar] [CrossRef]
  126. Fan, K.; Liu, H.; Pei, Z.; Brown, P.B.; Huang, Y. A study of the potential effect of dietary fishmeal replacement with cricket meal (Gryllus bimaculatus) on growth performance, blood health, liver antioxidant activities, intestinal microbiota and immune-related gene expression of juvenile channel catfish. Anim. Feed Sci. Technol. 2023, 295, 115542. [Google Scholar] [CrossRef]
  127. Abdel-Wareth, A.A.; Mohamed, E.M.; Hassan, H.A.; Eldeek, A.A.; Lohakare, J. Effect of substituting hydroponic barley forage with or without enzymes on performance of growing rabbits. Sci. Rep. 2023, 13, 943. [Google Scholar] [CrossRef]
  128. Wang, Y.; Luo, X.; Chen, L.; Mustapha, A.T.; Yu, X.; Zhou, C.; Okonkwo, C.E. Natural and low-caloric rebaudioside A as a substitute for dietary sugars: A comprehensive review. Compr. Rev. Food Sci. Food Saf. 2023, 22, 615–642. [Google Scholar] [CrossRef]
  129. Banday, M.T.; Adil, S.; Sheikh, I.U.; Hamadani, H.; Qadri, F.I.; Sahfi, M.E.; Sait, H.S.; Abd El-Mageed, T.A.; Salem, H.M.; Taha, A.E. The use of silkworm pupae (Bombyx mori) meal as an alternative protein source for poultry. World’s Poult. Sci. J. 2023, 79, 119–134. [Google Scholar] [CrossRef]
  130. Parrini, S.; Aquilani, C.; Pugliese, C.; Bozzi, R.; Sirtori, F. Soybean Replacement by Alternative Protein Sources in Pig Nutrition and Its Effect on Meat Quality. Animals 2023, 13, 494. [Google Scholar] [CrossRef]
  131. Guo, J.; Sun, Y.; Zhao, Y.; Huang, L.; Peng, D.; Hao, H.; Tao, Y.; Chen, D.; Cheng, G.; Wang, X. Metabolic Disposition and Elimination of Tritum-Labeled Sulfamethoxazole in Pigs, Chickens and Rats. Metabolites 2023, 13, 57. [Google Scholar] [CrossRef] [PubMed]
  132. Iori, E.; Masotti, M.; Falasconi, L.; Risso, E.; Segrè, A.; Vittuari, M. Tell Me What You Waste and I’ll Tell You Who You Are: An Eight-Country Comparison of Consumers’ Food Waste Habits. Sustainability 2023, 15, 430. [Google Scholar] [CrossRef]
  133. Katajajuuri, J.-M.; Silvennoinen, K.; Hartikainen, H.; Heikkilä, L.; Reinikainen, A. Food waste in the Finnish food chain. J. Clean. Prod. 2014, 73, 322–329. [Google Scholar] [CrossRef]
  134. Giamouri, E.; Papadomichelakis, G.; Pappas, A.C.; Simitzis, P.E.; Galliou, F.; Paßlack, N.; Zentek, J.; Lasaridi, K.; Fegeros, K.; Manios, T. Μeat Quality Traits as Affected by the Dietary Inclusion of Food Waste in Finishing Pigs. Sustainability 2022, 14, 6593. [Google Scholar] [CrossRef]
  135. Giamouri, E.; Pappas, A.C.; Papadomichelakis, G.; Simitzis, P.E.; Manios, T.; Zentek, J.; Lasaridi, K.; Tsiplakou, E.; Zervas, G. The Food for Feed Concept: Redefining the Use of Hotel Food Residues in Broiler Diets. Sustainability 2022, 14, 3659. [Google Scholar] [CrossRef]
  136. Hilborn, R.; Banobi, J.; Hall, S.J.; Pucylowski, T.; Walsworth, T.E. The environmental cost of animal source foods. Front. Ecol. Environ. 2018, 16, 329–335. [Google Scholar] [CrossRef]
  137. Banaeian, N.; Zangeneh, M. Study on energy efficiency in corn production of Iran. Energy 2011, 36, 5394–5402. [Google Scholar] [CrossRef]
  138. Bakshi, M.; Wadhwa, M.; Makkar, H.P. Waste to worth: Vegetable wastes as animal feed. CABI Rev. 2016, 11, 1–26. [Google Scholar] [CrossRef]
  139. Murugesan, K.; Srinivasan, K.R.; Paramasivam, K.; Selvam, A.; Wong, J. Conversion of Food Waste to Animal Feeds. In Current Developments in Biotechnology and Bioengineering; Elsevier: Amsterdam, The Netherlands, 2021; pp. 305–324. [Google Scholar]
  140. Padam, B.S.; Tin, H.S.; Chye, F.Y.; Abdullah, M.I. Banana by-products: An under-utilized renewable food biomass with great potential. J. Food Sci. Technol. 2014, 51, 3527–3545. [Google Scholar] [CrossRef] [PubMed]
  141. Manju Wadhwa, M.W.; Bakshi, M.P.; Makkar, H.P. Waste to worth: Fruit wastes and by-products as animal feed. CABI Rev. 2015, 2015, 1–26. [Google Scholar] [CrossRef]
  142. Kumar, S.; Sangwan, P.; Dhankhar, R.M.V.; Bidra, S. Utilization of rice husk and their ash: A review. Res. J. Chem. Env. Sci 2013, 1, 126–129. [Google Scholar]
  143. Siva Sankari, M.; Vivekanandhan, S.; Misra, M.; Mohanty, A. Oil Cakes as Sustainable Agro-Industrial Feedstock for Biocarbon Materials. ChemBioEng Rev. 2022, 9, 21–41. [Google Scholar] [CrossRef]
  144. Gupta, M.; Abu-Ghannam, N.; Gallaghar, E. Barley for brewing: Characteristic changes during malting, brewing and applications of its by-products. Compr. Rev. Food Sci. Food Saf. 2010, 9, 318–328. [Google Scholar] [CrossRef]
  145. Chen, Y.; Barzee, T.J.; Zhang, R.; Pan, Z. Citrus. In Integrated Processing Technologies for Food and Agricultural by-Products; Elsevier: Amsterdam, The Netherlands, 2019; pp. 217–242. [Google Scholar]
  146. Mamma, D.; Christakopoulos, P. Biotransformation of citrus by-products into value added products. Waste Biomass Valorization 2014, 5, 529–549. [Google Scholar] [CrossRef]
  147. Guo, S.; Awasthi, M.K.; Wang, Y.; Xu, P. Current understanding in conversion and application of tea waste biomass: A review. Bioresour. Technol. 2021, 338, 125530. [Google Scholar] [CrossRef] [PubMed]
  148. Sonthalia, M.; Sikdar, D. Production of starch from mango (Mangifera Indica L.) seed kernel and its characterization. Int. J. Tech. Res. Appl. 2015, 3, 346–349. [Google Scholar]
  149. Karandeep, K.; Navnidhi, C.; Poorva, S.; Garg, M.; Anil, P. Coconut meal: Nutraceutical importance and food industry application. Foods Raw Mater. 2019, 7, 419–427. [Google Scholar]
  150. Rokhayati, U.A. Coconut Meal Use as a Source of Protein Vegetable for Livestock Goat. ARTIKEL 2020, 1, 1–3. [Google Scholar]
  151. Jayant, M.; Sahu, N.P.; Deo, A.D.; Subodh, G.; Garg, C.K.; Valappil, R.K. Nutritional evaluation of fermented sweet potato leaf meal as a replacer of deoiled rice bran in the diet of Labeo rohita fingerlings. J. Exp. Zool. India 2020, 23, 61–70. [Google Scholar]
  152. Azrinnahar, M.; Islam, N.; Shuvo, A.A.S.; Kabir, A.A.; Islam, K.M.S. Effect of feeding fermented (Saccharomyces cerevisiae) de-oiled rice bran in broiler growth and bone mineralization. J. Saudi Soc. Agric. Sci. 2021, 20, 476–481. [Google Scholar] [CrossRef]
  153. Aengwanich, W.; Suttajit, M.; Chaleerin, P.; Thangklang, P.; Kapan, S.; Srikhun, T.; Boonsorn, T. Antibiotic Effect of Polyphenolic Compound Extracted from Tamarind (Tamarindus indica L.) Seed Coat on Productive Performance of Broilers. Int. J. Poult. Sci. 2009, 8, 749–751. [Google Scholar] [CrossRef]
  154. Makinde, O.; Sonaiya, B.; Adeyeye, S. Conversion of abattoir wastes into livestock feed: Chemical composition of sun-dried rumen content blood meal and its effect on performance of broiler chickens. In Proceedings of the Conference on international research on food security, natural meal. Int. J. Poult. Sci. 2008, 6, 875–882. [Google Scholar]
  155. Bampidis, V.; Robinson, P. Citrus by-products as ruminant feeds: A review. Anim. Feed Sci. Technol. 2006, 128, 175–217. [Google Scholar] [CrossRef]
  156. Katileviciute, A.; Plakys, G.; Budreviciute, A.; Onder, K.; Damiati, S.; Kodzius, R. A sight to wheat bran: High value-added products. Biomolecules 2019, 9, 887. [Google Scholar] [CrossRef] [PubMed]
  157. Ubalua, A. Cassava wastes: Treatment options and value addition alternatives. Afr. J. Biotechnol. 2007, 6, 2065–2073. [Google Scholar]
  158. Mazzafera, P. Degradation of caffeine by microorganisms and potential use of decaffeinated coffee husk and pulp in animal feeding. Sci. Agric. 2002, 59, 815–821. [Google Scholar] [CrossRef]
  159. Wilkinson, J.; Young, R. Strategies to reduce reliance on soya bean meal and palm kernel meal in livestock nutrition. J. Appl. Anim. Nutr. 2020, 8, 75–82. [Google Scholar] [CrossRef]
  160. Habeeb, A.; Gad, A.; El-Tarabany, A.; Mustafa, M.; Atta, M. Using of sugar beet pulp by-product in farm animals feeding. Int. J. Sci. Res. Sci. Technol 2017, 3, 107–120. [Google Scholar]
  161. Mottet, A.; Tempio, G. Global poultry production: Current state and future outlook and challenges. World’s Poult. Sci. J. 2017, 73, 245–256. [Google Scholar] [CrossRef]
  162. Siddiqui, Z.; Hagare, D.; Jayasena, V.; Swick, R.; Rahman, M.M.; Boyle, N.; Ghodrat, M. Recycling of food waste to produce chicken feed and liquid fertiliser. Waste Manag. 2021, 131, 386–393. [Google Scholar] [CrossRef] [PubMed]
  163. Buyse, K.; Delezie, E.; Goethals, L.; Van Noten, N.; Ducatelle, R.; Janssens, G.P.; Lourenço, M. Chestnut tannins in broiler diets: Performance, nutrient digestibility, and meat quality. Poult. Sci. 2021, 100, 101479. [Google Scholar] [CrossRef] [PubMed]
  164. Caipang, C.M.A.; Mabuhay-Omar, J.; Gonzales-Plasus, M.M. Plant and fruit waste products as phytogenic feed additives in aquaculture. Aquac. Aquar. Conserv. Legis. 2019, 12, 261–268. [Google Scholar]
  165. Mo, W.Y.; Man, Y.B.; Wong, M.H. Evaluation of nutritional values of food waste-based feed pellets and common feeding materials for culturing freshwater fish. In Environmental Sustainability and Education for Waste Management; Springer: Berlin/Heidelberg, Germany, 2019; pp. 305–321. [Google Scholar]
  166. Aluta, U.P.; Aderolu, A.Z.; Lawal, M.O.; Olutola, A.A. Inclusion effect of onion peel powder in the diet of African catfish, Clarias gariepinus: Growth, blood chemistry, hepatic antioxidant enzymes activities and SOD mRNA responses. Sci. Afr. 2021, 12, e00780. [Google Scholar] [CrossRef]
  167. Irabor, A.; Ekelemu, J.; Ekokotu, P.; Nwachi, O. The effect of garlic concentrates on the performance of hybrid catfish fingerlings (Heterobranchus longifilis x Clarias gariepinus). Int. J. Agric. Technol. 2021, 17, 503–516. [Google Scholar]
  168. Mpandeli, S.; Naidoo, D.; Mabhaudhi, T.; Nhemachena, C.; Nhamo, L.; Liphadzi, S.; Hlahla, S.; Modi, A.T. Climate change adaptation through the water-energy-food nexus in southern. Africa. Int. J. Environ. Res. Public Health 2018, 15, 2306. [Google Scholar] [CrossRef]
  169. Van Huis, A.; Oonincx, D.G. The environmental sustainability of insects as food and feed. A review. Agron. Sustain. Dev. 2017, 37, 43. [Google Scholar] [CrossRef]
  170. van Hal, O. Upcycling Biomass in a Circular Food System: The Role of Livestock and Fish. Ph.D. Thesis, Wageningen University and Research, Wageningen, The Netherlands, 2020. [Google Scholar]
  171. Iqbal, N.; Luqman, Z.; Jawad, H.; Aslam, S.; Farhab, M. Socio-economic impact of COVID-19 on livestock. In Veterinary Pathobiology Public Health; Unique Scientific Publishers: Faisalabad, Pakistan, 2021; p. 396. [Google Scholar]
  172. Anthony, O.C. Implementation of vision 20: 2020 agricultural policy and food production in nigeria, 2007–2015. Int. J. Res. Innov. Soc. Sci. 2019, 3, 42–64. [Google Scholar]
  173. Dou, Z.; Toth, J.D.; Pitta, D.W.; Bender, J.S.; Hennessy, M.L.; Vecchiarelli, B.; Indugu, N.; Chen, T.; Li, Y.; Sherman, R. Proof of concept for developing novel feeds for cattle from wasted food and crop biomass to enhance agri-food system efficiency. Sci. Rep. 2022, 12, 13630. [Google Scholar] [CrossRef]
  174. Daniel, J.L.P.; Bernardes, T.F.; Jobim, C.; Schmidt, P.; Nussio, L.G. Production and utilization of silages in tropical areas with focus on Brazil. Grass Forage Sci. 2019, 74, 188–200. [Google Scholar] [CrossRef]
  175. Suplicy, F.M. A review of the multiple benefits of mussel farming. Rev. Aquac. 2020, 12, 204–223. [Google Scholar] [CrossRef]
  176. Ryen, E.G.; Babbitt, C.W.J. The role of US policy in advancing circular economy solutions for wasted food. J. Clean. Prod. 2022, 369, 133200. [Google Scholar] [CrossRef]
  177. Munesue, Y.; Masui, T. The impacts of Japanese food losses and food waste on global natural resources and greenhouse gas emissions. J. Ind. Ecol. 2019, 23, 1196–1210. [Google Scholar] [CrossRef]
  178. Georganas, A.; Giamouri, E.; Pappas, A.C.; Papadomichelakis, G.; Galliou, F.; Manios, T.; Tsiplakou, E.; Fegeros, K.; Zervas, G. Bioactive compounds in food waste: A review on the transformation of food waste to animal feed. Foods 2020, 9, 291. [Google Scholar] [CrossRef] [PubMed]
  179. Westendorf, M.L.; Myer, R.O. Feeding Food Wastes to Swine; Citeseer: Princeton, NJ, USA, 2004. [Google Scholar]
  180. Salemdeeb, R.; Zu Ermgassen, E.K.; Kim, M.H.; Balmford, A.; Al-Tabbaa, A. Environmental and health impacts of using food waste as animal feed: A comparative analysis of food waste management options. J. Clean. Prod. 2017, 140, 871–880. [Google Scholar] [CrossRef] [PubMed]
  181. Nyachoti, C.; Zijlstra, R.; De Lange, C.; Patience, J. Voluntary feed intake in growing-finishing pigs: A review of the main determining factors and potential approaches for accurate predictions. Can. J. Anim. Sci. 2004, 84, 549–566. [Google Scholar] [CrossRef]
  182. Mallinson, L.J.; Russell, J.M.; Barker, M.E. Attitudes and behaviour towards convenience food and food waste in the United Kingdom. Appetite 2016, 103, 17–28. [Google Scholar] [CrossRef]
  183. Bräutigam, K.-R.; Jörissen, J.; Priefer, C. The extent of food waste generation across EU-27: Different calculation methods and the reliability of their results. Waste Manag. Res. 2014, 32, 683–694. [Google Scholar] [CrossRef] [PubMed]
Figure 1. Overview of classification of FW.
Figure 1. Overview of classification of FW.
Animals 13 01366 g001
Figure 2. Utilization of FWs to animal feeding by producers (A,B).
Figure 2. Utilization of FWs to animal feeding by producers (A,B).
Animals 13 01366 g002
Figure 3. Components of waste dryer. Figure 3 reprinted with permission (copyright © 2022, Elsevier Ltd., Amsterdam, The Netherlands) from Rahmani et al. [69].
Figure 3. Components of waste dryer. Figure 3 reprinted with permission (copyright © 2022, Elsevier Ltd., Amsterdam, The Netherlands) from Rahmani et al. [69].
Animals 13 01366 g003
Figure 4. Spray dryer working procedure.
Figure 4. Spray dryer working procedure.
Animals 13 01366 g004
Table 1. Country and households’ food waste.
Table 1. Country and households’ food waste.
CountryStudy AreaFood Waste (kg/Capita)Reference
IndiaAndhra Pradesh, Rajam58[34]
ChinaUrban China150[37]
Viet NamDa Nang67[39]
United States of AmericaNS59[42]
Saudi ArabiaNationwide105[43]
South AfricaNationwide134[51]
NS—Not specific.
Table 2. Techniques of analyzing different FWs and their use as animal feed.
Table 2. Techniques of analyzing different FWs and their use as animal feed.
Food WasteProcessing TechniquesWaste AmountAnimal FeedReference
Grape stemsSingle-cell production (SCP)7.5%Ruminants[84,85]
Mango peelingDehydration and consolidation using either paddy or corn stalks7–24%Broilers[86]
Restaurant FWsComposition contains corn, soybean meal, and other dietary supplements45%Pigs[87,88]
Pulp from a citrus fruitThe process involves drying and then composing the paddy or corn stalks.10 million MT of waste each yearMilk-producing cows[89,90,91,92]
Banana peelDrying and composition with a standard diet3.5 MT per year20 percent for growing pigs and 30 percent for rabbits.[93,94]
Banana leavesEnsiling with wheat straw (75/25)31%Cows and other animals that give milk[95,96]
Kitchen wastesDrying/high temperature composting37%Pigs[97,98]
Mango seeds
Bread waste
Seasonal fruits
Pomace of fruits and olives
Lemon peel and non-sterilized fish waste
Ethanolic extract
Solid-state fermentation
Ruminal fermentation
42%Broiler chickens
Cows and other animals that give milk
Milk-producing cows
Table 3. Types of FWs/by-products and their uses as animal feed.
Table 3. Types of FWs/by-products and their uses as animal feed.
Food WastesConstituentAnimals That Consume ItReference
Potato wasteSimilar to that of corn and barley in terms of energy
Crude protein (CP): 7.6%, Ether extract (EE): 7.0%, Crude fibre (CF): 4.0%
Excellent source of energy for cattle feed, 10% to 20% as feed pellets; also used for pigs and goats[138,139]
Banana root bulbsExcellent supply of carbohydrates
CP: 12.0%, Total digestible nutrients (TDN): 50.0%
Adult cattle can be fed 20–25 kg per day after cleaning and for pig feeding[139,140]
Apple wasteCP: 12.0%, TDN: 60.0%30% of this trash can completely replace corn in the feed of poultry and cattle after being chopped, ground, and dried[139,141]
Rice huskCF: 39.0–42.0%, EE: 0.8–1.2%, CP: 2.9–3.6%Cows, horses, and buffaloes[139,142]
Oil cakesVitamin-B- and protein-rich foodCows, goats, and horses[139,143]
Barley by-productsProtein 27.0–30.0%, TDN: 65.0%Dairy cows[139,144]
Citrus by-products:
citrus peel, pulp, rag, seeds
Total sugar (TS): 10.2–16.5%, Crude fat: 1.2–2.2%, CP: 2.2–4.2%, CF: 5.7–8.6%, Nitrogen-free extract 65.0–75.0%Adult cows 10 kg/day, up to 45% of the main source of energy for beef and other cattle[139,145,146]
Tea wasteTDN: 58%, CP: 17.94%, Tannic acid: 1.9%10–15% mixed with a tasty component are fed to cattle[139,147]
Mango seed kernelTDN: 55.0%, Protein 6%20 to 40% for growing calves and buffaloes, 10% for milch cattle, 50% for ruminants, and also as fish feed[139,148]
Coconut mealTDN: 70.0–75.0%, CF: 10.0%, CP: 25.0–30.0%Dairy cows can benefit from a highly helpful protein supplement that boosts milk fat content; also used for goat.[139,149,150]
Carrot wasteTDN: 75.0–80.0%, Protein 10.0–15.0%, Rich in vitamin AFor cattle, 20 kg/day[138,139]
Rice bran de-oiledTDN: 55.0–65.0%, CP: 13.0–16.0%, excellent source of protein, minerals, carbohydrate, vitamins, and high phosphorus content (1.3%)Cattle, pigs, broiler, fish, and ruminants[139,151,152]
Jackfruit wasteCP: 7.9%, CF: 14.1%, Calcium (Ca): 0.8%, Phosphorus (P): 0.1%Cattle, goats, etc.[138,139]
Tomato wasteTDN: 55.0%, CP: 15.0%For adult cows up to 50%, and for milch cows and poultry up to 16%[138,139]
Tamarind seedpowderTDN: 64.0%, CP: 12.0%Cattle, broilers, and bullocks[139,153]
Groundnut mealTDN: 75.0–85.0%, Protein 40.0–50.0%, High fibre contentCattle, goats, buffaloes,
sheep, and pigs
Citrus molassesTDN: 65.0–75.0%, CP: 10.0–14.0%, Sugar content 41.0–43.0%5–10% in the diets of broiler chickens and ruminant feed[139,155]
Wheat branTDN: 65.0–70.0%, CP: 13.0–16.0%, High phosphorus contentCows, pigs, and goats[139,156]
Tapioca wasteTDN: 60.0–65.0%, CP: 8.0–12.0%In order to maintain cattle body weight, 30% of tapioca waste can be fed to adult cattle.[139,157]
Coffee huskCP: 7.0–8.0%, Ca: 0.51%, P: 0.25%Cattle[139,158]
Soybean mealTDN: 75.0–84.0%, CP: 45.0–55.0%, Rich in Ca and PLivestock animal and cattle[139,159]
Beet molassesTDN: 65.0–75.0%, CP: 6.0–10.0%Cows and buffaloes[139,160]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Nath, P.C.; Ojha, A.; Debnath, S.; Sharma, M.; Nayak, P.K.; Sridhar, K.; Inbaraj, B.S. Valorization of Food Waste as Animal Feed: A Step towards Sustainable Food Waste Management and Circular Bioeconomy. Animals 2023, 13, 1366.

AMA Style

Nath PC, Ojha A, Debnath S, Sharma M, Nayak PK, Sridhar K, Inbaraj BS. Valorization of Food Waste as Animal Feed: A Step towards Sustainable Food Waste Management and Circular Bioeconomy. Animals. 2023; 13(8):1366.

Chicago/Turabian Style

Nath, Pinku Chandra, Amiya Ojha, Shubhankar Debnath, Minaxi Sharma, Prakash Kumar Nayak, Kandi Sridhar, and Baskaran Stephen Inbaraj. 2023. "Valorization of Food Waste as Animal Feed: A Step towards Sustainable Food Waste Management and Circular Bioeconomy" Animals 13, no. 8: 1366.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop