Search Results (319)

Prenatal and postnatal skeletal muscle development in ruminants is coordinated by interactions between genetic, nutritional, epigenetic, and endocrine factors. This review focuses on the influence of maternal nutrition during gestation on fetal myogenesis, satellite cell dynamics, and myogenic regulatory factors expression, including MYF5, MYOD1, and MYOG. Studies in sheep and cattle indicate that nutrient restriction or overnutrition alters muscle fiber number, the cross-sectional area, and the transcriptional regulation of myogenic genes in offspring. Postnatally, muscle hypertrophy is primarily mediated by satellite cells, which are activated via PAX7, MYOD, and MYF5, and regulated through mechanisms such as CARM1-induced chromatin remodeling and miR-31-mediated mRNA expression. Hormonal signaling via the GH–IGF1 axis and thyroid hormones further modulate satellite cell proliferation and protein accretion. Genetic variants, such as myostatin mutations in Texel sheep and Belgian Blue cattle, enhance muscle mass but may compromise reproductive efficiency. Nutritional interventions, including the plane of nutrition, supplementation strategies, and environmental stressors such as heat and stocking density, significantly influence muscle fiber composition and carcass traits. This review provides a comprehensive overview of skeletal muscle programming in ruminants, tracing the developmental trajectory from progenitor cell differentiation to postnatal growth and maturation. These insights underscore the need for integrated approaches combining maternal diet optimization, molecular breeding, and precision livestock management to enhance muscle growth, meat quality, and production sustainability in ruminant systems. Full article

Dietary bitter compounds such as caffeine have the potential to reduce backfat in pigs. However, the use of caffeine as a feed additive has restrictions in many countries. It was hypothesised that grape seed and gentian plant extracts (GG) could replace caffeine in feed due to their bitterness and antiadipogenic effects. The effect of caffeine (0.5 g/kg), GG (2 g/kg) alone or in combination with caffeine (BM) at increasing concentrations (0.5, 1, 1.5, or 2 g/kg) on feed efficiency, carcass, and meat quality was assessed in finishing pigs (Large White × Landrace). Growth performance and carcass traits were evaluated at a pen level (n = 14). Loins (longissimus thoracis) were removed from eight pig/treatment at the abattoir to assess drip loss, lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue angle (h°), pH, cook loss, and shear force. A linear increase (p < 0.05) in loin a*, b*, and C* values and a linear decrease (p < 0.05) in ADFI, ADG, backfat, dressing percentage, and HSCW were observed with increasing BM levels. At 1.5 g/kg, BM increased the loins a* (p < 0.05), b* (p < 0.05) and C* values (p < 0.05) compared to the control. Twenty-two proteins related to energy metabolism and myofibril assembly were identified to be upregulated (FDR < 0.05) in BM vs. control loins. In conclusion, GG could be used in combination with low doses of caffeine to modulate appetite and carcass leanness and improve pork colour. Full article

The increasing demand for sustainable poultry production has urged the exploration of alternative feed strategies supporting animal performance and environmental goals. The first section outlines the protein requirements in broiler nutrition (19–25% crude protein) and the physiological importance of balanced amino acid profiles. Vegetal conventional protein sources are discussed in terms of their nutritional value (12.7–20.1 MJ/kg), limitations (antinutritional factors), and availability. Emerging trends in broiler nutrition highlight the integration of supplements and the need for innovative feed solutions as support for the improvement in broiler body weight and feed efficiency increase. Microbial protein sources: yeast biomass (41–60% of 100 g dry weight), microbial mixed cultures (32–76% of 100 g dry weight), and beer by-products, such as brewer’s spent yeast (43–52% of 100 g dry weight), offer promising nutritional profiles, rich in bioactive compounds (vitamin B complex, minerals, enzymes, and antioxidants), and may contribute to improved gut health, immunity, and feed efficiency when used as dietary supplements. The review also addresses the regulatory and safety considerations associated with the use of microbial protein in animal feed, emphasizing EU legislation and standards. Finally, recent findings on the impact of microbial protein supplementation on broiler growth performance, carcass traits, and overall health status are discussed. This review supports the inclusion of microbial protein sources as valuable co-nutrients that complement conventional feed proteins, contributing to more resilient and sustainable broiler production and broiler meat products. Full article

Background: The current study aimed to evaluate the effects of the supplementation of protease sources on growth and carcass response, gut health, nutrient digestibility, and cecal microbiota profiles in broilers fed poultry-by-product-meal (PBM)-containing diets. Methods: In total, 800 one-day-old mixed-sex broilers (Arbor Acres) were weighed and allocated to one of the four dietary treatments in a completely randomized design, with eight replicates and 25 birds each per replicate. The treatments were as follows: (1) T₀, control diet (without protease supplementation and 3% PBM); (2) T₁, control diet supplemented with acidic protease at 100 g/ton (50,000 U/g); (3) T₂, control diet supplemented with alkaline protease at 200 g/ton (25,000 U/g); (4) T₃, control diet supplemented with neutral protease at 200 g/ton (25,000 U/g). Results: Protease supplementation enhanced (p < 0.05) body weight gain and the feed conversion ratio, predominantly in broilers fed PBM-based diets containing alkaline protease. Alkaline protease supplementation increased (p < 0.05) the apparent ileal digestibility of proteins (AIDP) by 4.3% and the apparent ileal digestibility of amino acids (AIDAA) by up to 5.8%, except for ornithine. Increments (p < 0.05) in carcass, breast, and leg quarter yields due to protease supplementation were evident, particularly in broilers fed diets containing alkaline protease. Alkaline protease improved (p < 0.05) the duodenal villus height (VH), reduced the crypt depth (CD), and increased the villus height to crypt depth ratio (VCR). Alkaline protease supplementation reduced (p < 0.05) cecal counts of Salmonella, Escherichia coli, and Clostridium in the broilers, whereas it increased (p < 0.05) the Lactobacillus counts. Conclusions: the supplemented alkaline protease resulted in improved growth performance and carcass traits, better gut health, as well as improved ileal digestibility of nutrients, including crude protein (CP) and acid insoluble ash (AIA), with a more balanced cecal microbial composition in broilers. Full article

Local horse breeds, particularly cold-blood types, are often marginalized in economic and social contexts, primarily due to the neglect of their economic, genetic, and cultural potential, as well as their role in preserving the identity of rural areas, local communities, and ecosystems. The valorization of these breeds is a crucial prerequisite for their economic repositioning. The Croatian Posavina horse is a local breed, well adapted to harsh, extensive production systems. Its sustainability is achieved through pasture-based meat production, primarily targeting foreign European markets. Ensuring the sustainability of conservation programs requires a thorough understanding of growth dynamics, carcass traits, and meat quality. This study assessed growth performance and carcass characteristics in a sample of 30 male foals, with ten animals selected for detailed analysis of fatty acid, amino acid, and volatile aromatic compound profiles. At eleven months of age, the foals reached a live weight of 347 kg and a dressing percentage of 60.62%. Color, tenderness, and water-holding capacity parameters were favorable for consumers. The meat’s high protein content (22.37%) and low intramuscular fat (3.61%) make it suitable for health-conscious or sensitive consumer groups. A high proportion of polyunsaturated fatty acids (28.5%) and a nutritionally balanced ω-6/ω-3 ratio (3.46) highlight the meat’s functional properties. The essential-to-non-essential amino acid ratio (0.81) further supports its nutritional value. Sensory analysis confirmed an attractive appearance, desirable texture and flavor, and a rich aromatic profile. The carcass and meat quality results, when compared with the production traits of other horse breeds, indicate that Croatian Posavina foal meat is a high-quality and nutritionally valuable alternative to conventional red meat. With optimized conservation and production strategies, the Croatian Posavina horse holds strong potential for market repositioning within sustainable and functional meat production systems. Full article

This study evaluated the effects of fermented banana agro-waste silage (BAWS) in finishing diets for KHAPS pigs (Duroc × MeiShan hybrid). BAWS was produced via 30 days of anaerobic fermentation of disqualified banana fruit, pseudostem, and wheat bran, doubling crude protein content and generating short-chain fatty acids, as indicated by a satisfactory Flieg’s score. Thirty-six pigs were assigned to control (0%), 5%, or 10% BAWS diets formulated to meet NRC nutritional guidelines. Over a 70-day period, BAWS inclusion caused no detrimental effects on growth performance, carcass traits, or meat quality; a transient decline in early-stage weight gain and feed efficiency occurred in the 10% group, while BAWS-fed pigs demonstrated reduced backfat thickness and increased lean area. Fore gut microbiome analysis revealed reduced Lactobacillus and elevated Clostridium sensu stricto 1, Terrisporobacter, Streptococcus, and Prevotella, suggesting enhanced fiber and carbohydrate fermentation capacity. Predictive COG (clusters of orthologous groups)-based functional profiling showed increased abundance of proteins associated with carbohydrate transport (COG2814, COG0561, COG0765) and stress-response regulation (COG2207). These results support BAWS as a sustainable feed ingredient that maintains production performance and promotes fore gut microbial adaptation, with implications for microbiota-informed nutrition and stress resilience in swine. Full article

Decreasing crude protein (CP) in broiler diets can improve sustainability but may compromise growth performance. Feed additives like coated cysteamine hydrochloride (CSH) and exogenous alkaline protease (EAP) can enhance protein utilization and promote gut health. While CSH modulates metabolism, EAP improves digestibility, but their combined effects in low CP diets remain unclear. This study examines the synergistic impact of CSH and EAP on broiler growth, gut histology, carcass traits, immune response, and nutrient digestibility, aiming to optimize performance while reducing environmental impact. Six-hundred, 1-day-old broiler Ross-308 chicks (male) were allotted to four treatments, each consisting of six replicates of twenty-five birds, in a factorial arrangement using a completely randomized design. The treatments comprised two inclusion levels of coated CSH (0.2 and 0.4 g/kg with or without EAP (0 and 0.2 g/kg) in reduced CP diets. A ten percent reduction in CP from the standard requirements of Ross-308 (20.7% vs. 23% in the starter, 19.35% vs. 21.5% in the grower, and 17.55% vs. 19.5% in the finisher phase) was made in all the dietary treatments. A notable interaction (p ≤ 0.05) between CSH and EAP was detected in body weight gain (BWG), feed conversion ratio (FCR), carcass characteristics, and gut morphology during the whole study duration. Similarly, nutrient digestibility and immune response were also influenced by the combined use of CSH and EAP. The synergistic use of coated CSH at 0.2 g/kg or 0.4 g/kg with EAP in reduced CP broiler diets can enhance performance, intestinal health, carcass characteristics, immune response, and nutrient digestibility. Implications of these findings in commercial feeding practices could substantially improve the efficiency and sustainability of broiler production systems. Full article

Crude protein, as a traditional standard for characterizing dietary nitrogen content, fails to reflect protein bioavailability. Digestible protein (DP) emphasizes the importance of total available proteins and offers better adaptability in low-protein diversified diets. The objective of this study was to establish and validate the digestible protein (DP) requirement for 80–110 kg finishing pigs (Duroc × Yorkshire × Landrace). In Experiment 1, 450 pigs were fed diets with graded DP levels (8.82–11.26%). Linear and quadratic regression models identified 9.55% DP as the optimal level, optimizing average daily gain and feed efficiency (R² ≥ 0.94). Experiment 2 validated this requirement using three diet treatments and 270 pigs: high-protein traditional, low-protein traditional, and low-protein diversified. No significant differences were observed in growth performance, carcass traits, or meat quality among diets, confirming the robustness of 9.55% DP across formulations. Plasma urea nitrogen and total amino acids increased linearly with DP (p < 0.05), while hepatic transcriptomics revealed immune and metabolic partial impairments in high-protein traditional diet pigs, which may be linked to nitrogen overload. Muscle tissues from different treatment groups showed minimal transcriptional differences, emphasizing efficient protein utilization when amino acid requirements are met. This study demonstrates that 9.55% DP, combined with balanced amino acids, supports productivity in both traditional and diversified diets, reducing reliance on resource-intensive feed ingredients. These findings advocate for DP as a precise metric in swine production, thereby promoting sustainable development. Full article

Objectives: The study investigates runs of homozygosity (ROH) and heterozygosity (ROHet), and their patterns in nine sheep breeds (772 animals in total) maintained in Poland (native and conserved), corresponding to their genetic diversity, inbreeding levels, and selection signatures. Methods: Genotypes were obtained using the Illumina OvineSNP50 BeadChip and quality-filtered SNPs were used to detect ROH and ROHet segments with the detectRUNS R package, following stringent parameters for segment length, SNP density, and genotype quality. Results: Significant variation in ROH characteristics was observed across breeds. Short ROH segments were predominant in all breeds, indicating historical inbreeding events. In contrast, longer ROH segments signified recent inbreeding, particularly in Swiniarka (SW) and Polish Merino of Colored Variety (MPC). The ROH-based genomic inbreeding coefficient (F_ROH) varied across breeds, with SW exhibiting the highest levels, suggesting reduced genetic diversity. ROHet analysis revealed that Uhruska (UHR) had the highest heterozygous segments span, while Black-headed (BH) sheep exhibited the lowest ROHet extent. ROH islands identified across breeds revealed regions under selection, associated with traits such as reproductive performance, wool quality, and body condition. Genes located within these islands (e.g., U6, SPP1, ABCG2) were linked to economically significant traits including milk production, growth, and carcass quality. Conclusions: The presented results highlight the genetic adaptations shaped by selection pressures, while also providing insights into the genetic architecture of sheep breeds maintained in Poland. Full article

This study evaluated the effects of dietary supplementation with guanidinoacetic acid (GAA) and zilpaterol hydrochloride (ZLH) on productive performance, carcass traits, and blood chemistry in non-castrated male lambs over 60 days. Twenty-four Pelibuey × Dorper crossbred lambs (16.3 ± 2.7 kg) were adapted to housing and diet for 14 days before being randomly assigned to one of three treatments: (1) Control: total mixed ration (TMR) without additives; (2) GAA: TMR with 0.06% GAA; and (3) ZLH: TMR with 6 mg/kg dry matter (DM) of ZLH for the last 30 days. No significant differences were observed in productive performance or carcass traits among treatments. However, lambs fed GAA showed higher serum glucose and creatinine levels than the control group (p < 0.05), suggesting a potential effect on energy metabolism. ZLH supplementation had no measurable impact on the parameters evaluated. These findings indicate that while GAA may influence certain metabolic indicators, further research with extended feeding periods or varying dosages is needed to clarify its effects on growth and carcass characteristics in lambs. Full article

This study investigated the effects of dietary guanidinoacetic acid (GAA) supplementation on growth performance, carcass traits, meat quality, intestinal morphology, and cecal microbiota composition in yellow-feathered broilers. A total of 360 one-day-old chicks were randomly assigned to five groups with diets containing 0 (control), 300 mg/kg, 600 mg/kg, 900 mg/kg, and 1200 mg/kg GAA. In the initial growth phase, GAA supplementation increased average daily gain (ADG) by 13.01%, 8.97%, and 12.95% for the 300, 600, and 900 mg/kg groups, respectively, and reduced the feed conversion ratio (FCR), though these changes were not statistically significant (p > 0.05). Higher GAA dosages (900 and 1200 mg/kg) improved post-slaughter pH levels in breast muscle, indicating better meat quality, and significantly enhanced intestinal barrier function by increasing villus height and the villus-to-crypt ratio. However, 1200 mg/kg GAA led to a significant increase in serum ALT levels, raising concerns about potential liver stress. Overall, 900 mg/kg GAA supplementation demonstrated the most beneficial effects across various parameters, suggesting it as an optimal dosage to enhance production performance and meat quality in yellow-feathered broilers. Future studies are encouraged to investigate its long-term safety and underlying mechanisms. Full article

Maternal overnutrition and targeted supplements during pregnancy strongly affect fetal development in beef cattle, influencing gene expression, tissue development, and productivity after birth. As modern feeding practices often result in cows receiving energy and protein above requirements, understanding the balance between adequate nutrition and overconditioning is critical for sustainable beef production. This review synthesizes findings from recent studies on maternal overnutrition and supplementation, focusing on macronutrients (energy, protein, methionine) and key micronutrients (e.g., selenium, zinc). It evaluates the timing and impact of supplementation during different gestational stages, with emphasis on fetal muscle and adipose tissue development, immune function, and metabolic programming. The role of epigenetic mechanisms, such as DNA methylation and non-coding RNAs, is also discussed in relation to maternal dietary inputs. Mid-gestation supplementation promotes muscle growth by activating muscle-specific genes, whereas late-gestation diets enhance marbling and carcass traits. However, maternal overnutrition may impair mitochondrial efficiency, encourage fat deposition over muscle, and promote collagen synthesis, reducing meat tenderness. Recent evidence highlights sex-specific fetal programming differences, the significant impact of maternal diets on offspring gut microbiomes, and breed-specific nutritional responses, and multi-OMICs integration reveals metabolic reprogramming mechanisms. Targeted trace mineral and methionine supplementation enhance antioxidant capacity, immune function, and reproductive performance. Precision feeding strategies aligned with gestational requirements improve feed efficiency and minimize overfeeding risks. Early interventions, including protein and vitamin supplementation, optimize placental function and fetal development, supporting stronger postnatal growth, immunity, and fertility. Balancing nutritional adequacy without excessive feeding supports animal welfare, profitability, and sustainability in beef cattle systems. Full article

This study evaluated the effect of mixed meal replacement of soybean meal on growth conditions, carcass traits, and meat quality of finishing pigs by partially and entirely replacing soybean meal with equal proportions of rapeseed, cotton, and sunflower meal. A total of fifty-four pigs with an average initial weight of 97.60 ± 0.30 kg were selected and randomly divided into three groups according to their initial weight, with six pens in each group and three pigs in each pen. The experimental groups were as follows: control group (CON), fed corn–soybean meal type basal diet; corn–soybean mixed meal group (CSM), using equal proportions of rapeseed meal, cotton meal, and sunflower meal (3.52% each) to replace 9.06% of soybean meal in the basal diet; and corn mixed meal group (CMM), using equal proportions of rapeseed meal, cotton meal, and sunflower meal (6.46% each) to replace soybean meal in the basal diet completely. According to the results, the use of mixed meal as a replacement for soybean meal did not have a significant impact (p > 0.05) on the average daily weight gain, average daily feed intake, feed-to-weight ratio, body size, carcass traits, and meat quality of finishing pigs. The entire replacement of soybean meal with a mixed meal resulted in a significant increase (p < 0.05) in leaf fat weight. The use of mixed meal as a substitute for soybean meal had no significant effect (p > 0.05) on the antioxidant capacity and fatty acid composition of the longissimus thoracis in finishing pigs. However, longissimus thoracis muscle fiber diameter was reduced in the mixed meal partially replaced soybean meal group compared to the mixed meal completely replaced soybean meal group (p < 0.05). In addition, mixed meal replacing soybean meal did not significantly affect (p > 0.05) the expression of the longissimus thoracis muscle fiber type genes MYHC1 and MYHC2. Mixed meal replacement of soybean meal did not significantly affect (p > 0.05) the expression of ACACA, FASN, and PPARG genes in the longissimus thoracis. This study showed that mixed meal as an alternative to soybean meal in diets did not have significant negative effects on the growth performance and meat quality of finishing pigs. These results can help develop further mixed meals as a functional alternative feed ingredient for soybean meals in pig diets. Full article

Glycerol can effectively replace corn as an energy source in lamb diets without negatively impacting productive performance. This study evaluated the effects of substituting ground corn with different glycerol levels on the productive performance, ruminal fermentation, carcass characteristics, and meat quality at 24 h, 7, 14, and 21 d post-slaughter. A total of 40 male Suffolk × Hampshire crossbred lambs (25 ± 5 kg live weight) were used in a completely randomized design with four treatment groups (n = 10 each): 0% glycerol (GLY₀), 5% glycerol (GLY0₅), 10% glycerol (GLY₁₀), and 15% glycerol (GLY₁₅). Including glycerol in the diet did not affect growth performance (p > 0.05). However, it did lead to an increase (p < 0.05) in the concentrations of NH₃-N and the proportions of propionic and butyric acids, while the acetic acid levels decreased (p < 0.05). The backfat thickness, loin eye area (LEA), and carcass yield were not significantly affected (p > 0.05) by the addition of glycerol. Additionally, pH and color were also unaffected (p > 0.05), although the water-holding capacity showed a decrease (p < 0.05) over the shelf life of the meat. The chemical composition of the meat remained similar across all treatments, time points, and interactions (p > 0.05). In contrast, the protein content was significantly affected (p < 0.05) by the glycerol inclusion, time, and interactions between treatment and time. The results indicate that substituting up to 15% of ground corn with glycerol in lamb diets does not negatively impact productive performance, backfat thickness, LEA, carcass traits, or meat quality during shelf life. Throughout the shelf life, the crude protein concentrations and water-holding capacity decreased, while the propionic acid and NH₃-N concentrations increased. Full article

Leonardite (LEO), a microbial derived product rich in humic and fulvic acids, has been tested, due to its beneficial properties for health and well-being, as a feed additive, mainly in non-ruminant species. Although there are some reports of LEO supplementation in ruminants fed with high-to medium-forage based diets, there is no information available of the potential effects of LEO in ruminants fed, under sub-tropical climate conditions, with high-energy diets during long-term fattening. For this reason, the objective of the present experiment was to evaluate the effects of LEO levels inclusion in diets for feedlot lambs finished over a long-term period. For this reason, 48 Pelibuey × Katahdin lambs (initial weight = 20.09 ± 3.55 kg) were fed with a high-energy diet (88:12 concentrate to forage ratio) supplemented with LEO (with a minimum of 75% total humic acids) for 130 days as follows: (1) diet without LEO, (2) diet supplemented with 0.20% LEO, (3) diet supplemented with 0.40% LEO, and (4) diet supplemented with 0.60% LEO. For each treatment, Leonardite was incorporated with the mineral premix. Lambs were blocked by weight and housed in 24 pens (2 lambs/pen). Treatment effects were contrasted by orthogonal polynomials. The average climatic conditions that occurred during the experimental period were 31.6 ± 2.4 °C ambient temperature and 42.2 ± 8.1% relative humidity (RH). Those values of ambient temperature and RH represent a temperature humidity index (THI) of 79.07; thus, lambs were finished under high heat load conditions. The inclusion of LEO in diet did not affect dry matter intake (p ≥ 0.25) and average daily gain (p ≥ 0.21); therefore, feed to gain ratio was not affected (p ≥ 0.18). The observed to expected dietary net energy averaged 0.96 and was not affected by LEO inclusion (p ≥ 0.26). The lower efficiency (−4%) of dietary energy utilization is an expected response given the climatic conditions of high ambient heat load presented during fattening. Lambs that were slaughtered at an average weight of 49.15 ± 6.00 kg did not show differences on the variables measured for carcass traits (p ≥ 0.16), shoulder tissue composition (p ≥ 0.59), nor in visceral mass (p ≥ 0.46) by inclusion of LEO. Under the climatic conditions in which this experiment was carried out, LEO supplementation up to 0.60% in diet (equivalent to 0.45% of humic substances) did not did not help to alleviate the extra-energy expenditure used to dissipate the excessive heat and did not change the gained tissue composition of the lambs that were fed with high-energy diets during long-term period under sub-tropical climate conditions. Full article