Search Results (52)

The objective of this study is to investigate the degradation characteristics of oat grass in the rumen of Mindong goats and changes in microbial community attached to the grass surface. Four healthy male goats, aged 14 months, with permanent rumen fistula, in eastern Fujian, were selected as experimental animals. The rumen degradation rate of oat grass was measured at 4, 12, 24, 36, 48, and 72 h using the nylon bag method. Surface physical structure changes in oat grass were observed using scanning electron microscopy (SEM), cellulase activity was measured, and bacterial composition was analyzed using high-throughput 16S rRNA gene sequencing technology. The findings of this study indicate that oat grass had effective degradation rates (ED) of 47.94%, 48.69%, 38.41%, and 30.24% for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and acidic detergent fiber (ADF), respectively. The SEM was used to investigate the degradation process of oat grass in the rumen. After 24 h, extensive degradation of non-lignified tissue was observed, resulting in the formation of cavities. At 36 h, significant shedding was observed, and by 72 h, only the epidermis and thick-walled tissue, which exhibited resistance to degradation, remained intact. Surface-attached microorganisms produced β-GC, EG, CBH, and NEX enzymes. The activity of these enzymes exhibited a significant increase between 4 and 12 h and showed a positive correlation with the degradation rate of nutrients. However, the extent of correlation varied. Prevotella and Treponema were identified as key genera involved in the degradation of roughage, with their abundance decreasing over time. Principle Coordinate Analysis (PCOA) revealed no significant differences in the rumen microbial structure across different time points. However, Non-Metric Multidimensional Scaling (NMDS) indicated a discernible diversity order among the samples. According to the Spearman correlation coefficient test, Ruminococcus, Fibrobacter, and Saccharoferments exhibited the closest relationship with nutrient degradation rate and surface enzyme activity, displaying a significant positive correlation. In summary, this study delineates a time-resolved correlative framework linking microbial succession to structural and enzymatic dynamics during oat grass degradation. Full article

Maize (Zea mays L.) silage in the irrigated and flat areas of Italy represents the most important large ruminant feed crop due to the high dry matter yield and nutritive value per hectare. The aim of the investigation was to evaluate the chemical composition and the in vitro fermentation patterns of five maize varieties (Tiesto, R700 1, MAS 78.T, DKC 7074 and KWS Kantico) freshly chopped and preserved via ensiling. The results indicated that the chemical composition was not significantly different among varieties. The substrates were incubated for 72 h with buffered rumen fluid collected from cow. The ensiling process slightly reduced gas production and fermentation kinetics, likely due to the consumption of soluble sugars during fermentation. Organic matter loss (OM loss) differed significantly (p < 0.01) among varieties in ensiled maize, correlating with their neutral detergent fiber (NDF) content. While total volatile fatty acid (VFA) production showed no significant differences between varieties, the buffer capacity ratio (BCR), an indicator of protein degradation, varied significantly. Ammonia production (NH₃) was significantly higher in ensiled samples, supporting previous findings that ensiling increases non-protein nitrogen (NPN) due to microbial proteolysis and plant enzyme activity. The gas production profiles and fermentation rates over time showed minor differences between fresh and ensiled samples, with fresh material exhibiting faster fermentation kinetics due to the presence of soluble sugars. These findings highlight the importance of evaluating maize silage quality to optimize ruminant nutrition and feed efficiency. Full article

The consumption of forages high in slow-degradable carbohydrates by dairy cattle leads to greater ruminal acetate production, which benefits milk fat content. Although tropical grasses are typically rich in fibrous materials, the milk fat content of dairy cows in Southeast Asia is low. Here, we investigate the effects of the species and harvest time of three common tropical grasses (Guinea, King, and Mulato II) harvested at three instances (early, normal, late) on in sacco degradation kinetics and in vitro gas production (IVGP) characteristics. Grass samples were subjected to (1) chemical analysis, (2) a fully automated in vitro gas recording system using rumen fluid to measure fermentation characteristics over 72 h, and (3) in sacco degradation using the nylon bag technique, employing seven incubation times up to 336 h. Forage quality decreased with maturity, as reflected in changes to digestibility and fiber content. Overall, early harvested grasses yielded the highest total gas production (311 ± 12.5 mL/g OM) followed by normal (300 ± 45.7 mL/g OM) and late (273 ± 19.5 mL/g OM) harvested grasses. The in vitro fermentable fraction (A1 + A2) was the highest for early harvested grasses, with the A2 parameter, relevant for milk fat content, being the highest for Guinea (81.6% A2/(A1 + A2)) and the lowest for King grass (71.0% A2/(A1 + A2)). Consequently, early harvested Guinea had the longest incubation times (10.5 h) and lowest fermentation rates (Rmax2 = 12.8 mL/g OM/h). Regression analysis showed relationships between NDF content and degradability. Harvesting tropical grass earlier than customarily practiced enhanced forage quality and ruminal degradability. Of the three grasses studied, each at three levels of maturity, early harvested Guinea grass was the most promising candidate for improving milk fat content in Southeast Asian dairy cows. This grass showed a high fermentable OM content, with a large proportion of slow-degradable carbohydrates. Full article

Pea (Pisum sativum L.) seeds are valuable feed ingredients due to their high-quality protein and starch digestibility, making them a viable alternative to soybean meal and corn grain. This study evaluated the nutritional value of three commercial pea varieties (Ganster, Peps, and Poseidon) through in vitro trials. Each variety was incorporated into an experimental diet (GNS, PES, and PNS) for dairy cows, partially replacing soybean and corn meals. These diets were compared to a control diet containing only soybean and corn meals. All diets were incubated anaerobically for 120 h with dairy cow rumen liquor. Results showed that GNS and PES diets enhanced protein degradability (p < 0.05) and fermentation kinetics (p < 0.001). Additionally, all experimental diets reduced ammonia production (p < 0.001), while the PES diet increased (p < 0.001) volatile fatty acid production. Among the tested varieties, Peps demonstrated the greatest potential by improving protein metabolism and volatile fatty acid production. These findings suggest that pea grains can be a suitable alternative in dairy cow diets, supporting efficient ruminal fermentation and nutrient utilization. Full article

This study aimed to evaluate the crude protein (CP) degradation kinetics and degradability (CPD) of cereal and legume fodder species grown at two geographically distant locations. Ten forage species, comprising six cereals (barley, maize, millet, oats, sorghum, and wheat) and four legumes (berseem, jantar, lucerne, and mustard), were evaluated to determine the effects of forage family, species, and location of growth on CP degradation fractions and effective CPD. The forage crops were cultivated under uniform agronomic practices at two distinct agro-ecological locations and were harvested at the booting stage (cereals) and 50% flowering stage (legumes). Dried and ground samples were incubated in the rumen of four Nili-Ravi buffalo fitted with rumen cannula. The incubation periods utilized in the experiment were 0, 4, 8, 16, 24, and 48 h, and a 4 × 2 × 2 split-plot design was employed. The results showed that the CP degradation fractions and CPD were significantly affected by forage family, species, and location of growth. Wide variations in degradation kinetics and degradability existed among and within the cereal and legume fodders, with wheat and jantar ranked at the top. Legume forages had larger soluble fractions, smaller potentially degradable fractions, and rapid rates and extent of degradation of dietary proteins than cereal forages. The cooler climatic conditions at location 2 increased the rapidly degradable protein fraction and overall CPD, whereas the warmer climatic conditions enhanced the slowly degradable protein fractions, thereby reducing the overall protein degradability in tropical forages. It was quite evident that some fodder species, such as maize among the cereal fodders and mustard among the legume fodders, remained quite non-responsive to the effects of the climatic conditions. A moderately positive and linear relationship between the rate of degradation and CPD was established for cereals, whereas a strongly positive and quadratic relationship was established for legume fodders. In conclusion, forage species, family, and location of growth significantly affected the degradation fractions and degradability of tropical cereal and legume fodders. Full article

A voluminous amount of knowledge has been collected about the effects of the rate and amount of intake and of the rate and amount of digesta flow out of the rumen on rumen fill and, hence, intake. However, the mechanisms by which small particles in the rumen are selected for passage have not been clearly identified. Grinding and pelleting have been alleged to either enhance or reduce entrapment; hence, the relationships between particle size and digestion and passage kinetics are not sufficiently clear, as it is not the effect of rumen digesta particle size on marker dilution kinetics. On these grounds, the aim of the present experiment was to examine the behaviour of small particles within the rumen and determine if their retention time by passage or digestion pathways alter under pelleting and control intake. In the present experiment, the effects of a low-quality alfalfa hay presentation (chopped vs. ground and pelleted) on intake, feeding behaviour, rumen fill and digestion, and passage were assessed in adult wethers. Pelleting increased intake without alteration of either the maximum amount of digesta present in the rumen or degradation rates. The faster dilution rate of the liquid phase with the pelleted hay, likely including significant amounts of particles <0.15 mm, should be the main factor for the higher intake with this diet. Full article

In temperate pasture-based dairy systems, ryegrass (Lolium perenne L.) is a key forage due to its high crude protein (CP) content, yet its rapid ruminal degradation could limit the supply of rumen-undegraded protein and essential amino acids (EAAs) to dairy cows. This study aimed to investigate the in situ ruminal degradability of CP and individual amino acids (AAs) in fresh ryegrass at the vegetative stage. Three second-parity, rumen-cannulated Holstein Friesian cows (487 kg body weight, 16.5 kg milk/day) were used for the incubation of ryegrass samples collected in different seasons at the vegetative stage. The degradation kinetics were assessed using the Ørskov and McDonald model, with mathematical corrections for microbial contamination. Results showed that the effective degradability (ED) of AAs was generally higher than that of CP (p < 0.05), exceeding 2%, and that some EAAs, particularly lysine, exhibited an ED up to 5.5% greater than CP (p < 0.05). These differences underscore the need for caution when using CP as a proxy for AA degradation in dietary formulations. Given the high degradability of ryegrass AAs, it would be important to monitor and adjust their supply in diets with high ryegrass inclusion to prevent potential deficiencies that could impair milk production and reduce feed efficiency. Full article

Enteric methanogenesis in ruminants is identified as one of the primary anthropogenic sources of total atmospheric methane. Recent evidence suggests that rumen methanogenesis is significantly suppressed by lovastatin. Nevertheless, it has not been reported whether the methane reduction by lovastatin depends on ruminant livestock type, nor has fiber degradability been examined. The current research aimed to analyze the in vitro effect of lovastatin on the major fermentation end-products, gas production (GP) kinetics, and fiber degradation of a forage-based diet using rumen inoculum from sheep, goats, and cows. The experiment was conducted as a 3 × 3 factorial arrangement of treatments (dose of lovastatin: 0, 80, and 160 mg/L and three inoculum sources) in a completely randomized design. The results suggested that lovastatin did not affect the GP kinetics parameters. The anti-methanogenic properties of lovastatin were variable depending on dose and inoculum source. Lovastatin demonstrated a superior methane-lowering effect in sheep rumen inoculum compared with goat and cow inocula. The total volatile fatty acid (VFA) production was unaffected by lovastatin, but changes in acetate and valerate proportions were registered. Remarkably, lovastatin decreased the NH3-N concentration with goat and sheep inocula and the in vitro neutral fiber detergent (NDF) degradation for all inoculum sources. Full article

Fodder scarcity, inadequate nutritional quality, and lack of degradation kinetics research are among the serious concerns hindering sustainable development of livestock globally. Rumen degradation kinetics data on neutral detergent fibre (NDF) in buffaloes are lacking for most tropical forage species. This study evaluated the effect of forage species, family, and growing location on NDF concentration and in situ degradability of six tropical cereal and four legume fodder crops. The fodder crops were grown following uniform recommended agronomic practices at three different agroecological locations and harvested at the appropriate growth stage: cereals at booting and legumes at 50% flowering. Later, the dried ground forage samples were incubated in the four rumen-cannulated Nili-Ravi buffalo cows in a four × two × three split-plot design for 0, 4, 8, 16, 24, 48, 96, and 168 h. The degradation fractions and degradability, expressed either on an NDF or dry matter basis, were considerably affected by forage family (cereal vs. legume) and growing locations and their interaction. Legume fodders degraded more rapidly but to a lesser extent than cereal fodders. The chemical components, notably the NDF, showed a significant but moderate negative relationship with the effective NDF degradability. Among studied fodders, the legumes had a significantly lower NDF concentration and subsequent degradability than the cereals. Although the cereals showed a slower rate of NDF degradation, their overall degradability was higher. The agro-climatic variability among three locations strongly impacted the NDF concentrations and fractions in the tropical forages. Effective NDF degradability was also correlated with the fodders’ NDF concentration, especially in cereals where the nature of the correlation was negative. In conclusion, the nutritional composition and NDF degradation parameters of the fodders were significantly affected by the species, family, and location of growth and their interactions. These results will help to improve agronomy and usage of these important fodder crops. Full article

An experiment was carried out to assess the effect of the incorporation of sun-dried foliage of Brosimum alicastrum into rations based on hay of Megathyrsus maximus on intake, rumen fermentation, kinetics of passage, microbial nitrogen supply to the small intestine, apparent digestibility in Pelibuey hair sheep. Four rations were randomly allotted to four rumen-cannulated lambs (BW = 37.4 ± 4.9 kg) using a 4 × 4 Latin square design to assess the effect of increasing levels (0, 15, 30 and 45% DM basis) of foliage of Brosimum alicastrum on a basal ration of M. maximus. Organic matter intake and water consumption increased linearly (p < 0.01) with increasing levels of B. alicastrum in the ration. The rate and potential extent of rumen fermentation of OM and CP of B. alicastrum were 10.6%/h and 86.6% and 11.4%/h and 95.2%, respectively, but no effect (p > 0.05) was found on the potential rumen degradation of DM (40.2%) or on the rate of degradation of DM (0.033%/h) of M. maximus, although a positive effect was found in the rumen degradation rate of NDF (p < 0.05). VFA and ammonia concentration in the rumen and the rate of passage of solids and liquids through the rumen (k₁) increased linearly (p < 0.01) with increasing levels of B. alicastrum. Rumen pH was not affected by the incorporation of B. alicastrum (p > 0.05). Microbial nitrogen supply to the small intestine (p < 0.001), apparent digestibility of dry matter (p < 0.01) and NDF (p < 0.05) of the rations were also significantly increased as a result of the incorporation of B. alicastrum foliage. Results from this experiment suggest that the foliage of Brosimum alicastrum can be readily incorporated at around 30% of the ration of dry matter in hair sheep with beneficial effects on feed intake, rate of passage and microbial N supply to the lower tract. Full article

Precise information about carbohydrates and proteins in relation to their utilization in the rumen is useful for the breeding purposes of perennial ryegrass cultivars used for animal nutrition. The objective of the current study was to evaluate 20 diploid perennial ryegrass accessions from the intermediary heading stage. The ruminal kinetics of different carbohydrate and protein fractions of grasses and legumes are important for forage breeding programs. The Cornell Net Carbohydrate and Protein System (CNCPS) was used to provide such information. Accession-based variation can be observed after considering dynamic degradation processes. Variation among the 20 accessions was observed. Ruminally digested (RDC) and undigested (UDC) carbohydrate and ruminally degraded (RDP) and undegraded (UDP) protein contents, total carbohydrate and total protein contents, and carbohydrate and protein fractions for the first cut and annual averages show significant differences. Although the variation was smaller for the protein fractions, the calculated usable protein content (uCP, sum of UDP and amount of synthesized microbial protein in the rumen) in the small intestine is mainly influenced by decreasing the neutral detergent fiber (NDF) and increasing the sugar content among cultivars. Carbohydrate and protein fractionation is suitable for characterizing perennial grass accessions as it uses parameters relevant to ruminant nutrition, allowing a step forward in forage plant breeding for forage quality. To conclude, using parameters related to ruminal degradation kinetics should favor the selection of accessions with higher amounts of ruminally digested carbohydrates (RDC). The selection of accessions based on protein quality (proportion of UDP) is less favorable for achieving a higher usable protein content. Full article

The present study investigated the effects of sprouted barley (SB) with different cultivation stages on fermentation characteristics and degradation kinetics in the rumen. The SB was cultivated in three different stages as follows: 0, 4, and 8 days. Dried samples from each cultivation stage of SB were incubated in the rumen buffer at 39 °C for 48 h in quadruplicate with three blanks. Dry matter (DM) and neutral detergent soluble carbohydrate concentrations of SB decreased linearly (p = 0.001) by increasing the cultivation stage, while crude protein, neutral detergent fiber (NDF), acid detergent fiber, and hemicellulose concentrations increased linearly (p ≤ 0.001). Total volatile fatty acid and butyrate in the rumen decreased linearly (p ≤ 0.020) by increasing the cultivation stage, while pH and propionate increased linearly (p < 0.001). The total degradation fraction of DM and NDF increased quadratically (p ≤ 0.003). The fraction degradation rate of DM and NDF decreased linearly (p ≤ 0.001) by increasing the cultivation stage, while the lag phase increased linearly (p ≤ 0.010). The present study concluded that cultivated SB at 4 days was recommended for animal feed due to the highest nutrient degradation in the rumen without any adverse effects on fermentation characteristics. Full article

The dietary inclusion of trace minerals (TMs), such as copper (Cu), manganese (Mn) and zinc (Zn), is of importance to cover the ever-evolving requirements for growth, production and reproduction in ruminants. Various sources of TMs are commercially available, such as inorganic (ITM), organic (OTM) or hydroxy (HTM) forms; however, their bioavailability and efficiency to improve ruminant zootechnical parameters may be highly influenced by ruminal solubility and effects on the rumen environment. The objective of this review was to compile the most up-to-date information on the ruminal solubility of ITMs, OTMs and HTMs and their effects on fermentation parameters and rumen microbiota, aiming to support specialists from the animal feed industry when choosing TM products for ruminant supplementation. Some commonly used ITM sources, like sulfates, have a high ruminal solubility, while oxides are less soluble. The ruminal solubility of OTMs is mostly found to be high; however, data on these TM forms are still lacking. Regarding HTMs, ruminal solubility is reported to be low; nevertheless, results are inconsistent. Considering rumen fermentation, ITMs show a negative effect, OTMs might improve, while HTMs do not affect parameters like dry matter degradability, volatile fatty acid production, pH or microbial protein synthesis. As for rumen microbiota, ITMs do not affect microbial populations; OTMs could decrease the abundance of some specific bacteria, like fibrolytic microorganisms, while studies with HTMs are missing or inconclusive. Further research is necessary to better understand the ruminal solubility kinetics of TM sources and the different interactions with fermentation parameters and rumen microbiota to successfully apply the precision TM supplementation of ruminants, tackling deficiency occurrences. Full article

Tannins can be utilized to increase rumen undegradable protein (RUP) by their capacity to form complexes with diverse nutrients present in the feed. In that regard, high-performance ruminants demand elevated RUP levels. The objective of this study was to evaluate the effects of incorporating varying levels of tannin into three protein sources (cottonseed, peanut, and soybean meals) on ruminal kinetic parameters, ruminal fermentation, and intestinal digestibility. Thus, three in situ experiments were conducted to investigate the ruminal degradation kinetics, where Fraction A represents the soluble portion, Fraction B relates to the portion potentially degraded in the rumen, and kd denotes the degradation rate of Fraction B, for both dry matter (DM) and crude protein (CP) in the rumen. Additionally, the study assessed dry matter effective degradability (ED), rumen undegradable protein (RUP), and intestinal digestibility (ID). These experiments utilized three cannulated animals for the in situ incubations. Regarding cottonseed meal in terms of DM degradation kinetics, tannin inclusion had a quadratic effect on fraction A (p < 0.01), B (p = 0.10, trend), kd (p = 0.03), and ED (p < 0.01). Fraction A of CP had a cubic effect (p = 0.03), being greater for the control compared with the other treatments. The inclusion of tannin linearly increased RUP (p < 0.01). The RUP proportion increased 29, 33, and 45% when 20, 40, and 60 g/kg tannin were used, respectively, compared to the control. For peanut meal, the A fraction of protein and RUP responded quadratically as tannin was included in peanut meal (p < 0.01). However, tannin levels did not affect fraction B of protein and ID. Regarding soybean meal, fractions A and B of DM and ED had cubic effects (p < 0.01), being greater for the control compared with the other treatments, and responded quadratically as tannin increased. Also, tannin inclusion had a cubic effect on fractions A and B of protein, RUP, and ID (p < 0.01). The cubic behavior showed greater B fraction and ID and lower A fraction and RUP for the control compared other treatments (p < 0.01). Tannins offer a promising avenue for elevating RUP levels in diets featuring cottonseed and peanut meals. Nevertheless, no advantages were observed when treating soybean meal with tannin. Full article

Currently, the scarcity of high-quality, expensive animal feed is a primary factor driving up the cost of animal husbandry. As a result, most researchers have focused on improving the potential of using alternative feed resources derived from the black soldier fly larva. In particular, the utilization of oil from black fly larvae is a byproduct of the industry. The aim of this study was to investigate the influence of black soldier fly larva oils and the proportion of roughage-to-concentrate ratios on gas kinetics, rumen characteristics, degradability, and mitigate CH₄ production by using in vitro gas production techniques. The in vitro investigation used a completely randomized design (CRD) with a 2 × 4 factorial arrangement. The level of R:C ratios (60:40 and 40:60) were factor A, while BSFO levels (0, 2, 4, and 6% of DM) were factor B. Under this investigation, the combined impact of R:C ratio and BSFO on the kinetics of gas and accumulative gas production was found to be significant (p < 0.01). After 4 h of incubation, the pH and ammonia-nitrogen (NH₃-N) concentration were found to be impacted by the inclusion of BSFO levels at different R:C-ratios (p < 0.01). Moreover, after 4 and 8 h of incubation, supplementing the BSFO at 4% with the level of R:C ratio at 40:60 resulted in a significant reduction in the amount of CH₄ in the rumen (p < 0.05). However, the inclusion of BSFO levels at different R:C ratios had no effect on the degradability of DM after 12 and 24 h of incubation (p > 0.05), whereas increasing the concentration of BSFO in concentrate at 6% reduced the DM degradability after 24 h of incubation (p < 0.05). Furthermore, adding BSFO to the diet at various R:C ratios enhanced the propionate (C3) concentration, with the highest level observed with the level of R:C ratio at 40:60 and 4% BSFO inclusion (p < 0.05). To summarize, the addition of BSFO at 4% with a 40:60 of R:C ratio increased C3 levels, decreased CH₄ emission, and preserved DM degradability. A R:C ratio of 40:60 could improve the total volatile fatty acids and digestibility. Moreover, the inclusion of 6% BSFO at different R:C ratios lowered the in vitro dry matter digestibility, in vitro organic matter digestibility, NH₃-N, and protozoal populations. Full article