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Alfalfa hay is a commonly used and important feed ingredient in dairy production. To better expand the alfalfa supply market, it is of great significance to explore the impact of alfalfa hay from different sources on dairy cow production performance. This study compared the effects of imported alfalfa hay from America (AAH) and Spain (SAH) on lactation performance and rumen microbiota of cows. Three hundred and sixty healthy mid-lactation Holstein cows with similar body weight, milk yield, and parity were randomly divided into two groups fed diets based on AAH or SAH for a 70-day experimental period. Each group was composed of four pens, with 45 cows in each pen. Daily records were kept for MY per cow and dry matter intake per pen. Twelve randomly selected cows per group were sampled to collect milk, feces, rumen fluid, and blood. The findings revealed no significant differences between the two groups in terms of production performance, nutrient apparent digestibility, serum biochemical indices, or rumen fermentation parameters. However, rumen microbial composition differed significantly between the two groups of cows based on β-diversity. On the genus level, the relative abundance of Prevotella , Succinivibrionaceae_UCG-002 increased while that of NK4A214_group , Ruminococcus , norank_f_F082 and Lachnospiraceae_NK3A20_group decreased in the SAH group compared with AAH group. There was no significant correlation between these core differential bacteria and the molar proportions of acetate and propionate, the concentration of total volatile fatty acids, and milk yield. In conclusion, the feeding effects of SAH were similar to those of AAH. These findings provided a reference for the application of alfalfa hay from different sources and for the improvement of the economic benefit of dairy farms. [ABSTRACT FROM AUTHOR]

Holocellulose (HC) fraction extracted from date-pits was evaluated as a novel feed additive for ruminant feeding. This study was performed to investigate the effectiveness of the HC additive on rumen fermentation, methane (CH4) production, and diet degradability over 24 h of in vitro incubation. Three independent incubation trials were conducted over three consecutive weeks, employing the same in vitro methodology to assess four treatment doses in a completely randomized design. The experimental diet incorporated four increasing doses of HC, containing HC at 0 (HC0), 10 (HC10), 20 (HC20), and 30 (HC30) g/kg dry matter (DM). In vitro gas production (GP) and CH4 production, volatile fatty acids (VFAs) concentration, protozoa accounts, degraded organic matter (DOM), metabolizable and net energy (ME and NE), and hydrogen (H2) estimates were measured. No significant differences in ruminal pH were observed as the HC doses gradually increased. All incremental doses of HC additive over 24 h resulted in a linear increase in GP (P < 0.001), DOM (P < 0.001), total VFAs (P = 0.011), and propionate (P < 0.001) concentrations, as well as estimated energy (ME and NE) (P < 0.05) and microbial protein (P = 0.017) values. However, the inclusion of increasing doses of HC in the diet displayed linear reductions in the net CH4 production (ml/kg DOM; P = 0.002), protozoa abundance (P = 0.027); acetate (P = 0.029), and butyrate (P < 0.001) concentrations, the acetate-to-propionate ratio (P < 0.001), and the estimated net H2 production concentration (P = 0.049). Thus, the use of date-pits HC additive generated positive ruminal fermentability, including increased total VFAs and a reduction in the acetate-to-propionate ratio, leading to decreased CH4 output over 24 h of in vitro incubation. Hence, HC could be considered a potent feed additive (at up to 30 g/kg DM), demonstrating promising CH4-mitigating competency and thereby enhancing energy-use efficiency in ruminants. [ABSTRACT FROM AUTHOR]

Simple Summary: Ruminant farming, which includes animals like cows and sheep, is resource-intensive and this is becoming more of an issue as the human population grows. People are also worried about the use of antibiotics in animal feed. Scientists are looking for new, sustainable ways to feed these animals to improve their health and production without antibiotics. One promising solution is using edible fungi, like Aspergillus oryzae. This fungus can provide important nutrients, such as proteins, which are usually obtained from plants or animals. By adding these fungi to animal feed, it can reduce the need for conventional protein sources and antibiotics, enhancing the quality of the feed and the well-being of the animals. This review paper explores the effects of including an Aspergillus oryzae fungal biomass in ruminant feed and explains how this fungus can be grown on organic residues. In summary, using Aspergillus oryzae in animal feed provides essential nutrients that can support animal health and productivity, all of which are valuable to society. The resource-intensive nature of the ruminant farming sector, which has been exacerbated by population growth and increasing pressure to reduce feed antibiotics and growth promoters, has sparked interest in looking for sustainable alternative feed sources to enhance ruminant production efficiency. Edible filamentous fungi, rich in macronutrients like proteins, offer promise in reducing the reliance on conventional protein sources and antimicrobials to improve feed quality and animal performance. The inclusion of single-cell proteins, particularly filamentous fungi, in ruminant feed has long been of scientific and industrial interest. This review focuses on the potential application of the extensively studied Aspergillus oryzae and its fermentation extracts in ruminant nutrition. It provides an overview of conventional ruminant feed ingredients, supplements, and efficiency. Additionally, this review analyzes the re-utilization of organic residues for A. oryzae cultivation and examines the effects of adding fungal extracts to ruminant feed on ruminal digestibility and animal performance, all within a circular bioeconomy framework. [ABSTRACT FROM AUTHOR]

Introduction: Crude protein is a key element in regulating the diet of ruminants and is considered one of the most expensive nutrients needed by livestock. Feeding management plays an important role in the elimination of nitrogen in the production environment and the emission of greenhouse gases in animal husbandry systems (Avathar et al 2021). When there is excessive discharge of nitrogen in the environment, it causes the ecological balance in surface waters to be disrupted and the groundwater to be polluted (Dijkstra et al 2011). Excretion of these compounds in the environment will increase with fermentation, digestion and inefficient metabolism, and the increase in inefficiency in the rumen is caused by the complex and competitive metabolic pathways in the rumen microbial population. Therefore, increasing efficiency in the use of nutrients, especially nitrogen, to minimize their excretion from the animal's body should be considered. Various methods can be implemented in an animal husbandry unit to improve the use of nitrogen in ruminants. One of these solutions is to reduce the crude protein in the diet, but it has been reported that this method can have a negative effect on animal production (Chibisa and Motswangwa 2013). Another solution is nutrient synchronization or synchronizing the fermentation rate of dietary protein and energy sources, which has led to limited success (Yelchi et al. 2020). Another solution is to create oscillating in the concentration of crude protein in the diet and feed it intermittently at intervals of one to three days, and previous reports show that this method has improved nitrogen retention and its utilization in the body compared to eating constant amounts of crude protein daily in sheep and cattle (Rach et al., 2021). This study was conducted in order to investigate the effect of constant and intermittent feeding of dietary crude protein on ruminal parameters and microbial protein synthesis in sheep. Material and methods: Three diets were adjusted with 12, 14 and 16% crude protein but with the same metabolizable energy and protein. 8 male sheep were used in metabolic cages in a 4x4 Latin square design (four treatments with 2 squares and 8 replications). The first treatment received a diet with a crude protein level of 14% constantly. The second, third and fourth treatments received diets with 12 and 16% crude protein at intervals of 24, 48 and 72 hours, respectively. Nitrogen balance and retention, rumen and blood parameters, volatile fatty acids and microbial protein synthesis were measured. Results and discussion: The lowest total excreted nitrogen (via urine and feces) was observed in the treatment with 48-hour raw protein consumption interval (P<0.05). The retained nitrogen showed a significant increase in this treatment as compared to the constant crude protein feeding treatment (P<0.05). It has been reported that the increase in nitrogen retention in ruminants that received diets with oscillating crude protein levels is due to increased urea recycling in the rumen (Cole 1999). It seems that the transfer of urea from the blood to the rumen during the consumption of diets with low crude protein level (times 24, 48 and 72 hours) in oscillating diets increased and it compensates for the shortage of nitrogen in the rumen. In this condition, nitrogen excretion through urine also decreases and the efficiency of nitrogen use increases. The highest rumen liquid ammonia nitrogen was observed in the treatment with 48-hour crude protein consumption interval, but the pH and concentration of volatile fatty acids did not show any significant difference among the experimental treatments. Comparing the treatment of constant crude protein feeding (14%) with the treatments with intermittent consumption of crude protein (12 and 16%) in terms of the concentration of volatile fatty acids in the rumen fluid of the experimental sheep, including acetate, propionate and butyrate, as well as total volatile fatty acids, there is not a significant difference. The same ratio of concentrate to fodder and the similarity of the feed ingredients in the diets can be a reason for the lack of significance between the experimental treatments, which is in line with the results of previous researches (Khattab and Abdulwahid 2018). A significant difference was observed between the experimental treatments in terms of allantoin, total purine bases excreted, as well as nitrogen and microbial protein production, and the treatment with oscillating consumption of raw protein at a time interval of 48 hours had the highest amount. Albumin and total blood protein measured between the experimental treatments showed no significant difference, but blood urea nitrogen was the highest in the treatment with 48- hour crude protein consumption interval (P<0.01). Microbial protein synthesis in the rumen is affected by many animal and dietary factors, including nitrogen amounts, nitrogen sources, carbohydrate and nitrogen degradation rates, type and amount of carbohydrates in the diet, dry matter consumption, stability of fermentation in the rumen, and synchronization between nitrogen and energy (Hall 2013). It seems that in diets that cause fluctuation in the entry of protein sources into the rumen, the recycling of nitrogen to the rumen is done more effectively through the blood vessels and the liver, which in addition to reducing the excretion of nitrogen from the body also increases the production of microbial protein, in other words, the efficiency of using feed nitrogen increases, which is evident in the results of this research. Conclusion: The results showed that using the strategy of oscillating dietary crude protein concentration in sheep's diet improved nitrogen retention, rumen fermentation activities and microbial protein synthesis. [ABSTRACT FROM AUTHOR]

ABSTRACT This study was carried out to evaluate the effects of corn dried distillers’ grains (DDG) levels in non-forage diets by in vitro, in situ (0 to 50%), and in vivo (0 to 40%) trials on kinetic parameters of gas production (GP) on rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) as well as on nitrogen (N) metabolism in Nellore cattle. For in vitro and in situ studies, three rumen cannulated Nellore males with body weight of 340.48 ± 22.22 kg were used. For the in vivo study, five non-castrated male Nellore cattle with an initial body weight of 355.20 ± 35.28 kg and 24 ± 3 months old were used to evaluate the effect of increasing DDG levels in non-forage diets on N metabolism by a 5 × 5 Latin square design. Experimental diets were based on ground corn, cottonseed cake, urea, mineral supplement, and increasing levels of DDG replacing ground corn. The DDG levels caused a linear decrease in GP and in vitro dry matter digestibility. The DDG presented a lower dry matter digestibility (DMD) and RDP and higher RUP than corn grain and cottonseed cake, making DDG diets present lower DMD and RDP than control. The DDG levels linearly increased the intake of crude protein, neutral detergent fiber, and ether extract, whereas non-fiber carbohydrates intake decreased and tended to decrease the DMD and organic matter digestibility. The DDG levels caused a linear increase in N intake and in total, fecal, and urinary N excretion, which was the major N excretion route, causing a quadratic drop in retained N and caused a quadratic effect on alanine aminotransferase. In contrast, triglycerides were cubically affected, and total blood protein increased. Thus, DDG levels negatively affect in vitro and in situ digestibility, increasing N intake but increasing urinary N excretion.

Alfalfa hay is a commonly used and important feed ingredient in dairy production. To better expand the alfalfa supply market, it is of great significance to explore the impact of alfalfa hay from different sources on dairy cow production performance. This study compared the effects of imported alfalfa hay from America (AAH) and Spain (SAH) on lactation performance and rumen microbiota of cows. Three hundred and sixty healthy mid-lactation Holstein cows with similar body weight, milk yield, and parity were randomly divided into two groups fed diets based on AAH or SAH for a 70-day experimental period. Each group was composed of four pens, with 45 cows in each pen. Daily records were kept for MY per cow and dry matter intake per pen. Twelve randomly selected cows per group were sampled to collect milk, feces, rumen fluid, and blood. The findings revealed no significant differences between the two groups in terms of production performance, nutrient apparent digestibility, serum biochemical indices, or rumen fermentation parameters. However, rumen microbial composition differed significantly between the two groups of cows based on β-diversity. On the genus level, the relative abundance of Prevotella, Succinivibrionaceae_UCG-002 increased while that of NK4A214_group, Ruminococcus, norank_f_F082 and Lachnospiraceae_NK3A20_group decreased in the SAH group compared with AAH group. There was no significant correlation between these core differential bacteria and the molar proportions of acetate and propionate, the concentration of total volatile fatty acids, and milk yield. In conclusion, the feeding effects of SAH were similar to those of AAH. These findings provided a reference for the application of alfalfa hay from different sources and for the improvement of the economic benefit of dairy farms.

Thirty-two primiparous and 31 multiparous Alpine goats were used to determine influences of diets varying in level and source of forage on performance in early to mid-lactation for 16 wk. Diets consisted of 40%, 50%, 60%, and 70% forage (designated as 40F, 50F, 60F, and 70F, respectively) with 60F and 70F containing coarsely ground grass hay (primarily orchardgrass) and 40F and 50F containing cottonseed hulls, alfalfa pellets, and coarsely ground wheat hay. Diets contained 15.9% to 16.3% crude protein and 37.8%, 42.1%, 53.5%, and 55.4% neutral detergent fiber (NDF) with 10.0%, 15.8%, 50.1%, and 55.5% particle retention on a 19-mm sieve, and 26.1%, 29.6%, 38.3%, and 40.0% physically effective NDF (peNDF) for 40F, 50F, 60F, and 70F, respectively. Dry matter intake (2.71, 2.75, 1.96, and 1.95 kg/d) and milk yield (2.82, 2.71, 2.23, and 2.10 kg/d for 40F, 50F, 60F, and 70F, respectively) were lower (P 0.05), but digestibility of NDF was greater (P 0.05) by diet and was lower (P 0.05) by diet or parity, but many interactions involving diet, period, hour, and parity were significant (P

ABSTRACT: Our goal was to investigate the effect of diets containing baleages harvested from alfalfa-grass or red clover–grass mixture on production performance, ruminal fermentation and microbiota taxa relative abundance, milk fatty acid profile, and nutrient utilization in dairy cows. Twenty Jersey cows (18 multiparous and 2 primiparous) averaging (mean ± SD) 148 ± 45.2 days in milk and 483 ± 65.4 kg of body weight in the beginning of the study were used in a randomized complete block design with repeated measures over time. The experiment lasted 9 wk, with a 2 wk covariate period followed by 7 wk of data and sample collection (wk 4 and 7 used in the statistical analyses). Cows were fed diets containing (dry matter basis) 35% of a concentrate mash and the following forage sources: (1) 65% second- and third-cut (32.5% each) alfalfa-grass mixture baleages (ALF) or (2) 65% second- and third-cut (32.5% each) red clover–grass mixture baleages (RC). Diets did not affect dry matter intake, milk yield, and concentrations of milk fat and true protein. In contrast, milk fat yield tended to decrease and energy-corrected milk yield decreased with feeding RC versus ALF. The apparent total-tract digestibilities of dry matter, organic matter, and ash-free neutral detergent fiber, milk proportions of trans-10 18:1, cis-9,cis-12,cis-15 18:3, and total n-3 fatty acids, ruminal molar proportion of acetate, and plasma concentrations of Leu, Phe, and Val all increased in RC versus ALF. Diet × week interactions were found for several parameters, most notably ruminal molar proportions of propionate and butyrate, ruminal NH3-N, milk urea N, plasma urea N, and plasma His concentrations, urinary N excretion, enteric CH4 production, and all energy efficiency variables. Specifically, ruminal NH3-N and plasma urea N concentrations, urinary excretion of N, and CH4 production decreased in cows fed RC in wk 4 but not in wk 7. Milk urea N concentration decreased and that of plasma His increased with feeding RC during wk 4 and 7, although the magnitude of treatments difference varied between the sampling periods. Efficiency of energy utilization calculated as milk energy/metabolizable energy decreased and that of tissue energy/ME increased in RC versus ALF cows in wk 4, suggesting that ME was portioned toward tissue and not milk in the RC diet. Interactions were also observed for the relative abundance of the rumen bacterial phyla Verrucomicrobiota and Fibrobacterota, with cows offered RC showing greater values than those receiving ALF in wk 4 but no differences in wk 7. Several diet × week interactions were detected in the present study implying short-term treatment responses and warranting further investigations.

Simple Summary: In China, high-grain diets for ruminants due to forage scarcity cause metabolic disorders. Yeast culture promotes rumen health by stabilizing microbial composition and enhancing nutrition and immunity. Therefore, the objective of this experiment was mainly to investigate the effect of the addition of two different species of yeast culture on goat production performance, rumen fermentation profile, microbial balance, and immunity under high-grain conditions. The results indicated that the incorporation of yeast culture into a high-grain diet significantly enhanced the production performance of goats, augmented their immunity, and stabilized the rumen environment. However, different types of yeast cultures acted by different mechanisms. The results provide a reference for the rational application of yeast culture in production. It is a common practice among farmers to utilize high-grain diets with the intention of promoting ruminant growth. However, this approach bears the risk of inducing rumen disorders and nutrient metabolism diseases. Yeast culture (YC) showed advantages in ruminant applications. The objective of this study was to evaluate the effects of adding two different types of YC to high-grain conditions on production performance, rumen fermentation profile, microbial abundance, and immunity in goats. A total of 30 male goats with similar body condition were randomly distributed into 3 dietary treatments with 10 replicates per treatment as follows: basic diet group (CON); basic diet + 0.5% yeast culture 1 (YC1) group; basic diet + 0.5% yeast culture 2 (YC2) group. The trial lasted for 36 days. The results demonstrated that dietary YC supplementation led to an increase in the average daily gain and a reduction in feed intake and weight gain ratio in goats. It increased the apparent digestibility of crude protein, NDF, and ADF (p < 0.05). The serum concentrations of interleukin (IL)-1β, IL-6, and Tumor Necrosis Factor-α in the control group were significantly higher than those of the YC groups (p < 0.05). The serum concentrations of Immunoglobulin (Ig)A and IgG in the control group were significantly lower than those in the YC groups (p < 0.05). The rumen concentration of microbial protein (MCP) in the control group was significantly lower than that in the YC groups (p < 0.05). There was a negative correlation between the concentration of IL-10 and Bacteroidota, Spirochaetota, and Succinivibrio, while there was a positive correlation between concentrations of IL-10 and Firmicutes. Nevertheless, discrepancies were observed in the impact of the two different types of YC on the physiological and biochemical indicators of the animals. The concentration of triglyceride in the YC1 group was significantly higher than that of the CON and YC2 groups, while the concentration of urea in the YC2 group was significantly higher than that of the CON and YC1 groups (p < 0.05). At the phylum level, the addition of YC2 to the diet significantly increased the relative abundance of Bacteroidota and Fibrobacterota and significantly decreased Firmicutes compared to the control. At the genus level, the addition of YC1 to the HGD significantly reduced the relative abundance of Rikenellaceae_RC9_gut_group, while the addition of YC2 to the HGD significantly increased the relative abundance of Prevotellace-ae_UCG-001, Fibrobacter, and Prevotellaceae_UCG-003 (p < 0.05). The addition of YC significantly improved growth performance, increased nutrient digestibility, beneficially manipulated ruminal fermentation and microbial diversity, and improved immune function. The choice of yeast cultures can be customized according to specific production conditions. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of replacing antibiotics with increasing doses of chitosan (CHI) on nutrient intake and digestibility, corn grain excretion, ruminal fermentation, nitrogen metabolism, and feeding behavior in finishing steers fed forage-free diets. Five ruminally cannulated crossbred steers were assigned to a 5 x 5 Latin square experimental design and given the following diets: C0= basal diet with no additives, ANT= basal diet with inclusion of virginiamycin 30 mg/kg DM, C375= basal diet with inclusion of chitosan 375 mg/kg DM, C750= basal diet with inclusion of chitosan 750 mg/kg DM, and C1500= basal diet with inclusion of chitosan 1500 mg/kg DM. Supplementation with CHI did not affect ruminal pH and ammonia nitrogen (N-NH3) concentration. Chitosan quadratically affected corn grain excretion and molar proportion of ruminal butyrate, with greater values for C750. Animals fed C375 showed greater dry matter intake and neutral detergent fiber intake; and greater digestibility of DM, starch, and NDF. Animals fed C750 and C1500 diets presented greater absorbed N compared to ANT. Animals fed ANT, C750, and C1500 spent more time eating and chewing than animals fed CON. More specifically, the dose of 375 mg/kg DM of diet was very promising for steers fed free-forage diet due to its ability to improve nutrient digestibility, with only slight changes in N metabolism. [ABSTRACT FROM AUTHOR]

Background: Hydroxytryptophan (5-HTP) can regulate the synthesis of 5- Hydroxytryptamine (5-HT) and melatonin (MT). In a previous metabolome analysis, we found that 5-HTP is an effective ingredient in yeast culture for regulating rumen fermentation. However, research on the effect of this microbial product (5-HTP) as a functional feed additive in sheep production is still not well explained. Therefore, this study examined the effects of 5-HTP on sheep rumen function and growth performance using in vitro and in vivo models. Methods: A two-factor in vitro experiment involving different 5-HTP doses and fermentation times was conducted. Then, in the in vivo experiment, 10 sheep were divided into a control group which was fed a basal diet, and a 5-HTP group supplemented with 8 mg/kg 5-HTP for 60 days. Results: The results showed that 5-HTP supplementation had a significant effect on in vitro DMD, pH, NH3-N, acetic acid, propionic acid, and TVFA concentrations. 5-HTP altered rumen bacteria composition and diversity indices including Chao1, Shannon, and Simpson. Moreover, the in vivo study on sheep confirmed that supplementing with 8 mg/kg of 5-HTP improved rumen fermentation efficiency and microbial composition. This led to enhanced sheep growth performance and increased involvement in the tryptophan metabolic pathway, suggesting potential benefits. Conclusion: Dietary 5-HTP (8 mg/kg DM) improves sheep growth performance by enhancing ruminal functions, antioxidant capacity, and tryptophan metabolism. This study can provide a foundation for the development of 5- HTP as a functional feed additive in ruminants’ production. [ABSTRACT FROM AUTHOR]

Simple Summary: Almond hull (AH) is a by-product of almond production that can be used in ruminant feeding, but their composition is variable and needs further characterization. We observed that there were significant differences in chemical composition and nutritional value of samples of AH from two varieties, with AH from Guara variety having more energy and protein than those from Soleta variety in samples collected in two different almond campaigns in the South of Spain. Moreover, harvesting year affected the chemical composition and nutritive value of AH, making necessary their chemical analysis before being used as feed in the practice. In addition, we conducted in vitro trials to investigate the effects of including increasing amounts of AH in diets for dairy ruminants on diet degradability and methane production. Methane is a greenhouse gas with high warming potential that is produced during feed fermentation in the rumen. The results indicate that dried AH can replace up to 16% of conventional feed ingredients in diets for dairy ruminants, but methane production was not reduced. In conclusion, the tested AH can be used as alternative feed for ruminants, although this by-product does not contain antimethanogenic compounds. Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations. [ABSTRACT FROM AUTHOR]

Our goal was to investigate the effect of diets containing baleages harvested from alfalfa-grass or red clover–grass mixture on production performance, ruminal fermentation and microbiota taxa relative abundance, milk fatty acid profile, and nutrient utilization in dairy cows. Twenty Jersey cows (18 multiparous and 2 primiparous) averaging (mean ± SD) 148 ± 45.2 days in milk and 483 ± 65.4 kg of body weight in the beginning of the study were used in a randomized complete block design with repeated measures over time. The experiment lasted 9 wk, with a 2 wk covariate period followed by 7 wk of data and sample collection (wk 4 and 7 used in the statistical analyses). Cows were fed diets containing (dry matter basis) 35% of a concentrate mash and the following forage sources: (1) 65% second- and third-cut (32.5% each) alfalfa-grass mixture baleages (ALF) or (2) 65% second- and third-cut (32.5% each) red clover–grass mixture baleages (RC). Diets did not affect dry matter intake, milk yield, and concentrations of milk fat and true protein. In contrast, milk fat yield tended to decrease and energy-corrected milk yield decreased with feeding RC versus ALF. The apparent total-tract digestibilities of dry matter, organic matter, and ash-free neutral detergent fiber, milk proportions of trans -10 18:1, cis -9, cis -12, cis -15 18:3, and total n-3 fatty acids, ruminal molar proportion of acetate, and plasma concentrations of Leu, Phe, and Val all increased in RC versus ALF. Diet × week interactions were found for several parameters, most notably ruminal molar proportions of propionate and butyrate, ruminal NH 3 -N, milk urea N, plasma urea N, and plasma His concentrations, urinary N excretion, enteric CH 4 production, and all energy efficiency variables. Specifically, ruminal NH 3 -N and plasma urea N concentrations, urinary excretion of N, and CH 4 production decreased in cows fed RC in wk 4 but not in wk 7. Milk urea N concentration decreased and that of plasma His increased with feeding RC during wk 4 and 7, although the magnitude of treatments difference varied between the sampling periods. Efficiency of energy utilization calculated as milk energy/metabolizable energy decreased and that of tissue energy/ME increased in RC versus ALF cows in wk 4, suggesting that ME was portioned toward tissue and not milk in the RC diet. Interactions were also observed for the relative abundance of the rumen bacterial phyla Verrucomicrobiota and Fibrobacterota, with cows offered RC showing greater values than those receiving ALF in wk 4 but no differences in wk 7. Several diet × week interactions were detected in the present study implying short-term treatment responses and warranting further investigations. [ABSTRACT FROM AUTHOR]

Ruminal fermentation of feed leads to methane production and wastes feed energy. Appropriate feed additives have shown to reduce ruminal methane production. Accordingly, it is important to identify compounds as feed additives to alter ruminal fermentation patterns to improve feed efficiency as well as reduce methane production. This experiment aimed to investigate the effect of inulin additive (as a prebiotic compound) on ruminal fermentation, feed digestibility, and methane production by in vitro techniques. Experimental treatments included control treatment (basal diet), 2% (w/w) inulin (basal diet with 2% inulin), and 4% (w/w) inulin (basal diet with 4% inulin). Gas production at 2, 4, 6, 12, 24, 48, 72, and 96 h of incubation as well as dry matter (DM) and organic matter digestibility (OMD) was determined. Also, some rumen fermentation parameters including pH, ammonia–nitrogen, volatile fatty acids, and methane production were determined. Per our findings, the addition of inulin increased gas production except for the first 2 h of incubation (p < 0.05). The addition of inulin changed the profile of ruminal volatile fatty acids (p < 0.05) so that the addition of inulin increased the concentration of propionic acid (p < 0.05). The addition of inulin also reduced lactic acid concentration (p < 0.05). Rumen ammonia–nitrogen was reduced by the addition of inulin (p < 0.05), which could indicate an improvement in rumen nitrogen metabolism. Addition of inulin reduced methane production from feed fermentation by rumen microbiota (p < 0.05). Dry matter and organic matter digestibility increased with the addition of inulin (p < 0.05). According to the results, the use of inulin (as a prebiotic of plant origin) not only does not disrupt ruminal fermentation but also improves the fermentation process, increases feed digestibility, and most importantly reduces methane excretion, which can increase production efficiency. [ABSTRACT FROM AUTHOR]

Understanding how different livestock species and breeds respond to consumption of brackish water could improve usage of this resource. Therefore, Angora, Boer, and Spanish goat doelings and Dorper, Katahdin, and St. Croix ewe lambs (6 animals per animal type [AT]; initial age = 296 ± 2.1 days) consuming water with varying concentrations of minerals of a natural brackish water source (BR) and sodium chloride (NaCl; SL) were used to determine effects on water and feed intake, nutrient digestion, heat energy, methane emission, ruminal fluid conditions, and blood constituent concentrations. There were 6 simultaneous 6 (water treatments [WT]) × 6 (AT) Latin squares with 3-wk periods. The WT were fresh (FR), BR alone (100-BR), a similar total dissolved solids (TDS) concentration as 100-BR via NaCl addition to FR (100-SL), BR with concentrations of all minerals increased by approximately 50% (150-BR), a similar TDS level as 150-BR by NaCl addition to FR (150-SL), and a similar 150 TDS level achieved by addition of a 1:1 mixture of BR minerals and NaCl to 100-BR (150-BR/SL). Concentrations (mg/kg) in BR were 4928 TDS, 85.9 bicarbonate, 224.9 calcium, 1175 chloride, 60.5 magnesium, 4.59 potassium, 1387 sodium, 1962 sulfate, and 8.3 boron, and TDS in other WT were 209, 5684, 7508, 8309, and 7319 mg/kg for FR, 100-SL, 150-BR, 150-SL, and 150-BR/SL, respectively. There were very few significant effects of WT or AT × WT interactions, although AT had numerous effects. Water intake was affected by AT (P = 0.02) and WT (P = 0.04), with greater water intake for 150-SL than for FR, 100-BR, 100-SL, and 150-BR. Dry matter intake among AT was lowest (P

The current issue of ruminant methane emissions is still being researched by animal nutritionists in an effort to find new approaches. In this study, five beef cattle were randomly assigned in a 5 × 5 Latin square design to examine the effects of supplementation with high-tannin and -polyphenol plant materials on nutrient utilization, rumen fermentation, and nitrogen partitioning. Cattle offered total mixed ration (TMR) silage diets with or without tannin-rich tree leaf or plant herbs, such as Piper sarmentosum Roxb., Cymbopogon citratus (DC.) Stapf, Anacardium occidentale L., and Careya arborea Roxb., were supplemented at a dose of 10 g/d. Prior to TMR feeding, the animals’ meals were supplemented with 10 g of fortified plant materials twice a day, along with 100 g of rice bran. The animals in the control group received only 100 g of rice bran and no other plant materials. The result showed that there was no difference in nutrient intake or digestibility between the supplemented and control groups. Although the effect of ruminal pH, NH3-N, Total VFA, acetate (C2), and butyrate (C4) was not significant (p > 0.05), the proportion of propionate (C3) tended to increase with supplementation (p = 0.07). There was no difference in the excretion of purine derivatives or the amount of microbial nitrogen supply, even though supplemented animals had significantly lower protozoal populations than the control group (p < 0.05). Moreover, when A. occidentale or C. arborea was added to the TMR silage diet, the nitrogen intake and retention increased considerably, although total nitrogen excretion decreased. In this approach, the leaves of Anacardium occidentale L. and Careya arborea Roxb. were particularly promising for strategic supplementation.

Simple Summary: The increasing expenses of animal feed, which are affected by the prices of protein and carbohydrates, emphasize the need for alternate sources of protein. Thailand is now doing research on tropical legumes, with a special focus on winged beans. The tubers of winged beans, which are rich in carbohydrates and protein, provide a viable alternative to animal feed. The process of pelletizing winged bean tubers has many benefits, including enhanced durability and prolonged preservation. This makes it a feasible substitute for corn meal in animal feed. The research assesses the replacement of corn meal with winged bean tuber pellets in ruminant diets, examining its impact on ruminal fermentation, gas production, and in vitro degradability. The objective of this study is to evaluate the effects of replacing corn meal in ruminant diets with winged bean (Psophocarpus tetragonolobus) tubers (WBT) on ruminal fermentation, gas production parameters, and in vitro degradability. The study employed a completely random design (CRD) in its execution. The experimental design employed was a completely randomized design (CRD), featuring eleven levels of corn meal substitution with winged bean tubers pellet (WBTP) at 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. The levels were grouped into four categories of replacement: control (0% in the diet), low levels (10%, 20%, and 30% in the diet), medium levels (40%, 50%, 60%, and 70% in the diet), and high levels (80%, 90%, and 100% in the diet). The experimental results indicated that substituting corn meal with WBTP at moderate and high levels in the diet could improve the performance of the fermentation process by increasing the gas production rate constant from the insoluble fraction (p < 0.01). The IVDMD exhibited a higher degree of in vitro degradation after 12 h (h), with the mean value being higher in the high group compared to the medium until the high group (p < 0.05). At the 4 h mark, the groups that substituted corn meal with WBTP exhibited a decrease in pH value (p < 0.05) in comparison to the control group. The substitution of corn meal with WBTP resulted in the lowest protozoal count after 8 h in the median group (p < 0.05). A significant difference in the effect of WBTP on total volatile fatty acid (TVFA) concentration was observed at 8 h after incubation (p < 0.05). The medium and high levels of WBTP replacement resulted in the lowest TVFA concentration at 8 h (p < 0.05). The mean proportion of acetic acid (C2) linearly declined and was lowest when a high level of WBTP replaced cornmeal (p < 0.05). The concentration of propionic acid (C3) at 8 h after incubation and average values were linearly significantly different when various levels of WBTP were utilized. Replacing corn meal with WBTP at a high level showed the highest concentration of C3. Moreover, substituting medium and high concentrations of WBTP for corn meal resulted in a significant reduction in both the C2:C3 ratio at 8 h and the mean value (p < 0.05). In conclusion, WBTP exhibits a nutritional composition that is advantageous and may be an energetic substitute for corn meal. [ABSTRACT FROM AUTHOR]

The administration of Bacilli to dairy cows exerts beneficial effects on dry matter intake, lactation performance, and milk composition, but the rationale behind their efficacy is still poorly understood. In this work, we sought to establish whether cellulases and xylanases, among the enzymes secreted by B. subtilis, are involved in the positive effect exerted by Bacilli on ruminal performance. We took advantage of two isogenic B. subtilis strains, only differing in the secretion levels of those two enzymes. A multi-factorial study was conducted in which eight feed ingredients were treated in vitro, using ruminal fluid from cannulated cows, with cultures of the two strains conveniently grown in a growth medium based on inexpensive waste. Feed degradability and gas production were assessed. Fiber degradability was 10% higher (p < 0.001) in feeds treated with the enzyme-overexpressing strain than in the untreated control, while the non-overexpressing strain provided a 5% increase. The benefit of the fibrolytic enzymes was maximal for maize silage, the most recalcitrant feed. Gas production also correlated with the amount of enzymes applied (p < 0.05). Our results revealed that B. subtilis cellulases and xylanases effectively contribute to improving forage quality, justifying the use of Bacilli as direct-fed microbials to increase animal productivity. [ABSTRACT FROM AUTHOR]

Simple Summary: Wheat straw is commonly utilized as a roughage source for ruminants; however, its main challenge lies in its limited rumen digestibility, leading to insufficient conversion into animal products following ingestion. Efforts must be made to explore methods for enhancing the rumen digestibility of wheat straw. The remarkable efficacy, specificity, and gentle operating conditions exhibited by biological enzymes in the processing and utilization of agricultural straws have engendered considerable interest among researchers. Hence, the identification of enzymes that can efficiently enhance the digestion of wheat straw in the rumen is of utmost significance. This study investigated a xylanase called RuXyn, which is a member of the GH 30 family, derived from the rumen metagenome. The findings demonstrate that the utilization of RuXyn can significantly enhance the ruminal digestibility of wheat straw by approximately 10 percentage points. This outcome signifies the emergence of a novel and highly efficient enzyme preparation that holds promise for the effective utilization of wheat straw, a by-product of crop production, in ruminants. The challenge of wheat straw as a ruminant feed is its low ruminal digestibility. This study investigated the impact of a xylanase called RuXyn, derived from the rumen metagenome of beef cattle, on the in vitro ruminal fermentation of wheat straw. RuXyn encoded 505 amino acids and was categorized within subfamily 8 of the glycosyl hydrolase 30 family. RuXyn was heterologously expressed in Escherichia coli and displayed its highest level of activity at pH 6.0 and 40 °C. RuXyn primarily hydrolyzed xylan, while it did not show any noticeable activity towards other substrates, including carboxymethylcellulose and Avicel. At concentrations of 5 mM, Mn2+ and dithiothreitol significantly enhanced RuXyn's activity by 73% and 20%, respectively. RuXyn's activity was almost or completely inactivated in the presence of Cu2+, even at low concentrations. The main hydrolysis products of corncob xylan by RuXyn were xylopentose, xylotriose, and xylotetraose. RuXyn hydrolyzed wheat straw and rice straw more effectively than it did other agricultural by-products. A remarkable synergistic effect was observed between RuXyn and a cellulase cocktail on wheat straw hydrolysis. Supplementation with RuXyn increased dry matter digestibility; acetate, propionate, valerate, and total volatile fatty acid yields; NH3-N concentration, and total bacterial number during in vitro fermentation of wheat straw relative to the control. RuXyn's inactivity at 60 °C and 70 °C was remedied by mutating proline 151 to phenylalanine and aspartic acid 204 to leucine, boosting activity to 20.3% and 21.8% of the maximum activity at the respective temperatures. As an exogenous enzyme preparation, RuXyn exhibits considerable potential to improve ruminal digestion and the utilization of wheat straw in ruminants. As far as we know, this is the first study on a GH30 xylanase promoting the ruminal fermentation of agricultural straws. The findings demonstrate that the utilization of RuXyn can significantly enhance the ruminal digestibility of wheat straw by approximately 10 percentage points. This outcome signifies the emergence of a novel and highly efficient enzyme preparation that holds promise for the effective utilization of wheat straw, a by-product of crop production, in ruminants. [ABSTRACT FROM AUTHOR]

Introduction and Objective: The use of agricultural by-products instead of grain seeds in livestock diets has been an important issue for scientific study. One of these products is potato waste that, if properly processed by methods such as ensiling, can replace cereal seeds such as barley in the diet, due to the proper nutritional value of this product, improving animal growth performance, reducing feed costsand prevent food from being wasting. Therefore, the purpose of this study was to investigate the effect of replacing different levels of potato waste silage with barley on growth performance, digestibility, and rumen and blood parameters of fattening lambs. Material and Methods: In this study, 30 Zell and Afshar mixed male lambs with a mean weight of 26±2 kg and mean age of 5.5±0.4 months were used in a completely randomized design (CRD) with 5 treatments and 6 replications for 90 days. The experimental treatments included the control treatment (without potato waste silage) and the treatments containing 25, 50, 75 and 100 potato waste silage replacement of barley seeds (based on dry matter). Results: The results of performance traits showed that there was a significant difference in fattening weight, daily weight gain, dry matter intake and feed conversion ratio between experimental treatments (p<0.05). The highest and lowest final weight, daily weight gain and dry matter intake were observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of the apparent digestibility of nutrients of experimental diets showed that there was a significant difference in the apparent digestibility of raw protein and neutral detergent fiber (NDF) between experimental treatments (p<0.05). The highest and lowest apparent digestibility of crude protein (CP) was observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of some blood serum parameters showed that there was a significant difference in the concentration of glucose, triglyceride, Low density Lipoprotein (LDL) and blood urea nitrogen (BUN) between the experimental treatments (p<0.05). The results of rumen fermentation parameters showed that there was a significant difference in the population of lactic acid bacteria, coliforms, protozoa, rumen liquid ammonia nitrogen, total volatile fatty acids (VFAs), acetic acid, propionic acid, butyric acid, valeric acid and isovaleric acid between experimental treatments (p<0.05). The highest population of lactic acid bacteria 100%, the lowest coli form population, the highest population of protozoa and the highest concentration of VFAs were observed in the treatment containing 100%, 70%, 100% and 50% of potato waste silage, respectively. Conclusion: The overall results of the present study showed that growth performance, the appearance of crude protein digestion, the total concentration of rumen fluid fatty acids and the population of bacteria and protozoa improved by consuming 50 % of potato waste silage. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the impact of potential probiotic strains of lactic acid bacteria (LAB), Apilactobacillus kunkeei EIR/BG-1 isolated from the gut of honeybees, and Enterococcus hirae EIR/CM-2 isolated from cow's milk, on rumen fermentation parameters and microbial population in a highconcentrate diet using a rumen simulation technique (Rusitec). The experiment consisted of 7 days of adaptation and 7 days of data collection. The dietary treatments were as follows: no additives (control), addition of 1 ml/fermenter (108 CFU) of Al. kunkeei EIR/BG-1, and addition of 1 ml/fermenter (108 CFU) of E. hirae EIR/CM-2. Alongside rumen fermentation characteristics, rumen microbial composition was investigated using real-time PCR. Supplementation with LAB strains did not affect ruminal pH, production of methane, and total and individual short chain fatty acids, ammonia-N concentration, dry matter digestibility and total protozoa. However, the abundance of Ruminococcus flavefaciens increased in the Al. kunkeei EIR/BG-1 treatment (P < 0.05). Moreover, the size of R. flavefaciens population in E. hirae EIR/CM-2 was comparable to that in the Al. kunkeei EIR/BG-1 treatment. Selenomonas ruminantium was more abundant in the Al. kunkeei EIR/BG-1 treatment compared to the E. hirae EIR/CM-2 treatment (P < 0.05). The abundance of Streptococcus bovis and Megasphaera elsdenii decreased with both Al. kunkeei EIR/BG-1 and E. hirae EIR/CM-2 supplementations (P < 0.05). In conclusion, Al. kunkeei EIR/BG-1 and E. hirae EIR/CM-2 exhibited beneficial effects on some members of the rumen microbial population, although these effects did not manifest in significant alterations in ruminal fermentation. Further research is required to clarify the probiotic potentials of these LAB strains as feed additives for ruminant rations. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of replacing antibiotics with increasing doses of chitosan (CHI) on nutrient intake and digestibility, corn grain excretion, ruminal fermentation, nitrogen metabolism, and feeding behavior in finishing steers fed forage-free diets. Five ruminally cannulated crossbred steers were assigned to a 5 x 5 Latin square experimental design and given the following diets: C0= basal diet with no additives, ANT= basal diet with inclusion of virginiamycin 30 mg/kg DM, C375= basal diet with inclusion of chitosan 375 mg/kg DM, C750= basal diet with inclusion of chitosan 750 mg/kg DM, and C1500= basal diet with inclusion of chitosan 1500 mg/kg DM. Supplementation with CHI did not affect ruminal pH and ammonia nitrogen (N-NH3) concentration. Chitosan quadratically affected corn grain excretion and molar proportion of ruminal butyrate, with greater values for C750. Animals fed C375 showed greater dry matter intake and neutral detergent fiber intake; and greater digestibility of DM, starch, and NDF. Animals fed C750 and C1500 diets presented greater absorbed N compared to ANT. Animals fed ANT, C750, and C1500 spent more time eating and chewing than animals fed CON. More specifically, the dose of 375 mg/kg DM of diet was very promising for steers fed free-forage diet due to its ability to improve nutrient digestibility, with only slight changes in N metabolism.

Extended Abstract Introduction and Objective: The use of agricultural by-products instead of grain seeds in livestock diets has been an important issue for scientific study. One of these products is potato waste that, if properly processed by methods such as ensiling, can replace cereal seeds such as barley in the diet, due to the proper nutritional value of this product, improving animal growth performance, reducing feed costsand prevent food from being wasting. Therefore, the purpose of this study was to investigate the effect of replacing different levels of potato waste silage with barley on growth performance, digestibility, and rumen and blood parameters of fattening lambs. Material and Methods: In this study, 30 Zell and Afshar mixed male lambs with a mean weight of 26±2 kg and mean age of 5.5±0.4 months were used in a completely randomized design (CRD) with 5 treatments and 6 replications for 90 days. The experimental treatments included the control treatment (without potato waste silage) and the treatments containing 25, 50, 75 and 100 potato waste silage replacement of barley seeds (based on dry matter). Results: The results of performance traits showed that there was a significant difference in fattening weight, daily weight gain, dry matter intake and feed conversion ratio between experimental treatments (p

Objective The present study aimed to evaluate the effects of extruded and unextruded feeding on the performance, milk composition, digestibility and ruminal fermentation of dairy cows through a meta-analysis. Methods The database was compiled from 53 studies in Scopus and PubMed. The data were analyzed using a random effects model in OpenMEE software. Extruded feed was grouped as the experiment group while and the others as control group. The bias of publication in the main parameter of dairy performance was evaluated by a funnel plot. Results The result showed that extruded feed enhanced the milk yield, dry matter and crude protein digestibility, butyrate and valerate acid production (p

The resource-intensive nature of the ruminant farming sector, which has been exacerbated by population growth and increasing pressure to reduce feed antibiotics and growth promoters, has sparked interest in looking for sustainable alternative feed sources to enhance ruminant production efficiency. Edible filamentous fungi, rich in macronutrients like proteins, offer promise in reducing the reliance on conventional protein sources and antimicrobials to improve feed quality and animal performance. The inclusion of single-cell proteins, particularly filamentous fungi, in ruminant feed has long been of scientific and industrial interest. This review focuses on the potential application of the extensively studied Aspergillus oryzae and its fermentation extracts in ruminant nutrition. It provides an overview of conventional ruminant feed ingredients, supplements, and efficiency. Additionally, this review analyzes the re-utilization of organic residues for A. oryzae cultivation and examines the effects of adding fungal extracts to ruminant feed on ruminal digestibility and animal performance, all within a circular bioeconomy framework.

ABSTRACT: The aim of this study was to evaluate the inclusion of alfalfa grazing during 8 h continuous or partitioned in 2 separated sessions of 4 h after each milking, on nutrient intake, digestibility, ruminal fermentation, feeding behavior, milk production, milk composition, and milk fatty acid profile, in late-lactation cows fed a partial mixed ration (PMR). Twelve dairy cows (193 ± 83 d in milk, 584 ± 71 kg of body weight) were housed in individual outdoor pens and assigned to treatments according to a 3 × 3 Latin square design replicated 4 times. The treatments were as follows: (1) control (T0), cows were fed a total mixed ration (TMR) provided ad libitum 20.0% crude protein (CP), 32.2% neutral detergent fiber (NDF); (2) fed a diet combining a PMR which had the same ingredient composition as the TMR (60% of ad libitum intake) + 1 session of 8 h of pasture (T8), continuous grazing alfalfa (Medicago sativa; 20.6% CP, 35.8% NDF) after the p.m. milking; and (3) PMR (60% of ad libitum intake) + 2 daily sessions of 4 h of access to pasture after each milking (T4+4). The experiment lasted 57 d and was divided into 3 periods of 19 d each. The first 12 d of each period was used for diet adaptation, and the last 7 d was used for data collection. No differences among treatments were observed for any of the productive variables, feeding efficiency, or purine derivatives excretion. Cows in T0 had greater intake and apparent digestibility of dry matter, organic matter, and nonfibrous carbohydrates compared with T4+4 and T8. Compared with T0, alfalfa grazing increased the concentration of C18:1 trans-11 and decreased those of C16:0 and C17:0 in milk fat. Cows in T4+4 consumed 1.1 more kg DM/d of alfalfa and N provided by alfalfa in the diet was 3 percentage points higher compared with T8 cows (266 vs. 229 g/d, respectively). In addition, T4+4 cows had a greater daily range of ruminal pH than T8 (0.73 vs. 0.93), and the highest concentrations of NH3-N were recorded during the a.m. grazing session while in T8 cows it occurred during the night. In conclusion, including 8 h of alfalfa grazing in T8 and T4+4 treatments allowed the substitution between 35.8 and 38.7% of the total dry matter intake (DMI) of a PMR (with a similar CP concentration to alfalfa) for pasture, maintaining milk solids production and increasing the C18:1 trans-11 of milk fat compared with a TMR in mid late–lactation cows. In an herbage plus PMR diet, splitting the 1 continuous grazing session of 8 h into 2 sessions of 4 h increased the proportion of energy and N provided by alfalfa pasture and reduced PMR intake, without modifying the total nutrient intake or productive performance of cows.

ABSTRACT: This experiment was designed to investigate the relation of high and low methane-yield phenotypes with body weight (BW), dry matter intake (DMI), lactation performance, enteric CH4 emissions, and rumen fermentation parameters in lactating dairy cows. A total of 130 multi- and primiparous Holstein cows were screened for enteric CH4 emissions using the GreenFeed system (C-Lock Inc.). Out of these 130 cows, 5 were identified as phenotypically high (HM) and 5 as phenotypically low (LM) CH4 emitters. Cows in the LM group had lower daily enteric CH4 emissions than cows in the HM group (on average 346 vs. 439 g/d, respectively), lower CH4 yield (15.5 vs. 20.4 g of CH4/kg of DMI), and CH4 intensity (13.2 vs. 17.0 g of CH4/ kg of energy-corrected milk yield). Enteric emissions of CO2 and H2 did not differ between HM and LM cows. These 10 cows were blocked by parity, days in milk, and milk production, and were used in a 5-wk randomized complete block design experiment. Milk composition, production, and BW were also not different between LM and HM cows. The concentration of total volatile fatty acids in ruminal contents did not differ between CH4 phenotypes, but LM cows had a lower molar proportion of acetate (57 vs. 62.1%), a higher proportion of propionate (27.5 vs. 21.6%, respectively), and therefore a lower acetate-to-propionate ratio than HM cows. Consistently, the 16S cDNA analysis revealed the abundance of Succinivibrionaceae and unclassified Veillonellaceae to be higher in LM cows compared with HM cows, bacteria that were positively correlated with ruminal propionate concentration. Notably, Succinivibrionaceae trigger the formation of propionate via oxaloacetate pathway from phosphoenolpyruvate via Enzyme Commission: 4.1.1.49, which showed a trend to be higher in LM cows compared with HM cows. Additionally, LM cows possessed fewer transcripts of a gene encoding for methyl-CoM reductase enzyme compared with HM. In this study, low and high CH4-yield cows have similar production performance and milk composition, but total-tract apparent digestibility of organic matter and fiber fractions was lower in the former group of animals.

ABSTRACT: The objective was to investigate the effect of nonprotein nitrogen source, dietary protein supply, and genetic yield index on methane emission, N metabolism, and ruminal fermentation in dairy cows. Forty-eight Danish Holstein dairy cows (24 primiparous cows and 24 multiparous cows) were used in a 6 × 4 incomplete Latin square design with 4 periods of 21-d duration. Cows were fed ad libitum with the following 6 experimental diets: diets with low, medium, or high rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio (manipulated by changing the proportion of corn meal, corn gluten meal, and corn gluten feed) combined with either urea or nitrate (10 g NO3−/kg of dry matter) as nonprotein nitrogen source. Samples of ruminal fluid and feces were collected from multiparous cows, and total-tract nutrient digestibility was estimated using TiO2 as flow marker. Milk samples were collected from all 48 cows. Gas emission (CH4, CO2, and H2) was measured by 4 GreenFeed units. We observed no significant interaction between dietary RDP:RUP ratio and nitrate supplementation, and between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity). As dietary RDP:RUP ratio increased, intake of crude protein, RDP, and neutral detergent fiber and total-tract digestibility of crude protein linearly increased, and RUP intake linearly decreased. Yield of milk, energy-corrected milk, and milk protein and lactose linearly decreased, whereas milk fat and milk urea nitrogen concentrations linearly increased as dietary RDP:RUP ratio increased. The increase in dietary RDP:RUP ratio resulted in a linear increase in the excretion of total purine derivatives and N in urine, but a linear decrease in N efficiency (milk N in % of N intake). Nitrate supplementation reduced dry matter intake (DMI) and increased total-tract organic matter digestibility compared with urea supplementation. Nitrate supplementation resulted in a greater reduction in DMI and daily CH4 production and a greater increase in daily H2 production in multiparous cows compared with primiparous cows. Nitrate supplementation also showed a greater reduction in milk protein and lactose yield in multiparous cows than in primiparous cows. Milk protein and lactose concentrations were lower for cows receiving nitrate diets compared with cows receiving urea diets. Nitrate supplementation reduced urinary purine derivatives excretion from the rumen, whereas N efficiency tended to increase. Nitrate supplementation reduced proportion of acetate and propionate in ruminal volatile fatty acids. In conclusion, no interaction was observed between dietary RDP:RUP ratio and nitrate supplementation, and no interaction between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity) was noted. Nitrate supplementation resulted in a greater reduction in DMI and CH4 production, and a greater increase in H2 production in multiparous cows than in primiparous cows. As the dietary RDP:RUP ratio increased, CH4 emission was unaffected and RDP intake increased, but RUP intake and milk yield decreased. Genetic yield index did not affect CH4 production, yield, or intensity.

Garlic, an important economic crop, provides nutrient-rich straw. When appropriately balanced with silage corn stalks, it is a high-quality forage resource. However, studies on the impact of garlic straw with silage corn stalks on Hu sheep's digestive metabolism and rumen microbiota are scarce. In this study, different addition ratios of garlic straw and silage corn stalks were utilized for in vitro experiments. We designed six experimental groups (CON, G0, G20, G40, G60, G80, and G100) based on varying ratios of garlic straw to silage corn stalks. Rumen microbiota was analyzed through 16S rRNA sequencing. Nutrient composition analysis indicated that garlic straw's relative feeding value (RFV) closely resembled that of silage corn stalks. After 24 h of fermentation, dry matter digestibility and in vitro gas production significantly increased, reaching peak values at a 60% addition ratio. Furthermore, volatile fatty acids (VFAs) such as acetic, propionic, and butyric acid exhibited elevated contents, with the highest yields observed at 60% inclusion. At the genus level, Prevotella, Rikenellaceae RC9 gut group, and Succiniclasticum were identified as the dominant bacterial groups. The gas production test showed a significant decrease in the G80 group compared to others. Microbial analysis revealed a higher abundance of Prevotella in G80 compared to G20, offering valuable insights for reducing greenhouse gas emissions from ruminant animals. Finally, this study predicted the impact of garlic straw with silage corn stalks' addition on Hu sheep's metabolic pathways and biological functions of the rumen microbiota. This research highlights the potential for effectively utilizing garlic straw as a feed resource for Hu sheep and proposes a rational proportion for combining garlic straw with silage corn stalks. [ABSTRACT FROM AUTHOR]

Fructans serve as the primary form of storage carbohydrate in cool-season grasses, but little is known about potential differences in ruminal fermentation of fructans between cattle and sheep. An ex vivo study was conducted to evaluate species differences in fructan catabolism. Buffered media containing ground orchardgrass (Dactylis glomerata L.) substrate was inoculated with uncultivated rumen microbiota obtained from cattle and sheep (n = 4 species−1). Fructan profiles were monitored over the incubation period (8 h; 39 °C) using high-performance anion-exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD). In both species, disappearance of long-chain fructans (degree of polymerization [DP] > 8) was evident by 2 h of incubation (p < 0.01), whereas short-chain fructans (DP 4–8) increased from 0 to 2 h prior to subsequent degradation (p < 0.01). However, the overall rate of long-chain fructan catabolism was greater in bovine versus ovine fermentations, particularly between 2 and 4 h (p < 0.01). Additionally, rapid utilization of short-chain fructans occurred from 2 to 4 h in bovine fermentations, but was delayed in ovine fermentations, with substantial degradation occurring only after 4 h of incubation (p < 0.01). These results indicate that rumen microbiota of cattle may have a greater capacity for fructan degradation. [ABSTRACT FROM AUTHOR]

Simple Summary: At present, cashmere goats are usually raised in a semi-intensive system to reduce the damage to grassland resources and ensure a more balanced intake of nutrients in China. Additionally, for maximizing production performance, intensive feeding management usually significantly increases the proportion of concentrate in the diet, which will seriously harm ruminant health in the long run. Noni fruit and its extracts showed good production-promoting and anti-inflammatory effects in poultry and freshwater fish production. However, it is unclear whether ethanol extract of noni fruit can alleviate the adverse effects of high-concentrate on goats. This study was conducted to investigate the effects of a high-concentrate diet supplemented with noni fruit extract (NFE) on growth performance, ruminal and colonic fermentation, nutrient digestion, and subacute rumen acidosis (SARA) of cashmere kids. The results showed that although a high-concentrate diet improved the growth performance of cashmere goats, it was at the expense of healthy fermentation modes of rumen and colon, such as significantly decreased pH and obviously increased lactic acid in rumen and colon. The supplementation of 0.10% NFE in a high-concentrate diet could not only effectively alleviate SARA and colon fermentation disorders induced by high-concentrate, but also improve the feed conversion efficiency in cashmere kids. This experiment was conducted to investigate the effects of noni fruit extract (NFE) on growth performance, ruminal and colonic fermentation, nutrient digestion, and subacute rumen acidosis (SARA) of cashmere goats with the high-concentrate diet. Twenty-four cashmere kids (17.9 ± 1.45 kg of BW ± SD) were randomly assigned to three treatments: low-concentrate diet, high-concentrate (HC) diet, or HC diet supplemented with NFE at 1 g per kg DM (0.1%). The results showed that although the HC diet improved the average daily gain (ADG) and feed conversion rate (FCR), it was accompanied by SARA with a decreased pH and an increased lactic acid of both rumen and colon, and decreased digestibility of neutral detergent fiber (NDF)and acid detergent fiber (ADF). The supplementation of 0.10% NFE in the HC diet could not only effectively alleviate SARA symptoms and colon fermentation disorders, such as reversing the decrease of pH and alleviating the increase of lactic acid in rumen and colon, but also mitigate the decline of fiber digestibility caused by long-term feeding in the HC diet, and increase the digestibility of crude protein(CP) and dry matter (DM), which improved the ADG and FCR of cashmere kids. Thus, NFE provides new strategies for alleviating SARA and promoting cashmere goat growth. [ABSTRACT FROM AUTHOR]

Featured Application: Livestock significantly contribute to greenhouse gas emissions, with methane production from animals like cows, sheep, and goats being a major concern. Reducing this methane output is crucial for environmental sustainability. There is also a growing interest in enhancing the nutritional quality of meat and milk from these animals. This study investigated the potential of natural additives—sage (SAG), pine (PIN), and clove (CLO) essential oils—to manipulate ruminal fermentation as well as biohydrogenation of polyunsaturated fatty acids (PUFA). The research focused on ruminal gas production, methane emissions, and fatty acid changes using in vitro methods. The essential oils led to lower gas and methane production. Additionally, they affected rumen pH, ammonia levels, and fatty acid profiles. These findings suggest that SAG, PIN, and CLO might reduce methane emissions and improve product quality in livestock. More research is needed to apply these findings practically. The livestock industry significantly contributes to greenhouse gas emissions, with ruminant animals, including cows, sheep, and goats, being responsible for a substantial share of these emissions due to methane production. Reducing methane emissions from ruminants is crucial for mitigating the environmental impact of livestock production. Additionally, there has been a growing interest in improving the nutritional quality of ruminant products through modifying their profile of fatty acids. The current study aimed to investigate the potential of sage (SAG), pine (PIN), and clove (CLO) essential oils as natural additives for modulating in vitro ruminal fermentation characteristics and biohydrogenation of polyunsaturated fatty acids (PUFA). Within the current experiment, three dose levels (300, 600, and 900 mg/L) of essential oils were evaluated using rumen inoculum from three mature Dalagh ewes (58 ± 2.84 kg body weight). The results revealed that the essential oils had a significant impact on gas production, methane and carbon dioxide production, ruminal fermentation parameters, and ruminal biohydrogenation of dietary PUFAs. The essential oil treatments resulted in reduced gas production compared with the control group. Methane production was significantly reduced by all doses of the essential oils, with the highest dose of CLO resulting in the lowest methane production. In addition, the essential oils affected ruminal fermentation parameters, including pH, ammonia concentration, and production of total volatile fatty acids. Promising modifications in ruminal biohydrogenation of PUFAs and the profile of fatty acids were also observed in the current study. These findings suggest that SAG, Pin, and CLO hold promise in mitigating methane emissions and improve the nutritional value of ruminant products. Further investigation is required to evaluate their effectiveness in practical feeding strategies for livestock. [ABSTRACT FROM AUTHOR]

Objective: The present study aimed to evaluate the effects of extruded and unextruded feeding on the performance, milk composition, digestibility and ruminal fermentation of dairy cows through a meta-analysis. Methods: The database was compiled from 53 studies in Scopus and PubMed. The data were analyzed using a random effects model in OpenMEE software. Extruded feed was grouped as the experiment group while and the others as control group. The bias of publication in the main parameter of dairy performance was evaluated by a funnel plot. Results: The result showed that extruded feed enhanced the milk yield, dry matter and crude protein digestibility, butyrate and valerate acid production (p<0.05). Meanwhile, the extruded feed significantly decreased the milk fat and protein concentration (p<0.05). Also, the iso-butyrate and iso-valerate in unextruded feeding was significantly higher than the extruded feed (p<0.05). Conclusion: It was concluded from the meta-analysis that extruded feed effectively improved the milk production and milk lactose concentration, dry matter and protein digestibility, but not the milk fat and protein concentration. [ABSTRACT FROM AUTHOR]

Dietary fibre concentration and particle size influence chewing behaviour, ruminal fermentation and digesta passage in dairy cows and through this, may impact nitrogen (N) use and excretion by the animals. The aim was thus to evaluate the effects of physically effective neutral detergent fibre (peNDF) concentration on chewing behaviour, ruminal fermentation, passage rate and protein metabolism in four lactating, rumen-cannulated Holstein cows in a 4 × 4 latin square design. Four total mixed rations with identical ingredients, chemical composition and a negative ruminal N balance (–2.1 g/kg dry matter) were tested. They varied in peNDF concentration, adjusted by feed mixing time: low (L), medium-low (ML), medium-high (MH) and high (H) peNDF. Nutrient intakes, number of total chews, organic matter digestibility and yield and efficiency of ruminal microbial protein synthesis responded quadratically to increasing peNDF concentration, with greater values for MH and ML diets. While rumination and total chewing intensity (min/kg dry matter) increased with increasing peNDF concentration, milk yield and composition, digesta passage rates and concentrations of ammonium-N and volatile fatty acids in rumen fluid were similar across diets. Energy-corrected milk yield and partitioning of N between milk and urine responded quadratically to increased peNDF concentration. Energy-corrected milk yield and the percentage of ingested N secreted via milk were lower, but the percentage of N intake excreted via urine was greater for MH and ML diets. Hence, feeding dairy cows a low-protein diet with varying peNDF concentrations affects their chewing behaviour, nutrient digestion and protein metabolism. [ABSTRACT FROM AUTHOR]

Industrial fruit by-products are now being utilized as animal feeds for several reasons. They may substitute the conventional cereal feeds, and also offer economic and environmental benefits. One of the most important industrial fruit by-products is apple pomace, which can be used as a source of energy in the ration of ruminant species, including dairy cattle. The aim of the present study was to evaluate the effect of feeding dried apple pomace to dairy cattle on ruminal fermentation, fatty acid concentration, microbial populations, and methane production. The experiment lasted 64 days and was conducted with 4 cannulated commercial dairy cows. The control animals received a standard diet, while the experimental animals was fed a standard diet supplemented with 150 g/kg DM dried apple pomace. Ruminal fluid samples were collected at three different time intervals. The samples were obtained at 0-, 3-, and 6-h post-feeding. The ruminal fluid was used to assess the ammonia concentration, pH, volatile fatty acids (VFA), long-chain fatty acids (FA), microbial population. A number of ruminal fermentation variables changed as a result of the addition of dried apple pomace to the standard diet. Ruminal pH slightly increased (p < 0.01) while the ammonia concentration decreased (p < 0.01) by 46%. There was a significant decrease in total protozoa count (p < 0.01) and an increase (p < 0.01) in total volatile fatty acids. In addition, there was a decline in methane emission (p = 0.05) by 8% due to dried apple pomace feeding. To sum up, this study demonstrated a positive effect of 150 g/kg DM dietary dried apple pomace on ruminal metabolism including a decrease in ammonia concentration and methane emissions, alongside with an increase in total ruminal VFAs, higher nutrient digestibility, and milk production. Also, beneficial changes to the ruminal fatty acid profile resulting from reduced biohydrogenation were observed although a decreased content of the C18:2 cis 9 trans 11 isomer was also noticed. The dietary inclusion of DAP can serve as a valuable, sustainable, and environmentally friendly dietary component for dairy cows. [ABSTRACT FROM AUTHOR]

It is a common practice among farmers to utilize high-grain diets with the intention of promoting ruminant growth. However, this approach bears the risk of inducing rumen disorders and nutrient metabolism diseases. Yeast culture (YC) showed advantages in ruminant applications. The objective of this study was to evaluate the effects of adding two different types of YC to high-grain conditions on production performance, rumen fermentation profile, microbial abundance, and immunity in goats. A total of 30 male goats with similar body condition were randomly distributed into 3 dietary treatments with 10 replicates per treatment as follows: basic diet group (CON); basic diet + 0.5% yeast culture 1 (YC1) group; basic diet + 0.5% yeast culture 2 (YC2) group. The trial lasted for 36 days. The results demonstrated that dietary YC supplementation led to an increase in the average daily gain and a reduction in feed intake and weight gain ratio in goats. It increased the apparent digestibility of crude protein, NDF, and ADF (p < 0.05). The serum concentrations of interleukin (IL)-1β, IL-6, and Tumor Necrosis Factor-α in the control group were significantly higher than those of the YC groups (p < 0.05). The serum concentrations of Immunoglobulin (Ig)A and IgG in the control group were significantly lower than those in the YC groups (p < 0.05). The rumen concentration of microbial protein (MCP) in the control group was significantly lower than that in the YC groups (p < 0.05). There was a negative correlation between the concentration of IL-10 and Bacteroidota, Spirochaetota, and Succinivibrio, while there was a positive correlation between concentrations of IL-10 and Firmicutes. Nevertheless, discrepancies were observed in the impact of the two different types of YC on the physiological and biochemical indicators of the animals. The concentration of triglyceride in the YC1 group was significantly higher than that of the CON and YC2 groups, while the concentration of urea in the YC2 group was significantly higher than that of the CON and YC1 groups (p < 0.05). At the phylum level, the addition of YC2 to the diet significantly increased the relative abundance of Bacteroidota and Fibrobacterota and significantly decreased Firmicutes compared to the control. At the genus level, the addition of YC1 to the HGD significantly reduced the relative abundance of Rikenellaceae_RC9_gut_group, while the addition of YC2 to the HGD significantly increased the relative abundance of Prevotellace-ae_UCG-001, Fibrobacter, and Prevotellaceae_UCG-003 (p < 0.05). The addition of YC significantly improved growth performance, increased nutrient digestibility, beneficially manipulated ruminal fermentation and microbial diversity, and improved immune function. The choice of yeast cultures can be customized according to specific production conditions.

Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations.

Abstract The aim of this study was to evaluate the effects of the inclusion of palm oil on the ruminal environment and nutrient digestibility of sheep diets. Twenty rumen-cannulated sheep were kept in individual stalls equipped with feeding and drinking troughs The animals were fed five diets based on Elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage and supplemented with 0, 25, 50, 75, or 100 g kg-1 of palm oil (based on total DM). The Elephant grass was harvested at 90 days of regrowth and the concentrate was based on ground corn grain, soybean meal and mineral mix (20 g kg-1 DM), offered to the sheep at a ratio of 1.5 g kg-1d-1 of body weight (restricted intake) to maintain a forage-to-concentrate ratio of 1:1, based on DM. There were no differences (P = 0.324) in ruminal disappearance and degradability parameters with up to 75 g of oil per kg of DM. Organic matter showed a linear reduction in apparent digestibility, while ether extract increased linearly. Palm oil affected the digestibility and nutritional parameters in ruminant diets.

Simple Summary: The use of plant bioactive compounds like tannins to modulate ruminal biohydrogenation is a good strategy to optimize the fatty acid composition of ruminant-derived products, which are closely associated with human health. Differently from terrestrial tannins, there is little information on the effect of phlorotannins (PTs) from brown seaweeds on ruminal biohydrogenation. Thus, this study aimed to evaluate the effect of PT extract from Sargassum on in vitro rumen fermentation, fatty acid composition and bacterial community. The inclusion of PT extract had a positive effect on rumen fermentation by increasing dry matter digestibility and gas production and reducing ammonia-N concentration. Rumen biohydrogenation was profoundly inhibited by PTs as reflected in an increased unsaturated fatty acid and reduced saturated fatty acid production. The addition of PTs also changed the rumen bacterial community significantly with elevated carbohydrate-mediated bacteria. Correlation analysis found that Prevotellaceae_UCG-001, Anaerovorax, Ruminococcus, Ruminobacter, Fibrobacter, Lachnospiraceae_AC2044_group and Clostridia_UCG-014 might be involved in the biohydrogenation process. The results suggest that the inclusion of PTs in the diet improved rumen fermentation and fatty acid composition through modulating rumen microbiota. The fatty acid profiles of ruminant-derived products are closely associated with human health. Ruminal microbiota play a vital role in modulating rumen biohydrogenation (BH). The aim of this study was to assess the influence of dietary supplementation with phlorotannins (PTs) extracted from Sargassum on rumen fermentation, fatty acid composition and bacterial communities by an in vitro culture study. The inclusion of PTs in the diet increased dry matter digestibility and gas production, and reduced ammonia-N concentration and pH. PT extract inhibited rumen BH, increasing the content of trans-9 C18:1, cis-9 C18:1, trans-9 and trans-12 C18:2 and reducing C18:0 concentration. 16S rRNA sequencing revealed that PTs caused an obvious change in rumen bacterial communities. The presence of Prevotella decreased while carbohydrate-utilizing bacteria such as Prevotellaceae_UCG-001, Ruminococcus, Selenomonas, Ruminobacter and Fibrobacter increased. Correlation analysis between rumen FA composition and the bacterial microbiome revealed that Prevotellaceae_UCG-001, Anaerovorax, Ruminococcus, Ruminobacter, Fibrobacter, Lachnospiraceae_AC2044_group and Clostridia_UCG-014 might have been involved in the BH process. In conclusion, the results suggest that the inclusion of PTs in the diet improved rumen fermentation and FA composition through modulating the rumen bacterial community. [ABSTRACT FROM AUTHOR]

This experiment was designed to investigate the relation of high and low methane-yield phenotypes with body weight (BW), dry matter intake (DMI), lactation performance, enteric CH 4 emissions, and rumen fermentation parameters in lactating dairy cows. A total of 130 multi- and primiparous Holstein cows were screened for enteric CH 4 emissions using the GreenFeed system (C-Lock Inc.). Out of these 130 cows, 5 were identified as phenotypically high (HM) and 5 as phenotypically low (LM) CH 4 emitters. Cows in the LM group had lower daily enteric CH 4 emissions than cows in the HM group (on average 346 vs. 439 g/d, respectively), lower CH 4 yield (15.5 vs. 20.4 g of CH 4 /kg of DMI), and CH 4 intensity (13.2 vs. 17.0 g of CH 4 / kg of energy-corrected milk yield). Enteric emissions of CO 2 and H 2 did not differ between HM and LM cows. These 10 cows were blocked by parity, days in milk, and milk production, and were used in a 5-wk randomized complete block design experiment. Milk composition, production, and BW were also not different between LM and HM cows. The concentration of total volatile fatty acids in ruminal contents did not differ between CH 4 phenotypes, but LM cows had a lower molar proportion of acetate (57 vs. 62.1%), a higher proportion of propionate (27.5 vs. 21.6%, respectively), and therefore a lower acetate-to-propionate ratio than HM cows. Consistently, the 16S cDNA analysis revealed the abundance of Succinivibrionaceae and unclassified Veillonellaceae to be higher in LM cows compared with HM cows, bacteria that were positively correlated with ruminal propionate concentration. Notably, Succinivibrionaceae trigger the formation of propionate via oxaloacetate pathway from phosphoenolpyruvate via Enzyme Commission: 4.1.1.49, which showed a trend to be higher in LM cows compared with HM cows. Additionally, LM cows possessed fewer transcripts of a gene encoding for methyl-CoM reductase enzyme compared with HM. In this study, low and high CH 4 -yield cows have similar production performance and milk composition, but total-tract apparent digestibility of organic matter and fiber fractions was lower in the former group of animals. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the inclusion of alfalfa grazing during 8 h continuous or partitioned in 2 separated sessions of 4 h after each milking, on nutrient intake, digestibility, ruminal fermentation, feeding behavior, milk production, milk composition, and milk fatty acid profile, in late-lactation cows fed a partial mixed ration (PMR). Twelve dairy cows (193 ± 83 d in milk, 584 ± 71 kg of body weight) were housed in individual outdoor pens and assigned to treatments according to a 3 × 3 Latin square design replicated 4 times. The treatments were as follows: (1) control (T0), cows were fed a total mixed ration (TMR) provided ad libitum 20.0% crude protein (CP), 32.2% neutral detergent fiber (NDF); (2) fed a diet combining a PMR which had the same ingredient composition as the TMR (60% of ad libitum intake) + 1 session of 8 h of pasture (T8), continuous grazing alfalfa (Medicago sativa ; 20.6% CP, 35.8% NDF) after the p.m. milking; and (3) PMR (60% of ad libitum intake) + 2 daily sessions of 4 h of access to pasture after each milking (T4+4). The experiment lasted 57 d and was divided into 3 periods of 19 d each. The first 12 d of each period was used for diet adaptation, and the last 7 d was used for data collection. No differences among treatments were observed for any of the productive variables, feeding efficiency, or purine derivatives excretion. Cows in T0 had greater intake and apparent digestibility of dry matter, organic matter, and nonfibrous carbohydrates compared with T4+4 and T8. Compared with T0, alfalfa grazing increased the concentration of C18:1 trans -11 and decreased those of C16:0 and C17:0 in milk fat. Cows in T4+4 consumed 1.1 more kg DM/d of alfalfa and N provided by alfalfa in the diet was 3 percentage points higher compared with T8 cows (266 vs. 229 g/d, respectively). In addition, T4+4 cows had a greater daily range of ruminal pH than T8 (0.73 vs. 0.93), and the highest concentrations of NH 3 -N were recorded during the a.m. grazing session while in T8 cows it occurred during the night. In conclusion, including 8 h of alfalfa grazing in T8 and T4+4 treatments allowed the substitution between 35.8 and 38.7% of the total dry matter intake (DMI) of a PMR (with a similar CP concentration to alfalfa) for pasture, maintaining milk solids production and increasing the C18:1 trans -11 of milk fat compared with a TMR in mid late–lactation cows. In an herbage plus PMR diet, splitting the 1 continuous grazing session of 8 h into 2 sessions of 4 h increased the proportion of energy and N provided by alfalfa pasture and reduced PMR intake, without modifying the total nutrient intake or productive performance of cows. [ABSTRACT FROM AUTHOR]

This study was investigated to compare the effects of thyme extract (Thymus vulgaris) on performance, ruminal fermentation, cellulase enzyme activity and microbial protein synthesis in fattening lambs and goat kids. For this purpose, 15 kids (average initial BW of 17.3±1.2 kg, 3 month-old) and 15 lambs (average initial BW of 21.4±1.5 kg, 3 month-old) were randomly assigned to 3 dietary treatment: 1) control (without thyme extract), 2) supplemented with 250 mg thyme extract, 3) supplemented with 500 mg thyme extract. Animals were housed in individual pens for 84 days. Experimental results showed that different levels of thyme extract had a significant effect on daily weight gain and feed intake in both species, so that in animals fed 250 mg of thyme extract was higher than the other treatments (P<0.01). Rumen pH was not affected by experimental treatments. The lowest NH3-N was observed in the treatment containing 250 mg of thyme extract (P<0.01). The total concentrations of volatile fatty acids (VFA) as well as butyrate and acetate in ruminal fluid decreased significantly with increasing thyme extract; but propionate was increased in kids and lambs fed with 250 mg of thyme extract (P<0.01). Microbial protein produced in the rumen were significantly affected by experimental treatments (P<0.01). The activity of cellulolytic enzymes was not affected by the treatments. Our findings indicate that 250 mg thyme extract can be used in diet without adverse effect on lambs and kids. The lambs were also more affected by the thyme extract than the kids. [ABSTRACT FROM AUTHOR]

Simple Summary: The global demand for mutton products has increased due to changes in consumer lifestyles, consumption concepts, and socio-economic developments. The feeding systems are widely acknowledged to significantly affect the growth, development, and body health of livestock. In this study, we evaluated the effects of different feeding methods on growth performance, serum biochemical indexes, rumen fermentation parameters, and fecal microorganisms of Huang-huai sheep. The results show that indoor feeding with restricted grazing artificial grassland can improve fattening performance, antioxidation and immune function activity, and rumen fermentation, as well as change fecal microbiota composition. This study investigated the effects of three feeding systems, indoor feeding (CONT), indoor feeding with time-restricted grazing artificial pasture (4 h/day, G4H), and indoor feeding with an eight-hour daily grazing artificial pasture (G8H), on the growth performance, serum metabolites, ruminal fermentation, and fecal microbiota composition of lambs. Average daily gain showed a tendency (p = 0.081) to be higher for the G4H group compared with the CONT group. Moreover, feeding systems did not have a significant effect on most of the serum biochemical indicators in lambs. Concentrations of serum glutathione peroxidase and immunoglobulins (IgA, gG, and IgM) were significantly lower (p < 0.01) in the CONT group. Additionally, a tendency towards higher levels of volatile fatty acids, acetate, and butyrate was found in animals of the G4H group compared to the CONT group. Furthermore, fecal microbiota composition was altered in G4H and G8H groups, resulting in the increased relative abundance of Firmicutes and Ruminococcaceae UCG-005, as well as the decreased relative abundance of Ruminobacter compared with the CONT group. Overall, these results suggest that indoor feeding with restricted grazing time does not significantly affect fattening performance or rumen fermentation but enhances antioxidation and immune function activity and also alters fecal microbiota composition. [ABSTRACT FROM AUTHOR]

The objective was to investigate the effect of nonprotein nitrogen source, dietary protein supply, and genetic yield index on methane emission, N metabolism, and ruminal fermentation in dairy cows. Forty-eight Danish Holstein dairy cows (24 primiparous cows and 24 multiparous cows) were used in a 6 × 4 incomplete Latin square design with 4 periods of 21-d duration. Cows were fed ad libitum with the following 6 experimental diets: diets with low, medium, or high rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio (manipulated by changing the proportion of corn meal, corn gluten meal, and corn gluten feed) combined with either urea or nitrate (10 g NO 3 −/kg of dry matter) as nonprotein nitrogen source. Samples of ruminal fluid and feces were collected from multiparous cows, and total-tract nutrient digestibility was estimated using TiO 2 as flow marker. Milk samples were collected from all 48 cows. Gas emission (CH 4 , CO 2 , and H 2) was measured by 4 GreenFeed units. We observed no significant interaction between dietary RDP:RUP ratio and nitrate supplementation, and between nitrate supplementation and genetic yield index on CH 4 emission (production, yield, intensity). As dietary RDP:RUP ratio increased, intake of crude protein, RDP, and neutral detergent fiber and total-tract digestibility of crude protein linearly increased, and RUP intake linearly decreased. Yield of milk, energy-corrected milk, and milk protein and lactose linearly decreased, whereas milk fat and milk urea nitrogen concentrations linearly increased as dietary RDP:RUP ratio increased. The increase in dietary RDP:RUP ratio resulted in a linear increase in the excretion of total purine derivatives and N in urine, but a linear decrease in N efficiency (milk N in % of N intake). Nitrate supplementation reduced dry matter intake (DMI) and increased total-tract organic matter digestibility compared with urea supplementation. Nitrate supplementation resulted in a greater reduction in DMI and daily CH 4 production and a greater increase in daily H 2 production in multiparous cows compared with primiparous cows. Nitrate supplementation also showed a greater reduction in milk protein and lactose yield in multiparous cows than in primiparous cows. Milk protein and lactose concentrations were lower for cows receiving nitrate diets compared with cows receiving urea diets. Nitrate supplementation reduced urinary purine derivatives excretion from the rumen, whereas N efficiency tended to increase. Nitrate supplementation reduced proportion of acetate and propionate in ruminal volatile fatty acids. In conclusion, no interaction was observed between dietary RDP:RUP ratio and nitrate supplementation, and no interaction between nitrate supplementation and genetic yield index on CH 4 emission (production, yield, intensity) was noted. Nitrate supplementation resulted in a greater reduction in DMI and CH 4 production, and a greater increase in H 2 production in multiparous cows than in primiparous cows. As the dietary RDP:RUP ratio increased, CH 4 emission was unaffected and RDP intake increased, but RUP intake and milk yield decreased. Genetic yield index did not affect CH 4 production, yield, or intensity. [ABSTRACT FROM AUTHOR]

The goal of this study was to investigate Candida tropicalis as a kind of environmentally friendly dietary additive to manipulate ruminal fermentation patterns, reduce methane emissions and nitrogen excretion, and to screen the appropriate dose for sheep. Twenty-four Dorper × thin-tailed Han crossbred ewes (51.12 kg ± 2.23 kg BW) were selected and randomly divided into four groups which were fed Candida tropicalis at dose of 0 (control), 4 × 108 (low dose), 4 × 109 (medium dose), and 4 × 1010 (high dose) colony-forming units (CFU)/d per head, respectively. The experiment lasted 33 days with 21 days for adaptation and 12 days for nutrient digestibility trial and respiratory gases sampling. The results showed that nutrients intake was not affected by Candida tropicalis supplementation (P > 0.05), whereas apparent digestibility of nutrients significantly increased compared with the control group (P < 0.05). Nitrogen and energy utilization increased with Candida tropicalis supplementation (P < 0.05). Compared with the ewes of the control group, rumen fluid pH and NH3-N concentration were not affected (P > 0.05), whereas total volatile fatty acid concentration and molar proportion of propionate were greater (P < 0.05), and molar proportion of acetate and the ratio of acetate to propionate were less (P < 0.05) when the ewes were fed Candida tropicalis. Daily total CH4 production (L/d) and CH4 emissions yield (L/d of CH4 per kg of dry matter intake, metabolic weight, or digestibility dry matter intake) were decreased at the low dose group (P < 0.05). The abundance of total bacteria, methanogen, and protozoa in rumen fluid was significantly higher at medium dose and high dose of Candida tropicalis supplementation (P < 0.05) compared with low dose and the control group. In summary, Candida tropicalis supplementation has a potential to reduce CH4 emissions and nitrogen excretion, and the optimal dose should be 4 × 108 CFU/d per head. [ABSTRACT FROM AUTHOR]

Abstract Background Unreasonable use of antibiotics in animals is a major concern and will remain so, thus affecting people's health. However, the application of plant extracts can better solve this problem. Objectives The purpose of this study was to study the effect of Moringa leaf flavonoids on the production performance, immunity, and rumen fermentation of dairy cows. Methods Nine Holstein multiparous cows (average weight: 550 kg; days of lactation: 150 ± 6 days) were used in the experiment, using a 3 × 3 Latin square design. Cows were divided into three groups, each of which was supplemented with 0, 50, or 100 mg/body weight (BW) Moringa oleifera leaf flavonoids. Each experimental period consisted of three periods of 21 days, and the prefeeding period lasted 15 days. Results Our results indicated that supplementation with Moringa leaf flavonoids increased the protein content and decreased the number of somatic cells in milk; had little effect on the biochemical indices of blood, the rumen fermentation, and serum biochemical indicators; and improved the activity of antioxidant enzymes, the antioxidant capacity, and immunity. Conclusions Addition of 50 mg/BW Moringa leaf flavonoids to cow enhanced the antioxidant and immunity capacity in dairy cows but did not affect physiological levels of common biochemical parameters in blood or fermentation parameters in rumen.

Abstract Higher dietary energy is often used to achieve better animal performance in mutton sheep production. Notably, changing the diet formula affects rumen fermentation and the microbiota of ruminants. In this study, we investigated the effect of dietary energy on rumen fermentation and ruminal microbiota in fattening sheep. Fifteen 2-month-old white-headed Suffolk sheep (♂) × Hu sheep (♀) crossbred lambs were randomly divided into three treatments based on the dietary energy of the feeds fed: 8.67 MJ/kg (Low energy (LE); n = 5), 10.38 MJ/kg (standard energy (CON); n = 5), and 12.31 MJ/kg (high energy (HE); n = 5) groups. After 70 days of feeding, sheep were slaughtered and the ruminal fluids were collected and analyzed to determine fermentation parameters. Microbiota was determined using metagenomics sequencing. Notably, the microbial cell protein (MCP) and butyric acid concentrations were significantly high in the HE group. Metagenomic sequencing revealed that ACE and Chao indexes of the HE group were significantly decreased. Four genera among the major classified taxa across all the kingdoms differed in relative abundance in the three dietary energy levels. The relative abundances of Prevotella_brevis, Succiniclasticum_ruminis, Prevotellace-ae_bacterium, and Lachnospiraceae_bacterium were significantly correlated with rumen fermentation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis further revealed that a high-energy diet increased lipid metabolism of microbiota. The Carbohydrate Active enzymes (CAZy) gene, which participates in energy metabolism, was upregulated, while genes regulating plant cell wall degradation were downregulated in the HE group. These results suggest that a high-energy diet had minimal influence on the rumen fermentation pattern but altered the composition of the rumen microbiota, enhancing microbial lipid metabolism and limiting crude fiber metabolism. The findings of this study provide scientific evidence of the effect of dietary energy on ruminant fermentation and fattening sheep production.

This study aimed to evaluate the effect of replacing jackfruit leaves (JF) for Para grass (PG) on intake, digestibility, nitrogen balance, ruminal fermentation, milk yield and composition in lactating goats. Four crossbred Saanen lactating goats in mid-lactation and milking 1676 ± 112 g/day were used in a 4 × 4 Latin square design. A basal diet consisted of concentrate and PG (C:F 40:60). Treatments were dietary replacement of JL for PG at ratios of 0, 50, 75 and 100% corresponding to JL0, JL50, JL75 and JL100 diets, respectively. Feeding JL increased linearly (P

Methane plays a major role in greenhouse gas emissions contributing to climate change. Therefore, reducing methane production by ruminants is a primary goal but significant challenge. In this study, five oriental medicine plant extracts (OMPEs), Hypericum ascyron L. (HYA), Rhododendron mucronulatum (RHM), Zizyphus jujube var. inermis (ZIJ), Vitis vinifera L. (VIV), and Rhus succedanea L. (RHS), with different polyphenol and flavonoid contents were evaluated for their effects on in vitro ruminal fermentation parameters, gas profiles, and changes in the microbial population of targeted groups including cellulolytic bacteria and methanogenic archaea (M. archaea). The total polyphenol and flavonoid content of the OMPEs was in the range of 30.53–266.62 mg GAE·g-1 and 4.95–125.43 mg CHE·g-1, respectively. Each OMPE was tested at a fixed dose (50 mg·L-1) after 48 h incubation in a batch culture system. Total gas production in the RHM treatment was significantly higher than that in the control group after 24 h of incubation, whereas methane production decreased by 34.08–41.01% in the RHM, ZIJ, VIV, and RHS treatment groups. Quantification of microbial populations showed that the relative abundance of two Ruminococcus species was decreased by treatment of all OMPEs whereas the relative abundance of Fibrobacter succinogenes increased. The abundance of M. archaea was reduced by VIV and RHS treatment groups. In conclusion, this study suggests that polyphenols and flavonoids extracted from OMPEs have potential to reduce methane production in ruminants, which should be further validated testing in vivo feeding trials for implementation.Highlight Some oriental medicine plants rich in polyphenol and/or flavonoid contents can be used to mitigate ruminant methane production. Supplementation of Vitis vinifera L. and Rhus succedanea L. extracts could reduce methane production and the abundance of methanogenic archaea.