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Newborn goat kids exposed to environmental stress are susceptible to diarrhea due to immature intestinal functions and undeveloped gut microbiota. Butyrate-producing bacteria as next generation probiotics benefit the maintenance of intestinal health, but the mode of regulation is still unclear. Herein, a novel butyrate-producing strain was isolated from sheep rumen and identified as Clostridium beijerinckii (C. beijerinckii) R8, thereafter goat kids were treated with C. beijerinckii R8 to elucidate its regulatory mechanisms on diarrhea. Thirty-six goat kids were assigned to four groups: control (CON), low dose (LCB; supplementation with 5 × 107 CFU/mL of C. beijerinckii R8, each with 10 mL/d), middle dose (MCB; supplementation with 5 × 108 CFU/mL of C. beijerinckii R8, each with 10 mL/d), high dose (HCB; supplementation with 5 × 109 CFU/mL of C. beijerinckii R8, each with 10 mL/d). The experiment lasted for 15 d, and 6 goat kids were randomly selected from each group for slaughter on the last day of the trial. The results showed that this isolate reduced the diarrhea rate (P

ABSTRACT: Inhibition of methyl-coenzyme M reductase can suppress the activity of ruminal methanogens, thereby reducing enteric methane emissions of ruminants. However, developing specific and environmentally friendly inhibitors is a challenging endeavor. To identify a natural and effective methane inhibitor that specifically targets methyl-coenzyme M reductase, molecular docking technology was employed to screen a library of phytogenic compounds. A total of 52 candidate compounds were obtained through molecular docking technique. Rosmarinic acid (RA) was one of the compounds that could traverse a narrow channel and bind to the active sites of methyl-coenzyme M reductase, with a calculated binding free energy of −9.355 kcal/mol. Furthermore, the effects of RA supplementation on methane production, rumen fermentation, and the microorganism community in dairy cows were investigated through in vitro rumen fermentation simulations according to a random design. Supplementation of RA resulted in a 15% decrease in methane production compared with the control. In addition, RA increased the molar proportion of acetate and propionate, whereas the sum of acetate and butyrate divided by propionate was decreased. At the bacterial level, the relative abundance of Rikenellaceae RC9 gut group, Christensenellaceae R7 group, Candidatus Saccharimonas, Desulfovibrio, and Lachnospiraceae FE2018 group decreased with RA supplementation. Conversely, the addition of RA significantly increased the relative abundance of DNF00809 (a genus from Eggerthellaceae), Denitrobacterium, an unclassified genus from Eggerthellaceae, an unclassified genus from Bacteroidales, and an unclassified genus from Atopobiaceae. At the archaeal level, the relative abundance of Methanobrevibacter decreased, whereas that of Methanosphaera increased with RA supplementation. These findings suggested that RA has the potential to be used as a novel natural additive for inhibiting ruminal methane production.

Abstract The rumen microbiome plays an important role in providing energy and protein to the host. Manipulation of rumen microbiome during early life may have a long-term beneficial effect on the health, growth performance, and feed efficiency of ruminants. To better understand the profiles and functional potentials of rumen microbiome in young ruminants, metagenomic binning was performed to investigate the rumen microbiome of goat kids from one to 84 days of age. A total of 797 metagenome-assembled genomes (MAGs) were recovered from the rumen of 42 Laiwu black goat kids. Our findings provide fundamental knowledge of the rumen microbiome during early life based on metagenomic binning, which may provide insights into effective strategies to achieve long-term beneficial effects on animal health and production.

Abstract Although early solid diet supplementation is a common practice to improve the growth and development in goat kids, its biological mechanism how solid diet induces rumen microbiota and epithelial development is still unknow. In this study, rumen fermentation parameters, 16S rRNA sequencing for rumen content and epithelial microbiota, transcriptomics and proteomics of epithelium were determined to classify the effects of solid diet supplementation. Here, we classified the changes of goat phenotypes (i.e., growth performance, rumen fermentation and development) and linked them to the changes of rumen microbiota, transcriptome and expressed proteins. The mechanism of solid diet improving rumen development was elucidated preliminarily. Moreover, different roles between the rumen content and epithelial microbiota were identified. Thess datasets expands our understanding of the association between the early diet intervention and rumen development, providing the useful information how nutrient strategy affects rumen function and subsequently improves the host growth. The generated data provides insights in the importance of rumen niche microbiota and microbe-host interactions, which benefits future studies.

IntroductionThe Hainan Dong goat (DG) is a local meat breed widely raised in Hainan, China because of its good adaptability to local hot and humid weather. However, the growth rate of these DG is much slower than that of commercialised breeds improved in European countries, resulting in poor carcase characteristics, including smaller slaughter weight and carcase weight, which have become increasingly prominent. In recent decades, Nubian goats have been continuously imported into China to improve the production performance of local breeds.MethodsIn this study, the effects of breed on growth performance, carcase and meat quality, and ruminal microbiota were analysed in 40 goats, including 20 DGs and 20 hybrid F3 offspring generated by crossing the DG and Nubian hybrids (NH). All the goats were averagely aged 90 days and weighed at 11 ± 1.34 kg. They were assigned to two treatments, with three replicates per treatment. The two groups were fed the same diet for 90 days before slaughter.ResultsThe results showed that the average daily gain, F/G ratio, slaughter weight, and carcase weight of the NH group were higher than those of the DG group (p

Abstract Background Rumen bacterial groups can affect growth performance, such as average daily gain (ADG), feed intake, and efficiency. The study aimed to investigate the inter-relationship of rumen bacterial composition, rumen fermentation indicators, serum indicators, and growth performance of Holstein heifer calves with different ADG. Twelve calves were chosen from a trail with 60 calves and divided into higher ADG (HADG, high pre- and post-weaning ADG, n = 6) and lower ADG (LADG, low pre- and post-weaning ADG, n = 6) groups to investigate differences in bacterial composition and functions and host phenotype. Results During the preweaning period, the relative abundances of propionate producers, including g_norank_f_Butyricicoccaceae, g_Pyramidobacter, and g_norank_f_norank_o_Clostridia_vadinBB60_group, were higher in HADG calves (LDA > 2, P

Abstract Background Sustainable strategies for enteric methane (CH4) mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure. The present study aimed to investigate the effects of dietary xylooligosaccharides (XOS) and exogenous enzyme (EXE) supplementation on milk production, nutrient digestibility, enteric CH4 emissions, energy utilization efficiency of lactating Jersey dairy cows. Forty-eight lactating cows were randomly assigned to one of 4 treatments: (1) control diet (CON), (2) CON with 25 g/d XOS (XOS), (3) CON with 15 g/d EXE (EXE), and (4) CON with 25 g/d XOS and 15 g/d EXE (XOS + EXE). The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period. The enteric CO2 and CH4 emissions and O2 consumption were measured using two GreenFeed units, which were further used to determine the energy utilization efficiency of cows. Results Compared with CON, cows fed XOS, EXE or XOS + EXE significantly (P

The Lycium barbarum branches and leaves (LBL) are known to contain a range of active substances that have positive effects on animal immunity and antioxidation. This study aimed to examine how LBL impacts the growth and slaughter performance as well as rumen fermentation and microbiota in Hu sheep. A total of 50 male Hu sheep of indigenous origin, aged 3 months, were randomly divided into 5 groups of 10 sheep each. The groups were given different levels of LBL supplementation (0%, 3%, 6%, 9%, and 12%) to evaluate growth performance and nutrient apparent digestibility. Rumen fluid samples were collected for analysis of the fermentation parameters and rumen chyme was examined to study the rumen microbiota. The slaughter performance, meat quality, and organ index were evaluated at the conclusion of the experiment. The results showed that the final body weight and average daily gain of the LBL1 group were significantly higher than those of the CON group, LBL3 group, and LBL4 group (p < 0.05). The average dry matter intake of the LBL4 group was significantly lower than that of other experimental groups (p < 0.05). The apparent digestibility of CP in the LBL1 and LBL2 groups was higher than that in other experimental groups (p < 0.05). At the same time, the eye muscle area and grade-rule (GR) value of Hu sheep in the LBL1 group significantly increased and the quality of Hu sheep meat improved (p < 0.05). There was no significant difference in organ weight and organ index between the experimental groups (p > 0.05). The pH of the rumen fluid in the LBL1 group was significantly lower than that in the CON group (p < 0.05). There was no significant difference in the NH3-N content between the experimental groups (p > 0.05). The propionate and valerate in the rumen fluid of Hu sheep in the LBL2 group were significantly higher than those in other experimental groups (p < 0.05). In addition, this had no significant effect on the structure and abundance of the rumen microbiota (p > 0.05). LBL is a promising functional feed. Adding an appropriate amount of LBL to the diet can improve the feed efficiency, growth performance, and meat quality of Hu sheep but has no adverse effects on the rumen. In this experiment, the appropriate supplemental level of LBL in the diet was 3%.

ABSTRACT The use of milk replacer (MR) is a modern strategy to ensure the health and growth of neonatal ruminants. Some studies have confirmed that dietary factors have significant effects on ruminal antimicrobial resistance genes (ARGs), which, as a potential threat to livestock, have received more attention. However, the effect of different milk sources (milk or MR) on the rumen resistome of yaks is still largely unknown. Here, using metagenome technology, we investigated the occurrence of ruminal ARGs in yaks and their relationship with rumen bacteria in response to different milk sources. The metagenomic result showed that MR feeding significantly increased the abundance of Prevotella members compared to milk feeding. A total of 138 rumen resistome-conveying ARGs to 17 different classes of antimicrobials were detected, of which tetracycline resistance was the predominant. MR feeding also drove the changes in the rumen resistome, and the predicted bacterial origins of ARGs had complex and various manifestations. Moreover, enzymes of butyrate metabolism and carbohydrate-active enzymes encoding carbohydrate and cellulose degradation were increased. This study revealed that MR feeding increased the abundance of beneficial bacteria Prevotella members, changed the microbial resistome, and promoted the metabolic function of volatile fatty acid biosynthesis in the rumen of yaks, which could provide beneficial evidence for the regulation of the rumen microbiome and the intervention of antimicrobial resistance in ruminants by dietary or nutritional methods. IMPORTANCE Yaks, as ruminants inhabiting high-altitude environments, possess a distinct rumen microbiome and are resistant to extreme living conditions. This study investigated the microbiota, resistome, and functional gene profiles in the rumen of yaks fed milk or milk replacer (MR), providing insights into the regulation of the rumen microbiome and the intervention of antimicrobial resistance in yaks through dietary methods. The abundance of Prevotella members increased significantly in response to MR. Tetracycline resistance was the most predominant. The rumen of yaks contained multiple antimicrobial resistance genes (ARGs) originating from different bacteria, which could be driven by MR, and these ARGs displayed intricate and complex interactions. MR also induced changes in functional genes. The enzymes associated with fiber degradation and butyrate metabolism were activated and showed close correlations with Prevotella members and butyrate concentration. This study allows us to deeply understand the ruminal microbiome and ARGs of yaks and their relationship with rumen bacteria in response to different milk sources.

The purpose of this study was to investigate the effects of feed ingredients with different protein-to-fat ratios on growth, slaughter performance and meat quality of Small-Tail Han lambs. Forty-five Small-Tail Han lambs (♂) (BW = 34.00 ± 2.5 kg, age = 120 ± 9 d) were randomly divided into groups with three different experimental treatments: (1) PF 5, with the ratio of protein to fat (CP:EE) of 50 to 5; (2) PF10, CP: EE = 50:10; (3) PF20, CP: EE = 50:20. Each treatment group had 15 lambs, and each sheep was a repeat. This experiment lasted for 65 days, with feed intake recorded daily, and animals being weighed on days 0, 30, and 65. At the conclusion of the experiment, eight lambs from each group were slaughtered to assess slaughter performance and meat quality. The results showed that the average daily gain (ADG) of the three groups were 315.27, 370.15 and 319.42 g/d, respectively. The PF10 group had the highest ADG (370.15 g) (p < 0.05). Forestomach weights (1216.88 g) of the PF10 group were significantly higher than those of the other groups (p < 0.05). There were no differences (p > 0.05) in fat percentages in various parts of body among treatments. Feed conversion of the PF10 group was higher (p < 0.05) than that of PF 5 and PF 20 groups. Furthermore, the PF10 group had a higher (p > 0.05) carcass weight and slaughter rate and there were few differences between the other groups in terms of dry matter intake, meat quality, organ weight, and fat deposition (p > 0.05). The protein–energy supplement with protein-to-fat ratio, PF10 appeared to be more desirable to promote the growth and development in Small-Tail Han Lambs.

This study aimed to investigate the effect of feeding level on the growth and slaughter performance, and allometric growth of tissues and organs in female growing dairy goats. The trial included 10–20 and 20–30 kg weight stages with 48 female goat kids. The 24 goat kids in each stage were divided into 8 blocks based on weight, with 3 kids per block. Then, three kids from each block were randomly assigned to one of the three treatments, namely ad libitum (AL100), 70% of ad libitum (AL70), or 40% of ad libitum (AL40). The slaughter trial was conducted when the AL100 kids reached the target weight of 20 or 30 kg. The results showed that the ADG and feed conversion rate showed a linear decline as the feed level decreased (p < 0.05). Compared with the AL70 and AL100 groups, the AL40 group exhibited lower shrunk body weight, empty body weight, hot carcass weight, net meat rate, carcass meat rate, and visceral fat weight (p < 0.05) in both stages. Moreover, the AL40 group showed lower weights for skin and mohair, blood, rumen, small intestine, large intestine, mammary gland, and uterus than the AL70 and AL100 groups (p < 0.05) in both stages. However, feeding level did not affect organ indices in the two stages (p > 0.05). The bone, skin and mohair were isometric (b ≈ 1), but the muscle, visceral fat, and most internal organs were positive (b > 1) in both stages. In conclusion, feeding level affects the growth and development of dairy goats, which vary depending on the body weight stage and specific tissues and organs.

Objective The present study was conducted to examine the gas production, fermentation characteristics, nutrient degradation, and methanogenic community composition of a rumen fluid culture with Broussonetia papyrifera (B. papyrifera) subjected to ensiling or steam explosion (SE) pretreatment. Methods Fresh B. papyrifera was collected and pretreated by ensiling or SE, which was then fermented with ruminal fluids as ensiled B. papyrifera group, steam-exploded B. papyrifera group, and untreated B. papyrifera group. The gas and methane production, fermentation characteristics, nutrient degradation, and methanogenic community were determined during the fermentation. Results Cumulative methane production was significantly improved with SE pretreatment compared with ensiled or untreated biomass accompanied with more volatile fatty acids production. After 72 h incubation, SE and ensiling pretreatments decreased the acid detergent fiber contents by 39.4% and 22.9%, and neutral detergent fiber contents by 10.6% and 47.2%, respectively. Changes of methanogenic diversity and abundance of methanogenic archaea corresponded to the variations in fermentation pattern and methane production. Conclusion Compared with ensiling pretreatment, SE can be a promising technique for the efficient utilization of B. papyrifera, which would contribute to sustainable livestock production systems.

Abstract Background The resistome describes the array of antibiotic resistant genes (ARGs) present within a microbial community. Recent research has documented the resistome in the rumen of ruminants and revealed that the type and abundance of ARGs could be affected by diet and/or antibiotic treatment. However, most of these studies only assessed ARGs using metagenomics, and expression of the resistome and its biological function within the microbiome remains largely unexplored. Results We characterized the pools of ARGs (resistome) and their activities in the rumen of 48 beef cattle belonging to three breeds (Angus, Charolais, Kinsella composite hybrid), using shotgun metagenomics and metatranscriptomics. Sixty (including 20 plasmid-associated) ARGs were expressed which accounted for about 30% of the total number of ARGs (187) identified in metagenomic datasets, with tetW and mefA exhibiting the highest level of expression. In addition, the bacterial hosts of 17 expressed ARGs were identified. The active resistome was less diverse in Kinsella composite hybrid than Angus, however, expression of ARGs did not differ among breeds. Although not associated with feed efficiency, the total abundance of expressed ARGs was positively correlated with metabolic pathways and ‘attenuation values’ (a measurement of stability) of the active rumen microbiome, suggesting that ARGs expression influences the stability and functionality of the rumen microbiome. Moreover, Ruminococcus spp., Prevotella ruminicola, Muribaculaceae spp. and Collinsella aerofaciens were all identified as hosts of expressed ARGs, possibly promoting the dominance of these carbohydrate degraders within the rumen microbiome. Conclusions Findings from this study provide new insight into the active rumen resistome in vivo, which may inform strategies to limit the spread of ubiquitously found ARGs from the rumen to the broader environment without negatively impacting the key functional outcomes of the rumen microbiome.

Abstract Background This study investigated greenhouse gas (GHG) emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures. GreenFeed system was used to measure the amount of methane (CH4) and carbon dioxide (CO2) emitted by the cows through respiration. Data from a commercial cow farm were used to observe the effects of parity, body weight, milk yield, and milk component yield on CH4 and CO2 emissions. Results Mean herd responses throughout the study were as follows: 111 cows completed all experimental processes, while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times. On average, lactating days of cows was 138 ± 19.04 d, metabolic weight was 136.5 ± 9.5 kg, parity was 2.8 ± 1.0, dry matter intake (DMI) was 23.1 ± 2.6 kg/d, and milk yield was 38.1 ± 6.9 kg/d. The GreenFeed system revealed that CH4 production (expressed in CO2 equivalent, CO2-eq) was found to be 8304 g/d, C H 4 ( C O 2 − e q ) $$ {\mathrm{CH}}_{4\left({\mathrm{CO}}_2-\mathrm{eq}\right)} $$ /DMI was 359 g/kg, C H 4 ( C O 2 − e q ) $$ {\mathrm{CH}}_{4\left({\mathrm{CO}}_2-\mathrm{eq}\right)} $$ /energy-corrected milk (ECM) was 229.5 g/kg, total CO2 production (CH4 production plus CO2 production) was 19,201 g/d, total CO2/DMI was 831 g/kg, and total CO2/ECM was 531 g/kg. The parity and metabolic weight of cows had no significant effect on total CO2 emissions (P > 0.05). Cows with high milk yield, milk fat yield, milk protein yield, and total milk solids yield produced more total CO2 (P

Ruminal microorganisms play a crucial role in the energy supply of ruminants and animal performance. We analyzed the variations in rumen bacteria and fungi at 45 d, 75 d, and 105 d by using 16SrRNA and ITS sequencing data and investigated their correlation with rumen fermentation. According to the results, rumen microflora tended to gradually mature with age, and bacterial and fungal establishment gradually stabilized. Upon comparing the three periods, the concentration of propionic acid increased significantly (p < 0.05) after weaning, and weaning accompanied by a transition in diet remarkably decreased (p < 0.05) rumen diversity in the short term and induced a corresponding change in the rumen microbiota composition. Bacteroidota, Actinobacteriota, and Firmicutes were the core bacterial phyla for all age periods. Ruminococcus, NK4A214_group, Sharpea, Rikenellaceae_RC9_gut_group, and norank_f__Butyricicoccaceae were the markedly abundant bacterial genera in pre-weaning. After weaning, the relative abundance of Erysipelotrichaceae_ UCG-002, Eubacterium_ruminantium_group, and Solobacterium significantly increased (p < 0.05). The relative abundance of Acetitomaculum increased with age with the greatest abundance noted at 105 d (37%). The dominant fungal phyla were Ascomycota and Basidiomycota, and Aspergillus and Xeromyces were the most abundant fungal genera after weaning. Trichomonascus, Phialosimplex, and Talaromyces were enriched at 105 d. However, the low abundance of Neocallimastigomycota was not detected throughout the study, which is worthy of further investigation. In addition, correlations were observed between age-related abundances of specific genera and microbiota functions and rumen fermentation-related parameters. This study revealed that rumen microbiota and rumen fermentation capacity are correlated, which contributed to a better understanding of the effects of age and diet on rumen microbiology and fermentation in calves.

BackgroundThis study examined the effects of substituting cottonseed meal (CSM) or rapeseed meal (RSM) for soybean meal (SBM) on Hu sheep performance, rumen fermentation, and bacterial composition. 51 four-month-old indigenous male Hu sheep with starting body weights of 22.51 ± 2.84 kg and similar origins were randomly assigned to three treatments; (1) non-fermented total mixed ration (TMR) with SBM (CK), (2) fermented TMR containing CSM (F-CSM group), and (3) fermented TMR containing RSM (F-RSM group).ResultsThe three groups’ intake of dry matter differed significantly (p

The objective of this experiment was to evaluate the effect of supplementing rumen-protected Lys based on a Lys-deficient diet on liver metabolism in growing Holstein heifers. The experiment was conducted for 3 months with 36 Holstein heifers (initial body weight: 200 ± 9.0 kg; 7-month-old). Heifers were randomly assigned to 2 diets based on corn, soybean meal, alfalfa hay, and wheat bran: control, Lys-deficient diet (LD; 0.66% Lys in diet), and Lys-adequate diet (LA; 1.00% Lys in diet). The results showed no difference in growth performance between the 2 groups (P > 0.05). However, there was a clear trend of increasing feed conversion rate with Lys supplementation (0.05

The purpose of this experiment was to evaluate changes in fermentation quality, chemical composition, aerobic stability, anti-nutritional factors, and in situ disappearance characteristics of various protein-based total mixed rations. Soybean meal (control, non-fermented), fermented cottonseed meal (F-CSM), and fermented rapeseed meal (F-RSM) group were used to prepare the TMRs with corn, whole-plant corn silage, corn stalks, wheat bran, and premix. The test groups were inoculated at 50% moisture with Bacillus clausii and Saccharomyces cariocanus and stored aerobically for 60 h. The nylon-bag method was used to measure and study the rumen’s nutrient degradation. The pH of all TMRs after 48 h of air exposure was below 4.8, whereas that of the F-CSM and control and F-RSM groups increased to 5.0 and >7.0, respectively. After 8 h of aerobic exposure, the temperatures of all groups significantly increased, and 56 h later, they were 2 °C higher than the surrounding air. The lactic acid concentration in the F-CSM and F-RSM groups increased after 12 h of aerobic exposure and then decreased. The acetic acid concentrations in the fermented groups decreased significantly with the increasing air-exposure time. The yeast population of the TMRs increased to more than 8.0 log10 CFU/g before 72 h of air exposure, followed by a decrease in the population (5.0 log10 CFU/g). After fermentation, the free gossypol (FG) concentration in F-CSM decreased by half and did not change significantly during the air-exposure period. Fermentation with probiotics also reduced the F-RSM’s glucosinolate concentration, resulting in a more than 50% detoxification rate. Compared with the F-CSM and F-RSM groups, the effective degradation rates of nutrients in the control group were the lowest, and the dry matter (DM), crude protein (CP), natural detergent fiber (NDF), and acid detergent fiber (ADF) all degraded effectively at rates of 28.4%, 34.5%, 27.8%, and 22.8%, respectively. Fermentation with B. clausii and S. cariocanus could improve the fermentation quality and nutrient composition, decrease the anti-nutritional factor, and increase nutrient degradation of the TMR with cottonseed meal or rapeseed meal as the main protein source, thus achieving detoxification.

This experiment aims to study the effects of dietary fat level during the suckling period on growth performance and meat characteristics in twin lambs. Thirty pairs of male twin Hu lambs were divided into two groups, namely high fat (HF) and normal fat (NF). Lambs in the HF group were fed milk replacer and starter containing 26.89% and 5.07% of fat, whereas those in the NF group were fed milk replacer and starter containing 15.15% and 2.80% of fat, respectively, from eight to 60 days of age. From 60 to 120 days of age, all lambs were fed a starter feed containing 2.80% fat. The results showed that lambs fed HF diet had higher body weight (12.78 kg versus 11.63 kg, P = 0.020), average daily gain (162.4 g/day versus 141.1 g/day, P = 0.019), apparent digestibility of organic matter (P = 0.018) and gross energy (P < 0.001). No difference was observed between HF and NF group in slaughter performance during eight to 60 days of age. Lambs fed HF diet had higher body weight at 120 days of age (P = 0.035). However, no difference was observed in nutrient digestibility, slaughter performance or meat quality at 120 days of age. In summary, the HF diet in the suckling period showed long-lasting beneficial effects on the growth performance of lambs.

Objective The study was conducted to investigate the effects of Broussonetia papyrifera L. (B. papyrifera) silage on growth performance, serum biochemical parameters, meat quality, and meat amino acids and fatty acids compositions in beef cattle. Methods Sixty-four male Angus beef cattle were assigned to 4 groups with 4 pens in each group and 4 beef cattle in each pen, and fed with the total mixed ration supplemented with 0%, 5%, 10%, or 15% B. papyrifera silage for 100 days (control group, 5% group, 10% group and 15% group) separately. Results Beef cattle had significantly higher final body weight (BW) in 15% group, higher average daily gain (ADG) and dry matter intake (DMI) in 5% group, 10% group and 15% group, and higher feed conversion ratio (FCR) in 10% group and 15% group. Significantly higher blood superoxide dismutase (SOD) concentration was noted in 15% group, higher blood total antioxidant capacity (TAC) in 10% group and 15% group, lower 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) in 15% group. Meat had lower pH in 15% group, higher Commission International DeI’Eclairage (CIE) L* in 5% group, 10% group, and 15% group, and lower drip loss in 15% group. Greater concentration of meat polyunsaturated fatty acids (PUFA) was observed in 10% group and 15% group, and docosahexaenoic acid (DHA) in 15% group. Conclusion Diet with 15% B. papyrifera silage could improve performance and increase final BW, ADG, DMI, and FCR, enhance the antioxidant functions by decreasing blood 8-OHdG and MDA and increasing blood SOD and TAC, improve the meat quality by lowing pH and drip loss and increasing CIE L*, increase the meat PUFA and DHA concentration. Polyphenols and flavonoids might be the main components responsible for the antioxidant activity and anti-biohydrogenation in the B. papyrifera silage. And B. papyrifera silage could be used as a new feedstuff in beef cattle nutrition.

Early feeding regime has a substantial lifelong effect on lambs and weaning ewe's milk can lead to the intestinal injury of lambs. To explore the molecular regulatory mechanism of intestinal injury of lambs under weaning stress, the jejunum was conducted transcriptome and then integrated analyzed with our previous proteome data. A total of 255 upregulated genes and 285 downregulated genes were significantly identified. These genes showed low overlapping with differentially expressed proteins identified by isobaric tags for relative and absolute quantification (iTRAQ). However, according to their functions, the differentially expressed genes (DEGs) and proteins with the same expression trend were enriched for the similar Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as intestinal lipid absorption, urea cycle, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and ferroptosis. Furthermore, the DEGs, including FABP2, ACSL3, APOA2, APOC3, and PCK1, might play essential roles in intestinal lipid absorption and immune response through the PPAR signaling pathway and ferroptosis. This study could provide new insights into early lamb breeding at the molecular level.

The study was conducted to evaluate the effects of Anemoside B4 on diarrhea incidence, serum indices, and fecal microbial of suckling calves. Sixty newborn Chinese Holstein calves with similar body weight (43.7 ± 3.9 kg) were randomly divided into four groups with 15 calves each, fed the diet which was supplied 0 (CON), 15 (A1), 30 (A2), and 45 (A3) mg/day of Anemoside B4, respectively. The trial period is 56 days. The blood and fecal samples were collected at 28 and 56 days of age. Results show that during the whole trial period, the diarrhea incidence in Group A1, A2, and A3 was significantly lower than that in Group CON (p < 0.05). Compared with the Group CON, Anemoside B4 supplementation significantly decreased the contents of serum D-lactic acid and diamine oxidase at 28-day-old (p < 0.05). At 56-day-old, the content of serum D-lactic acid in Group A3 tended to be higher (0.05 < p < 0.01), and the content of serum diamine oxidase in Group A3 increased significantly, in comparison with Group CON (p < 0.05). Group A3 increased the level of Chao1 and Simpson indices at 28-day-old (0.05 < p < 0.01), and Chao1, Observed_species, Shannon, and Simpson indices at 56-day-old (p < 0.05), in comparison to Group CON. Compared with Group CON, 45 mg / day Anemoside B4 supplementation significantly increased the contents of Bacteroidota (at the phylum level), Prevotella (at the genus level) at 28-day-old (p < 0.05), and the content of Sutterella (at the genus level) at 56-day-old (p < 0.05), promoted the processes of energy metabolism, glycan biosynthesis and metabolism, metabolism of cofactors and vitamins (p < 0.05). A positive correlation was observed between Prevotella and metabolism of cofactors and vitamins, energy metabolism, and glycan biosynthesis and metabolism. A positive correlation was observed between Sutterella and energy metabolism. In conclusion, Anemoside B4 could effectively alleviate calf diarrhea, protect the integrity of intestinal mucosa, and change the structure of intestinal microbiota, indicating the potential value of Anemoside B4 in regulating intestinal microbiota and the prevention of intestinal diseases.

Rumen microbiota are closely linked to feed utilization and environmental adaptability of ruminants. At present, little is known about the influence of different extreme environments on the rumen microbiota of yaks. In this study, 30 ruminal fluid samples from 30 healthy female yaks (average 280 kg of BW) in 5–8 years of life were collected from three regions in Tibet, China, and compared by gas chromatography and high-throughput sequencing. Results showed that propionic acid, butyric acid, and total volatile fatty acids were significantly (p < 0.05) higher, while microbial abundance and diversity were significantly (p < 0.05) lower, in the Nagqu (4,500 m altitude) compared with the Xigatse (4,800 m altitude) and Lhasa (3,800 m altitude) regions. Principal coordinate analysis revealed significant (p < 0.05) differences in rumen microbial composition of yaks from different regions. Specifically, Bacteroidetes and Firmicutes were identified by linear discriminant analysis effect size (LDA > 3) as being the signature phyla for Xigatse and Nagqu regions, respectively. In addition, the relative abundance of Rikenellaceae_RC9_gut_group, Quinella, Prevotellaceae_UCG-003, Lachnospiraceae_NK3A20_group, Papillibacter, Ruminococcaceae_UCG-010, Prevotellaceae_NK3B31_group, and Ruminococcaceae_UCG-005 correlated with altitude and rumen fermentation parameters (p < 0.05). Finally, the predicted function of rumen microbiota was found to differ between regions (p < 0.05). In summary, our results reveal that regions located at different altitudes influence microbiota composition and fermentation function of yaks’ rumen. The present findings can provide mechanistic insights on yak adaptation to high altitudes and improve the feeding efficiency of these animals in extreme regions.

Under current breeding conditions, multiple stressors are important challenges facing animal husbandry in achieving animal wellbeing. For many years, the use of antibiotics has been a social concern in the livestock industry. With the implementation of the non-antibiotics policy, there is an urgent need to find relevant technologies and products to replace antibiotics and to solve the problem of disease prevention during animal growth. Phytogenic extracts have the unique advantages of being natural and extensive sources, having a low residue, and being pollution-free and renewable. They can relieve the various stresses, including oxidative stress, on animals and even control their inflammation by regulating the signaling pathways of proinflammatory cytokines, improving animal immunity, and improving the structure of microorganisms in the gastrointestinal tract, thereby becoming the priority choice for improving animal health. In this study, we reviewed the types of antioxidants commonly used in the livestock industry and their applicable effects on ruminants, as well as the recent research progress on their potential mechanisms of action. This review may provide a reference for further research and for the application of other phytogenic extracts and the elucidation of their precise mechanisms of action.

This study aimed to evaluate the effects of coconut oil and palm oil in milk replacer (MR) on the growth performance, blood lipids, rumen fermentation, rumen microbiota, and fatty acid profile of hepatic and muscle of suckling calves. Thirty-six Holstein male calves were randomly assigned to three treatments. Three milk replacers containing different fat sources were as follows: control group (CON, milk fat), coconut oil group (CCO, coconut oil powder as fat), and palm oil group (PLO, palm oil powder as fat). Calves were weighed and blood sampled at 14, 28, 42, and 56 days old, respectively, and the feed intake and fecal score were recorded daily. Fat sources in milk replacers had no effects on body weight, ADG, DMI, fecal score, or days of abnormal fecal in suckling calves among the three groups, while the PLO group tended to decrease starter intake compared with the other groups. Serum concentrations of TC, HDL-C, LDL-C, and VLDL-C in the CCO group increased compared with those of the CON group. Palm oil also decreased the serum GLU concentration of calves but had no effects on serum lipids compared with milk fat. Coconut oil or palm oil had no effects on rumen fermentation, rumen chyme enzyme activity, rumen bacterial community richness and diversity, and dominant phyla and genera when compared with milk fat. However, compared with the CON group, the CCO group increased the proportion of MCFAs and n-6 PUFAs, and decreased the proportion of UFAs and MUFAs in liver tissue, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in liver tissue. In addition, compared with the CON group, the CCO group increased the proportion of MCFAs, and decreased the proportion of UFAs and n-3 PUFAs in longissimus dorsi, while the PLO group increased the proportion of PUFAs and decreased the proportion of n-3 PUFAs in longissimus dorsi. In conclusion, compared with milk fat, coconut oil or palm oil in MR had no effects on growth performance, rumen fermentation, and rumen microflora but significantly increased serum lipids concentration and changed some proportions of MCFAs and PUFAs in liver and longissimus dorsi in suckling calves. These results indicate that coconut oil or palm oil as the sole fat source for MRs has no adverse effect on calf rumen fermentation and rumen microbiota but has a detrimental effect on n-3 PUFAs deposition in the liver and longissimus dorsi muscle.

The health of young ruminants is highly dependent on early rumen microbial colonization. In this study, the effects of milk replacer on growth performance, rumen fermentation, and the rumen microflora in yak calves were evaluated. Sixty yak calves (body weight = 22.5 ± 0.95 kg, age = 30 ± 1 d) were assigned to the CON group (breastfed) or TRT group (milk replacer fed) and evaluated over 120 d. At 120 d, ruminal fluid samples were collected from 14 calves and then conducted for rumen fermentation and microbiota analyses. There was no difference in growth performance; however, calf survival was higher in the TRT group than in the CON group. The concentration of total volatile fatty acids and the molar proportion of butyric acid and lactic acid were increased with milk replacer feed in the TRT group (p < 0.05), but iso-valeric acid concentration was highest in the CON group (p < 0.05). Firmicutes and Bacteroidetes were the most dominant phyla in the CON and TRT groups, respectively. In the TRT group, Bacteroidetes, Prevotellaceae, Bacteroidia, Bacteroidetes, and Prevotella_1 were the dominant flora in the rumen of calves. The relative abundances of various taxa were correlated with rumen fermentation parameters; the relative abundance of Quinella and iso-butyrate levels were positively correlated (r = 0.57). The relative abundances of the Christensenellaceae_R-7_group and A/P were positively correlated (r = 0.57). In summary, milk replacer is conducive to the development of the rumen microflora, the establishment of rumen fermentation function, and the implementation of early weaning in yaks.

This study investigated the effects of circadian rhythm on rumen nutrient digestibility using the nylon bag method and the digestibility characteristics of dietary nutrients during the daytime and at night. It also presents modification suggestions for evaluating the nutritional value of raw feed materials. The rumen nutrient digestibility was measured and investigated for correlation with circadian rhythm using the nylon bag method. We established a sheep-feeding program to determine the differences in rumen nutrient digestibility between the daytime and nighttime. The digestibility of 18 standard feed samples was investigated in 6 Hu sheep with ruminal fistulas (body weight: 33.59 ± 0.39 kg, 12 months old). Samples were incubated in the rumen for three periods: daytime (12 h, 6:00 AM to 6:00 PM), night (12 h, 6:00 PM to 6:00 AM), and the entire day (24 h, 6:00 AM to 6:00 AM). The activities of enzymes amylase, lipase and cellulase were higher during the day than at night. The rumen digestibility of organic matter was significantly higher during the daytime than at night compared to the digestibilities of dry matter (DM), crude protein (CP), and ether extract (EE). Among them, the rumen digestibility of DM and CP was higher, but the digestibility of EE was lower during the daytime than at night in cereal feed fed sheep. The rumen digestibility of DM was higher in roughage-fed sheep but lower in rice straw- and corn silage-fed sheep during the day than at night. Circadian rhythms correlate strongly with the activities of major digestive enzymes in the rumen and the rumen digestibility of nutrients. Moreover, the nylon bag method needs to be modified and improved to ascertain the appropriate time for placing the nylon bag in the rumen and thus establish a unified procedure.

All organisms have a biological clock system which is strongly tied to how well an organism digests food and develops. This study aimed to understand the effects of circadian rhythm and feeding modes on rumen fermentation and microorganisms in Hu sheep. Forty-five healthy Hu sheep were randomly divided into three treatment groups of 15 sheep in each group, wherein they were fed the same concentrate and roughage. Under the condition that the nutrient-feeding amount was consistent throughout the day, the concentrate-to-forage ratio was dynamically adjusted during the day and night. Rumen fluid collected after the feeding experiment was used to determine the study parameters; the results showed a connection between rumen fermentation and the circadian clock. Volatile fatty acids (VFAs), pH, and NH3-N were significantly influenced by the fermentation duration (p < 0.05). The activities of digestive enzymes also showed a relationship with nutrition and circadian rhythm, and there were differences in the digestive enzyme activities of amylase, lipase, and cellulase (p < 0.05). Dominant microorganisms, such as Saccharomycetes and Mucor, were more abundant in the daytime of the high-concentrate fed group. The correlation among the study objectives was evident from the differences in enzyme activity and microbial diversity among the treatment groups. On the basis of the circadian rhythm characteristics of Hu sheep, changes in the feeding mode of Hu sheep and only adjusting the proportion of concentrate and forage in the morning and evening showed that feeding diets with the high-concentrate ratio in the day significantly reduced rumen PH and increased NH3-N concentration (p < 0.05). Under this feeding pattern, the activities of major digestive enzymes in the rumen, such as amylase and lipase, were significantly increased (p < 0.05), and the microbial diversity was also improved.

Objective The current study analysed the relationships between methane (CH4) output from animal and dietary factors. Methods The dataset was obtained from 159 Dorper×thin-tailed Han lambs from our seven studies, and CH4 production and energy metabolism data were measured in vivo by an open-circuit respiratory method. All lambs were confined indoors and fed pelleted diet during the whole experimental period in all studies. Data from two-thirds of lambs were used to develop linear and multiple regressions to describe the relationship between CH4 emission and dietary variables, and data from the remaining one third of lambs were used to validate the established models. Results CH4 emission (g/d) was positively related to dry matter intake (DMI) and gross energy intake (GEI) (p

This study compared the growth performance, nutrient utilization, and slaughter traits of Dorper crossbred male lambs fed as per the established nutrition recommendations for sheep, with an aim to verify the efficacy of different feeding standards. A total of 576 lambs (4 months of age, 28.3 ± 0.86 kg BW) were randomly allotted to 3 treatments with 12 replicates per treatment (16 lambs per replicate). The lambs were fed diets formulated according to the following 3 nutritional systems: the nutrient requirements of Dorper crossbred lambs established by Chinese Academy of Agricultural Sciences (CAAS), NRC (National Research Council), (2007), and AFRC (Agricultural and Food Research Council) (1993). The experiment lasted for 81 d. Feed intake was recorded every 3 days, and lambs were weighed every 20 days. Digestibility trials were conducted with 6 lambs each group from d 42 to 53 and d 70 to 81. At the end of the experiment, 10 lambs randomly chosen from each group were sacrificed to determine the carcass traits and meat quality. The results indicated that the lambs in the NRC group had the highest dry matter intake (DMI), followed by those in the AFRC and CAAS groups (P 0.05). In conclusion, Dorper crossbred lambs fed diets formulated according to the CAAS recommendations exhibited superior growth performance than those fed diets formulated according to the American or British feeding standards. Keywords: Feeding standard, Lamb, Requirement, Energy, Protein

A total of 144 cross-bred (Duroc × Landrace × Yorkshire) finishing pigs with a similar initial weight (65.4 ± 1.03 kg) were used to investigate the effect of moringa leaf meal on growth performance, meat quality, fatty acid composition, and amino acid profile. The moringa leaf meal-inclusion rates were 0% (M0 or control), 3% (M3), 6% (M6) and 9% (M9). The results showed that supplementing moringa leaf meal significantly increased the daily weight gain of finishing pigs, but had a minor impact on pork quality indicators and the amino acid profile in the Longissimus dorsi. The fatty acid profile in the Longissimus dorsi was significantly modified when pigs were fed moringa leaf meal diets. The relative percentage of total unsaturated fatty acid and monounsaturated fatty acid was higher in the meat of pigs fed a 6% moringa leaf meal diet than in the meat of those receiving the control diet. In contrast, the percentage of total saturated fatty acids was lower in the meat of pigs fed the moringa leaf meal diets. Moreover, the omega-6/omega-3 ratio decreased with moringa leaf meal supplementation. Addition of the moringa supplement into the diet of pigs improved growth performance and modified pork fatty acid profile positively. The results suggest that moringa leaf meal could be used as a diet supplement for producing healthier pork.

Objective This study was carried out to investigate the possible application of Broussonetia papyrifera (B. papyrifera) silage as a functional feeding stuff in dairy cattle. Methods Seventy-two Holstein cows were divided into four groups randomly and allocated to 6 pens with 3 individuals in each group and fed the original total mixed ratio (TMR) in the dairy farm or the new TMR with 5%, 10%, and 15% B. papyrifera silage, separately. Feed intake were recorded, milk and blood samples were collected, and milk composition, blood metabolites and milk fatty acids composition were measure at the end of the experiment. Results Dry matter intake of cows decreased when they fed on diet with B. papyrifera, but no differences were observed in body condition score, milk yield, milk protein and lactose, feed efficiency and serum metabolites between groups. Both 10% or 15% of B. papyrifera silage in the diet significantly increased the immunoglobulin A (IgA) and IgG in serum, 15% of B. papyrifera silage increased the content of serum catalase, superoxide dismutase, total antioxidant capacity, and decreased the content of 8-hydroxy-2′-deoxyguanosine. Furthermore, 10% or 15% of B. papyrifera silage resulted in a significant decrease in the milk somatic cell count, and increased the polyunsaturated fatty acids content in the milk. Conclusion The diets with 10% to 15% of B. papyrifera silage might enhance the immune and antioxidant function of dairy cows and increase the polyunstaturated fatty acid concentration in the milk.

Abstract Background The rumen bacterial community plays a critical role in feeds degradation and productivity. The effects of different forage to concentrate ratios on the ruminal microbial population structure have been studied extensively; however, research into changes in the ruminal bacterial community composition in heifers fed different energy level diets, with the same forage to concentrate ratio, has been very limited. The purpose of this study was to investigate the effects of different dietary energy levels, with the same forage to concentrate ratio, on ruminal bacterial community composition of heifers. Furthermore, we also determine the relationship between rumen bacteria and ruminal fermentation parameters. Results The 16S rRNA gene sequencing showed that, under the same forage to concentrate ratio of 50:50, an 8% difference in dietary energy level had no significant impact on the alpha diversity and the relative abundance of the major phyla and most of the major genera in heifers. In all the treatments groups, Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla. Spearman correlation analysis between the relative abundances of the rumen bacteria at the genus level and the fermentation parameters showed that the relative abundances of Prevotella and BF311 were positively correlated with the ammonia nitrogen and butyrate concentrations, and these two genera were negatively correlated with the propionate and isovalerate concentrations, respectively, and the genus Bifidobacterium was positively correlated with the butyrate concentration and was negatively correlated with propionate and isovalerate concentration. The total volatile fatty acid concentration was positively correlated with BF311 abundances, and was negatively correlated with Trichococcus and Facklamia abundances. Conclusions Under the same forage to concentrate ratio condition of 50:50, an 8% difference in dietary energy levels had little impact on rumen bacterial community composition in heifers. The correlations between some genera of ruminal bacteria and the concentrations of volatile fatty acids and ammonia nitrogen might be indicative that the ruminal fermentation parameters are strongly influenced by the rumen bacterial community composition.

Weaning affects the development of ruminal bacteria in lambs during early life. However, the temporal dynamics of rumen microbiota in early weaned lambs is unknown compared to conventionally weaned lambs. In this study, one group was reared with their dams (control, CON) and conventionally weaned at 49 days (d), while the other lambs were weaned at 21 d (early weaning, EW) using starter. Rumen microbial samples collected at 26, 35, and 63 d were used for next-generation sequencing. Here, we found that the abundance and diversity of rumen microbiota in EW were significantly lower at 26 and 35 d than the CON. Linear discriminant analysis Effect Size (LEfSe) analysis was performed to identify the signature microbiota for EW at these three ages. At 26 d, Prevotella 7, Syntrophococcus, Sharpea, Dialister, Pseudoscardovia, and Megasphaera in the rumen of the EW group had greater relative abundances. At 35 d, the Lachnospiraceae_NK3A20_group was enriched in CON. On 63 d, Erysipelotrichaceae_UCG-002 was abundant in EW. Syntrophococcus and Megaspheaera in EW lambs were abundant at 26 and 35 d, but kept similar to CON at 63 d. The relative abundance of Erysipelotrichaceae_UCG-002 at all-time points was consistently higher in the EW group. In conclusion, early weaning led to a significant decrease in rumen microbiota richness and diversity in the short term. The changes in rumen microbiota are associated with the persistence of weaning stress. The temporal dynamics of relative abundances of Syntrophococcus, Megasphaera, and Ruminococcaceae_UCG-014 reflect the weaning stress over a short period and rumen recovery after early weaning.

High-cost milk proteins necessitate cheaper, effective milk replacer alternatives, such as plant proteins. To examine plant protein-based milk replacer’s impact on growth performance, serum immune and antioxidant indicators, and liver transcriptome profiles in suckling calves. We assigned 28 newborn Holstein calves (41.60 ± 3.67 kg of body weight at birth) to milk (M) or milk replacer (MR) and starter diets pre-weaning (0–70 d of age) but with the same starter diet post-weaning (71–98 d of age). During the pre-weaning period, compared with the M group, MR group had significantly lower body weight, withers height, heart girth, average daily gain, feed efficiency, serum immunoglobulin (Ig) M concentration, superoxide dismutase concentration, and total antioxidant capacity; whereas they had significantly higher serum aspartate aminotransferase concentration. During the post-weaning period, MR group presented significantly higher average daily gain, alanine transaminase, aspartate aminotransferase, and malonaldehyde concentrations; whereas they had significantly lower serum IgA and IgM concentrations than the M group. Transcriptome analysis revealed 1, 120 and 293 differentially expressed genes (DEGs; MR vs. M group) in the calves from pre- and post-weaning periods, respectively. The DEGs related to xenobiotic and lipid metabolism and those related to energy metabolism, immune function, and mineral metabolism were up- and downregulated, respectively, during the pre-weaning period; during the post-weaning period, the DEGs related to osteoclast differentiation and metabolic pathways showed difference. In this study, compared with M group, MR group had the same growth performance during the overall experimental period; however, MR affected the hepatic metabolism, immune, and antioxidant function of calves. These observations can facilitate future studies on milk replacers.

Objective This study was conducted to investigate the effects of weaning times on the growth performance, rumen fermentation and microbial communities of yellow cattle calves. Methods Eighteen calves were assigned to a conventional management group that was normally weaned (NW, n = 3) or to early weaned (EW) group where calves were weaned when the feed intake of solid feed (starter) reached 500 g (EW500, n = 5), 750 g (EW750, n = 5), or 1,000 g (EW1,000, n = 5). Results Compared with NW, the EW treatments increased average daily gain (p0.05), but changes in bacterial composition were found. Conclusion From the present study, it is inferred that EW is beneficial for rumen fermentation, and weaning when the feed intake of the starter reached 750 g showed much better results.

Abstract The aim of this study was to investigate the effects of dietary supplementation with two alternatives to antibiotics (Candida tropicalis and mulberry leaf flavonoids) on intestinal microbiota of preweaned calves challenged with Escherichia coli K99. Sixty Holstein calves were randomly assigned to 5 treatments: fed a basal diet (N-CON); fed a basal diet and challenged with E.coli K99 (P-CON); fed a basal diet supplemented with C.tropicalis (CT), mulberry leaf flavonoids (MLF), and the combination of the two additives (CM), respectively, and challenged with E.coli K99. The MLF and CM groups had significantly higher average daily grain and feed efficiency, and significantly lower fecal scores compared with the P-CON group after E. coli K99 challenge. The supplementation groups increased the relative abundance, at the phylum level, of Bacteroidetes and Proteobacteria, whereas at the genus level, they increased the relative abundance of Prevotella, Lactobacillus, and Enterococcus. Quantitative PCR revealed that the CT, MLF, and CM groups had significantly lower copy numbers of E.coli K99 compared with the P-CON group. The CT, MLF, and CM treatments reduce days of diarrhea, improve intestinal health, and beneficially manipulate the intestinal microbiota in preweaned calves.

Abstract Background Dorper is an important breed for meat purpose and widely used in the livestock industry of the world. However, the protein requirement of Dorper crossbred has not been investigated. The current paper reports the net protein (NP) and metabolizable protein (MP) requirements of Dorper crossbred ram lambs from 20 to 35 kg BW. Methods Thirty-five Dorper × thin-tailed Han crossbred lambs weaned at approximately 50 d of age (20.3 ± 2.15 kg of BW) were used. Seven lambs of 25 kg BW were slaughtered as the baseline animals at the start of the trial. An intermediate group of seven randomly selected lambs fed ad libitum was slaughtered at 28.6 kg BW. The remaining 21 lambs were randomly divided into three levels of dry matter intake: ad libitum or 70% or 40% of ad libitum intake. Those lambs were slaughtered when the lambs fed ad libitum reached 35 kg BW. Total body N and N retention were measured. Results The daily NP and MP requirements for maintenance were 1.89 and 4.52 g/kg metabolic shrunk BW (SBW0.75). The partial efficiency of MP utilization for maintenance was 0.42. The NP requirement for growth ranged from 12.1 to 43.5 g/d, for the lambs gaining 100 to 350 g/d, and the partial efficiency of MP utilization for growth was 0.86. Conclusions The NP and MP requirements for the maintenance and growth of Dorper crossbred male lambs were lower than the recommendations of American and British nutritional systems.

Our objective was to investigate the effect of methionine restriction and resuming supply on liver antioxidant response in lambs. The concentrations of methionine and its metabolites and the expression of the nuclear factor erythroid 2-related factor 2 (Nrf2), a redox sensitive factor, were detected after methionine restriction treatment for 50 days and methionine supply recovery for 29 days. The expression of glutathione (GSH) S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were characterized at the level of transcription and translation. Methionine restriction can directly change the content of methionine and its metabolites in plasma and liver, and affect the redox state of lambs by activating the Nrf2 signaling pathway. Liver tissue can adapt to oxidative environment by upregulating the expression of antioxidant enzymes such as GSH-Px and SOD. Moreover, it was found that there was a lag effect in the recovery of metabolism after methionine supplementation.

Early microbial colonization in the gut impacts animal performance and lifelong health. However, research on gut microbial colonization and development in young ruminants, especially after weaning, is currently limited. In this study, next-generation sequencing technology was performed to investigate the temporal dynamic changes of the microbial community in the jejunum and colon of goats at 1, 7, 14, 28, 42, 56, 70, and 84 days (d) of age. As age increased, significant increases in microbial diversity, including the number of Observed OTUs and the Shannon Index, were observed in both the jejunum and colon. Regarding beta diversity, significant shifts in community membership and structure from d1 to d84 were observed based on both Bray–Curtis and Jaccard distances. With increasing age, dominant genera in the jejunum shifted from Lactobacillus to unclassified Ruminococcaceae, unclassified Lachnospiraceae and unclassified Clostridiales through starter supplementation, whereas colonic dominant genera changed from Lactobacillus and Butyricicoccus, within d1–d28, to unclassified Ruminococcaceae, unclassified Clostridiales and Campylobacter after solid diet supplementation. The linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed bacterial features that are stage-specific in the jejunum and colon, respectively. In the jejunum and colon, a significantly distinct structure and membership of the microbiota was observed across all ages. The growth stage-associated microbiota in each gut compartment was also identified as a marker for biogeography. Our data indicate the temporal and spatial differences of the gut microbiota in goats are important for their performance and health. Early microbial colonization can influence microbial composition in later life (e.g., post-weaning phase). This study provides insights that the temporal dynamics of gut microbiota development from newborn to post-weaning can aid in developing feeding strategies to improve goat health and production.

This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs. Forty-eight newborn Hu lambs (birth weight, 2.53 ± 0.14 kg) were randomly divided into 4 groups. The lambs in control group (ER) suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10, 20, and 30 days of age (EW10, EW20, and EW30 groups), respectively. The results were as follows: 1) lambs in EW10 and EW30 groups had a lower (P 0.05) among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower (P

As a new type of methane control agent, natural plant extract has been widely studied in recent years, but in vivo studies are few. This study was to investigate the effects of the dietary supplementation of 2 different polyphenols on the methane (CH4) emission and digestion metabolism in sheep. Ten healthy crossbred sheep (Dorper ♂ × small-tailed Han ♀; BW 60.0 ± 1.73 kg) were used in a change-over design. The sheep were fed the following 3 diets in the present study: the basal diet (CON) with no supplementation; the basal diet supplemented with 2 g mulberry leaf flavonoid (MLF) per day per sheep; the basal diet supplemented with 0.25 g resveratrol (RES) per day per sheep. Both MLF and RES reduced CH4 emission scaled to metabolic weight per kilogram of DMI and CO2 output scaled to metabolic weight, but the effect of RES was significant (P 0.05). In conclusion, MLF and RES can improve the digestibility of nutrients, the utilization of nutrients and energy, and reduce CH4 emission, but they are not conducive to nitrogen retention.

This study investigated the effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves. Fifty Chinese Holstein bull calves with similar BW and age were randomly allocated to 5 groups (1 control and 4 treatments) of 10 calves in each group. Five types of milk replacers were designed to have the same level of energy and protein. The protein source for milk replacers of the control group was full milk protein (MP). The protein source of milk replacers of the 4 treatment groups was composed of MP and one vegetable protein (VP) (30 and 70% of total protein). The 4 types of VP were soybean protein concentrate (SP), hydrolyzed wheat protein (WP), peanut protein concentrate (PP), and rice protein isolate (RP). Results of the experiment showed: 1) there was no significant difference on average daily gain (ADG) and feed:gain ratio (F:G) among the MP, SP and RP groups (P > 0.05), whereas the ADG and F:G of the WP and PP groups were significantly lower compared with the MP group (P 0.05). Thereby the 4 VP milk replacers had no adverse effects on body size of calves; 3) all groups showed no significant difference in the serum contents of urea nitrogen, total protein, albumin, globulin, β-hydroxybutyrate, growth hormone, insulin-like growth factor-1, and the ratio of albumin to globulin (A:G) (P > 0.05). In conclusion, SP or RP (accounts for 70% of the total protein) as calf milk replacers could substitute MP, whereas wheat gluten and PP had a significant adverse effect on growth performance in this experiment.

When Lambs are weaned off ewe's milk, metabolic, structural, and functional changes often occur in the small intestine. Because information on the effects of weaning stress on the proteome of the intestine is limited, an animal model was established with eight pairs of twin lambs divided into artificially reared and ewe-reared groups, which was followed by proteome analysis using iTRAQ technology. Changes occurred in the morphology of the intestine and 5,338 proteins in three biological replicates with less than a 1.2% false discovery rate were identified and quantified. Among them, a subset of 389 proteins were screened as significantly up- (143) and down-regulated (246) in artificially reared compared with ewe-reared. According to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, the differentially expressed proteins that were strongly down-regulated were enriched in immune system processes, biological adhesion, and metabolic processes. The up-regulated proteins were enriched in gene expression, cellular biosynthetic processes, ribosome and RNA binding in response to weaning stress. A series of proteins associated with intestine morphology and immune function were identified, and levels of the mRNAs encoding these proteins were analyzed by real-time quantitative reverse transcription PCR. The results of this study increased our understanding of the response of lambs weaned off ewe's milk and helped to determine the mechanisms underlying weaning stress.

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.