Animal Bioscience最新文献

Objective: The study aimed to assess how the additive from co-fermented edible plants and probiotics (AEPP) impacted growth performance, disease resistance, plasma and rumen metabolites, and bacterial communities in the rumen and feces of pre-weaned calves.

Methods: Twenty female Holstein calves (7 ± 0.50 d, 41.65 ± 6.20 kg) were randomly assigned to one of two treatments: the Control group or the Treatment group (30 g/head/day AEPP supplementation). Measurements of growth performance, blood, and fecal samples were regularly conducted. On day 30 of the trial, rumen fluid and fecal samples were collected for multi-omics analysis.

Results: Dietary supplementation with AEPP enhanced calf growth and improved disease resistance, as evidenced by a reduced incidence of respiratory disease and diarrhea, and a decreased frequency of antibiotic therapy (P < 0.05). The Treatment group exhibited enrichment of rumen microorganisms Prevotella, Ruminococcus, and Xylanibacter (LDA > 2, P < 0.05), along with increased activity in beneficial metabolites such as indoleacetic acid, which activated Starch and sucrose metabolism and Tryptophan metabolism pathway. This significantly improved average daily gain (ADG), feed efficiency, immunoglobulin G (IgG), total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px) activities, as well as significantly reduced levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) (P < 0.05), promoting calf growth and health. The elevated abundance of fecal microorganisms, Subdoligranulum and Bifidobacterium, in the Treatment group altered fecal pH, short-chain fatty acids, and butyrate proportions (P < 0.05).

Conclusion: Feeding AEPP improved growth performance, disease resistance, and antioxidant function. It altered the bacterial communities and metabolic profiles in the rumen and feces of preweaning dairy calves, providing a data reference for the use of AEPP in young ruminant production.

Objective: Mammary development and lactation are vital for piglet survival, but gene expression profiles from gestation to early involution in sows remain unclear. This study profiles key transcriptomic changes to reveal molecular features.

Methods: Mammary gland tissue samples were collected from hybrid half-sibling sows (Danish Landrace × Yorkshire) at five physiological stages: mid-gestation (MG), late gestation (LG), early lactation (EL), peak lactation (PL), and early involution (day 2 after weaning, W2). Transcriptome sequencing (RNA-seq) was performed on 30 samples (n=6 per stage). Differential expression analysis and clustering were conducted to identify expression patterns. Functional enrichment, pathway analysis, and weighted gene co-expression network analysis (WGCNA) were used to identify stage-specific regulatory networks and hub genes involved in mammary gland development, metabolism, immune response, and structural remodeling.

Results: Transcriptome profiling yielded over 61,000 expressed transcripts, with 27,244 shared across all stages. A total of 12,239 transcripts were differentially expressed, with the greatest transcriptomic shift occurring between PL and W2 (4,829 DETs). DETs were grouped into five expression clusters, each showing stage-specific enrichment in biological processes. W2-associated transcripts were enriched in pathways related to cell junction integrity and apoptosis, while MG and LG stages were associated with proliferation and metabolic pathways. EL and PL stages showed enrichment in immune and lipid metabolism pathways. WGCNA identified nine gene modules, with modules linked to gestational growth (brown, blue), lactation (green, turquoise), and involution (yellow, turquoise). Key regulatory genes such as EGF, AKT1, SRC, GATA3, STAT6, TNFSF11, and NFKB1 were identified as central hubs within six major functional networks.

Conclusion: This study constructed a time-resolved transcriptomic atlas of porcine mammary gland development, lactation, and involution, revealing gene expression dynamics, candidate pathways, and molecular signatures associated with structural and functional changes in the mammary gland, and providing potential targets and a theoretical basis for improving sow lactation performance and regulating mammary function.

Distillers' grains (DG), including wet (WDG), dried (DDG), and dried with solubles (DDGS), represent valuable coproducts for beef cattle feeding due to their high digestible energy, rumen-undegradable protein, and functional fiber content. This review integrates current knowledge on the nutritional, productive, environmental, and economic implications of DG use in feedlot systems across temperate and tropical regions. At moderate inclusion levels (15-30% of dietary dry matter), DG consistently enhance feed efficiency and reduce feeding costs without compromising growth performance or carcass traits. Their low starch concentration contributes to more stable ruminal fermentation and a lower risk of subacute acidosis compared with high-grain diets. Nevertheless, excessive ether extract and sulfur concentrations may depress fiber digestibility and increase the incidence of metabolic disorders such as polioencephalomalacia when diets are improperly formulated. Environmentally, DG improve resource efficiency by recycling ethanol coproducts and reducing reliance on conventional feed grains; however, their high nitrogen and phosphorus contents can elevate nutrient excretion and potential environmental load if not properly managed. Economically, DG enhance profitability for feedlots located near ethanol plants, though market volatility and transportation costs remain key constraints. Recent advances in coproduct processing and fractionation have mitigated several nutritional limitations, broadening the applicability of DG in precision feeding programs. Future progress will rely on refining nutrient characterization, optimizing phase-specific inclusion, and integrating DG within sustainable beef production frameworks. When strategically incorporated, DG serve as efficient, cost-effective, and environmentally responsible ingredients for modern beef production systems.

Objective: This study aimed to estimate non-genetic factors, variance components, and genetic parameters (heritability, genetic/phenotypic correlations) for birth weight (BW), weaning weight (WW), average daily gain (ADG), and Kleiber ratio (KR) traits of Dorper sheep under localized Chinese conditions.

Methods: Data from 2,022 Dorper sheep lambs (2019-2021) in Inner Mongolia Sano Sheep Breeding Co., Ltd. were analyzed. Traits included BW, WW (adjusted to 90 days), ADG, and KR. GLM (R 4.3.1) assessed non-genetic factors (recipient dam age, sex, birth year, month, herd). Six animal models were compared using ASReml's AIREML to determine the optimal model for genetic parameter estimation, with bivariate models analyzing genetic/phenotypic correlations.

Results: Recipient dam age, sex, birth year, month, and herd significantly affected all traits (P<0.05). Model 2 (direct additive genetic and maternal permanent environmental effects) was optimal. Heritability was low (BW: 0.0215; WW: 0.0287; ADG: 0.0391; KR: 0.0504). BW genetically correlated negatively with WW, ADG, and KR; WW showed strong positive genetic correlations with ADG (0.9952) and KR (0.9984), and high phenotypic correlations with them (0.9829 and 0.8819).

Conclusion: Low heritability limit direct selection for pre-weaning traits. Prioritizing WW enhances indirect genetic gains for ADG and KR, aiding the optimization of Dorper sheep breeding strategies under Chinese intensive systems.

Objective: The study aimed to evaluate the effects of varying blend ratios of dietary α-glycerol monolaurate (GML) and glyceryl tributyrate (TB) on growth performance, antioxidant capacity, and immune function in weaned piglets.

Methods: A total of 120 weaned piglets (Duroc × [ Landrace × Yorkshire], initial body weight 6.87 ± 0.15 kg, 28 days old) were assigned randomly to three treatments with five replicate pens per treatment for the 28-day experiment. The treatments consisted of a basal diet supplemented with 0.1% GML/TB blend at the following ratios:1) HM (higher GML; GML/TB=7:3); 2) BR (balanced ratio; GML/TB=1:1); 3) LM (lower GML; GML/TB=3:7).

Results: Dietary BR supplementation increased apparent total tract digestibility (ATTD) of crude protein and gross energy (GE, p<0.05) on day 14, and ATTD of GE on day 28 compared with other groups. Compared with LM group, piglets fed BR diet had higher (p<0.05) concentrations of alanine aminotransferase (ALT) and interleukin-1β (IL-1β) and lower (p<0.05) level of diamine oxidase on day 14, had higher (p<0.05) concentration of IL-1β and lower (p<0.05) concentration of IL-6 on day 28 in serum. Dietary BR supplementation increased (p<0.05) the ALT content, decreased (p<0.05) the IL-6 content on day 14 and AST and IL-1β contents on day 28, decreased (p<0.05) the IL-10 contents on day 28 in serum compared with HM group. Furthermore, dietary BR supplementation increased (p<0.05) the activities of glutathione peroxidase in duodenum, total antioxidant capacity in jejunum, and catalase in ileum. Compared with LM group, piglets fed another two diets had lower (p<0.05) level of malondialdehyde (MDA) in duodenum, jejunum, and ileum.

Conclusion: In conclusion, dietary supplementation with a 0.1% GML/TB blend (1:1) improves nutrient digestibility, enhances intestinal antioxidant capacity, modulates inflammatory responses, and supports overall health in weaned piglets.

Objective: This study aimed to investigate the relationship between colonic microbiota and estrous cycle transition in rabbits by integrating 16S rRNA gene sequencing and metabolomic analyses, and to identify key microbial taxa and metabolites involved in estrus regulation.

Methods: Female New Zealand white rabbits were divided into diestrus and early estrus groups based on vulvar mucosa color and serum estradiol (E2) concentration. Colonic microbiota dynamics were assessed via 16S rRNA sequencing, while metabolomes of colonic contents were profiled using UHPLC-MS/MS. Fecal microbiota transplantation (FMT) was performed by orally administration of colonic contents from diestrus or early estrus rabbits to mice with disrupted estrous cycles, to evaluate the regulatory effects of microbiota. Exogenous indole-3-acetic acid (IAA) was administered to both mice and rabbits to assess its role in estrus onset and cyclicity restoration.

Results: Colonic microbial composition differed significantly between diestrus and early estrus rabbits. The genera Anaerostipes and Ruminiclostridium were enriched in early estrus, while the genera Oscillospirales UCG_010 and UCG_005 were more abundant in diestrus. FMT from early estrus donors restored cyclicity in mice with disrupted cycles, whereas diestrus FMT did not. Metabolomics identified IAA as a key elevated metabolite in early estrus, and this metabolite accelerated estrus onset and restored cyclicity in both mice and rabbits.

Conclusion: These findings demonstrate that gut microbiota restructuring regulates the estrous transition of rabbits, providing a basis for developing microbiota-targeted strategies to enhance reproductive efficiency in rabbit production and optimize animal reproductive management.

Objective: To evaluate the effects of four processing methods: intact corn (IT), ground corn (GD; ground to 2 mm), steam-flaked corn (SF; steamed at 85-100°C for 90 min and flaked to 2.5 mm thickness), and whole steamed corn (WS; steamed at 85-100°C for 90 min without flaking), on growth performance, digestibility, blood biochemistry, rumen microbiota, carcass traits, and meat quality in fattening lambs.

Methods: Eighty-four male crossbred lambs (Small tailed Han × Northeastern Fine wool; 4.5 months; 34.2 ± 3.5 kg) were blocked by stratifying body weight and then randomly assigned to four treatments (n=21), each with 50% (as-fed) corn in the diet. In GD and WS treatments, corn was pelleted with other ingredients; in IT and SF treatments, corn was fed separately alongside non-corn pellets at a 1:1 (as-fed) ratio. After a 14 d adaptation period, lambs were fed for 60 d. Body weights were recorded on d 0, 30, and 60; blood samples were collected on d 31 and 60; and rumen fluid was sampled on d 35. Apparent total tract digestibility was determined by total fecal collection in a subset of lambs, and six lambs per treatment were slaughtered for carcass evaluation.

Results: Lambs fed the WS diet showed the greatest average daily gain (ADG) at 319 g/d, improving 22%, 24%, and 7% over GD (261 g/d), SF (257 g/d), and IT (298 g/d) diets, respectively (p=0.013). Dry matter intake did not differ significantly among treatments (p=0.307), though WS, GD, and IT numerically exceeded SF by 6.7%-10.8%. Apparent total tract dry matter digestibility was greatest in SF (74.1%) and WS (72.1%), exceeding GD (69.3%) and IT (66.3%; p=0.001) for the overall diet. Corn processing also altered rumen microbiota: WS tended to increase Erysipelotrichaceae_UCG 002 abundance sixfold over IT, SF enriched Actinobacteria, and IT uniquely harbored minor phyla such as Acidobacteriota. Hot carcass weight tended to be higher in WS (18.4% over GD; p=0.078), while heart and kidney indices were greater in IT and SF (p<0.05). Meat quality parameters were not significantly affected by corn processing.

Conclusion: Whole steamed corn enhanced growth performance, likely associated with improved starch utilization and modulation of the rumen microbiota, without compromising meat quality. Compared with grinding or flaking, steaming corn kernels provided a practical and energy-efficient approach, yielding 22%-24% higher ADG. Further research should refine steaming conditions and evaluate the economic viability of this method.

Objective: This study aimed to investigate the effect of dietary glycine (Gly) and betaine (Bet) on productive performance, egg quality, liver health, intestinal characteristics, and stress response in aged laying hens under heat stress (HS) conditions.

Methods: A total of 384 aged laying hens were allotted to 1 of 4 dietary treatments in a completely randomized design with a 2 × 2 factorial arrangement, including 2 supplemental levels of Gly (0 and 0.65%) and Bet (0 and 0.20%) in diets. Each treatment had 8 replicates. All hens were exposed to a cyclic HS condition at 31.7 ± 1.7°C for 8 hour/day and 27.2 ± 1.3°C for the remaining time during a 12-week feeding trial.

Results: No main and interactive effects of dietary Gly and Bet supplementation were identified for productive performance and egg quality in aged laying hens under HS conditions. However, for the main effects, Gly supplementation decreased liver color score (p < 0.01) and malondialdehyde (MDA) levels (p < 0.05), while Bet supplementation also decreased liver MDA levels (p < 0.05). An improvement in intestinal barrier function (p < 0.01) and a decrease in feather corticosterone concentrations (p  < 0.01) were observed by individual and combined supplementation of Gly and Bet. However, combined supplementation of Gly and Bet showed no synergistic benefits over individual supplementation.

Conclusion: Dietary supplementation of 0.65% Gly and 0.20% Bet improved liver health, intestinal barrier function, and reduced stress responses in aged laying hens under HS conditions with little interactive effects of their combined supplementation.

Objective: Peanut vine is a widely available agricultural byproduct with high nutritional value, but its utilization is limited by poor ensiling characteristics. This study aimed to improve the fermentation quality of peanut vine silage using lactic acid bacteria (LAB), compound enzymes, and molasses, applied individually and in combination, and to evaluate their effects on growth performance and metabolic indicators in fattening Hu sheep.

Methods: Peanut vine was treated with different levels of LAB, enzymes, and molasses to determine optimal dosages. The optimal combination of 2 g/t LAB, 200 mL/t enzyme preparation, and 10 kg/t molasses was identified based on fermentation characteristics. Treatments included a control (no additive), single additives, and the combined treatment. After 60 d of ensiling, silage pH, lactic acid, ammonia-N, fiber degradation, and bacterial community structure were analyzed. A 56 d feeding trial was subsequently conducted with 56 Hu sheep (28.4±1.3 kg), randomly assigned to two groups: peanut vine hay and peanut vine silage. Growth performance and serum biochemical indices were evaluated.

Results: The optimized additive combination significantly improved fermentation by reducing pH (from 4.74 to 4.36), ammonia-N/total nitrogen (from 2.82 to 1.50% DM) and detergent fiber contents (neutral detergent fiber from 43.9 to 41.3% and acid detergent fiber from 34.6 to 32.2%), while increasing lactic acid concentration (from 3.55 to 5.00% DM). Microbial analysis revealed a higher relative abundance of Lactobacillus plantarum and increased microbial diversity. In the animal trial, no significant differences were found in average daily gain, dry matter intake, or feed conversion ratio between groups. However, sheep fed silage showed lower blood urea nitrogen and higher serum triglyceride concentrations, indicating improved nitrogen and lipid metabolism.

Conclusions: Peanut vine silage supplemented with LAB, enzymes, and molasses enhances fermentation quality and supports comparable growth performance to hay while improving nutrient metabolism in fattening Hu sheep.

Objective: Larger body size and enhanced reproductive performance correlate with increased profitability for sheep farmers. Notably, Hu sheep have smaller statures compared to other meat sheep breeds, necessitating improvement. Moreover, the molecular mechanisms underlying the high fecundity of Hu sheep remain unclear. Body size and reproductive traits are economically important traits in Hu sheep production, and further research is required.

Methods: To address this, we directly measured the body size (body weight, body height and length, chest circumference and cannon bone circumference) traits of 558 Hu sheep, and statistically recorded their reproductive (litter size and teat number) traits. Using mixed linear model, candidate genes for these traits were identified through genome-wide association study (GWAS). The significant single nucleotide polymorphism (SNP) threshold was determined using a 1000 permutation test. Subsequently, functional annotations were conducted on the candidate genes.

Results: We identified a key candidate gene (CHST3) affecting the body size and two key candidate genes (SCMH1 and BAZ2B) influencing reproductive traits in Hu sheep. The CHST3 affected multiple body size traits and was highly expressed in the muscle tissues of Hu sheep. The SCMH1 and BAZ2B were significantly annotated by GWAS and selection signature, and they were highly expressed in the reproductive system of Hu sheep. Furthermore, through a phenome-wide association study (PheWAS) in humans, we found that these key candidate genes were significantly associated with similar traits in humans.

Conclusion: This is the first evidence linking these genes to body size and fecundity in Hu sheep. These findings provide genetic markers for selective breeding, and contribute to the selection of high-quality breeding sheep.