Animal Bioscience最新文献

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.

Objective: Accurate early prediction of final body weight (BW) is essential for optimized feeding strategies and slaughter planning in beef cattle production. This study evaluated the performance of three machine learning models (k-nearest neighbors, Random Forest, eXtreme Gradient Boosting), and one deep learning model [long short-term memory (LSTM)] to forecast the final BW of Hanwoo steers at various time points prior to slaughter.

Methods: A total of 196 Hanwoo steers (7 to 31 months of age) from a commercial farm were utilized. Input data included monthly BW and feed nutrient intake (crude protein, ether extract, neutral detergent fiber, total digestible nutrients) across three growth stages. Six input configurations (I1-I6) were designed to predict the final BW at 17, 13, 9, 6, 3, and 1 month(s) before slaughter, with a target age of 31 months. The machine and deep learning models were assessed by five-fold cross-validation (training set) and a test set and evaluated via the coefficient of determination (R²) and root mean squared error (RMSE).

Results: Among the tested models, the LSTM achieved the highest prediction accuracy across all the configurations. The performance of the LSTM improved as the prediction point approached the target slaughter age: I1 (R² = 0.60, RMSE = 52.80), I2 (0.72, 45.40), I3 (0.76, 40.92), I4 (0.83, 35.84), I5 (0.90, 33.12), and I6 (0.97, 22.62).

Conclusion: These results demonstrated that LSTM effectively captured temporal dependencies in sequential data, enabling more accurate BW forecasting under commercial conditions. While I6 achieved the highest prediction accuracy, the 3-6 month predictions (I4 and I5) demonstrated reasonably high accuracy, which could provide a practical timeframe for farm-level management and planning. This approach could be utilized in evidence-based decision-making in Hanwoo production by providing reliable predictions well ahead of slaughter.

Purpose: This study evaluated the effects of reducing crude protein (CP) and supplementing arginine plus glutamine-glutamate on growth performance, diarrhea incidence, blood metabolites, amino acid profiles, nutrient digestibility, and nitrogen (N) utilization in nursery pigs.

Methods: A total of 200 piglets (20 d of age; 4.8±0.58 kg) were allotted to 5 diets in a randomized block design: 22.5, 21.0, 19.5, or 18.0% CP, and 18.0% CP supplemented with 5 g/kg L-arginine and 10 g/kg L-glutamine+glutamate. Pigs were fed in two phases (20-32 and 32-44 d of age) over a 24-d period.

Results: Reducing CP linearly decreased average daily gain and worsened feed efficiency, with the lowest performance observed in pigs fed the 18.0% CP diet with arginine and glutamine-glutamate. Serum urea N and gamma-glutamyl transferase increased linearly with CP level. Plasma arginine and ornithine were elevated by supplementation. Methionine, threonine, and valine were highest in pigs fed 18.0% CP diets. In contrast, phenylalanine and tyrosine declined with reduced CP. Diarrhea incidence and fecal scores were greater in pigs fed 22.5% CP, with each 1% CP increase raising diarrhea incidence by 3.55% points. Digestibility of protein and energy improved with increasing CP, and pigs fed 22.5% CP showed the greatest N absorption but also higher fecal N excretion.

Conclusion: Collectively, results indicate that reducing CP from 22.5 to 18.0% compromises growth and nutrient digestibility, even when supplemented with arginine and glutamine-glutamate, but lowers diarrhea incidence and N output. These findings highlight trade-offs between growth efficiency, gut health, and environmental sustainability in nursery pig nutrition.

Objective: This study aimed to elucidate the mechanisms underlying milk composition divergence between naks (female yaks) and Simmental cows (S-cows) by integrating longitudinal multi-omics analyses of gut microbiota and metabolomes.

Methods: We determined the gut microbiota and metabolites of both species over a 54-day period (day 26 to 80 of lactation) of ten naks and ten S-cows. Gut microbiota dynamics were assessed via 16S rRNA sequencing, while serum and fecal metabolomes were profiled using ultra-high performance liquid chromatography-tandem mass spectrometry. Statistical analyses included Wilcoxon rank-sum tests, linear discriminant analysis effect size (linear discriminant analysis>2, p<0.05), and Spearman correlations (r>0.70).

Results: Milk yield was lesser (0.53-0.91 vs. 2.07-3.88 kg/d) but concentrations of fat (5.63%-6.30% vs. 3.30%-3.74%), protein (5.66%-6.30% vs. 3.39%-3.74%), and conjugated linoleic acid (CLA) (1.74%-2.35% vs. 1.40%-1.75%) were greater (p<0.001) in nak than Scow milk. Species-specific microbial signatures emerged. In naks, the g-Family-XIIIAD3011-group and g-norank-Ruminococcaceae were correlated with bile acid metabolism and CLA synthesis via 13-hydroxyoctadecadienoic acid transport. Additionally, the naks gut had a greater concentration of 13-hydroxyoctadecadienoic acid, a precursor of CLA, which may be transported to mammary cells via phosphatidylcholine and converted to CLA under the catalysis of fatty acid desaturase2. S-cows harbored g-Succinivibrio and g-Eubacterium-ruminantium-group, which are linked to galactose utilization and mTORmediated amino acid allocation. Metabolomics revealed naks-enriched steroid biosynthesis and taurine pathways (false discovery rate<0.05), while S-cows exhibited a lactating network associated with greater milk yield.

Conclusion: Host-specific gut microbiota mediated nutrient allocation trade-offs. Naks optimized lipid-rich milk through bile acid and CLA metabolic networks, whereas S-cows enhanced yield via microbial-galactose synergies. This research underscores the pivotal role of the gut microbiome in mediating milk composition and suggests that microbiome manipulation could be a promising strategy to enhance milk quality in ruminants.

Objective: The objective of this study was to delineate the genetic architecture of ileal amino acid digestibility in Duroc×(Landrace×Yorkshire) hybrid (DLY) pigs through genomewide association study (GWAS). The goal was to identify associated single nucleotide polymorphisms (SNPs) and candidate genes to inform precision breeding strategies for enhanced nutrient utilization and environmental sustainability.

Methods: We conducted a GWAS on 600 DLY pigs to identify genetic markers associated with ileal amino acid digestibility, employing the GGP Porcine 50K SNP Chip and analyzing fifteen amino acid digestibility traits. GLM and FarmCPU-based GWAS approaches were utilized to detect SNP associations, followed by gene annotation to identify candidate genes near significant SNP loci.

Results: We identified two SNPs, chr3:33019982 and Chr17:34715741, significantly associated with the digestibility of multiple amino acids. SNP chr3:33019982 was linked to threonine, leucine, histidine, proline, and arginine digestibility, while Chr17:34715741 was associated with arginine. Gene annotation revealed Trans-Golgi network vesicle protein 23 homolog A (TVP23A) and Synapse differentiation-induced gene I (SynDIG1) as potential candidates for amino acid metabolism in the terminal ileum.

Conclusion: Our study identified key SNPs and genes linked to amino acid digestibility in DLY pigs, specifically highlighting the pleiotropic effects of the SNP WU_10.2_3_33019982 and the potential roles of TVP23A and SynDIG1 genes. These findings contribute to the molecular breeding of DLY pigs for improved amino acid utilization and provide insights into the genetic control of this trait.

Objective: This study aimed to explore the effects of spray-dried porcine plasma (SDPP) in pre-starter feed of piglets on performance, fecal consistency, gut integrity biomarkers, and gene expression patterns related to intestinal function.

Methods: Ninety piglets (18 pens; 5 pigs/pen; 8.16±1.29 kg initial body weight) were offered pre-starter feed with either soy protein concentrate (control) or SDPP for 14 d postweaning, and a common commercial starter feed between 14 and 35 d. Pigs' performance was recorded at 0, 7, 14 and 35 d of trial and their fecal consistency was assessed on the first 2 weeks. At 7 d, one piglet per pen (18 in total) was sampled for blood, intestinal mucosa, and bile. Blood serum calprotectin and citrulline and bile sIgA were quantified with ELISA, and gene expression in the mucosa from ileum, jejunum, and caecum was analyzed with high-throughput microfluidic technology.

Results: Relative to control, SDPP improved feed intake (215 vs 280 g/d; p<0.05), weight gain (133 vs. 205 g/d; p<0.05) and gain-to-feed ratio (0.61 vs. 0.74; p<0.05) between d 0 to 7. Serum calprotectin and citrulline, and bile sIgA at d 7 were not affected. Piglets fed SDPP had higher expressions of IL-1β (p = 0.033) in jejunal mucosa, and of IL-1β (p = 0.018), IL-8/CXCL8 (p = 0.010), GBP1 (p = 0.014) and TGF-β1 (p = 0.015) in ileal mucosa, at 7 d post-weaning. No effects on fecal scores were observed.

Conclusion: It is concluded that the administration of SDPP during the pre-starter phase improves piglet's performance during the first week post-weaning. These SDPP associated benefits appear to have been achieved through the modulation of gut homeostasis, potentially involving the regulation of inflammatory factors in the small intestinal mucosa.

This study aimed to investigate the transition towards sustainable livestock farming, emphasizing the role of policy instruments, challenges in implementation, and future directions. There are many ways to help move towards sustainable livestock farming. The primary methods in major Organization for Economic Co-operation and Development (OECD) countries are regulation, economic incentives, and supportive measures. The most important tools are regulation and financial support. This study looked at the effectiveness of these tools, the role of government in supporting sustainable livestock, and ways to improve these policies. It also discussed using smart technology for sustainable farming, introducing a certification system for sustainable livestock products, increasing public interest and willingness to pay for sustainable products, training future experts, and creating partnerships between the public and private sectors. The study concluded that effective policy implementation requires a combination of regulation and support. Necessary regulations should be applied with enough time and agreement from society, even if the livestock industry opposes. Support policies are currently scattered and not well-connected, so they need to be comprehensively linked to sustainable livestock farming. It is important to have a consistent policy system that sets measurable goals, provides budget support, and evaluates performance step by step to achieve the goal of sustainable livestock farming in South Korea.