Animal Bioscience最新文献

Objective: Navel orange residue (NOR) is considered to improve the silage quality of whole-plant mulberry (WPM) because of its high water-soluble carbohydrate (WSC) content. In order to investigate the mechanism underlying NOR regulated WPM silage quality, the chemical composition, fermentation quality, bacterial community and in vitro digestibility of WPM and NOR mixed silages were analysed.

Methods: WPM and NOR were mixed at ratios of 10:0 (MCK), 7:3 (M7O3), 5:5 (M5O5), and 3:7 (M3O7) on a dry matter (DM) basis. Samples were collected after 15, 30 and 45 days of ensiling to study their chemical composition, fermentation quality, bacterial community and in vitro digestibility. The optimal treatment was identified through membership function analysis.

Results: In comparison with MCK, incorporating 30-70% NOR ensiled for 15-45 days significantly increased DM, WSC, lactic acid, and acetic acid (AA) contents (p<0.05). At the same time, it resulted in a significant decrease in the levels of crude protein, neutral detergent fiber, acid detergent fiber, pH, and NH3-N (p<0.05). The NOR addition encouraged the beneficial heterofermentative species Lactobacillus pontis, Lactobacillus panis, and Lactobacillus buchneri, whilst preventing unfavourable microorganisms (p<0.05). In addition, in vitro rumen fermentation analysis demonstrated that adding 30-70% NOR and ensiling for 15-30 days markedly increased in vitro dry matter digestibility, gas production, total volatile fatty acids, AA, and propionic acid (PA) (p<0.05), along with a significant decrease in the AA/PA ratio (p<0.05). M3O7 ensiled for 15 days and M5O5 ensiled for 30 days achieved high membership function values of 0.839 and 0.732, respectively.

Conclusion: Co-ensiling WPM with 30-70% NOR for 15-45 days significantly enhanced fermentation quality, improved bacterial diversity, and increased in vitro digestibility. Overall, the optimal strategies for producing high-quality silage are co-ensiling WPM with either 70% NOR for 15 days or 50% NOR for 30 days.

Objective: Heat stress adversely affects feed intake, milk production, and overall reproductive performance. One suggested nutritional strategy to mitigate these adverse effects is the optimization of dietary electrolyte balance (dEB) with bicarbonate supplementation, which regulates acid-base homeostasis and thermoregulatory responses. This study aimed to evaluate the effects of different dEB levels on lactating sow reproductive performance during heat stress.

Methods: A total of 40 lactating sows were assigned to four dietary treatments with varying dEB (mEq/kg) levels (230: sodium chloride 0.47%; 250: sodium chloride 0.34%+sodium bicarbonate 0.14%+potassium bicarbonate 0.05%; 270: sodium chloride 0.25%+sodium bicarbonate 0.26%+potassium bicarbonate 0.09%; 290: sodium bicarbonate 0.52%+potassium bicarbonate 0.13%) to evaluate the effects on reproductive performance, hair cortisol, the acid-base balance, inflammation, gut integrity, behavior, and intestinal microbiota of lactating sows during heat stress.

Results: Increasing dietary dEB levels during heat stress (temperature: 26.0-31.1 °C; temperature to humidity index: 78-84) linearly increased average daily feed intake of sows during lactation and improved piglet weaning weight. Blood pH decreased linearly with rising dEB levels, while hair cortisol content showed a decreasing trend. IL-1β tended to decrease with increasing dEB levels, and IL-10 showed a trend to a quadratic peak at 250 mEq/kg before declining. Behavioral analysis showed a quadratic response in standing behavior, peaking at 250 mEq/kg, while position changes decreased linearly with increasing dEB. Beta diversity analysis revealed differences in unweighted UniFrac Principal Coordinate Analysis between 230 and 290 mEq/kg dEB groups. The abundance of the actinobacteriota phylum tended to decrease linearly, however, the abundance of major phyla including the firmicutes and bacteroidota was unaffected.

Conclusion: In conclusion, increasing dietary dEB from 230 to 270-290 mEq/kg with bicarbonate supplementation improved feed intake and piglets weight at weaning, suggesting that a dEB around 270 mEq/kg is optimal for supporting sow reproductive performance under heat stress.

Objective: Rising poultry feed costs and shortages in Southeast Asia, particularly in Thailand, underscore the need for sustainable alternatives. This study evaluated shrimp meal (SM), a protein-rich byproduct, and yam bean (YB), an underutilized energy-rich root crop, as promising alternative feed ingredients for laying hens.

Methods: An in vitro analysis was conducted to determine the chemical composition and digestibility of diets containing SM and varying levels of YB. An 8-week in vivo trial was conducted using 90 ISA-Brown hens (25-week-old), divided into nine dietary groups: one control and eight treatment groups with 10% or 15% SM combined with 0%, 3%, 6%, and 9% YB. Laying performance, egg quality and composition, and nitrogen (N) retention were assessed.

Results: SM was rich in protein, while YB contained high nitrogen-free extracts and gross energy, supporting their use as alternative protein and energy sources, respectively. The inclusion of SM and YB had no negative effect on in vitro dry matter or protein digestibility. In vivo, combined inclusion of up to 15% SM and 9% YB did not adversely affect laying performance, egg quality, nutrient composition, or N retention compared to the control. Main effect analysis revealed that SM significantly enhanced yolk color, eggshell weight, and eggshell thickness, while reducing egg fat content. Although higher levels of SM were independently associated with reduced hen-day egg production and egg mass, these effects were mitigated when SM was combined with YB, resulting in no significant differences from the control group at the highest inclusion levels (15% SM and 9% YB).

Conclusion: SM and YB are viable, eco-friendly alternatives to conventional poultry feed ingredients. Their combined inclusion, up to 15% SM and 9% YB, is recommended to maintain laying performance and egg quality while promoting sustainable feeding practices through the utilization of processing byproducts and underutilized local crops.

Objective: The Licha Black pig (LC) is a nationally protected Chinese indigenous breed known for its superior meat quality and strong environmental adaptability. However, its population has declined rapidly due to extensive crossbreeding with commercial lines. Understanding the genetic basis of its economically important traits is crucial for conservation and genomic improvement.

Methods: Whole-genome resequencing was performed on 120 LC pigs and combined with genomic data from 285 pigs representing 32 global populations, including wild boars, commercial breeds, and other Chinese indigenous pigs. Population structure was investigated using phylogenetic trees, PCA, ADMIXTURE and TreeMix analysis. Selection signatures were identified through four complementary approaches (FST, θπ ratio, XP-CLR, and Tajima's D). Candidate genes were examined by functional enrichment analysis, protein structure prediction, and cross-referencing with trait association and tissue-specific expression databases. Phenotypic data on body size and teat number were also collected in LC pigs for targeted genotype-phenotype analysis.

Results: Phylogenetic analyses showed clear stratification among global pig populations, with Chinese indigenous breeds broadly separated by the Qinling-Huaihe Line. LC pigs formed a distinct genetic cluster between northern Chinese and European breeds. Selective sweep analyses revealed several candidate genes under positive selection, including SOCS6 and ATP2B4 (skeletal muscle development), RASAL2 (adipogenesis), and DOCK2 (male fertility). Trait-focused analyses identified ZNRF3 as a major locus for body size, with a missense mutation (g.46228935G>A; Gln→Arg) predicted to influence Wnt/β-catenin signaling. Signals of selection in ADGRB3, a gene potentially involved in teat patterning and mammary gland vascularization, were associated with variation in teat number.

Conclusion: Our comprehensive genomic analyses provide new insights into the genetic architecture underlying economically important traits and environmental adaptation in the LC. These findings establish a foundation for genomic-informed selective breeding and offer valuable molecular tools for the genetic improvement and sustainable utilization of this indigenous genetic resource.

Genomic selection (GS) has become an indispensable tool in the beef cattle industry, offering the potential to significantly increase genetic gain and prediction accuracy by integrating genomic, pedigree, and phenotypic information to estimate genomic breeding values. In the Korean Peninsula, Hanwoo cattle (HC) are valued for their exceptional marbling and distinct flavour. Thus, genetic improvement breeding programs for Hanwoo have been undertaken to improve beef production and profitability, with a particular focus on carcass and meat quality traits. The success of a breeding program incorporating genomic information in HC largely depends on prediction accuracy, making genomic prediction (GP) essential for accelerating genetic gain. Hence, breeders should acknowledge the superiority of GS and choose the most suitable prediction model depending on the genetic architecture and biological nature of the trait of interest. Several GP methods have already proven their ability in terms of carcass and meat quality traits over the traditional pedigree-based best linear unbiased prediction (PBLUP) method. Therefore, there are no alternative approaches to GS for breeders to accelerate the innovative development of Hanwoo beef cattle. Thus, the main objective of this review is to provide an overview of how GP methods are being applied to improve the ultimate meat quality of HC. Furthermore, this review presents the transversal analysis of interest in GS for Hanwoo breeders when choosing the best prediction method for specific traits. We believe this review literature would be a significant resource for future exploitation of Hanwoo's potential in the Korean beef industry.

Objective: Pelleted feed has multiple advantages in animal production, but its hardness may limit the intake of young lambs with underdeveloped teeth and digestive systems, especially when the feed contains alfalfa and is produced with a high compression ratio in small diameters. This study aimed to evaluate the effects of removing alfalfa from starter feed or post-pelleting crumbling on lamb performance. We hypothesized that crumbling pelleted feed could reduce hardness, thereby increasing intake and enhancing performance.

Methods: A total of 118 healthy, 7-day-old Hu lambs (4.02±0.94 kg) were allocated to three groups: (1) a pelleted starter with alfalfa (CON), (2) a non-alfalfa pelleted starter (NA), and (3) a crumbled starter with alfalfa (CA). Feed intake, growth performance, nutrient digestibility, and rumen microbial composition were measured.

Results: The CA group demonstrated significantly reduced pellet hardness than the CON and NA groups (p<0.05), while NA group had higher starch gelatinization (p<0.05). CA notably increased feed intake, particularly after day 21 (p<0.05), and achieved the highest overall intake, body weight and average daily gain from days 7-49. The interaction between feed type and sex had significant impacton the digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF). In male lambs, both NA and CA groups demonstrated significantly higher digestibility of NDF and ADF compared to the CON group (p<0.05). Rumen microbiota diversity was influenced by feed composition more than pellet form, with alfalfa inclusion affecting a greater number of microbial genera. Crumbling increased the abundance of Methanobrevibacter (p<0.05).

Conclusion: These findings suggest that post-pelleting crumbling using a roller mill enhances feed intake and growth performance in young lambs, while feed composition plays a predominant role in shaping rumen microbial diversity.

Objective: Precocious puberty can shorten reproductive cycles, enhance reproductive capacity, and reduce feeding costs. Consequently, precocious livestock are widely utilized in cross-breeding. This study aims to elucidate the key molecular mechanisms by which circular RNA (circRNA) regulates the sexual maturation of sexually precocious goats.

Methods: In this study, we analyzed the circRNA expression profiles of hypothalamic tissue from Jining grey goats at four distinct postnatal developmental stages (1 day, 2 months, 4 months, 6 months).

Results: A total of 23,993 circRNAs were identified across these stages, predominantly derived from exonic regions, with 1,052 circRNAs exhibiting differential expression. Additionally, competitive endogenous RNA (ceRNA) analysis suggested that novel_ circ_0002274/chi-miR-197-5p/ estrogen receptor 1 (ESR1) and novel_circ_0002274/chimiR-30c-3p/oxytocin/neurophysin I prepropeptide (OXT) may regulate sexual maturation in goats via the estrogen signaling pathway and the oxytocin signaling pathway.

Conclusion: This study contributes to understanding the function of circRNAs in hypothalamic regulation of sexual maturation and provides valuable insights for breeding superior goat breeds.

Objective: This study aimed to elucidate how dietary energy levels regulate the hypothalamic-pituitary-gonadal axis in Holstein heifers during initial breeding, with a focus on rumen microbiota-host interactions.

Methods: Forty-four pubertal heifers (398.96±6.56 kg BW, 12.72±0.02 months) were stratified by body condition score and estrous cyclicity, then randomly allocated to control (CON, 8.64 MJ/kg DM NEL) or high-energy (HE, 9.50 MJ/kg DM NEL) diets (n = 22/group). Although practical constraints limited pen replication, we implemented rigorous matching procedures: Pens were matched for surface area (120 m2), feed bunk space (0.8 m/head) and growth performance, serum biochemical/immune/antioxidant markers, reproductive hormones, rumen fermentation parameters, microbiota, and metabolome profiles were analyzed.

Results: The HE group exhibited elevated gonadotropins (follicle-stimulating hormone, luteinizing hormone [LH]) and prolactin (PRL), indicating enhanced hypothalamic-pituitary activity. Serum triglycerides increased, while immune markers showed the altered state of immunoregulation characterized by significant increases in interleukin (IL)-2 and IL-6, reductions in IL-4, and decreases in tumor necrosis factor-α and interferon-γ. Antioxidant capacity improved with lower malondialdehyde levels. Rumen pH decreased, accompanied by elevated total volatile fatty acid, bacterial crude protein, acetic acid, propionic acid, butyric acid, and valeric acid concentrations. Microbial shifts included Treponema and Prevotellaceae_UCG_003 showing positive correlations with PRL and LH, while Ruminococcus was associated with acetyl-CoA precursors through enriched pyruvate metabolism.

Conclusion: HE diets (9.50 MJ/kg NEL) enhance hypothalamic-pituitary signaling and rumen fermentation efficiency, advancing first-service conception rates by 15% (55% vs. 70%) in pasture-based systems. This strategy optimizes reproductive management in intensive dairy operations through microbiota-driven metabolic modulation.

Objective: This study aims to reveal the transcriptional regulatory mechanism and effects of poly(A)-binding protein nuclear 1 (PABPN1) on adipogenesis, along with associated polymorphisms.

Methods: Transcription factors were identified using dual-luciferase reporter assay, overexpression techniques site-directed mutagenesis, real-time quantitative polymerase chain reaction (qPCR), electrophoretic mobility shift assays and chromatin immunoprecipitation-qPCR. Preadipocyte differentiation was measured with gain- and loss-of-function, Oil Red O staining and extraction assays. Single nucleotide polymorphisms (SNPs) were identified with direct sequencing of PCR products in the promoter, and the effects of these SNPs on PABPN1 expression were identified with dual-luciferase reporter assay.

Results: CCAAT/enhancer-binding protein (C/EBP) α and β regulate PABPN1 expression by directly binding to its promoter. PABPN1 promotes the preadipocyte differentiation in pigs. Three SNPs were identified, with the Haplotype GCC mutation significantly increasing the promoter activity of PABPN1.

Conclusion: PABPN1 promotes the preadipocyte differentiation as a downstream gene of C/EBP α and β. Haplotype GCC may serve as a molecular marker for selection of fat traits in pigs.

Objective: The objective was to evaluate the effects of replacing soybean meal (SBM) with enzyme-treated soy oligopeptide (ESO) in nursery pig diets on intestinal health, growth performance, and feed preference.

Methods: In Exp. 1, 128 pigs (average 5.2 kg) were housed in pens (4 pigs/pen), assigned to 4 diets supplemented with 0%, 1%, 2%, or 3% of ESO, and fed for 32 d. On d 32, blood, tissues, and mucosa from the duodenum and jejunum were collected. In Exp. 2, 24 pigs (average 6.2 kg) were assigned to 6 pens (4 pigs/pen). Each pen had two separate feeders containing two diets with 0% or 2% of ESO for 27 d.

Results: Increasing dietary ESO tended to quadratically change serum tumor necrosis factor-α (p = 0.059; minimum at 1.6% of ESO) and duodenal villus height to crypt depth ratio (p = 0.062; maximum at 1.8% of ESO). Increasing dietary ESO linearly reduced feed intake both linearly and quadratically (p<0.05) during phase 2 (maximum at 0.9% of ESO). Increasing dietary ESO both linearly and quadratically changed (p<0.05) weight gain during phase 2 (maximum at 1.0% of ESO). Increasing dietary ESO linearly changed (p<0.05) and tended to quadratically change (p = 0.077) weight gain during the overall phase. Increasing dietary ESO tended to linearly change (p = 0.059) gain to feed ratio during phase 1 and quadratically change (p<0.05) gain to feed ratio during phase 2 (maximum at 1.4% of ESO). Feed preference of the diet containing 2% of ESO was negatively associated with post-weaning days (R2 = 0.542).

Conclusion: Gradually replacing SBM with ESO at levels from 1.4% to 1.8% enhanced intestinal health and gain to feed ratio, whereas exceeding 0.9% to 1.0% reduced feed intake and weight gain, suggesting that optimal level of ESO in nursery pig diets is 0.9%.