Animal Bioscience最新文献

Objectives: This meta-analysis evaluated the effects of dietary crude glycerol (CG) supplementation on growth performance, carcass traits, meat quality, and blood biochemical parameters in broiler chickens.

Methods: A systematic search of peer-reviewed studies in Scopus, ScienceDirect, and Google Scholar was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Twenty-five eligible studies were included. Effect sizes were calculated as standardized mean differences (SMDs) using a random-effects model in OpenMEE software. Subgroup analyses were performed according to strain, sex, rearing phase, and inclusion level.

Results: CG supplementation significantly increased body weight gain (p < 0.05) and improved feed conversion ratio (p < 0.05), while feed intake was unaffected. Among carcass traits, breast yield significantly increased (p < 0.05), whereas carcass yield and thigh yield were not affected. CG inclusion also reduced meat ash content and ultimate pH, while drip loss increased, indicating potential negative effects on water-holding capacity. Blood biochemical indices, including reduced alanine aminotransferase (ALT) and elevated alkaline phosphatase (ALP), indicated adaptive physiological responses without evidence of toxicity. Subgroup analyses revealed that strain, sex, and inclusion level significantly moderated growth outcomes (p < 0.05).

Conclusion: Crude glycerol can be incorporated into broiler diets as an alternative energy source to enhance growth performance without compromising carcass yield. However, its influence on meat quality highlights the need to optimize inclusion levels and consider variability among glycerol by-products before large-scale application.

Objective: The methane (CH₄) emission prediction method, using predicted CO₂ emissions and the CH₄:CO₂ concentration ratio, faces challenges in evaluating the efficacy of CH₄-reducing feed additives due to CO₂ prediction bias associated with energy utilization efficiency. We hypothesized that incorporating dry matter intake (DMI), along with metabolic body weight (MBW) and energy-corrected milk (ECM) as explanatory variables, would eliminate this bias. The primary objective was to compare the performance of CO₂ emission models with and without including DMI. The secondary objective was to assess the CO₂-based method's applicability for quantifying CH₄-reducing effects, through a case study of 3-nitrooxypropanol (3-NOP).

Methods: Prediction models for CO₂ emissions were developed including DMI, MBW, and ECM as explanatory variables, based on 219 records obtained from previous experiments with Holstein cows using respiration chambers or headboxes. Model performance was evaluated using cross-validation. Bias associated with energy utilization efficiency was assessed. The applicability of the CO₂-based method to quantify the CH₄-reducing effect of 3-NOP was assessed using data obtained from the literature, including 10 studies with 22 treatment and control mean comparisons. The agreement between the observed and predicted CH₄ reductions was assessed.

Results: Incorporating DMI along with MBW and ECM improved the predictive performance of CO₂ emissions. While the models without DMI showed bias associated with energy utilization efficiency, the bias was eliminated when DMI was incorporated. Applicability assessment demonstrated that the models without DMI systematically underestimated the CH₄-reducing effect of 3-NOP. In contrast, the models that included DMI showed smaller discrepancies between observed and predicted CH₄ reductions.

Conclusion: This study highlights the importance of incorporating DMI as an explanatory variable to achieve accurate and unbiased predictions of CO₂ emissions. These findings would contribute to the appropriate application of the CO₂-based method for evaluating the CH₄-reducing effects of feed additives.

Objective: To determine how dietary vitamin A (VA) level and duration affect intramuscular fat (IMF), meat quality, storage stability, and antioxidant gene expression in Yanbian yellow cattle.

Methods: Twenty 15-month-old Yanbian yellow cattle (314.13 ± 13.30 kg) were assigned to five treatments: CON (supplemental VA 2200 IU/kg DM), NVA1 (0 IU/kg DM supplemental VA for 180 d), NVA2 (0 IU/kg DM supplemental VA for 240 d), LVA1 (supplemental VA 1100 IU/kg DM for 180 d) and LVA2 (supplemental VA 1100 IU/kg DM for 240 d). Growth performance, carcass traits, physicochemical characteristics, and storage stability were measured. Serum biochemical and muscle antioxidant indexes were analyzed, and the mRNA expression of antioxidant-related genes (FOXO1, GSTA1, SOD) was quantified by qPCR. Statistical significance was set at p < 0.05.

Results: All VA-restricted groups showed higher IMF, marbling score, and lower muscle fiber diameter, drip loss, and shear force than the CON group (p < 0.05). Serum SOD and glutathione peroxidase (GSH-Px) levels in the NVA1/NVA2 group were lower than those in the LVA groups and CON (p < 0.05). During storage, NVA2/LVA1/LVA2 had lower drip loss and shear force on days 1, 3, and 5 (p < 0.05); on day 7, b* was higher in NVA1/NVA2 than CON, and drip loss, cooking loss, and shear force were lower in NVA2, LVA1, and LVA2 than CON (p < 0.05). At the transcriptional level, antioxidant-related genes were upregulated across all VA-restricted groups, with FOXO1 and GSTA1 peaking in LVA1 and SOD elevated in all restricted groups (p < 0.05).

Conclusion: Restricting dietary VA to 50% of the recommended level for 180 days significantly improved marbling, tenderness, and oxidative stability without compromising growth performance. These findings highlight a feasible nutritional strategy to enhance beef quality and extend shelf life in Yanbian yellow cattle.

Objective: This study investigated the effects of chemically protected sodium butyrate (CSB) on growth performance, serum indicators, rumen fermentation parameters, and microbial communities in Gangba sheep.

Method: Twenty-four healthy 5-month-old male Gangba sheep with an initial body weight of 19.54±1.04 kg were randomly assigned to 4 groups and fed diets containing 0, 1.0, 5.0, and 10.0 g/kg CSB for 74 days. After a 14-day adaptation period, the daily feed intake of Gangba sheep was recorded. Fecal samples were collected during the last 7 days of the trial, and serum and rumen fluid were sampled on the final day.

Results: CSB improved final body weight, average daily dry matter intake, and average daily gain while reducing the feed conversion ratio of Gangba sheep (p < 0.05). In addition, CSB improved the apparent digestibility of crude protein and neutral detergent fiber (p < 0.05). Moreover, CSB increased serum immunoglobulin G levels while decreasing tumor necrosis factor-α levels (p < 0.05). Meanwhile, CSB increased serum growth hormone-releasing hormone levels (p < 0.05). Moreover, CSB increased rumen fluid pH and enhanced concentrations of ammonia nitrogen, acetic acid, iso-butyric acid, butyric acid, and total volatile fatty acids, as well as activities of lipase and butyrate kinase (p < 0.05). Besides, CSB enhanced the rumen microbiota structure by increasing the relative abundance of Fibrobacter, unclassified _Oscillospiraceae, and Ruminococcus.

Conclusion: CSB improved serum immune and hormone indicators, enhanced the rumen ecological environment, and increased feed digestibility and utilization, thereby promoting the growth of Gangba sheep. It is recommended to use a dosage of 5.0 g/kg dry matter for optimal growth performance and health benefits.

This systematic literature review aims to evaluate advancements in sensor systems for detecting health conditions in dairy cows especially on mastitis, fertility, locomotion, and metabolic disorders. Relevant articles published between 2014 and 2024 were identified from Scopus. Each article was categorized by health condition and assigned to one of four development levels: sensor technique (level I), data interpretation (Level II), integration of information ( Level III), and decision making (Level IV). Relevant information from the articles was systematically reviewed and discussed. We identified 132 articles published in the past 10 years, describing a total of 151 sensor systems. Most sensor systems were aimed at mastitis and reproduction, followed by locomotion and metabolic disorders. The far majority of the articles were at level II (data interpretation) presenting research on (novel) algorithms to detect disease. A large number of different statistical or machine-learning or deep-learning models were described and evaluated, amongst others random forests. Level II systems applied statistical analysis or machine-learning/deep-learning models (e.g., random forests, You Only Look Once (YOLO), Support Vector Machine (SVM), or Convolutional Neural Network (CNN)). These algorithms did use a wide range of sensor data. Only few articles aimed at level III research, integration of information and decision support. This review highlights the need for sensor systems research to be driven by real-world requirements for on-farm decision making. To move from proof-of-concept toward practical, future research must integrate sensor outputs with herd records and financial models, validate systems across multiple farms and at higher data frequencies, and embed economic evaluation alongside sensitivity and specificity metrics. Addressing these technical, integration, and economic challenges is essential before sensor systems can fully support automated, value-driven health management on commercial dairy farms.

Objective: Intramuscular fat (IMF) deposition is a key factor for meat quality traits like juiciness, tenderness, and flavor. Although fibro/adipogenic progenitor cells (FAPs) participate in adipogenesis, the roles of other stromal cells in the muscle microenvironment are unclear. This study aimed to characterize cellular heterogeneity in cattle IMF deposition and identify key cell types and molecular mechanisms regulating intramuscular adipogenesis.

Methods: We performed single-nucleus RNA sequencing (snRNA-seq) on Longissimus dorsi muscle samples from three cattle breeds-Angus, Hereford, and Simmental-which exhibit divergent IMF content. Cell populations were annotated using multiple reference-based methods. We applied Scissor to identify phenotype-associated cells, CellChat to infer intercellular communication, hdWGCNA to detect co-expression modules, and scFEA to evaluate metabolic activity. Virtual gene perturbation was conducted using scTenifoldKnk, and drug-responsive cell subpopulations were assessed with scRank.

Results: We identified ten distinct cell types in bovine skeletal muscle. Angus cattle, known for high marbling, had elevated proportions of adipocytes, FAPs, and vascular endothelial cells (VEndoCs), while Hereford cattle were enriched in type II fibers. VEndoCs were consistently linked to high IMF and acted as central signaling hubs, interacting extensively with adipocytes and FAPs. These cells also showed high glucose metabolic activity. Co-expression analysis within VEndoCs identified 40 candidate regulators, including nine BMP signaling pathway genes. Virtual knockdown highlighted BMPR1A as the top regulator, altering expression of 13 lipid metabolism-related genes. Neurocytes were most sensitive to resveratrol treatment, largely via ALDH2, whereas FAPs were least responsive.

Conclusion: Our findings establish VEndoCs as active regulators of intramuscular adipogenesis via a BMPR1A-mediated signaling pathway. These results provide new insights into the cellular and molecular basis of marbling in cattle and highlight BMPR1A as a potential target for genetic or nutritional strategies aimed at improving meat quality.

Objective: This study aimed to investigate the potential of the ASAP1 gene as a genetic biomarker for brucellosis resistance/susceptibility in goats.

Methods: This study collected samples from female Shaanbei white cashmere (SBWC) goats to investigate the association between the ASAP1 gene and brucellosis susceptibility. Peripheral blood mononuclear cells (PBMCs) were isolated from goats of different haplotypes and Brucella status, and the association was evaluated via PCR, qRT-PCR, and LPS stimulation assays.

Results: The results demonstrated that the expression level of the ASAP1 gene was highest in the spleen, significantly higher than that in other tissues such as the kidney and heart (p<0.05). In the SBWC goats population, three genotypes Insertion/Insertion (II), Insertion/Deletion (ID), and Deletion/Deletion (DD) were identified at the P2, P5, and P7 sites of goat ASAP1 gene. Association analysis showed that P2 and P7 sites were associated with host resistance to Brucella infection (p<0.05). Specifically, significant associations between brucellosis risk and genotypes at the P2 and P7 lociwere identified by logistic regression analysis with the II genotype used as reference (p<0.05; p<0.01). These associations were maintained after multiple testing correction. Significantly lower expression of the ASAP1 gene was observed in testicular tissues of Brucella infected adult SBWC goats compared to healthy controls (p<0.01). Through haplotype analysis, Hap3 and Hap5 were identified as being associated with brucellosis resistance when compared to Hap1 (p<0.05). PBMCs were isolated from goats carrying Hap1, Hap3, and Hap5. Following lipopolysaccharide (LPS) stimulation, significantly reduced ASAP1 expression was detected in the susceptible haplotype Hap1 compared to the resistant haplotypes by quantitative PCR (qPCR). The highest expression level was exhibited by the most resistant haplotype Hap5. Furthermore, more rapid activation of key inflammatory pathways and pro-inflammatory cytokines (NF-κB, IL-6, TNF-α, IFN-γ) was demonstrated in resistant haplotypes compared to susceptible Hap1, and accelerated resolution of the inflammatory response was observed, particularly in the most resistant haplotype Hap5.

Conclusion: In summary, this study demonstrates that ASAP1 gene InDel variants influence brucellosis resistance in SBWC goats, providing a theoretical basis for breeding resistant populations.

Objective: Compare cold adaptation mechanisms between cold-tolerant Hezuo and cold-sensitive Bama pigs.

Methods: Lung histology, W/D ratio, oxidative and inflammatory markers, apoptosis, and transcriptomics were analyzed.

Results: The results showed that the lung of Hezuo pigs displayed less severe alveolar septal thickening, inflammatory infiltration, and fine bronchial fold extension during cold exposure compared to Bama pigs. The W/D ratio dramatically decreased in Hezuo pigs and increased in Bama pigs. Hezuo pigs exhibited significantly higher AQP-1(Aquaporin-1) and AQP-5(Aquaporin-5) expressions than Bama pigs in the middle and late phases. Bama pigs displayed increased ROS(Reactive Oxygen Species), MDA(Malondialdehyde), TNF-α(Tumor Necrosis Factor-alpha), IL-1β(Interleukin-1 beta) and decreased GSH(Glutathione). However, Hezuo pigs maintained stable GSH and showed no significant late-phase inflammatory marker changes. Bama pigs had a higher apoptosis density and number of TUNEL-positive cells than Hezuo pigs, which was related to the down-regulation of Bcl-2(B-Cell Lymphoma 2) and the up-regulation of Bax(BCL2-Associated X Protein) and Caspase-3. Furthermore, Transcriptomic analysis revealed that, in Bama pigs, the distinctive genes-MUC5B(Mucin 5B), MMP9(Matrix Metallopeptidase 9), AMCF-II(Alveolar Macrophage Chemotactic Factor-II), IL22RA1(Interleukin 22 Receptor Subunit Alpha 1), CCL16(C-C Motif Chemokine Ligand 16), SOX9(SRY-Box Transcription Factor 9), KRT5(Keratin 5) function to drive mucus hypersecretion, extracellular matrix degradation, and sustained inflammatory chemotaxis, thereby exacerbating tissue damage. In contrast, the distinctive genes of Hezuo pigs-ALDH1A2(Aldehyde Dehydrogenase 1 Family Member A2), ACSL6(Acyl-CoA Synthetase Long Chain Family Member 6), ACSM5(Acyl-CoA Synthetase Medium Chain Family Member 5), AKR1C1(Aldo-Keto Reductase Family 1 Member C1), NR4A3/2(Nuclear Receptor Subfamily 4 Group A Member 3/2), GNG4(G Protein Subunit Gamma 4), GYS2(Glycogen Synthase 2) primarily enhance lipid metabolism, facilitate aldehyde detoxification, and mitigate oxidative stress, collectively orchestrating a cellular protection mechanism.

Conclusion: Hezuo pigs exhibit protective molecular mechanisms, suggesting candidate targets for cold-resistance breeding.

Objective: This study aimed to develop a recombinant gonadotropin-releasing hormone (GnRH) vaccine and to investigate the effects of different immunization doses on immunocastration efficacy and growth performance in male goats, providing an animal welfare-friendly alternative to surgical castration.

Methods: Forty male goats were randomly assigned to four groups (n = 10 per group): the saline-injected control (NC), surgical castration (SC), low-dose vaccine (LD), and high-dose vaccine (HD). The vaccine was administered according to a scheduled immunization program. Anti-GnRH antibody titers, serum testosterone concentrations, libido scores, histological characteristics of testicular tissues, and growth performance were evaluated to assess immunocastration efficacy.

Results: Both LD and HD groups exhibited significantly higher anti-GnRH antibody titers than the NC group (p < 0.01). Serum testosterone concentrations and libido scores were markedly reduced in the immunized groups (p < 0.01), indicating effective suppression of reproductive function. Histological and quantitative analyses demonstrated pronounced testicular atrophy in immunocastrated goats, characterized by a significant reduction in seminiferous tubule diameter and spermatogenic cell number, as well as the absence of spermatozoa within the lumen. Although only limited time points showed significant differences between the two immunization doses, the overall immunocastration efficacy of the low- and high-dose regimens was largely comparable, with the low-dose group exhibiting slightly stronger suppression at certain parameters or time points. Additionally, immunocastrated goats had significantly higher body weight and weight gain compared with surgically castrated goats (p < 0.01), while differences with the NC group were not significant (p > 0.05).

Conclusion: The recombinant GnRH vaccine effectively suppresses reproductive function in male goats. Compared with surgical castration, immunocastration was associated with improved growth performance, while no significant differences were observed relative to intact animals. These findings support immunocastration as a non-invasive and welfare-friendly alternative to surgical castration in livestock production.

Objective: The present experiment aimed to determine standardized ileal digestibility (SID) of amino acids (AA) and digestible energy (DE) in 4 bakery byproducts fed to nursery pigs and to develop prediction equations for estimating SID of AA and DE in bakery byproducts.

Methods: Five barrows with an initial body weight of 16.6 kg (standard deviation = 1.7) were fitted with a T-cannula at the distal ileum and individually housed in pens. A 5×5 Latin square design was used with 5 treatments, 5 pigs, and 5 periods. Four sources of bakery byproducts containing 9.1% to 38.4% neutral detergent fiber (NDF) were used. Three experimental diets contained each bakery byproduct at 96.6% as the sole source of nitrogen and energy. The fourth experimental diet consisted of a source of bakery byproduct (38.4% NDF) at 70.0% as the sole source of nitrogen. A nitrogen-free diet was prepared to determine the basal endogenous AA losses. Each period consisted of 6 d of adaptation, 1 d of fecal collection, and 3 d of ileal collection.

Results: The SID of most AA and DE differed (p<0.05) among 4 bakery byproducts. The NDF concentration was negatively correlated (p<0.05) with the SID of indispensable AA except Lys and DE in bakery byproducts. Prediction equations were developed for estimating SID of AA and DE: SID of Met (%) = 86.7-0.54×NDF (r2 = 0.74 and p<0.001); SID of Thr (%) = 73.4-1.00×NDF (r2 = 0.57 and p<0.001); and DE (kcal/kg as-is) = 4,819-81.96×NDF (r2 = 0.93 and p<0.001), where NDF is expressed as % as-is.

Conclusion: Amino acid digestibility and DE differed among various bakery byproducts fed to nursery pigs. Neutral detergent fiber can be used to estimate SID of AA and DE in bakery byproducts for nursery pigs.