Animal Bioscience最新文献

Objective: Skeletal muscle growth is an important economic trait for meat production, with notable differences between Tibetan pigs (TIBPs, a slow-growing breed) and Large White pigs (LWPs, a fast-growing breed). However, the genetic underpinnings of this disparity remain unclear.

Methods: In the current study, we integrated differentially expressed genes (DEGs) and proteins (DEPs) from 60-day-old embryonic muscle tissue, along with whole-genome single nucleotide polymorphisms (SNPs) displaying absolute allele frequency differences (ΔAF) of 0.5 or more between the TIBP and LWP breeds, to unravel the genetic factors influencing skeletal muscle growth.

Results: Our analysis revealed 3,499 DEGs and 628 DEPs with SNPs having a ΔAF equal to or greater than 0.5. Further functional analysis identified 145 DEGs and 23 DEPs involved in biological processes related to skeletal muscle development, and 22 DEGs and 3 DEPs implicated in the mechanistic target of rapamycin kinase signaling pathway, which is known for positively regulating protein synthesis. Among these genes, several DEGs and DEPs, enriched with TIPB-specific SNPs in regulatory or/and coding regions, showed marked ΔAF between the TIBP and LWP breeds, including MYF5, MYOF, ASB2, PDE9A, SDC1, PDGFRA, MYOM2, ACVR1, ZIC3, COL11A1, TGFBR1, EDNRA, TGFB2, PDE4D, PGAM2, GRK2, SCN4B, CACNA1S, MYL4, IGF1, and FOXO1. Additionally, genes such as CAPN3, MYOM2, and PGAM2, identified as both DEPs and DEGs related to skeletal muscle development, contained multiple TIBP-specific and LWP-predominant SNPs in regulatory and/or coding regions, underscoring significant ΔAF differences between the two breeds.

Conclusion: This comprehensive investigation of SNPs in DEGs and DEPs identified a significant number of SNPs and genes related to skeletal muscle development during the prenatal stage. These findings not only shed light on potential causal genes for muscle divergence between the TIBP and LWP breeds but also offer valuable insights for pig breeding strategies aimed at enhancing meat production.

Objective: The liver plays a dual role in regulating temperature and immune responses. Examining the influence of heat stress (HS) on liver T cells contributes significantly to understanding the intricate interplay between the immune system and hepatic tissues under thermal stress. This study focused on investigating the characteristics of the T-cell receptor (TCR) β chain CDR3 repertoire in bovine liver samples under both HS and pairfed (PF) environmental conditions.

Methods: Sequencing data from six samples sourced from the GEO database underwent annotation. Utilizing immunarch and VDJtool software, the study conducted comprehensive analyses encompassing basic evaluation, clonality assessment, immune repertoire comparison, diversity estimation, gene usage profiling, VJ gene segment pairing scrutiny, clonal tracking, and Kmers analysis.

Results: All four TCR chains, namely α, β, γ, and δ, were detected, with the α chains exhibiting the highest detection frequency, followed closely by the β chains. The prevalence of αβ TCRs in bovine liver samples underscored their crucial role in governing hepatic tissue's physiological functions. The TCR β CDR3 repertoire showcased substantial inter-individual variability, featuring diverse clonotypes exhibiting distinct amino acid lengths. Intriguingly, HS cattle displayed heightened diversity and clonality, suggesting potential peripheral T cell migration into the liver under environmental conditions. Notably, differential VJ gene pairings were observed in HS cattle compared to the PF, despite individual variations in V and J gene utilization. Additionally, while most high-frequency amino acid 5-mers remained consistent between the HS and PF, GELHF, and YDYHF were notably prevalent in the HS group. Across all samples, a prevalent trend of high-frequency 5mers skewed towards polar and hydrophobic amino acids was evident.

Conclusion: This study elucidates the characteristics of liver TCR β chain CDR3 repertoire under HS conditions, enhancing our understanding of HS implications.

Objective: The objective was to investigate the effects of dietary benzoic acid (BA) on nitrogen (N) balance, urinary pH, slurry pH, and odorous compounds in feces and slurry of pigs.

Methods: Twelve barrows with an initial body weight of 56.2±2.6 kg were individually housed in metabolism crates. The animals were allocated to a replicated 6×4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per treatment. The basal diet consisted mainly of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% at the expense of corn starch. Each period consisted of a 4-day adaptation period and a 24-h collection period for slurry, followed by a 4-day collection period for feces and urine. On day 5, feces and urine were collected for 24 h and mixed to obtain slurry samples.

Results: The daily digested N linearly increased (p<0.05) with increasing BA supplementation. Supplemental BA lowered urinary pH (p<0.001) and slurry pH (p<0.05) in a linear and quadratic manner. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (p<0.05) with supplemental BA. In the slurry samples, the concentrations of butyrate, isovalerate, and skatole linearly decreased (p<0.05) by supplemental BA.

Conclusion: In conclusion, supplemental benzoic acid has the potential to improve nitrogen digestion in a dose-dependent manner for pigs. Additionally, dietary benzoic acid lowers urinary pH, slurry pH, and concentrations of odorous compounds in pig feces and slurry.

Objective: This trial was conducted to explore the impact of different wilting time of Italian ryegrass (IRG) in the field on the nutritional quality and fermentation characteristics of its silage.

Methods: The harvested IRG was directly wilted in the field for 0 day (W0), 1 day (W1), 2 days (W2), and 3 days (W3), respectively, and tedded every 6 hours. And the preserved IRG was sampled at 1, 2, 3, 5, 10, 20, 30, and 45 days after ensiling and three replicates per treatment.

Results: With the extension of wilting, the dry matter (DM) content and pH value of wilted IRG gradually increased (p<0.05). There was a downward trend in; neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose with the increase of wilting time, but only W2 and W3 were significantly different from W0 (p<0.05). Crude protein (CP), in vitro DM digestibility), total digestible nutrients (TDN), and relative feed value decreased significantly with the increase of wilting time (p<0.05), except for W1. After 45 days of ensiling, W1 had the highest CP, TDN, and the lowest ADF and NDF. During ensiling, the increase of acetic acid and the decrease of WSC in W0 and W1 were similar, but the accumulation rate of lactic acid in W0 was faster than that in W1, resulting in the lowest pH value in W0. After 5 days of ensiling, the ratio of lactic acid to acetic acid in W1 stabilized at around 3:1, while W0 kept changing.

Conclusion: Italian ryegrass that wilted in the field for 1 day effectively improved the dynamic changes in CP, TDN, ADF, and NDF and fermentation quality of silage. Therefore, in practice, W1 was more recommended in production of IRG silage.

Objective: Despite the considerable body of research on the effects of heat stress coupled with water scarcity (either through restriction or deprivation) on goats, aimed at enhancing their welfare, there remains a notable gap in the literature regarding the subsequent period following water restoration, during which the cumulative impact is fully alleviated. In response to this gap, we propose a strategy grounded in the assessment of body-thermal status to improve the welfare of heat-stressed and water-deprived goats. Specifically, our strategy seeks to determine the minimally required recovery interval necessary to completely mitigate the residual effects of water deprivation endured for a duration of 72 hours.

Methods: Eight healthy Aardi bucks, aged 10 months and weighing 30 kg, were subjected to three distinct stages: euhydration, dehydration, and rehydration. Each stage spanned for 72 hours except for the rehydration stage, which was left unrestricted. Various meteorological, biophysiological, and thermophysiological measurements were subsequently recorded.

Results: Exposure of heat-stressed goats, as indicated by the temperature-humidity index values, to a 72 hours deprivation period resulted in noticeable (p<0.05) alterations in their biophysiological (daily feed intake, body weight, and feces water content) and thermophysiological responses (core, rectal, skin, and surface temperatures, respiratory and heart rates, internal, external, and total body-thermal gradients, heat tolerance and adaptability coefficients, heterothermial total body-heat storage, and total water conservation). Remarkably, our findings demonstrate that all assessed variables, whether measured or estimated, returned to their baseline euhydration levels within 10 days of commencing the rehydration phase.

Conclusion: In order to improve the welfare of heat-stressed and 72 hours water-deprived goats, it is imperative to allow a recovery period of no less than 10 days following the restoration of water access prior to initiating any subsequent experiments involving these animals. Such experiments, addressing these critical aspects, serve to advance our understanding of goat welfare and obviously hold promise for contributing to future food security and economic viability.

Objective: The objective of this study was to unravel the genetic traits of Guanling cattle, pinpoint genes advantageous for muscle growth, and lay a foundation for the preservation of genetic diversity and further analysis of regulation mechanism of important economic traits in local cattle breed.

Methods: In this study, we sequenced the whole genome of 3 Guanling cattle in Guizhou province using the Illumina HiSeq cBo sequencing platform. And, high- multiplex polymerase chain reaction technology was employed to detect high-quality single nucleotide polymorphism (SNP) sites of other 55 Guanling cattle.

Results: Our study identified 166,411 non-synonymous SNPs (nsSNPs) and 42,423 insertions and deletions (indels). Through SNP annotation, gene function enrichment analysis, and comparing with Simmental, Angus, and Limousin cattle, we identified six genes (LEPR, AKAP9, SIX4, SPIDR, PRG4, FASN) which are potentially influential on meat quality traits, playing crucial roles in muscle growth, fat metabolism, and bodily support. We also examined polymorphisms at seven SNP sites in Guanling cattle and found that all seven were in Hardy-Weinberg equilibrium.

Conclusion: These findings suggested that these gene sites are stable and widespread in the Guanling cattle population. Our research lays the groundwork for future genetic enhancement and variety identification of Guanling cattle.

Objective: This study investigated the impact of supplementation of protease and organic acid on growth performance and other biological parameters in broilers fed poultry byproduct meal (PBM) based diet.

Methods: Five hundred 1-day-old broiler chicks (Ross 308) were distributed into five treatments with 5 replicates, each pen having 20 birds, and fed each group one of five isocaloric and isonitrogenous diets in two phases: stater phase (1 to 21 days) metabolizable energy (ME) 3000 kcal/kg; crude protein (CP) 22%, and a finisher phase (22 to 35 days) ME 3,200 kcal/kg; CP 19.5%. The dietary treatments were: i) standard broiler ration (Cont); ii) The control diet with 25% of the soybean meal replaced by PBM on an equivalent protein basis (PBM); iii) PBM diet supplemented with 0.5 g/kg of protease (PBMP); iv) PBM diet supplemented with 1 g/kg organic acid (PBMO); and v) PBM diet addition with 0.5 g/kg protease and 1 g/kg organic acid (PBMPO).

Results: The overall data showed that feed conversion ratio was improved (p<0.05) in the PBMP group. Apparent CP digestibility was higher (p<0.05) in both Cont and PBMP groups. Jejunal villus height increased (p<0.05) in PBMP and PBMPO groups, while only the PBMO group exhibited a higher (p<0.05) crypt depth. Lipase activity was increased (p<0.05) in the PBMP, PBMO, and PBMPO dietary treatments. However, trypsin activity showed a significant increase (p<0.05) in the PBMP and PBMO groups. Serum biochemistry increased (p<0.05) globulin and total protein levels in the PBMP group.

Conclusion: PBM could partially replace the soybean meal with supplementation of either protease or organic acid in broiler diets without impairing overall growth performance. Furthermore, careful optimization must be considered when combining protease and organic acids.

Objective: Black soldier fly (BSF) as an animal protein feed source is currently becoming a hot research topic. This study investigated the effects of the BSF as a protein feed source for goats on slaughter performance, muscle nutrient composition, amino acids, fatty acids, minerals, and antioxidant levels.

Methods: Thirty Qianbei Ma goats (20.30±1.09 kg) were randomly divided into three groups: the control group (GRPC) supplemented with 10% full-fat soybean, treatment 1 (GRPU) supplemented with 10% untreated BSF, and treatment 2 (GRPT) supplemented with 10% heat-treated BSF. One-way analysis of variance among groups (with Fisher's least significant difference post hoc comparison) was used in this study.

Results: The nutrients, amino acids, fatty acids, minerals, and antioxidants in muscle were analyzed. The results showed that there were no significant differences in the moisture, dry matter, crude protein, ash, amino acids, and mineral content of the muscles among the three feeding groups. The slaughter rate and carcass weight of the GRPU and GRPT groups were significantly lower (p<0.05). The overall meat quality of the GRPU and GRPT groups decreased (p<0.05). The individual unsaturated fatty acids and total unsaturated fatty acids in the GRPU group were higher (p<0.05) than those in the GRPC and GRPT groups. Both GRPU and GRPT decreased (p<0.05) the antioxidant capacity of the meat.

Conclusion: Therefore, the heat-treated BSF had a better effect on meat quality compared to untreated BSF, but there were greater negative effects on the meat quality of GRPU and GRPT than GRPC.

Objective: The objective was to investigate growth performance, antioxidant enzyme activity, intestinal morphology, immune cell distribution, short chain fatty acid (SCFA) profile, and microbiota in broiler chickens fed a diet containing Lacticaseibacillus paracasei NSMJ15.

Methods: A total of 120 1-day-old Ross 308 male broilers were allocated to 2 dietary treatments in a randomized complete block design. A control group was fed a corn-soybean meal control diet, and an NSMJ15-supplemented group was fed a control diet supplemented with 1 g/kg L. paracasei NSMJ15 at the expense of cornstarch. Each dietary treatment had 6 replicates with 10 birds per cage. Growth performance was recorded on day 9. On day 10, one bird representing median body weight was selected to collect serum for antioxidant enzyme activity, jejunal tissue for immune cell isolation and morphometric analysis, and cecal digesta for 16S rRNA gene sequencing and SCFA analysis.

Results: Supplementation of L. paracasei NSMJ15 did not affect growth performance, serum antioxidant enzyme activity, and jejunal histomorphology compared to the control group. In the NSMJ15-supplemented group, the population of CD3+CD4+CD8- T cells increased (p = 0.010), while the population of CD3+CD8+TCRγδ+ T cells decreased (p = 0.022) compared to the control group. The L. paracasei NSMJ15 supplementation decreased (p = 0.022) acetate concentration in the cecal digesta compared to the control group. The 16S rRNA gene sequencing analysis showed that NSMJ15-supplemented group differentially expressed (p<0.05) 10 more amplicon sequence variants compared to control group without affecting alpha and beta diversity indices of the cecal microbiota. Genera Mediterraneibacter and Negativibacillus were positively (p<0.05) correlated with CD4+ T cells, while genera Gemmiger, Coprococcus, Sellimonas, Massilimicrobiota, and Blautia were negatively (p<0.05) correlated with SCFA concentration.

Conclusion: The results of the present study suggest dietary L. paracasei NSMJ15 supplementation may increase percentage of CD4+ T cells and decrease acetate concentration in broiler chickens by increasing the differential expression of specific microbial genera.

Objective: The present study aimed to investigate the effectiveness of dietary β-mannanase supplementation on growth performance, intestinal morphology, digesta viscosity, and dietary nutrient utilization in broiler chickens through a meta-analysis. The effects were further examined by a meta-regression analysis with activity levels of β-mannanase in broiler diets.

Methods: A total of 23 studies, which were conducted in 11 countries and completed between December 2003 and August 2023, were selected for this meta-analysis. The standardized mean difference and its 95% confidence interval were calculated as the effect size metrics using random effect model, with I2 value being utilized to measure heterogeneity. Investigated measurements included body weight gain (BWG), feed intake, feed conversion ratio (FCR), villus height (VH), crypt depth (CD), VH:CD ratio, digesta viscosity, nitrogencorrected metabolizable energy (n), apparent ileal digestibility (AID), and apparent total tract retention (ATTR) of dry matter (DM), gross energy (GE), and nitrogen (N). All statistical analyses were performed using R version 4.3.3.

Results: Results revealed significant positive effects of dietary β-mannanase supplementation on BWG (p = 0.005), FCR (p<0.001), VH (p<0.001), VH:CD (p<0.001), digesta viscosity (p<0.001), AMEn (p = 0.011), AID of GE (p = 0.002) and N (p = 0.003), and ATTR of DM (p = 0.019), GE (p = 0.002), and N (p = 0.005) in broiler chickens. In the meta-regression analysis, increasing activity levels of β-mannanase in broiler diets increased VH:CD (p< 0.001; R2 = 79.2%) and AID of N (p = 0.038; R2 = 67.4%).

Conclusion: The current meta-analysis indicates that dietary β-mannanase supplementation improves energy and nutrient utilization in broiler diets possibly by decreasing digesta viscosity and enhancing intestinal morphology in broiler chickens. These beneficial effects can contribute to improved growth performance in broiler chickens.