Animal Bioscience最新文献

Objective: This research aimed to analyze the prevalence, molecular characteristics, toxinotyping, alpha toxin production potential, and antibiotic resistance pattern of Clostridium perfringens (C. perfringens) isolates in meat samples collected from various sources.

Methods: Sixty meat samples were screened for alpha toxin using Enzyme-Linked Immunosorbent Assay (ELISA), revealing a positivity rate of 13.3%, predominantly in raw poultry meat. Subsequent culturing on Perfringens agar identified nine samples harboring characteristic C. perfringens colonies, primarily isolated from raw poultry meat. Molecular confirmation through 16S rRNA gene amplification and sequencing authenticated twelve isolates as C. perfringens, with nine strains exhibiting genetic resemblance to locally isolated strains. Toxinotyping assays targeting alpha toxin-specific genes confirmed all nine isolates as type A C. perfringens, with no detection of beta or epsilon toxin genes. Hemolytic assays demonstrated varying alpha toxin production potentials among isolates, with accession number OQ721004.1 displaying the highest production capacity. Moreover, antibiotic resistance profiling revealed multi-drug resistance patterns among the isolates.

Results: The study identified distinct clusters within C. perfringens strains, indicating variations. Phylogenetic analysis delineated genetic relatedness among strains, elucidating potential evolutionary paths and divergences.

Conclusion: The findings underscore the need for robust surveillance and control measures to mitigate the risk of C. perfringens contamination in meat products, particularly in raw poultry meat. Enhanced monitoring and prudent antimicrobial stewardship practices are warranted in both veterinary and clinical settings to address the observed antibiotic resistance profiles and prevent foodborne outbreaks.

Objective: The objective of this study was to determine if a formulated blend of capsicum oleoresin, clove essential oil, and garlic essential oil (Fytera® Advance - Selko® USA, Indianapolis IN; CCG) influences measures of cattle growth, efficiency, or carcass traits, during the finishing phase in steers fed a concentrate-based diet.

Methods: Charolais × Angus steers (n = 96; initial shrunk BW = 391± 34.0 kg) were used in a 144-d (16 February 2023 to 9 July 2023) finishing feedlot experiment in Brookings, SD. Steers were individually weighed and allotted to one of 14 pens (6 to 7 steers; 7 pens/treatment) in a randomized complete block design and randomly assigned to 1 of 2 treatments: control diet without the test product (CON) or a diet including CCG at 500 mg/steer daily (CCG). Steers were fed twice daily, and bunks were managed according to a slick bunk system.

Results: There were no differences (P ≥ 0.10) in any growth performance outcomes from d 1 to 35, 36 to 70, or 71 to 98. From d 99 to 144 steers from CCG tended to have 5% greater ADG (P = 0.09) and 8% improved G:F (P = 0.01). No differences (P ≥ 0.15) were noted for cumulative growth performance measures. No differences were noted for any carcass measurements or categorical carcass outcomes, nor lung or liver health outcomes (P ≥ 0.15).

Conclusion: The use of CCG had no influence on cumulative growth performance responses. However, the use of CCG improved G:F during the late feeding period.

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 pair-fed (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: 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 3499 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 mTOR 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: s: 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: This study aimed to identify, discover and explore the characteristics of the mtDNA genomes of Cemani chicken (Gallus gallus).

Methods: This study used gDNA of Cemani chicken isolated from liver tissue. mtDNA sequencing was performed using WGS mtDNA analysis with nanopore technology by Oxford Nanopore Technologies GridION. Bioinformatics and data analysis were then performed.

Results: This study showed that the length of the mtDNA genome is 16,789 bp, consisting of two ribosomal RNA (12S rRNA, 16S rRNA), 22 transfer RNA genes (trnR, trnG, trnK, trnD, trnS, trnY, trnC, trnN, trnA, trnW, trnM, trnQ, trnl, trnL, trnV, trnF, trnP, trnT, trnE, trnL, trnS, trnH), 13 protein-coding genes (PCGs) (ND4l, ND3, COX3, ATP6, ATP8, COX2, COX1, ND2, ND1, CYTB, ND6, ND5, ND4), and a noncoding control region (Dloop). Furthermore, analysis showed there were polymorphic sites and amino acid alterations when mtDNA Cemani chicken was aligned with references from GenBank.

Conclusion: Site (988T>*) in Dloop genes and (328A>G) in ND3 genes which alter glycine to stop codon, were specific markers found only in Cemani chicken.

Objective: In this study, we explored the effect of fruit and vegetable waste addition on the quality of corn stalk silage.

Method: Corn stalks were ensiled 20 days after ear harvesting and mixed with fruit and vegetable waste (FVW) consisting of apple, orange, broccoli, and Chinese cabbage waste as 3% of fresh matter (FM). Fruit waste consisted of solid residue obtained after juicing, and vegetable waste was collected from farms and cut into small pieces (2-3cm). The materials were stored anaerobically in 20-L silo buckets and opened after 60 days of fermentation.

Results: There were significant differences in dry matter (DM), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN), and relative feed value (RFV) levels in FVW derived from all tested raw materials (P < 0.05). Corn stalk mixed with orange waste (CSOW) had the highest DM content (28.77%), lowest ADF and NDF content (47.78% and 26.62% of DM, respectively), and highest TDN and RFV content (69.21 and 133, respectively). After 60 days, there were significant differences in all chemical parameters examined (P < 0.05). Corn stalk mixed with broccoli waste (CSBW) had the lowest DM loss (2.23%), and the CSOW group had the lowest NDF and ADF content and highest in vitro DM digestibility. CSBW had the lowest pH and ammonia nitrogen content, but the highest lactic acid/acetic acid ratio among the treatment groups. CSOW had the highest lactic acid content (2.27% of DM). The microbial contents of each group differed only in lactic acid bacteria counts before and after ensiling, showing a slight increase (P > 0.05) and significant decreases in yeast and mold counts (P < 0.05) after ensiling.

Conclusion: These findings confirmed that mixing various FVW materials, particularly orange waste, with corn stalks improved the nutritional value of silage. Adding broccoli waste resulted in better fermentation quality than the addition of other FVW materials.

Objective: The objectives were to validate a previously published equation for estimating basal endogenous losses (BEL) of crude protein (CP) in pigs fed nitrogen-free diets and to develop prediction equations for BEL of CP and amino acids (AA).

Methods: A total of 139 observations from 123 experiments in 117 papers that determined the BEL of CP and AA in pigs were collected. For the validation of the previous equation for the BEL of CP, 94 observations that were not used for developing the previous equation were used. All observations were used to develop novel equations for estimating BEL of CP in pigs based on the initial body weight (IBW).

Results: The validation study indicated that the slope for BEL of CP, representing a linear bias, was less than zero (-0.56; SE = 0.130; p<0.001). The intercept for BEL of CP, representing a mean bias, was less than zero (-3.21; SE = 0.488; p<0.001). The models for estimating BEL of CP (g/kg dry matter intake) in pigs fed a nitrogen-free diet were developed: 20.36 - 0.077 × IBW with R2 = 0.11 and p<0.001 and 20.80 × e(-0.00475 × IBW) with R2 = 0.12 and p<0.001. Novel linear models for estimating BEL of AA were developed using BEL of CP as the independent variable.

Conclusion: The accuracy of the previous equation for estimating BEL of CP in pigs has been improved by reflecting additional data from recent publications. In the novel linear models for estimating BEL of AA of pigs, BEL of CP was used as an independent variable.

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

Methods: The harvested Italian ryegrass was directly wilted in the field for 0 day (W0), 1day (W1), 2 days (W2) and 3 days(W3), respectively, and tedded every 6 hours. And the preserved Italian ryegrass 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 DM content and pH value of wilted IRG gradually increased (p<0.05). There was a downward trend in; NDF (neutral detergent fiber), ADF (acid detergent fiber) and HEM (hemicellulose) with the increase of wilting time, but only W2 and W3 were significantly different from W0 (p<0.05). CP (crude protein), IVDMD (in vitro dry matter digestibility), TDN (total digestible nutrients) and RFV (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: Black soldier fly (BSF) as an animal protein feed source is currently becoming a research hot 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 ANOVA among groups (with Fisher's least significant difference (LSD) 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 (DM), crude protein (CP), 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-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.