Animal Science Journal最新文献

The study was aimed at examining the effect of maternal IgY levels on embryonic development, gut microbiota colonization, and resistance to Salmonella pullorum infection in offspring chicks. A total of 60 thirty-six-week-old breeders that were sorted from 969 breeders according to their yolk IgY content were allocated to two groups: a high egg yolk IgY levels group (HIgY) and a low egg yolk IgY levels group (LIgY). Fertilized eggs of breeders were collected for hatching. On Day 8, offspring chicks were challenged with S. pullorum. Results showed that compared with the LIgY group, the HIgY group exhibited a considerable increase in embryonic weight, significant enhancement in the richness and diversity of gut microbiota, along with an increased relative abundance of Lactobacillus in 7-day-old chicks (p < 0.05). The bacterial load in the spleen, liver tissue, and cecal contents, the mRNA expression of nitric oxide synthase 2 (NOS2) and interleukin-1β (IL-1β) in the cecal tonsils and spleen of offspring chicks in the HIgY group markedly reduced on 1-day post-infection (dpi) compared with the LIgY group (p < 0.05), and mucin-2 (MUC2) and Occludin mRNA expression in the jejunum of offspring chicks in the HIgY group was markedly increased compared with the LIgY group (p < 0.05). In summary, maternal IgY increased the richness and diversity of gut microbiota, enhanced the colonization of Lactobacillus, improved the immunity and intestinal barrier function, thereby increasing the resistance against S. pullorum infection.

This study evaluated the straw of brittle mutant rice (Oryza sativa L.) as an alternative forage for dairy cows. In vitro incubation was conducted to investigate nutrient digestibility in Bermuda hay (BH), wild-type (WT), purple brittle (PB), and green brittle (GB) rice straws. After in vitro analysis, three treatment diets including (i) diet 100% BH, (ii) diet 25% WT (mixed 75% BH), and (iii) diet 25% GB (mixed 75% BH) were used in a feeding trial for Holstein cows. After 48-h in vitro incubation, both brittle straw varieties showed higher dry matter (DM) digestibility than the WT (p < 0.05) and similar to BH. GB and BH showed higher crude protein (CP) digestibility than other treatments (p < 0.05) with no significant difference in neutral detergent fiber (NDF) digestibility. The in situ analysis revealed that the 25% GB diet demonstrated superior DM and CP digestibility compared to the 25% WT diet. Including 25% GB in diets significantly (p < 0.05) improved rumination time but had no significant effect on daily DM intake or ruminal pH, although ruminal ammonia nitrogen concentrations tended to decrease. These results suggest that brittle rice straw varieties could be potential alternative forages for dairy cows.

In this study, we investigated the ruminal properties and gas production of cows fed bean sprout residue. Six Holstein cows (average age 24.8 ± 1.0 months) were used and divided into two groups: one that was fed bean sprout residue and one that was not fed bean sprout residue. Three cows were placed in each group in a 2 × 2 crossover design. In the bean sprout residue feeding group, each cow was given 4 kg of raw bean sprout residue in two separate feedings per day, in the morning and in the evening. The survey items were ruminal pH, volatile fatty acid (VFA) concentration, protozoa number, and ruminal gas production, and differences in these items were examined between groups. No significant differences were observed between the groups for any detected VFA concentration. No significant difference was observed in ruminal pH between the groups. The number of protozoa tended to be higher in the bean sprout residue group (p < 0.10). The ruminal methane production was significantly lower in the bean sprout residue-fed group than in the control group (p < 0.01). These results suggest that feeding bean sprout residue may be able to reduce methane emissions without affecting the production of VFAs.

The present study evaluated the effects of feeding a newly found thermophile, Bacillus hisashii, on broiler chickens fed a low crude protein (CP) diet. One hundred day-old male Ross 308 broiler chicks are randomly assigned to four treatment groups of five replicates (five birds per replicate). The groups were fed the isocalorically formulated diets containing normal CP (NCP) or low CP (LCP; −2.0% pt) and the diets supplemented with the B. hisashii probiotics (Pro) until 42 days of age. The LCP diet significantly reduced body weight at 42 days, and the probiotics partially suppressed the reduction. There was no difference in feed intake between the groups, and Pro significantly lowered the feed conversion ratio and fecal nitrogen content in the LCP diet (p < 0.05). The probiotics significantly decreased mucosal interleukin-6 concentration in the LCP diet. There were no differences in α-diversity indices of the cecal microbial community, while Pro improved the relative abundance of the genera Lactobacillus and Escherichia-Shigella in the LCP diet. There were significant differences in β-diversity between the groups, excluding NCP/Pro versus LCP. The results suggest that B. hisashii supplementation improved growth performance and intestinal inflammatory status, possibly through improving intestinal microbial composition and balance in broiler chickens.

We conducted two experiments to investigate the effects of a high-dose blend of essential oils (BEO) on rumen microbial community structure and methane (CH₄) production. The first was an in vitro study that measured gas production, methane emissions, and microbial composition when two BEO levels (0.1% and 1.0% of the substrate) were added to a forage-based substrate incubated with rumen fluid from dry cows. The second was a feeding trial using a crossover design with four Japanese native goats to evaluate the effects of BEO at 1 g/DM feed on rumen fermentation characteristics and microbial composition. Both experiments demonstrated that BEO supplementation reduced CH₄ production and influenced rumen fermentation parameters. However, BEO altered microbial composition and carbohydrate fermentation patterns differently between the two experiments. In in vitro study, many of the major bacterial groups exhibited population shifts, whereas only one family, Acidoaminococcaceae, decreased in the rumen community of goats fed BEO for 3 weeks. Overall, the results suggest inconsistencies in the microbial response, which may underlie variations in methane emissions and rumen microbiota composition. Our findings imply that BEO broadly suppresses microbial activity, shifting fermentation toward the utilization of readily digestible carbohydrates and leading to reduced methane production.

Fatty acid composition is a key trait affecting meat quality in Japanese Black cattle. In this study, a genome-wide association study (GWAS) was conducted on Hyogo population of Japanese Black cattle (n = 432) for the percentage of oleic acid (C18:1). Quantitative trait loci (QTLs) were detected on chromosomes 6 and 19 (BTA6 and BTA19). Focusing on the QTL on BTA6, we conducted a detailed search for candidate polymorphisms. Using whole-genome resequencing data (n = 42), all polymorphisms were detected within 83 genes located on the candidate region (chr6: 55–83 Mbp). Based on variant annotations and linkage disequilibrium coefficients with the most significantly associated single nucleotide polymorphism from GWAS (top SNP), 93 variants were extracted as potential causal polymorphisms. Validation revealed that four variants, located within four different genes, had p values comparable to the top SNP. Among them, CWH43 emerged as a strong candidate, as it regulates the intracellular Mn²⁺ concentrations, which influence fatty acid metabolism. Notably, the SNP in CWH43 was located upstream of the gene, suggesting a possible regulatory role in gene expression. These findings provide important insights into the genetic basis of fatty acid composition and support the identification of functional polymorphisms in Japanese Black cattle.