Effect of rumen microbiota transfaunation on the growth, rumen fermentation, and microbial community of early separated Japanese Black cattle

Is early life programming a promising strategy for methane mitigation and sustainable intensification in ruminants?

Sustainable animal production requires lowering emissions and adapting to climate change. Numerous nutritional and management interventions that enhance adult ruminants' efficiency and resilience produce only temporary results, reducing the sustainability of the programs. This is because only short-lived changes in the host and rumen microbiome occur, which revert to the original levels when the intervention ceases. Early life programming (ELP) is a promising approach to increase sustainable livestock production, enhance efficiency and reduce greenhouse gas emissions. Early influences using ELP have profound and enduring effects on molecular pathways, physiological adaptations, and long-term phenotypic consequences later in life. These effects occur from the embryonic stage to birth (foetal programming, FP), birth to weaning, and beyond. The underlying mechanisms of ELP include the sequential development of the rumen and microbial colonisation in the rumen, orchestrated through molecular changes, including transcriptomic and epigenetic modifications. This review highlights the key mechanisms behind ELP and explores strategies across different production systems that can improve livestock performance while helping to achieve net-zero emissions. Management strategies like step-down weaning, dietary modifications including increasing solid feed and high-fibre diets and adding anti-methanogenic agents and other feed additives to target the desired rumen microbial community, such as propionate-producing Prevotella, Sharpea, Coprococcus and Megasphaera, are promising strategies for implementing ELP. Creating alternate hydrogen sinks through ELP by favouring metabolic pathways that enhance propionate production can also be targeted. Furthermore, recent innovative strategies, such as using methanotroph-methylotroph consortium as probiotics and oxidising feed additives, are worth researching for ELP.

Assessing the impact of three feeding stages on rumen bacterial community and physiological characteristics of Japanese Black cattle

In Japan, Japanese Black cattle, known for their exceptional meat quality owing to their abundant intramuscular fat, undergo a unique three-stage feeding system with varying concentrate ratios. There is limited research on physiological and rumen microbial changes in Japanese Black cattle during these stages. Therefore, this study aimed to examine Japanese Black steers in these three stages: early (T1, 12-14 months), middle (T2, 15-22 months), and late (T3, 23-30 months). The rumen bacteria of 21 cattle per phase was analyzed using 16S rRNA gene sequencing. Rumen bacterial diversity was significantly higher in T1, with a distinct distribution, than in T2 and T3. Specific phyla and genera were exclusive to each stage, reflecting the shifts in feed composition. Certain genera dominated each stage: T1 had Flexilinea, Streptococcus, Butyrivibrio, Selenomonas, and Kandleria; T2 had Bifidobacterium, Shuttleworthia, and Sharpea; and T3 had Acetitomaculum, Mycoplasma, Atopobium, and Howardella. Correlation analysis revealed significant associations between certain microbial populations and physiological parameters. These findings indicate that changes in energy content and feed composition are associated with physiological and ruminal alterations. This study may guide strategies to improve rumen health and productivity in Japanese Black cattle by modifying diets to specific fattening stages.

Exploring the Rumen Microbiota and Serum Metabolite Profile of Hainan Black Goats with Different Body Weights before Weaning

The critical role of the rumen microbiota in the growth performance of livestock is recognized, yet its significance in determining the body weight of goat kids before weaning remains less understood. To bridge this gap, our study delved into the rumen microbiota, serum metabolome, rumen fermentation, and rumen development in goat kids with contrasting body weights before weaning. We selected 10 goat kids from a cohort of 100, categorized into low body weight (LBW, 5.56 ± 0.98 kg) and high body weight (HBW, 9.51 ± 1.01 kg) groups. The study involved sampling rumen contents, tissues, and serum from these animals. Our findings showed that the HBW goat kids showed significant enrichment of VFA-producing bacteria, particularly microbiota taxa within the Prevotellaceae genera (UCG-001, UCG-003, and UCG-004) and the Prevotella genus. This enrichment correlated with elevated acetate and butyrate levels, positively influencing rumen papillae development. Additionally, it was associated with elevated serum levels of glucose, total cholesterol, and triglycerides. The serum metabonomic analysis revealed marked differences in fatty acid metabolism between the LBW and HBW groups, particularly in encompassing oleic acid and both long-chain saturated and polyunsaturated fatty acids. Further correlational analysis underscored a significant positive association between Prevotellaceae_UCG-001 and specific lipids, such as phosphatidylcholine (PC) (22:5/18:3) and PC (20:3/20:1) (r > 0.60, p < 0.05). In summary, this study underscores the pivotal role of the rumen microbiota in goat kids' weight and its correlation with specific serum metabolites. These insights could pave the way for innovative strategies aimed at improving animal body weight through targeted modulation of the rumen microbiota.