Mao Huiling, Zhang Yanfang, Yun Yan, Ji Wenwen, Jin Zhao, Wang Chong, Yu Zhongtang
College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A & F University, Hangzhou, China.
Department of Animal Sciences, The Ohio State University, Columbus, OH, United States.
Front Microbiol. 2021 Mar 23;12:636865. doi: 10.3389/fmicb.2021.636865. eCollection 2021.
Weaning plays an important role in many animal processes, including the development of the rumen microbiota in ruminants. Attaining a better understanding of the development of the rumen microbial community at different weaning stages can aid the identification of the optimal weaning age. We investigated the effects of weaning age on ruminal bacterial and archaeal communities in Hu lambs. Thirty male Hu lambs were randomly assigned to two weaning-age groups: a group weaned at 30 days of age (W30) and a group weaned at 45 days of age (W45), with each group having five replicate pens. On the weaning day (day 30 for W30 and day 45 for W45) and at 5 days postweaning [day 35 for W30 (PW30) and day 50 for W45 (PW45)], one lamb from each replicate was randomly selected and sacrificed. Rumen contents were collected to examine the ruminal microbiota. Compared to W30, PW30 had a decreased relative abundance of . At genus level, the extended milk replacer feeding (W45 vs. W30) increased the relative abundance of while decreased that of and . Compared to W30, PW30 exhibited decreased relative abundances of , and but an increased unclassified . No significant difference was noted in the detected archaeal taxa among the animals. The function "biosynthesis of secondary metabolites" was less predominant in PW30 than in W30, whereas the opposite held true for "metabolism of cofactors and vitamins." Some bacterial genera were significantly correlated with rumen volatile fatty acid (VFA) concentration or other animal measures, including negative correlations between ruminal VFA concentration and unclassified and unclassified ; positive correlations of ruminal papillae length with and , but negative correlations with and ; and negative correlations between plasma D-lactate concentration and , unclassified , and . Our results revealed that the ruminal bacterial community underwent larger changes over time in lambs weaned at 30 days of age than in lambs weaned half a month later. Thus, extending milk replacer feeding to 45 days weaning was recommended from the perspective of the rumen microbial community in the Hu lamb industry.
断奶在许多动物生理过程中起着重要作用，包括反刍动物瘤胃微生物群的发育。更好地了解不同断奶阶段瘤胃微生物群落的发育情况有助于确定最佳断奶年龄。我们研究了断奶年龄对湖羊瘤胃细菌和古菌群落的影响。30只雄性湖羊被随机分为两个断奶年龄组：30日龄断奶组（W30）和45日龄断奶组（W45），每组有5个重复栏。在断奶日（W30为第30天，W45为第45天）和断奶后5天[W30为第35天（PW30），W45为第50天（PW45）]，从每个重复栏中随机选择一只羔羊并屠宰。采集瘤胃内容物以检测瘤胃微生物群。与W30相比，PW30的相对丰度降低。在属水平上，延长代乳粉喂养时间（W45与W30相比）增加了……的相对丰度，同时降低了……和……的相对丰度。与W30相比，PW30的……、……和……相对丰度降低，但未分类的……相对丰度增加。在所检测的动物古菌类群中未发现显著差异。“次生代谢物的生物合成”功能在PW30中不如在W30中占主导地位，而“辅因子和维生素的代谢”则相反。一些细菌属与瘤胃挥发性脂肪酸（VFA）浓度或其他动物指标显著相关，包括瘤胃VFA浓度与未分类的……和未分类的……呈负相关；瘤胃乳头长度与……和……呈正相关，但与……和……呈负相关；血浆D - 乳酸浓度与……、未分类的……和……呈负相关。我们的结果表明，30日龄断奶的羔羊瘤胃细菌群落随时间的变化比半个月后断奶的羔羊更大。因此，从湖羊产业瘤胃微生物群落的角度来看，建议将代乳粉喂养延长至45日龄断奶。
