Rumen Fermentation, Digestive Enzyme Activity, and Bacteria Composition between Pre-Weaning and Post-Weaning Dairy Calves

• Main Authors: Yangyi Hao, Chunyan Guo, Yue Gong, Xiaoge Sun, Wei Wang, Yajing Wang, Hongjian Yang, Zhijun Cao, Shengli Li
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Animals
• Subjects: calf; weaning; rumen; fermentation; enzyme; bacteria
• Online Access: https://www.mdpi.com/2076-2615/11/9/2527

To better understand the transition of rumen function during the weaning period in dairy calves, sixteen Holstein dairy calves were selected and divided into two groups: pre-weaning (age = 56 ± 7 day, <i>n</i> = 8) and post-weaning (age = 80 ± 6 day, <i>n</i> = 8). The rumen fluid was obtained by an oral gastric tube. The rumen fermentation profile, enzyme activity, bacteria composition, and their inter-relationship were investigated. The results indicated that the post-weaning calves had a higher rumen acetate, propionate, butyrate, and microbial crude protein (MCP) than the pre-weaning calves (<i>p</i> < 0.05). The rumen pH in the post-weaning calves was lower than the pre-weaning calves (<i>p</i> < 0.05). The protease, carboxymethyl cellulase, cellobiohydrolase, and glucosidase in the post-weaning calves had a lower trend than the pre-weaning calves (0.05 < <i>p</i> < 0.1). There was no difference in α and β diversity between the two groups. Linear discriminant analysis showed that the phylum of <i>Fibrobacteres</i> in the post-weaning group was higher than the pre-weaning group. At the genus level, <i>Shuttleworthia</i>, <i>Rikenellaceae</i>, <i>Fibrobacter</i>, and <i>Syntrophococcus</i> could be worked as the unique bacteria in the post-weaning group. The rumen bacteria network node degree in the post-weaning group was higher than the pre-weaning group (16.54 vs. 9.5). The <i>Shuttleworthia</i> genus was highly positively correlated with MCP, propionate, total volatile fatty acid, glucosidase, acetate, and butyrate (r > 0.65, and <i>p</i> < 0.01). Our study provided new information about the rumen enzyme activity and its relationship with bacteria, which help us to better understand the effects of weaning on the rumen function.