Rumen-protected glucose supplementation in transition dairy cows shifts fermentation patterns and enhances mucosal immunity

Xiaoli Zhang; Xiaopeng Li; Jian Wu; Jinzhen Jiao; Zhixiong He; Zhiliang Tan; Xuefeng Han

doi:10.1016/j.aninu.2021.08.002

Rumen-protected glucose supplementation in transition dairy cows shifts fermentation patterns and enhances mucosal immunity

Anim Nutr. 2021 Dec;7(4):1182-1188. doi: 10.1016/j.aninu.2021.08.002. Epub 2021 Oct 2.

Authors

Xiaoli Zhang^{1

2}, Xiaopeng Li¹, Jian Wu^{1

2}, Jinzhen Jiao¹, Zhixiong He¹, Zhiliang Tan¹, Xuefeng Han¹

Affiliations

¹ CAS Key Laboratory of Agro-ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, 410125, China.
² University of the Chinese Academy of Sciences, Beijing, 100049, China.

Abstract

Manipulation of perinatal diets, such as supplementing feed with rumen-protected glucose (RPG), has been positively regarded as a strategy to improve milking performance. This study was conducted to assess the effects of RPG on the fermentation profiles, resident microbiota and mucosal immunity in the cecum. Ten Holstein dairy cows were randomly assigned to either a 25 g/kg RPG diet (DM basis) or a 11 g/kg coating fat diet (control, CON). Compared with the CON group, the acetate-to-propionate ratio was lower in the RPG group. Gene expression analysis indicated that RPG supplementation tended to upregulate the expression of Na⁺/H⁺ hydrogen exchanger 3 (NHE3) (P = 0.076). RPG supplementation downregulated the expression of genes involved in self-rehabilitation such as matrix metalloproteinase 1 (MMP1), MMP3, MMP9 and MMP13. Additionally, the mRNA expression of genes involved in immunity including Toll-like receptors (TLR4, TLR6 and TLR7) and proinflammatory cytokines (immune interferon gamma [IFNG] and interleukins interleukin 17A [IL17F], IL17A, IL22), was downregulated by RPG supplementation. Nonetheless, no differences existed in the bacterial copy number and beta diversity between the 2 groups. Overall, supplementation with RPG would probably cause a shift towards propionate production in the cecal digesta, and promote the immune homeostasis of the cecal mucosa in transition dairy cows. Our results extended the basic understanding of RPG supplementation and utilization in transition dairy cows in terms of host microbe interplay in the cecum.

Keywords: Cecum; Fatty acid metabolism; Fermentation; Microbiota; Rumen-protected glucose.