Effect of Total Mixed Ration on Growth Performance, Rumen Fermentation, Nutrient Digestion, and Rumen Microbiome in Angus Beef Cattle during the Growing and Fattening Phases
Wei Li,
Boping Ye,
Baoyun Wu,
Xin Yi,
Xiang Li,
Runa A,
Xiaojing Cui,
Zhiyu Zhou,
Yang Cheng,
Xiaowen Zhu,
Xiren Tang,
Xinyue Fu,
Ning Li,
Hao Wu,
Zhenming Zhou
Affiliations
Wei Li
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Boping Ye
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Baoyun Wu
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xin Yi
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xiang Li
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Runa A
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xiaojing Cui
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Zhiyu Zhou
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Yang Cheng
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xiaowen Zhu
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xiren Tang
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Xinyue Fu
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Ning Li
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Hao Wu
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
Zhenming Zhou
The State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China
This study investigates the impact of varying concentrate levels in the diets of Angus beef cattle on their performance, nutrient digestion, and metabolism during the growth (7 to 12 months) and fattening (13 to 30 months) phases. Fifteen Angus steers were continuously fed and divided into low-concentrate (L) and high-concentrate (H) groups based on the fattening period and dietary formulations. Throughout each 9-week trial phase, a comprehensive range of parameters was systematically measured, including dry matter intake (DMI), average daily gain (ADG), gain-to-feed ratio (G/F), blood parameters, rumen fluid composition, and microbial diversity. In the fattening phases, an increase in concentrate levels resulted in a significant rise in the cattle’s DMI. Although there was a minor increase in ADG compared to the growing phases, this increase was not statistically significant. The efficiency of nitrogen (N) utilization in the cattle decreased, accompanied by a significant reduction in the apparent digestibility of nutrients. Ruminal fermentation produced more energy substances; however, there was a notable decrease in the abundance of fiber-decomposing microbes (such as the NK4A214_group, Ruminococcus, Papillibacter, and Acetitomaculum) and a significant increase in the abundance of starch-degrading microbes (including Bacteroidota and Prevotellaceae). Additionally, there was a significant reduction in the abundance of immune system-related functional pathways. This suggests that high-concentrate fattening does not necessarily lead to improved growth performance and may negatively affect metabolic health and nutrient digestion.
