The impact of lactating Hu sheep’s dietary protein levels on lactation performance, progeny growth and rumen development

Abstract

This study aimed to investigate whether lactating Hu sheep’s dietary protein levels could generate dynamic effects on the performance of their offspring. Twelve ewes with similar parity were fed iso-energy diets which contained different protein levels (P1: 9.82%, P2: 10.99%) (n = 6), and the corresponding offspring were divided into SP1 and SP2 (n = 12). At 60 days, half of the lambs were harvested for further study: the carcass weight (p = 0.043) and dressing percentage (p = 0.004) in the SP2 group were significantly higher than SP1. The acetic acid (p = 0.007), propionic acid (p = 0.003), butyric acid (p < 0.001) and volatile fatty acids (p < 0.001) in rumen fluid of SP2 were significantly lower than SP1. The expression of MCT2 (p = 0.024), ACSS1 (p = 0.039) and NHE3 (p = 0.006) in the rumen of SP2 was lower than SP1, while the HMGCS1 (p = 0.026), HMGCR (p = 0.024) and Na+/K+-ATPase (p = 0.020) was higher than SP1. The three dominant phyla in the rumen are Bacteroidetes, Proteobacteria and Firmicutes. The membrane transport, amino acid metabolism and carbohydrate metabolism of SP1 were relatively enhanced, the replication and repair function of SP2 was relatively enhanced. To sum up, the increase of dietary protein level significantly increased the carcass weight and dressing percentage of offspring and had significant effects on rumen volatile fatty acids, acetic acid activation and cholesterol synthesis related genes.

HIGHLIGHTS

• In the early feeding period, the difference in ADG of lambs was mainly caused by the sucking effect.

• The increase in dietary protein level of ewes significantly increased the carcass weight and dressing percentage of offspring.

• The dietary protein level of ewes significantly affected the volatile fatty acids (VFAs) and genes related to acetic acid activation and cholesterol synthesis in the rumen of their offspring.

• The membrane transport, amino acid metabolism and carbohydrate metabolism of the offspring of ewes fed with a low protein diet were relatively enhanced.

• The replication and repair function of the offspring of ewes fed with a high protein diet was relatively strengthened.

Keywords:

• Lactation Hu sheep
• rumen development
• rumen microbiota
• volatile fatty acid

Acknowledgments

We thank the staff at the Laboratory of Animal Nutrition and Human Health, College of Life Sciences, Hunan Normal University for support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contributions

Y. C. Wang and X. Wang performed the experiments; Y. C. Wang and Q. Y. Wang performed the statistical analyses and wrote the manuscript; Q. Y. Wang and H. S. Yang contributed to experimental concepts and design, provided scientific direction and finalized the manuscript with the help of C. P. Dai, P. F. Huang, Y. L. Li, X. Q. Ding, J. Huang and T. Hussain. All authors have read and agreed to the published version of the manuscript.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.

Additional information

Funding

This work was supported by Hunan Province’s Strategic and Emerging Industrial Projects (2018GK4035), and Hunan Province’s Changsha-Zhuzhou-Xiangtan National Independent Innovation Demonstration Zone projects (2017XK2058).