Dietary rumen-protected choline supplementation regulates blood biochemical profiles and urinary metabolome and improves growth performance of growing lambs

Abstract

This study aimed to assess the growth performance and blood metabolites, as well as metabolic profiles in the urine of lambs fed on dietary rumen-protected choline (RPC). Thirty-six Dorper × Hu lambs weighing approximately 20 kg were equally assigned to three groups, and fed on three diets supplemented with different RPC concentrations (0, 0.25% and 0.75%) for 45 days. Supplementation of RPC significantly increased average daily gain (ADG) and decreased feed-to-gain ratio (F/G) of lambs (p < 0.05). Dietary RPC was significantly associated with elevated plasma high-density lipoprotein (HDL) and suppressed low-density lipoprotein (LDL) levels when compared to the control group (p < 0.05). Moreover, concentrations of very-low-density lipoprotein (VLDL) exhibited an increasing trend (p = 0.065), whereas β-hydroxybutyrate (BHBA) levels decreased (p = 0.086) in plasma. Analysis of urine metabolome revealed that RPC supplementation significantly suppressed urinary concentrations of pyruvate (p < 0.05), while increased urinary concentrations of trimethylamine oxide, p-cresol, phenylacetylglycine and hippurate (p < 0.05). These findings suggest that RPC supplementation can promote weight gain, alter plasma lipid metabolism and modify urinary metabolome which is correlated with energy metabolism, lipid metabolism and intestinal microbial metabolism in lambs. In conclusion, based on our findings, we recommend 0.25% RPC as a supplement for growing lambs.

Keywords:

• Rumen-protected choline
• lambs
• growth performance
• urine metabolomics
• blood metabolites

Acknowledgments

We thank the Home for Researchers editorial team (www.home-for-researchers.com) for editorial assistance with this manuscript.

Disclosure statement

The authors declare that they have no competing interests.

Additional information

Funding

This study was funded by the National Key Research and Development Plan [2017YFD0500500], the National Natural Science Foundation of China (NSFC) [31872988], the Top Talent Award Plan of Yangzhou University (2016), the earmarked fund for Jiangsu Agricultural Industry Technology System (JAST) and by Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).