Metabolomics for the Effect of Biotin and Nicotinamide on Transition Dairy Cows

This is the authors' abstract. We don't add key points for this paper.

The objective of this study was to evaluate alterations in serum metabolites of transition dairy cows affected by biotin (BIO) and nicotinamide (NAM) supplementation. A total of 40 multiparous Holsteins were paired and assigned randomly within a block to one of the following four treatments: control (T 0 ), 30 mg/day BIO (T B ), 45 g/day NAM (T N ), and 30 mg/day BIO + 45 g/day NAM (T B+N ). Supplemental BIO and NAM were drenched on cows from 14 days before the expected calving date. Gas chromatography time-of-flight/mass spectrometry was used to analyze serum samples collected from eight cows in every groups at 14 days after calving. In comparison to T 0, T B, T N, and T B+N had higher serum glucose concentrations, while non-esterified fatty acid in T N and T B+N and triglyceride in T B+N were lower. Adenosine 5′-triphosphate was significantly increased in T B+N . Both T N and T B+N had higher glutathione and lower reactive oxygen species. Moreover, T B significantly increased inosine and guanosine concentrations, decreased β-alanine, etc. Certain fatty acid concentrations (including linoleic acid, oleic acid, etc.) were significantly decreased in both T N and T B+N . Some amino acid derivatives (spermidine in T N, putrescine and 4-hydroxyphenylethanol in T B+N, and guanidinosuccinic acid in both T N and T B+N ) were affected. Correlation network analysis revealed that the metabolites altered by NAM supplementation were more complicated than those by BIO supplementation. These findings showed that both BIO and NAM supplementation enhanced amino acid metabolism and NAM supplementation altered biosynthesis of unsaturated fatty acid metabolism. The improved oxidative status and glutathione metabolism further indicated the effect of NAM on oxidative stress alleviation.