Analysis of differential colostrum metabolism in high and low yielding Guanzhong dairy goats

Abstract

In order to identify and analyze the metabolites of colostrum differences between high yielding and low yielding Guanzhong dairy goats from metabolomics point of view. Six high-yielding (milk yield (3.68 ± 0.57) kg/d) and six low-yielding (milk yield (1.17 ± 0.64) kg/d) Guanzhong dairy goats of similar age, litter size, body weight, and days of lactation (2 nd day postpartum) were selected. The colostrum samples were examined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the results were combined with orthogonal partial least squares discriminant analysis (OPLS-DA) and Student's t-test. The metabolites were screened for differential metabolites based on the principle of variable importance in the projection (VIP) > 1, P < 0.05, and the differential metabolites were subjected to cluster analysis, significant difference screening, and enrichment of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The results showed that 95 differential metabolites were screened from the colostrum of Guanzhong dairy goats in the two groups, and the clustering heatmap showed that 9 of the top 50 differential metabolites were the most abundant in relative terms. The metabolites with significantly increased content in the colostrum of Guanzhong dairy goats in the high-yield group were D-alanine-Dserine, α-lactose, isoflavoprotein 2"-(6'-p-coumaroylglucoside), D-maltose, pravastatin, and diketoglucuronic acid, whereas the differential metabolites with relatively decreased content were taurocholate, L-carnitine, and thiamphenicol A. KEGG pathways enrichment analysis identified 8 potential metabolic pathways The results of this experiment provide a theoretical basis for the subsequent analysis of the mechanism of milk production traits in dairy livestock and the selection and breeding of high-yielding dairy goats.