Acta Veterinaria et Zootechnica Sinica ›› 2022, Vol. 53 ›› Issue (5): 1396-1408.doi: 10.11843/j.issn.0366-6964.2022.05.008

• ANIMALGENETICS AND BREEDING • Previous Articles     Next Articles

Metabolomic Analysis of Milk from Holstein Cows with High and Low Milk Fat Percentage

WANG Ying1, WEN Liang2, MU Tong1, FENG Xiaofang1, LIU Jiamin1, ZHANG Juan1, WEN Wan3, GU Yaling1*   

  1. 1. School of Agriculture, Ningxia University, Yinchuan 750021, China;
    2. Ningxia Agriculture Helanshan Dairy Corporation Ltd., Yinchuan 750000, China;
    3. Animal Husbandry Extension Station, Yinchuan 750001, China
  • Received:2021-10-12 Online:2022-05-23 Published:2022-05-25

Abstract: The study aimed to screen the potential landmark differential metabolites in milk with different milk fat levels. In this study, 245 fresh milk samples (4:3:3 mixture) were collected from the early, middle and late shifts of healthy first-calf Holstein cows with similar weight and age in the middle and late stages of lactation (180-210 d) from the Maosheng pasture of Helanshan in Ningxia state farm. After DHI determination, 26 samples with the number of somatic cells less than 200 000 pcs·mL-1 and extreme differences in milk fat percentage were screened. Among them, the milk with higher milk fat percentage than 4.4% was the high milk fat percentage group (HF group, 13 samples), and the milk with less milk fat percentage than 3.0% was the low milk fat percentage group (LF group, 13 samples). The samples were then subjected to metabolomic analysis using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). The results of PLS-DA showed that, compared with LF group, the metabolic profile of HF group changed, and 343 metabolites were identified in HF and LF groups. According to VIP value (VIP>1) and univariate statistical analysis (P<0.05), 60 significantly differential metabolites were screened out in positive and negative ion modes (P<0.05). Among them, according to P<0.5 and FC>2.0 and P<0.5 and FC<0.5, the content of 15 metabolites in milk samples of HF group was higher than that of LF group, and the content of 6 metabolites was lower than that of LF group.Further, through ROC curve, it was found that there were 18 kinds of differential metabolites which had remarkable distinguishing ability to the two groups of milk, among which the differential metabolites with AUC>0.85 were N-oleoylglycine, cortisol, δ-tocopherol and PC (14:0e/9:0). The results showed that there were 60 metabolites with significant differences in different milk fat levels, and the metabolites N-oleoylglycine, cortisol, δ-tocopherol and PC (14:0e/9:0) could be used as potential landmark metabolites of high milk fat percentage. The results of this study provide valuable theoretical basis for milk fat synthesis of dairy cows, and also provide data for studying the lactation process of dairy cows.

Key words: Holstein cow, milk fat percentage, metabolomics, marker metabolite

CLC Number: