Serum metabolomic profile in genetically modified cows carrying human α-lactalbumin gene

The present study aimed to investigate the serum metabolomic profiles in genetically modified cows carrying and expressing human lactalbumin α (LALBA) and non-LALBA cows, and identify altered metabolic characteristics following the genetic modification. Serum biochemistry indexes were measured according to protocols recommended by International Federation of Clinical Chemistry. The metabolomic profiles were determined using the serum samples collected from LALBA (n=6) and non-LALBA cows (n=6). Welch's two-sample t-test was used to identify the metabolites that significantly differed between the LALBA and non-LALBA groups (fold-change ≠ 1 and P<0.05), followed by random forest and pathway analysis. The serum biochemistry indexes of LALBA and non-LALBA cows were within the normal ranges of healthy cows. A total of 273 metabolites were detected, among which 79 metabolites, including 46 increased and 33 decreased metabolites, differed significantly between the LALBA and non-LALBA groups. Random forest analysis identified 30 potential key metabolites, including 14 elevated and 16 reduced metabolites. These metabolites were primarily involved in pathways concerning the metabolism of leucine, isoleucine, valine, tryptophan and lipids, such as myristate and eicosapentaenoate. However, the serum in LALBA cow had unique metabolomic signature compared with non-LALBA cows. The accumulation of polyunsaturated fatty acids and amino acids, and the reduced levels of long chain saturated fatty acids in serum may benefit LALBA cows. However, further investigations are required to validate these benefits and the corresponding mechanisms.