Triglyceride and fatty acid composition of bovine colostrum and transition milk in pasture‐based dairy cows supplemented prepartum with inorganic selenium, organic selenium or rumen‐protected choline

The objectives of this study were to determine the effects of prepartum supplementation with inorganic selenium (INORG), organic selenium (ORG) or a rumen‐protected choline, on the triglyceride (TAG) and total fatty acid (TFA) profiles of bovine colostrum and transition milk. Fifty‐seven Holstein Friesian (HF) and HF × Jersey cows were supplemented daily from 49 ± 12.9 days prior to calving until day of calving. Milk samples were analysed for TAG and TFA composition using GC‐FID. Prepartum supplementation did not have a significant effect on the milk lipid profiles. This study quantified colostrum lipids not previously reported in the literature. The impact of supplementing inorganic selenium, organic selenium or rumen‐protected choline during the prepartum period on the lipid composition of colostrum has not been previously investigated. Supplementing these three micro‐nutrients did not significantly affect the lipid composition of colostrum or transition milks. However, this study quantified numerous triglycerides and fatty acids within colostrum from pasture‐based dairy cows previously not reported in the literature.