Evaluation of genes expression affecting mammary gland growth and development in cows fed fish oil

This study was conducted to evaluate the effects of feeding fish oil compared to palm oil on the expression of genes affecting the mammary gland growth and development in Holstein cows. Ten cows with at least one parturition were randomly assigned to fish oil (FO) or palm oil (PO) groups, from 42 days before expected parturition date up to 63 days of lactation. Blood samples were taken at 21 days intervals and mammary tissue sampling were taken in two-month intervals (seven and 63 days after parturition). There was no significant difference in serum estradiol and progesterone concentration between two groups. The result of gene expression analysis showed that the relative expression of IGF-I gene in the fish oil group decreased (P