Gene expression levels in some candidate genes for mastitis resistance, milk yield, and milk quality of goats reared under different feeding systems

Abstract

This study aimed to identify the expression levels of some candidate genes for mastitis resistance ( LT F and BRCA1 ), milk yield ( POU1F1 and IGF-1 ), and milk quality ( PPARγ and CSN2 ) in different feeding systems (pen- and pasture-based) used for Damascus goats. Milk samples were taken from all goats in both pen and pasture groups at 4 times, at the 1st, 3rd, 5th, and 7th months of the study. It was found that, compared to the pen group, the LT F and CSN2 genes in the pasture group had significant levels of upregulation in the 7th month of lactation (3.538- and 5.436-fold, respectively), the PPARγ gene had downregulation at the beginning of lactation (0.399-fold), and the IGF-1 gene had upregulation in the 3rd month of lactation (2.313-fold) but had significant levels of downregulation (2.332-fold) in the 5th month of lactation. It was determined that LT F gene expression levels in goats might be used as a criterion in identifying mastitis resistance, IGF-1 for lactation milk yield, and PPARγ for milk fat yield. This study is the first report that presents LT F , BRCA1 , IGF-1 , and PPARγ gene expression levels in goat milk and udder epithelial cells and the effect of BRCA1 , POU1F1 , and PPARγ genes on milk protein yield.