RESUMO
BACKGROUND: The second half of the first pregnancy is a critical period in the growth and development of the mammary gland. The use of functional compounds during this period may positively impact livestock performance. OBJECTIVES: In this study, changes in lipogenic enzyme gene expression in the mammary gland of Saanen goats in response to different dietary fat sources were analysed. METHODS: Goats from four groups (10 each) received these diets from the last two months of pregnancy through four months of lactation: C-, no added fat (negative control group), C+, with saturated palm oil (positive control group), SB, with roasted soybeans (omega-6 group) and FS, with extruded flaxseed (omega-3 group). The fat content was about 4% of dry matter. Milk yield, milk fatty acid profile, milk health index (HI) and gene expression of four lipogenic enzymes in mammary tissue were measured. RESULTS: The FS group had significantly higher milk production with lower omega-6 to omega-3, monounsaturated to polyunsaturated, and total saturated fatty acids compared to other groups. The shorter and longer than16-carbon chain of total milk fatty acid indicates significantly higher values for the C- and C+ groups, respectively. The milk HI for the SB group was significantly higher. The gene expression profile for acetyl-coenzyme A carboxylase was higher in the C- group than other experimental groups. CONCLUSIONS: The results show that manipulation of the diet with unsaturated fat supplements improved milk production, synthesis of milk fat and molecular expression of lipogenic enzymes in mammary tissue in primiparous Saanen goats.