Dry Matter Intake, Milk Yield and Milk Fatty Acid Composition of Dairy Cows Fed Raw or Microwave Irradiated Safflower Seed as a Substitution to Cottonseed

The present study was conducted to evaluate the effects of using raw or microwave irradiated safflower seed on dry matter intake, milk production and composition, milk fatty acid profile, blood parameters, and nutrient apparent digestibility in early lactation cows. Nine multiparous Holstein cows at early lactation were randomly assigned to one of three treatments based on 3 × 3 balanced latin square design. Dietary treatments included whole linted cottonseed (control), 40 g/kg DM raw safflower seed (RSS), and 40 g/kg DM microwave irradiated safflower seed (MSS). Results showed no significant effect of dietary treatments on milk production, milk fat, protein, and lactose content, and dry matter intake. Feeding RSS and MSS diets increased milk long chain fatty acids, C18:1 trans, C18:2, and polyunsaturated fatty acid concentrations, while milk C16 fatty acid (P<0.05) decreased. The cis-9, trans-11 conjugated linoleic acid (CLA) concentration tended to be higher in cows fed MSS diet. It was concluded that there are no negative impacts of raw and microwave irradiated safflower seed supplementation on lactation performance, while milk quality was meliorated by increasing unsaturated fatty acid concentrations.