Omega-3 supplementation, milk quality and cow immune-competence

This study aimed to assess the effect of a dietary supplementation rich in n-3 fatty acids from algae (Schizochytrium sp.) on cow immune-competence and milk quality. Twenty-one lactating Italian Friesian cows (at 220±20 days of lactation) were equally allocated to 3 treatments: group C received no supplementation, group D was offered 136 g of docosahexaenoic acid (DHA) per day and group E was supplemented with 136 g of DHA + 2000 U.I. of vitamin E per day. Individual milk production was recorded weekly and samples were collected for analysis of milk composition and fatty acid profile. At the end of the trial and 2 weeks later animals were subcutaneously injected with 5 mg of keyhole limpet haemocyanin (KLH), whereas at the end of the trial and 8 weeks later skinfold thickness was measured after intradermal injection with 500 mg phytohaemagglutinin. Dietary treatment showed no effect on milk production. Concentrations of DHA were higher (P