Comparison of the effect of feeding fish oil versus palm oil in the transition period on Holstein milk fatty acid profile

Because of milk fat importance of providing some special fatty acids in human nutrition, there is increasing attention to the milk fatty acid profile designing. For studying the effect of feeding fish oil and palm oil on milk fatty acid profile, ten multiparous Holstein cows, based on their expected parturition dates, from six weeks before up to 63 days after calving, randomly received palm oil or fish oil. Milk production was measured daily and milk compositions were determined weekly. The milk fatty acid profile was determined by gas-chromatography. Fish oil supplement decreased saturated fatty acid content in milk fat (P<0.05) and increased its polyunsaturated fatty acid content (P<0.05), but had no effect on monounsaturated fatty acid content in milk fat (P>0.05). Milk fat omega-6 to omega-3 fatty acid ratio, decreased (P<0.05) and health index increased (P<0.05) with inclusion of fish oil in the diet. Likewise, milk fat to protein ratio and monounsaturated to polyunsaturated fatty acid ratio, which has been linked to negative energy balance, were decreased with feeding fish oil (P<0.05). These results suggest, that the supplementation of dairy cows diet with fish oil from dry period, could improve the milk fatty acid profile to human health and also alleviate the intensity of negative energy balance in early lactation.