The effects of supplementing diet with unsaturated oil on productive performances of Holstein dairy cows in early lactation

To examine the effect of including oil in diets on early lactating productive performance parameters including; dry matter intake, milk production and components, body condition score, body weight and negative energy balance; twenty multiparous Holstein cows were randomly assigned to the experimental diets from 21 days before predicted calving time to 50 days in milk. Treatments including 1) control (no supplemented oilin both pre and postpartum, n=10) and 2) supplemented diets (supplemented with fish oil and canola oil in 50:50 ratio in amount 1% DM in prepartum and 2% DM in postpartum). Prepartum and postpartum dry matter intake, body condition score and body weight were not affected by the diets (P>0.05). Negative energy balance in early lactation was similar between diets (P>0.05). Daily milk production increased in oil supplemented diet (P<0.05) and milk fat percentage decreased in the supplemented diet (P<0.05), but including oil in diets had no effects on protein percentage and production, fat and lactose production in milk (P>0.05). According to results, supplementing diet with fish oil and canola oil from prepartum to early lactation had no adverse effects on the productive parameters in early lactation and also increased milk production. Keywords; oil, early lactation, milk production, DM