effect of conjugated linoleic acid supplement and sesame as source of n-6 on performance and milk fatty acid profile of holstein dairy cows during transition period

Background: feeding unsaturated fatty acids sources in dairy cows is considered as a strategy to improve animal health during postpartum period and milk fatty acid profile. objectives: this study aimed to investigate the effects of conjugated linoleic acid supplement and combination of sesame meal and oil on performance and milk fatty acid composition of dairy cows during transition period. methods: twenty-one multiparous holstein cows (249 days of pregnancy) were randomly assigned to 3 dietary treatments including: 1) control with a source of calcium salts of palm oil (0.95 and 1.68% of the dry matter in prepartum and postpartum diets, respectively), 2) conjugated linoleic acid supplementation (0.4 and 0.5% of the dry matter in prepartum and postpartum diets, respectively) 3) sesame meal (2.18 and 4.32% of the dry matter in prepartum and postpartum diets, respectively) and calcium salt of sesame oil (0.83 and 1.4% of the dry matter in prepartum and postpartum diets, respectively) as source of n-6. results: dry matter intake, body weight, body condition score, average milk yield and component including fat, protein and lactose were not affected by dietary treatments. the proportion of short and medium chain fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were not affected by dietary treatments. conjugated linoleic acid supplement numerically increased content of cis-9, trans-11 conjugated linoleic acid and reduced short chain fatty acids (<12 carbons) in milk fat compared to control and sesame treatments. conclusions: feeding conjugated linoleic acid supplement and combination of sesame meal and oil had no effect on performance, milk composition and fatty acid profile.