اثر منابع مختلف نشاسته در جیره‌های دارای دانه پنبه کامل بر الگوی اسیدهای چرب پلاسمایگاوهای شیرده هلشتاین

Background:starch source in diets containing unsaturated fatty acids influence plasma fatty acid profile of lactating cows.objectives: thisexperiment was conducted to investigate the effects of different starch sources including corn grain, wheat grain, barley grain and potato in diets contacting whole cottonseed as a source of unsaturated fatty acids on plasma fatty acid profiles, dry matter intake and milk production and composition of lactating holstein cows.methods:in this experiment, eight multiparous holstein cows with 83 ± 9 days in milk, 33 ± 3 kg milk production and 683 ± 31 kg of body weight were used in a repeated 4 × 4 latin square design with 4 diets and 4 periods. experimental diets were consisted of diet containing 25.20 % wheat grain, diet containing 26 % barley grain, diet containing 25 % corn grain and diet containing 25 % potato on dry matter basis. dry matter intake, milk production and composition and plasma fatty acids profile were measured.results:plasma concentration of 18:2 cis-9 cis-12 and total unsaturated fatty acids were higher in cows fed diet contacting wheat or barley compared to those fed corn or potato. cows fed diet containing potato had the lowest daily raw milk yield, 4% fat corrected milk or energy corrected milk production. milk fat percentage was higher in cows fed corn containing diet compared to other diets. dry matter intake and concentration of milk protein and lactose were not affected by the experimental diets. conclusions:according to these results, wheat and barley starch compared to corn and potato starch increased plasma concentration of total unsaturated fatty acids of lactating cows that can improve fatty acids profile of ruminant milk and tissue.