The responses of multiparous Holstein cows to grain type in prepartum diets and non-fiber carbohydrate level in post-partum diet on milk yield and content and plasma metabolites in peripartm period

An experiment was conducted to determine the interaction effects of grain type with different ruminal fermentability of starch in prepartum diet (ground barley and corn) and nonfiber carbohydrate level in postpartum diet sixty multiparous Holstein cows randomly assigned to experimental diets. The cows were used based on expected calving date and fed 24±3 d prepartum diets and then randomly assigned to postpartum diets during 28 d. Blood samples were collected at beginning and calving day and d 21 of the trial. Daily milk production and weekly milk content were measured during 28 d. Data was analyzed to determine the interaction effects of peripartm diets. There were no significant difference between prepatum diets for plasma metabolites except for total protein and non strified fatty acids (P<0.05) which was higher for barley based diet. There were no significant difference between prepartum diets for milk production and contents. In postpartum, the cows fed low level of non-fiber carbohydrate diet had greater fat corrected milk and fat percentage and total solid (P<0/01). Also these cows had lower levels of plasma glucose and albumin (P<0/01) and higher level of phosphorous and betahydroxy butyric acid (P<0/01) and alanine amino transferase (P<0/05). The interaction effects were not significant. Generally the results showed that increased rumen fermentability of starch in prepartum diets hadnt positive effects in postpartum cows and postpartum responses are dependent to postpartum diets. Decreased non fiber carbohydrate (starch as a most fraction) in postpartum diets can improve multiparous postpartum Holstein cows’ performance.