Effect of some trace mineral-vitamin supplements on negative energy balance, lactation performance and colostrum quality of high production Holstein cows during summer season
This study was conducted to evaluate the effects of some nutritional and injectable mineral-vitamin supplements on milk performance, colostrum quality and negative energy balance in transition dairy cows. One hundred multiparous Holstein cows were randomly assigned to four groups. The treatments were consisted of: (1) control, (2) injection of Se- vitamin E supplement, (3) Feed minerals- vitamins bolus supplement, and (4) injection and feed mineral-vitamin supplements. The injectable supplement was contained vitamin E and Se and the dietary bolus was contained Cu, Co, Se, Mn, I, Zn, and vitamins A, E and D3. The data showed beta-hydroxybutyrate and NEFA was the lowest (P<0.05) in group which received injectable and nutritional bolus supplement and negative energy balance was reduced. The nutritional bolus increased (P<0.05) milk yield of cows. The group supplemented with injectable vitamin E-Se along nutritional bolus had higher (P<0.05) milk protein yield (kg/d). The treatments affected milk solids non fat and the control group had lower content (P<0.05) than those others. The nutritional bolus decreased (P<0.05) milk somatic cell score (SCS) compared with control group. The treatments just affected the colostrum fat content. It was concluded that the nutritive bolus with or without injectable supplement had positive effects on milk and milk components and colostrum composition and negative energy balance.
Keywords: Mineral- vitamin supplements, Negative energy balance, Dairy cow