Effect of Supplementation of Niacin on Milk Yield and its Composition in Lactating Crossbred Cows During Summer

摘要

The present study was conducted on eighteen crossbred lactating cows (Days in milk= 11.56; 2nd to 4th lactation) divided into three groups on the basis of average milk production. All the animals were fed basal ration consisting of wheat straw (20%),chaffed green maize fodder (40%) and compounded concentrate mixture (40%) as per NRC (2001). Animals in treatment group were fed the same basal diet along with the daily niacin supplementation of 600 (T_1) and 800 (T_2) mg/kg of DM. The trial lasted for120 days (25th April to 25th September, 2012). The maximum temperature, minimum temperature, relative humidity and dry-wet bulb temperature were recorded daily in morning (7:30 am) and afternoon (2:30 pm) and TH1 was computed. Animals were in moderate stress during morning, whereas in the afternoon the animals were severely stressed. The milk yield, 4% FCM, ECM, SCM and milk energy remained unaffected by supplementation of niacin. The results of average milk components and yield (% and kg/d) viz., milkfat, protein, lactose, SNF and total solids were also not influenced by different treatments. Milk urea concentration was significantly (P<0.05) higher in T_2 However, there was no difference between control and T_1 group. Milk niacin (mg/L) was significantly higher (P<0.01) in T_1 (0.32±0.01) and T_2 (0.32±0.01) as compared to control (0.22±0.01). It was concluded that niacin supplementation had no effect on milk yield and its composition, however, milk niacin level was improved.