Exogenous enzyme supplementation and lactation performance of dairy cows

The effect of supplementing exogenous enzymes as a biotechnological tool on lactational performance of 18 Jersey and crossbred (J x K) lactating cows was evaluated in terms of body weight changes, milk production, milk composition, feed efficiency and economics of milk production. The cows were assigned at random in three groups (6 in each) following completely randomized design after 33–45 days of parturition and attaining the peak production. First group (T1) was fed concentrate mixture without enzyme (control). In second group (T2) control concentrate mixture with enzyme-A and the cows under third group (T3) were fed control concentrate mixture with enzyme-B. The respective enzymes were added at the time of preparation of concentrate mixture in dry powder form. The average daily milk production of cows under T1, T2 and T3 was 7.79,10.01 and 8.28 kg. Cows fed enzyme A (T2) produced significantly higher amount of milk than the cows fed either control (T1) or T3 diet (P<0.05). Similarly, the average daily FCM production under T2 was significantly higher than the T1 and T3 (P<0.01). Milk fat and milk total solids percentage were also higher (P<0.01) for cows fed enzyme treated diets (T2 & T3). At the same time, no differences were observed in percentage of other milk components and body weight changes for the whole experimental period. Efficiency of feed utilization was higher (P<0.05) for cows fed T2 diet than that of the cows fed either control (T1) or T3 diet. The cost of feed per kg milk and FCM produced was Rs. 4.98 (T1), 4.62 (T2) and 5.20 (T3) & Rs. 5.11 (T1), 4.14 (T2) and 4.84 (T3), respectively during the experimental period of 24 weeks. Cows under T2 were economically more efficient by 7.23 and 11.15 per cent to produce milk & 18.98 and 14.46 percent to produce 4% FCM in comparison to cows fed T1 or T3 diet. Supplementation of enzyme-A in concentrate mixture of dairy cows after attaining peak improved their lactational performance during entire experimental period.