Effect of vitamin E supplementation on growth, nutrient utilization, blood biochemical and enzymatic profile in male crossbred (Bos indicus × Bos taurus) calves

Twenty male crossbred [Hariana (Bos indicus) × Jersey (Bos taurus)] calves (7–15 days old; 22.7 kg average body weight) were divided randomly into four groups of 5 calves in each on the basis of their body weight to study the effect of graded levels of α-tocopherol supplementation on their growth, nutrient utilization and blood biochemical profile. All the calves were fed on milk and calf starter up to 8 weeks of their age, and afterwards they were fed on concentrate mixture and oat hay up to 32 weeks of age. In addition, the calves in group I, II, III and IV were supplemented with 0, 125, 250 and 500 IU feed grade DL-α- tocopheryl acetate, respectively. Vitamin E was mixed in milk up to 8 weeks and later on it was mixed in the concentrate mixture of the calves. All the calves were weighed at 14 days intervals up to 32 weeks, to assess their growth rate. Blood samples were collected at 0 day and subsequently at 1, 2, 4, 6 and 8 months of their age to monitor the blood biochemical profile of crossbred calves. After 6 months of feeding trial, a metabolism trial was conducted to estimate the digestibility of nutrients. Results revealed no significant effect of vitamin E supplementation on total body weight (kg) gain, which was 82.0, 102.3, 87.6 and 87.1 kg in group I, II, III and IV, respectively, indicating a non-significant (P>0.05) different daily gain (g) of 366.0, 456.7, 391.0 and 388.8, in 4 groups, respectively. Digestibility of proximate principles (dry matter, organic matter, crude protein, ether extract) and fibre fractions (neutral detergent fibre, acid detergent fibre, cellulose and hemicelluloses) were similar in 4 groups, without showing any effect of vitamin E supplementation. Results revealed that the mean values of plasma glucose showed a decreasing trend, while the mean values of serum total protein, globulin, urea, creatinine, ALP, SGOT, LDH and CK showed an increasing trend with the advancement of age in all the 4 groups. Studies on blood enzyme profile revealed non-significant variation in alkaline phosphatase and SGOT level due to vitamin E supplementation. The cumulative group mean values for ALP (KA units/dl) and SGOT (units/ml) were 17.98, 18.42, 17.80, 17.59 and 21.94, 19.51, 20.54 and 20.56 in group I, II, III and IV, respectively. The activity of lactic dehydrogenase (units/litre) in the serum of calves given 250 IU vitamin E (group III) was significantly (P<0.05) lower than group I (control) and similar to group II and IV. Similarly, the activity of serum creatine kinase (units/litre) in calves of group III (137.59) was significantly (P<0.05) lower as compared to group I (161.96), but statistically similar to group II (152.46) and group IV (146.55). It may be concluded that supplementation of vitamin E at different levels in the diet of young calves did not affect the growth, digestibility of nutrients, and blood biochemical profile, except muscle enzymes i.e. lactic dehydrogenase and creatine kinase, which were significantly reduced due to α-tocopherol supplementation.