Effect of graded levels of zinc supplementation on growth and nutrient utilization in male buffalo (Bubalus bubalis) calves

Eighteen Murrah male buffalo (Bubalus bubalis) calves (219.2±5.76 kg body weight; ∼14–15 months of age) were assigned into three groups of six animals in each in a randomized block design. Experimental feeding was similar in the three groups (concentrate mixture and ad libitum wheat straw), except for the level of zinc (as zinc sulphate) supplementation, which were 0, 35 and 70 ppm in Gr. I, II and III, respectively. The study was conducted for a period of 120 days including a 6 days metabolism trial. The mean dry matter (DM) intake was comparable (P>0.05) at 73.83, 72.76 and 75.59 g/kgW^0.75 in Gr. I, II and III, respectively. Intake and digestibility of organic nutrients including fibre fractions were also similar (P>0.05) among the three groups. Intake of N, Ca and P, their excretion through faeces and urine and balances were also similar (P>0.05) among the three groups. However, average daily gain of the calves was significantly (P<0.05) higher in Gr. III (601.4 g/d), as compared to Gr. I (547.4 g/d) and Gr. II (566.7 g/d). Feed (DM) required per unit of body weight gain was also significantly (P<0.05) lower in Gr. III (8.97), as compared to Gr. I (10.3). These results indicated that supplementation of 70 ppm zinc in the basal diet containing about 35 ppm zinc may improve the growth performance and feed conversion efficiency in the male buffalo calves. However, further studies with more number of animals are suggested.