Effect of Dietary Protein Levels on Performance, Nutrient Balance, Plasma Enzyme and Hormone Profiles of Growing Sahiwal Calves

The present study was carried out to observe the effect on performance, nutrient utilization, plasma enzymes and hormones in growing Sahiwal calves fed with three levels of proteins in the form of total mixed rations (TMRs). Fifteen male Sahiwal calves (12-18 month age) were distributed into three equal groups (147.35 ± 5.46 kg) and were fed on isocaloric diets containing different protein levels of 15% (T1), 13.5% (T2) and 16.5% (T3) for 90 days. Nutrient intake and their digestibility except CP digestibility did not differ significantly irrespective of treatment groups. CP digestibility was higher in T3 as compared to T2, though T3 did not differ from T1. DCP (g/100 kg BW/day) intake was significantly higher (P<0.05) in T3 than T2 but comparable to T1. TDN (kg/100 kg BW/day) intake was significantly higher (P<0.05) in T2 than T1 and T3, but was comparable between T1 and T3. The intake and retention of nitrogen were similar between the treatments. The average daily gain was highest in T2 followed by T3 and T1. The plasma enzymes alanine amiontransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) along with hormones (insulin and growth hormone) were comparable among all groups and were within normal physiological range. From the results, it was concluded that the performances of Sahiwal calves in terms of growth rate and feed conversion ratio was satisfactory even with low dietary protein level of 13.5%. Variation in dietary protein levels also did not affect the blood enzyme and hormone profiles of Sahiwal calves.