A study was conducted to assess the influence of dietary protein levels on pregnant heifers. Twelve crossbred heifers at mid pregnancy having average body weight of 331 kg ± 12.20 kg divided into 3 equal groups were offered concentrate mixture (19.78%CP) supplemented with wheat straw and green fodder. The animals of control group T1 were fed individually as per NRC (1989) standards and those in T2 and T3 were fed 10 and 20% higher CP, respectively. Total dry matter intake did not differ significantly owing plane of protein, but intake of R: C ratios narrow down due to higher level of protein and were 62:38, 56:44 and 52:48, in respective treatments. Body weight gain of heifers and calf birth weight were significantly (P<0.05) more by feeding 10% higher crude protein. The nutritive value w.r.t. DCP & TDN percent of the daily diet intake in T2 was significantly (P<0.05) high as compared to control group, but at par with T3. Similarly, DCP intake of T2 (716g) and T3 (735g) were significantly (P<0.05) more than T1 (637g). The digestibility coefficients of DM, OM, NDF, ADF and hemi-cellulose did not differ significantly between different groups. The digestibility of CP, EE and NFE was significantly (P<0.05) higher in pregnant cattle fed 10% higher protein, however, reverse trend was observed in case of CF digestibility. Average daily milk yield was 9.51, 11.35 and 10.26 kg in treatments T1, T2 and T3, respectively. The results revealed that by increasing 10% CP in the diet, milk yield and 4% FCM yield increased significantly (P<0.05). The highest peak yield was attained by animals under treatment T2, but days required to attain peak yield were more. Present investigation inferred that feeding of 10% higher CP over NRC standards to the pregnant heifers significantly (P<0.05) increased the body weight gain, calf birth weight, nutrient utilization and milk production.
Heifers, Digestibility, Pregnant, Calf birth weight, Milk yield
