Effect of Level of Feeding on the Performance of Crossbred Cows during Pre- and Post-partum Periods

다국어 초록 (Multilingual Abstract)

The study was undertaken to see the effect of elevated feeding during pre-partum or pre- as well as post-partum period on the productive and reproductive performance of crossbred cows. The experiment lasted for 60 d pre-partum to 120 d post-partum. Eighteen dry pregnant crossbred cows divided into three equal groups were fed either as per NRC feeding standard (C) or 20% above NRC during 60 d pre-partum ($T_1$) or fed 20% above NRC during both 60 d pre-partum to 120 d post-partum ($T_2$) period. During prepartum period body weight gain was significantly ($p{\leq}0.05$) higher in $T_1$ and $T_2$ groups than that of control group. The animals fed at higher plane of nutrition ($T_1$ and $T_2$) took significantly lesser time for complete relaxation of pelvic muscles, act of calving and for expulsion of placenta than that of control group. Moreover, such cows delivered 2 to 3 kg heavier calves as compared to normal fed dams. During post-partum period, the average daily milk yield was significantly higher in $T_2$ group than that in $T_1$ and control groups. The peak yield was significantly higher in $T_2$ group, it took longer time to reach peak production but it was more persistent in this group as compared to $T_1$ and control groups. Average milk fat, solids-not-fat (SNF) and total solids were significantly higher in $T_1$ and $T_2$ groups as compared to control group. Body weight losses incurred during early lactation were not even compensated by end of 4th month of lactation in C and $T_1$ groups whereas the animals in $T_2$ group gained 2.0 kg. The 1st post-partum estrus and conception rate were better in high fed groups ($T_1$ and $T_2$) than that of control group. The returns over feed cost of milk production were higher in $T_2$ group followed by $T_1$ and control groups indicating the advantage of elevated feeding during pre- and post-partum periods.