Post-partum reproductive performances of crossbred cows

Abstract

The object of the present investigation was to study the various aspects of the post-partum reproductive performances of crossbred cows and to assess the reproductive efficiency by breeding cows before and after 60 days post-partum. Fifty two freshly calved and randomly selected crossbred cows, belonging to the University Livestock Farm, Mannuthy formed the materials for the study of genital involution, cyclic ovarian acivity and post-partum oestrus. These animals were grouped into normal and abnormal calvers and data recorded and analysed. Twenty four crossbred cows, selected at random, were weighed at fortnightly intervals, commencing from the day of calving till 90 days post-partum to study the pattern of gain or loss in weight and its influence on the post-partum heat and conception. To study the effect of early breeding on the future reproductive efficiency 38 crossbred cows in oestrum were grouped into three. Group I was inseminated between 30 and 45 days, group II between 46 and 60 days and group III after 60 days post-partum and fertility assessed. Data collected were subjected to statistical analysis. The observations made and inferences drawn are summarized below: Abnormal calving significantly delayed the involution of uterus, cessation of uterine lochia, involution of vulva, regression of pregnancy corpus luteum and onset of first observed oestrus, The rate of uterine and vulval involution were significantly higher in primpara than pluripara. In contrast, primparous cows took a significantly longer interval for the onset of first observed heat. However, breed of the cow, milk yield and sex and weight of calf did not influence any of the parameters studied. Animals gained in body weight after calving exhibited early oestrum and better fertility. Further, breeding of cows, between 30 and 60 days after calving yielded high fertility without adversely affecting milk yield, thus reducing the service period and calving interval.