Relation of milk parameters with postpartum reproductive efficiency in cattle

Abstract

The high producing dairy cow is under high metabolic demandduring the period immediately following parturition due to themetabolic demands of increased milk production. Negative energy balance probably acts similarly to under nutrition and may manifest in delayed ovarian activity by impinging on pulsatile secretion of LH. Recent studies revealed that certain milk parameters indicate the postpartum reproductive performance in exotic cattle. In the present study, milk parameters i.e. milk yield, lactose and milk urea nitrogen (MUN) were correlated with the day of first postpartum heat exhibition. Milk samples were collected from 25 lactating animals on 10 ^th day of calving and after weekly intervals up to 12 weeks. Milk yield was recorded and the samples were analyzed for lactose and MUN. There was a significant positive correlation between milk yield and day of first heat. Animals with high milk yield took long time to exhibit the first postpartum heat. There was no significant difference in the milk yield between the groups of animals, which conceived within 3 months and the group of animals which conceived after 3 months. Non significant negative correlation was found between milk lactose concentration and day of occurrence of first postpartum heat. There was a significant positive correlation between MUN and day of occurrence of first heat but no significant difference was found in group of animals which conceived within 3 months and the group which conceived after 3 months.