EFFECT OF PREPARTUM TREATMENT OF VITAMIN E-SELENIUM ON POSTPARTUM REPRODUCTIVE AND PRODUCTIVE PERFORMANCE. OF EXOTIC COWS AND THEIR CALVES UNDER SUBTROPICAL CONDITIONS

摘要

This study was carried out at the Livestock Experiment Station, Bhunikey (Pattoki), District Kasur,Pakistan. Forty exotic cows (20 each of Holstein Friesian and Jersey breed) in their last trimester of pregnancywere randomly selected. These cows were divided into two equal groups. Animals of group-I served as controland were injected with 20 ml sterile normal saline intramuscularly, while each cow in group-II was treated withvitamin E-selenium (vitamin E acetate 50.0 mg and sodium selenite 0.5 mg/ml) twice (20 ml at each time) withone-week interval. First injection was given at about 40-60 days prior to the expected date of calving. Calvesborn to the experimental cows were monitored to study the carry over effect of treatment, if any, from dams tothe calves. The reproductive parameters, viz. placental expulsion period, uterine involution period, postpartuminsemination interval, service period and number of services per conception in the cows of treated group weresignificantly (P<0.05) lesser compared with those of the control group. However, the differences in productionparameters, i.e., lactation milk yield, lactation length and wet average between the two groups were statisticallynon significant. The same was true for birth weight, weaning weight and growth rate upto weaning betweencalves of the two groups. In conclusion, it appears that administration of vitamin E-selenium before calvingmay be beneficial in improving the postpartum reproductive parameters in exotic cows. However, number ofanimals used in each group was too small to draw any definite conclusion.