Significance of vitamin A and E during periparturient period in dairy cows and buffaloes-A review

Abstract

Nutrition has a primary role for optimum expression of genetic potential, and most of the dairy farmers have limited resources of green fodder. Hence, a fat-soluble vitamin, especially vitamin A and E remained most critical in the dairy animal's ration and affects their productive and reproductive performance adversely. Animals cannot be able to produce these vitamins in their bodies; hence, an exogenous regular supply is needed to fulfil the physiological needs and to maintain high production performance. Dairy animals undergo intense changes in mammary gland during the periparturient period and become ready for the production of colostrum and milk. Since the concentration of both vitamins A and E are very high in colostrum, so the circulating levels of these vitamins drop during the time of calving causing many health problems and thus reduced the feed intake during the periparturient period. The precursor of vitamin A, and β-carotene is responsible for normal vision, cell growth, maintaining epithelial cells, healthy teeth, skeletal function and, therefore, protect the mucosal surface integrity. The β-carotene also acts as an antioxidant against free radicals. An intracellular antioxidant like vitamin E maintains cell membrane integrity by the protective effect against oxidation of polyunsaturated fatty acids which are enriched in the membranes of immune cells; especially lymphocyte membrane has high free fatty acids, making them prone to oxidative damage. It also increases the production of immunoglobulins in the body and increased the killing of intracellular microorganisms by neutrophils during calving. Vitamin E supplementation improves reproductive efficiency in farm animals by reducing the number of free radicals in tissues of the ovaries.