Pashu Sandesh, 14th January 2019
Mamata Joysowal, Anchal Keshri, Digvijay Singh,Zahid Beshir Khanday, Smriti Shukla and Anupama Tarun
The persification in the physiological status throughout the time of transition period from dry and pregnant to lactating is the most critical time faced by a dairy cow during her life time. Through continued efforts of long term genetic selection for high milk yield, cattle have been driven to produce higher quantities of milk in a shorter period of time than evolutionarily required. The seek for high milk yield is associated with a rise in micronutrients, amino acids and energy requirements. During the period of insufficient levels of these nutrients and metabolites, the animals become more vulnerable to an array of metabolic and infectious diseases. These so-called “transition disorders” are responsible for reduced monetary returns to dairy producers and also increased the awareness for animal welfare issues in the dairy industry among consumers. In an attempt to alleviate the risk of these transition disorders, nutritional practices have been employed to improve nutrition and animal welfare during the transition period.
Role of micronutrients in dairy animals
Trace minerals are important for execution of immune function, oxidative and energy metabolism and maintaining health and function of reproductive tract in dairy cows. Alterations in carbohydrate, protein and nucleic acid metabolism due to trace mineral deficiency cause faulty changes in the synthesis of reproductive and other hormones in the body. Their improper level may affect embryonic development, resumption of post-partum ovarian and uterine activities and over all fertility of animal. Mostly micronutrient deficiencies exert their effects upon reproduction through depression of the activity of rumen microflora reduction in enzyme activity affecting energy and protein metabolism and the synthesis of hormones; and the integrity of rapidly piding cells within the reproductive system. Micronutrients (minerals and vitamins) have significant effect upon fertility of cattle. The role of micronutrients as antioxidants, which are responsible for protecting cells from the effects of free radicals and that would be the possible cause of their role in immune system and maintenance of the membrane integrity of cells involved in milk production and reproduction.
The preponderance of data relating nutrition and bovine mastitis involves selected micronutrients.
Vitamin A and beta-carotene aid in maintaining the health of mucosal surfaces, and beta-carotene may also have antioxidant properties
Vitamin-E and Selenium
Vitamin E and Se are among the most efficient and stabilized antioxidants available in body cells. These micronutrients basically act through enhancing the immune functions of body rendering animal unaffected by the diseases. Vitamin E is an important fat soluble vitamin which prevents calf against white muscle disease. Vitamin E plays an important role in the maintenance of membrane integrity in almost all cells of body against toxic oxygen free radical against its per oxidation . Selenium plays its role being as an structural part of glutathione peroxidase enzyme. The biochemical function of glutathione peroxidase is to reduce lipid hydroperoxides to their corresponding alcohols and to reduce free hydrogen peroxide to water inhibiting the formation of other highly reactive oxygen free radical and protecting cell membrane against lipid peroxidation or oxidative damage . Selenium is also associated with thyroxine, a thyroid hormone that regulates metabolism, reproduction, circulation and muscle function. Selenium deficiency in dry cows has been reported to cause abortions, poor postpartum fertility, increased incidence of metritis, an increased incidence of retained placenta
Vitamin A and β-carotene
The Vitamin-A is well absorbed from digestive tract under normal conditions. The preferred form of vitamin-A supplementation is the retinyl palmitate whose absorption efficiency in a normal animal is >80%. The absorption of β-carotene from digestive system for its proper utilization is a complex phenomenon as it requires all the necessary factors to initiate a suitable micelle formation for its absorption; Under ideal conditions, no more than 60% of available β-carotene is absorbed by the animal system.
The trace minerals and vitamins play an important role to improve the health status of animals in every physiological state like pregnancy, transition, dry period and transition also they are major antioxidants in the animal system by scavenging free radicals generating in animal body through various biochemical and physiological processes inside the body
Mamata Joysowal*1, Anchal Keshri1, Digvijay Singh1,Zahid Beshir Khanday2, Smriti Shukla2 and Anupama Tarun2
1 Ph.D. Scholar, National Dairy Research Institute, Karnal (Haryana)-132001
2 M.V.SC Scholar, National Dairy Research Institute, Karnal (Haryana)-132001
Corresponding author*email; email@example.com