Maurya, V. P., Kant, Lata, Majumder, Susmita, Verma, Preeti, Das, Pravasini, Pandey, Anamika, Chouhan, V. S., Samad, H. A., and Singh, Gyanendra
The adoption of various practices for higher milk production from the animals is very pertinent, which generally increases peripartum disorders. In the period of transition phase (3 weeks before parturition and 3 weeks after parturition), an animal is in huge demand of energy for the developing fetus, colostrum production, and subsequent milk production for the postnatal development of the calf, and thus animals undergo a complex set of physiological and metabolic adaptations. The transition stress drastically has an impact on immunological function which leads the metabolic disorders in animals. In many experiments, it has been reported that immune dysfunction causes early lactation disorders during the period around the dryoff. The stress and dietary changes occur during the period of transition phase which may affect immunity, metabolic and physio-biochemical changes which finally affect the productive efficiency of animals. Several nutritional strategies and mental strategies have been adopted to minimize the detrimental consequences on the immune system during the transition phase. A suitable environment and a healthy balanced diet should be given to the transition cow to minimize transition phase challenges. Just after parturition, Dry matter (DM) consumption increases more slowly than milk energy output, therefore the animals cannot meet their nutritional needs only through feed consumption. During the last 3 weeks of pregnancy, nutrient demands by the fetal calf and placenta are at their greatest, and in a few animals, DM consumption may decrease by 10 to 30% as compared with consumption during the initial phase of the dry period. In such conditions, animals are exposed to negative energy balance and most of the animals attempt to make up energy balance by lipolysis of stored body fat. This leads to an increase in the non-esterified fatty acid (NEFA) in the blood and further, there is an accumulation of NEFAS in the liver causing fatty liver, which in turn stimulates cytokines. Cytokines activate receptors on different target cells leading to systemic inflammatory reactions resulting in several biochemical changes, such as elevated glucocorticoid and adrenocorticotrophic hormone production, the stimulation of the blood clotting process, decreased serum concentrations of calcium, zinc, copper, iron, and vitamin E. Ascorbic acid and vitamin E are typical antioxidant substances that break the chain of lipid radicals and transform them into more stable metabolites. Cu-Zn superoxide dismutase (SOD) and ceruloplasmin are two enzymes that copper and zinc are involved in, and these enzymes participate in the antioxidant system. In the cytosol, superoxide radicals are transformed into hydrogen peroxide by Cu-Zn SOD. Selenium aids in boosting neutrophil activity. Just before parturition, there is an increase in the level of serum cortisol and estrogen, which suppresses the immunity of animals by reducing the phagocytic index and lymphocyte proliferation in the animals. The animals become immune compromised and under such situations animals used to have different types of metabolic diseases viz, metritis, mastitis and retained placenta. The successful transition phase is of prime importance and concern to animal keepers by reducing macro-mineral deficiencies, lipid mobilization and immune suppression. The animal owner can get rid of transition problems of animals by supplementation of Vit E, Se, Cu, Zn, Chromium and 20-25% additional energy. This supplement may help animals to pass the transition phase successfully with minimal incidence of having metabolic diseases like mastitis, metritis and retained placenta. Further, it improves the quality of colostrums and milk and subsequently promotes the growth and health of newborn calves. [ABSTRACT FROM AUTHOR]