Prevention of Mastitis by Nutritional Intervention in Dairy Animals
Dr.Shally Nagar, Dr.Manoj Ahirwar, Dr. A.K. Patil
Nanaji Deshmukh Veterinary Science University, Jabalpur, (M.P.)
Mastitis is inflammation of the mammary gland usually caused by a bacterial infection. Mastitis is an important disease of dairy animal and a threat for dairy farmers in many parts of the world, because this disease reduces the milk yield, lowers the quality of milk and shorten the productive life of animal thereby leading to heavy economic loss. Mastitis namely, clinical and subclinical, is an economically damaging disease of the dairy industry, which causes physical, chemical and bacteriological changes in the milk along with morpho-pathological changes in the mammary gland. Annual economic loss due to mastitis has been calculated to be Rs. 7165.51 crores; losses being almost same for cows (3649.56 crores) and buffaloes (3515.95 crores). Subclinical mastitis has been estimated to account for 57.93% (4151.61 crores) of total economic loss due to mastitis.
Poor nutrition does not cause mastitis, but poor nutrition can make it easier for bacteria to become established in the mammary gland, resulting in increased rates of mastitis. There are many factors responsible for causing mastitis such as climate, housing, bedding, quality of indoor air, stress, genetics and nutrition. Nutrition can affect the outcome of mastitis via modulation of immune system of animal.
Effect of various nutritional interventions in controlling mastitis
All of the essential nutrients, e.g., energy, protein, macrominerals, microminerals and vitamins, can influence some aspect of immune function. Nutritional status can have direct and indirect effects on immune function. Immune cells have specific requirements for certain nutrients, and diets that do not provide adequate amounts of those nutrients can impair immunity while still providing adequate nutrients for other functions, such as producing milk. In other words, a diet might support high levels of milk production but at the same time increase the risk of mastitis because of suboptimal immune function. The another way proper nutrition can enhance immune function and reduce mastitis risk is by reducing the prevalence of metabolic conditions that inhibit or suppress immunity. The roles of various nutrients in controlling the mastitis are described below:
The importance of dietary energy in mastitis
The highest rates of mastitis generally occur during early lactation, and early lactation is the time when most cows experience negative energy balance. During early lactation, dry matter intake (DMI) by dairy cows is low, whereas nutrient demand is high, which leads to cows being in negative energy balance. Body fat is mobilized to provide the energy needed for maintenance functions and to produce milk. The energy deficient experienced by most cows usually starts a few days before calving and continues for several weeks after parturition. The concentrations of nonesterified fatty acids (NEFA) and beta-hydroxybutyrate (BHBA) in plasma increase as cows mobilize greater amounts of body fat, and experiments have shown that both high concentrations of NEFA and BHBA have direct negative effects on the functionality of certain immune cells in cattle. It is well known that cows in negative energy balance are at a higher risk of ketosis.
Importance of Calcium-Phosphorus ratio in mastitis
Cows with hypocalcemia spend more time lying down, increasing teat-end exposure to pathogens. Making this worse is that calcium is needed by muscles, and the teat-end sphincter in cows with hypocalcemia may contract slower and less completely, allowing bacteria to enter the mammary gland. Additionally, calcium is needed for immune cells to function properly, and these cells do not work as well when cows have hypocalcemia. An inadequate Ca to P ratio in rations results in problems with milk fever at calving.
The roles of vitamin A and β-carotene in mastitis
Vitamins and minerals have long been recognized as antioxidants in the animal health and production. Vitamin A (VA) and its precursor- beta carotene (BC) are important in maintaining epithelial tissue health and play a vital role in mucosal surface integrity and stability. These functions may affect cow resistance to pathogen entry into the mammary gland as well as resistance post-entry. VA is an important factor in improving immune function and attenuating oxidative stress. In addition, BC appears to function as an antioxidant, reducing superoxide formation within the phagocyte, and it play an important role in protecting udder tissue and milk from the harmful effect of free radicals.
The roles of vitamin C in mastitis
Ascorbic acid is the most abundant and important water-soluble antioxidant for mammals. Even though it can be synthesized in the body of most mammals except primates and guinea pigs which have a dietary vitamin C requirement. Thus, ascorbic acid is not a required nutrient for dairy cows; some data are accumulating that suggest vitamin C is related to mastitis. The cows suffering from mastitis have lower concentrations of vitamin C in their milk and plasma. Ascorbic acid scavenges aqueous reactive oxygen species by rapid electron transfer, thus inhibiting lipid peroxidation, and represents one of the important antioxidant defences against oxidative damage. In bovine mastitis, it has been identified as oxidative stress biomarkers.
Significance of zinc in mastitis:
Zinc helps in maintaining the health and integrity of skin due to its role in cellular repair, wear and tear and also increases the speed of wound healing. Along with its healing effect, Zn reduces SCC due to its role in keratin formation. Zinc plays a critical role in function and effectiveness of some immune components. Zn deficiency has been associated with reduced formation of both T and B lymphocytes and phagocytes. It is an essential component of several enzymes involved in the synthesis of DNA and RNA, and has an antioxidant role by being part of a group of elements that induces the synthesis of metallothionein, which binds to free radicals. Zn is required for the formation of Mn-Zn SOD, deficiency of Zn affect the activity of SOD in blood and tissues, which results in increased superoxide radicals.
Role of copper in mastitis:
Copper has also been associated with immune function. It is a component of the enzyme ceruloplasmin, which is synthesized in the liver that assists in iron absorption and transport. Furthermore, Cu is an important part of superoxide dismutase, an enzyme that protects cells from the toxic effects of oxygen metabolites released during phagocytosis. Both functions may be important in reducing the incidence of mastitis during the periparturient period. Copper supplemented to heifers starting 60 d pre-calving and continuing to 30 d postpartum decreases the severity of Escherichia coli mastitis cases.
Role of selenium and vitamin E in mastitis
Vitamin E and selenium (Se) are integral components of the antioxidant defence of tissues and cells. Cattle consuming stored forages are likely to be low in vitamin E, unless supplemented, and vitamin E deficiencies are frequently observed in peripartum dairy cows. The vitamin E (VE) is the most important lipid soluble membrane antioxidant, and the biologically active form is known as α-tocopherol. Selenium is an essential micronutrient present in tissues throughout the body and is important physiologically because it is an integral component of the enzyme glutathione peroxidase. Glutathione peroxidase functions in the cytosol of the cell and vitamin E within lipid membranes. The supplementation of vitamin E and Se reduces the incidence and duration of clinical mastitis. The supplementation of vitamin E and Se were associated with improved phagocytic cell activity and function. Conclusion
Mastitis is associated with release of free radicals, increased total oxidant capacity and decreased total antioxidants capacity in milk. Antioxidant vitamins and minerals protect the body from free radicals either by directly scavenging free radicals or by inhibiting the activity of oxidizing enzymes. The supplementation of mastitic dairy cows with antioxidant vitamins as vitamin A, C, E and β-carotene, and antioxidant minerals as selenium, Zinc and copper is very important to help the animal recover early.
