Treating infertility, a common problem in cattle

Reproduction is the first system to be affected by malnutrition

Right Nutrition

Cattle should be fed with a well balanced diet to increase conception rate. Infertility In cattle accounts for major economic losses in dairy farming and dairy industry in India. Maintaining an infertile animal is an economic burden and in most countries such animals are driven to slaughterhouses. In cattle, nearly 10-30 per cent of lactations may be affected by infertility and reproductive disorders. To attain good fertility or high calving rate both the male and female animals should be well fed and free from diseases.

Many reasons

The causes of infertility are many and can be complex. Infertility or failure to conceive and give birth to a young one can be due to malnutrition, infections, congenital defects, management errors and ovulatory or hormonal imbalances in the female, according to Dr. Cecilia Joseph, Associate Professor,Department of Clinics, Madras Veterinary College,Chennai.

Sexual cycle

Both cows and buffaloes have the sexual cycle (oestrus) once in 18-21 days for 18-24 hours. But in buffaloes, the cycle is silent posing a big problem to the farmers. Successful heat deduction is possible only when the animals can be properly identified when they come in

oestrus (heat), proper maintenance of records and proper training of staff. The farmers should closely monitor the animals 4-5 times from early morning to late night. Poor heat deduction can cause increased levels of infertility. Considerable skill is needed to deduct the animals in heat for visible signs. Farmers who maintain good records and spend more time watching the animals obtain better results. "To avoid fertilization failure, breeding should be done during the oestrus period. Animals that do not show oestrus or do not come to cycle should be checked and treated," she said. Deworming once in 6 months should be done for worm infestations to maintain the health status of the animals.

Periodic deworming

A small investment in periodic deworming can bring greater gains in dairying. Generally vaccinations are avoided during pregnancy. For successful dairy farming, nutrition plays an important role.

Balanced diet

Cattle should be fed with a well balanced diet with energy, protein, minerals and vitamin supplements. This helps in increased conception rate, healthy pregnancy, safe parturition, low incidence of infections and a healthy calf. Care of young female calves with good nutrition helps them to attain puberty in time with an optimum body weight of 230-250 kgs, suitable for breeding and thereby better conception, explained Dr. Cecilia Joseph.

Feeding adequate quantity of green fodder during pregnancy will avoid blindness in newborn calves and retention of placenta (after birth). In natural service, breeding history of the bull is very important to avoid congenital defects and infections. Infections of the uterus can be largely avoided by having cows served and calved under hygienic conditions. After 60-90 days of insemination, the animals should be checked for confirmed pregnancy by qualified

veterinarians. When conception occurs, the female enters a period of anestrus (not exhibiting regular oestrus cycles) during pregnancy. The gestation (pregnancy) period for cow is about 285 days and for buffaloes, 300 days.

Avoid transportation

Unwarranted stress and transportation should be avoided  during the last stages of pregnancy. The pregnant animal should be housed away from the general herd for better

feeding management and parturition care, they elaborated. Pregnant animals should be drained of their milk two months before delivery and given adequate nutrition and exercise.

This helps in improving the health of the mother, delivery of a healthy calf with average birth weight, low incidence of diseases and early return of sexual cycle.

Breeding cycle

Breeding can be started within four months or 120 days after delivery to achieve the goal of one calf per year for economic and profitable dairy farming, according to them.

Dr. T. Senthilkumar, Assistant Professor, Directorate of Extension

Education, TANUVAS, Chennai - 600 051, Tamil Nadu

Animal Feeding Strategy under Current Feed Scarcity Scenario

Introduction

India is endowed with world's largest and most diverse asset of livestock in terms of species and breeds within the species. It posses one of the world's best dairy buffaloes, draught cattle, carpet wool sheep and highly prolific goat breeds. India has a share of 2.4% of the world's areas with 15% and 17.5% of world livestock and human population respectively. The number of livestock per hectare is 1.58 and there is one livestock per 2.1 human beings in the country. Because of large human 

population, there is huge demand for land for food in the country, and there is a stiff competition for food between humans and animals. The food grains chiefly wheat, paddy, maize, barley, bajra, jowar and ragi are grown for human consumption and only a smaller part is meant for livestock and poultry feeding, a chunk of which is again diverted towards feeding of poultry and swine. Apart from this feed grains, oil cakes and by-products are one of the chief components of the concentrate feeds commonly fed to ruminant livestock. Cottonseed cake and meal are often used in cattle feed throughout the country followed by rapeseed meal whereas groundnut meal is less popular because of aflatoxin problem. Though the oil cakes are supposed to be rich in protein and energy, the real scenario is something different. In commercial feed preparations, the cakes used are mostly solvent extracted which have been already drained out of maximum oil for human consumption and hence 

contain negligible oil content. The problem of adulteration in oil cakes viz. groundnut husk for cake, ureas for soybean meal, argemone for mustard seed etc. is also present. Unlike solvent extraction process during expeller processing, a lot of heat is generated which detoxifies some of the naturally prevalent toxic principles viz. gossypol in cottonseed cake, glucosinolates in mustard seed cake, rapeseed cake and protease in soybean meal etc. By considering the above it is clear that solvent extracted cakes are of poor quality and thus of low nutritive value. Another inherent issue is regarding the import policy of oil cakes in India. India regularly imports edible oil instead of the intact oil seeds which creates problems for the country's crushers, with the solvent extraction units running at only 50% of capacity. Another chief and usual ingredient of ruminant ration is fodders and forages, which are again short in supply. Currently, there is scarcity of land for fodder cultivation giving rise to a deficit of 25% dry fodder, 20% green and 32% deficit of concentrate mixture (NIANP, 2012) and the gap between requirement and availability is predicted to rise further. Since years a large proportion of our animals are underfed. Through natural selection and human interventions though those animals rose into stress tolerant and optimal producing breeds but gene responsible for economical traits might have been suppressed. So, the concern regarding nutrition of animals need to be taken more seriously by all groups of animal science researchers.

Strategies undertaken to solve the animal feed scarcity issue

Improving productivity in areas already under fodder cultivation, improving productivity of grazing and pasture ands, raising perennial fodder crops on field bunds and boundaries, peri-urban areas and exploiting ununtilized and under-utilized fodder crops are some of the promising options to enhance fodder availability. In 12th five year plan period promotion of fodder cactus in arid ecosystem especially in states of Rajasthan and Gujarat is taken up. Accelerated fodder development programme taken up by the Ministry of Agriculture (2011) aims at accelerating production of fodder through promotion of integrated technologies and processes by production of quality seeds and organized demonstration of appropriate forage equipments through state Agricultural Universities and adoption of technologies like fodder block making units, chaff cutter for fodder processing and silage making. Silage has nutritive value comparable or slightly lower than that of green forage. Corn silage is a very good source of fodder for dairy animals. It can be complemented with a protein source such as Lucerne fodder or urea while making silage. Reports suggest that corn silage provides adequate energy for growing cattle and buffalo. Variation in fodder availability and quality year through reduces the intake and digestibility due to change in microbial population during the transit of fodder, which can be avoided by silage feeding. Silage processing reduces the daily wages towards labour for cutting and transport of fodder from field to farms and also leaves the field open for new crop sowing leading to efficient utilization of land. Thus, more crops could be obtained from limited land. Another very easy energy saving method of fodder preservation in tropical climate without compromising quality is by drying the fodders before reaching maturity in the form of hay. Mostly fodders like Lucerne, oat, cowpea, berseem etc. Are dried for hay making . Progressive farmers in Punjab state report that guinea and Lucerne hay could exclusively support milk yield up to 10 litre. Over the years, 

considerable technological advancement has taken place in the feed and fodders focus in gon enhancement of their nutritional quality and subsequently productivity enhancement. One such very effective and well adopted technology is bypass nutrient technology which has been taken up by private feed manufactures as well as National Dairy Development Board (NDDB) and dairy federations. Its benefits have percolated to the ground level. The area specific mineral mixture technology has also helped to a considerable extent in overcoming the problem of infertility at field level. The livestock productions systems in India predominantly sustain on feeding of crop residues. Fodder and crop residue enhancement and densification are also the strategies adopted to solve the issue of their poor nutritive value. In Feb 2012, National Dairy Plan I (NDP-I) was initiated to achieve the objective of 150 million ton milk yield by the year 2016-17 under which along with production of high genetic merit bulls, semen production, doorstep AI emphasis was laid upon ration balancing and fodder development programme. Unless provided balanced diet, it's not possible to exploit the genetic potential of animal for higher productivity. The rations balancing can be done with the feed ingredients available with the farmer with extra addition of some minerals, vitamins and some concentrate feeds to fill the deficit of energy and protein in the ration leading to least cost ration formulation and also efficient utilization of locally available feed resources. Research and field trials conducted with this idea lead to increased milk yield, reduced cost of milk production along with reduced methane emission. Under fodder development programme, focus is laid upon improving productivity of fodder crops and common grazing lands and conservation of surplus green fodder for availing during lean season. Local resource persons demonstrate silage making and re-vegetation of common grazing lands with high yielding cultivated fodder crops, grasses and pasture legumes. Crops residues form the chief basal diet of the Indian ruminant livestock though they are not sufficient or balanced regarding their nutritive value. Hence, they can be enriched with cakes, brans, grains, molasses, hay and minerals and then densified into blocks. This aspect of enriching the poor quality feeds is also undertaken in NDP-I. Such densified blocks can be produced and transported at cheaper cost compared to the crop residues and areas to achieve optimum production from the animals. Scientists at IGFRI, Jhansi made the process easy, simple by adding a gadget to existing threshing machine used in the wheat-fields which lead to wheat straw treatment in the field without any additional cost (CAR News, Jan-March, 2014). The scarcity of crop residues is likely to rise in due course, since a part of cellulose rich crop residues are partitioned towards paper mill, plywood industry etc. since fibrous feeds are usual in ruminant ration, there is need to explore additional similar resources. Plant breeders in India have identified a number of varieties/hybrids which could give a better quality and higher yield of crop residue without any compromise in grain yield. This would provide an opportunity for augmenting the availability of fodder from crops like pearl millet, sorghum, maize and oats. Development of many interspecies hybrids in Trifolium is in progress in IGFRI, Jhansi. Systemic forage crop breeding programme at ICAR institutions and State Agricultural Universities have led to development of a large number of improved varieties of forage crops suitable for different agro-ecological zones. Integrated fodder production system can also be adopted to adjust the cultivation of fodder crops with that of main crops and harvest them as per the needs. This can easily be practiced by all classes of farmers under both irrigated and rainfed conditions. A plant like Azolla contains 25-30% protein, 10-15% minerals and 7-10% of amino acids on dry matter basis and is rich in essential amino acids, vitamins (vitamin A, vitamin B12 and ß-Carotene), growth promoter metabolites and minerals like Ca, P, K, Fe, Cu, Mg etc. It has been tested to be palatable to cattle and other ruminants with a potential to increase milk production by 15-20% in milch cows. Aqua plants and vegetable wastes can be very good alternative feed resources for ruminant feeding after reducing the moisture content to certain limit. With the scarcity in land for fodder cultivation of aqua plants and their field trials. As regards aquatic cultivation one of the emerging technology of fodder cultivation is hydroponics. It is a method of growing plants in water using mineral nutrient solutions and no soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only. Through the concept of hydroponics is an old one, it has been attracting interest from feed manufactures. Fruits and vegetable wastes viz. carrot fresh tops and pomace, carrot wet, cauliflower leaves, sweet potato, tomato pomace dried, tomato pulp, citrus pulp, baby corn husk and fodder, bottle gourd pulp, banana peels, muskmelon peels and watermelon peels are produced on a large scale from processing industries. As per FAO (2012) fruit and vegetable processing, packing, distribution and consumption in the organized sector in India generate a total of approximately 1.81 million tones of fruit and vegetable wastes. A large proportion of these wastes are dumped in landfills or rivers, causing environmental pollution. Alternatives to such disposal methods could be recycling through livestock as feed resources or further processing to extract or develop value-added products which will economize the animal feed and also alleviate the environmental pollution associated with disposal of fruits and vegetable wastes.

Conclusion

Feed scarcity is a major challenge to livestock sector in India. So far though various strategies have been adopted to combat the existing problem, but it has not yet reached to farmers levels. So, there is need to rigorously implement the strategies at all levels of ruminants feeding system. Improved utilization of straw, stover and crop residues are very important. Fodder variety development with emphasis on multi-cut needs attention. By products of Food industry and their utilization in ration balancing should reach the needy dairy farmers. Hay and silage preparations and feeding can also solve the problem during lean periods.

Sonali Prusty (Ph.D. Scholar, DCN Division, NDRI, Karnal)

Vijay Kumar Sharma (SMS, J&K)

Akash Mishra (Ph.D. Scholar, DCN Division, NDRI, Karnal)

S.S.Kundu (Principal Scientist, DCN Division, NDRI, Karnal)

Approach 5000+ Veterinarians/ Animal Health Experts

ANIMAL MANAGMENT DURING SUMMER STRESS

Introduction

Dairy animal produce milk most efficiently in environments where they can maintain their body temperature at around 38oC. Tissue and cellular metabolism and the underlying biochemical reactions that sustain life and productive functions need body temperature to be maintained within very narrow limits. Relatively small increases in body temperature of at least 1oC result in detectable, deleterious effects on metabolism and tissue integrity, in particular, the breakdown of body protein and a significant depression in production. The condition resulting in this, where heat load on the body of the animal exceeds heat dissipation is called heat stress. The dairy animal, dissipates heat by two distinct methods; evaporative and non-evaporative pathways.

Evaporative cooling is mainly effected through sweating and respiration. Heat stress itself is a function of time, temperature and humidity, because animal rely on water evaporation via sweating and panting to dissipate an excess of heat they have generated metabolically or absorbed from the environment. The primary factors that cause heat stress in dairy animal are high environmental temperatures and high relative humidity. In addition, radiant energy from the sun contributes to stress if animals are not properly shaded. As the environmental temperature increases, the difference between the temperature of the animal surroundings and their body decreases and her reliance on evaporative cooling (sweating and panting) to dissipate body heat increases. However, high relative humidity reduces the effectiveness of evaporative cooling and during hot, humid summer weather, the animal cannot eliminate sufficient body heat and her body temperature rises. The tremendous amount of body heat that the high yielding dairy cow produces is helpful in cold climates but is a severe liability during hot weather and in hot climates. The physical heat production of an animal is also

controlled by both internal factors and external factors of an animal. Internal heat load comes from basic functions such as respiration, digestion, as well as other daily maintenance requirements. These factors will be influenced by stage of lactation, production levels, as well as quantity, quality and type of feed consumed. External physical heat loads are management factors that affect physical activity and performance. Animal comfort, layout of facilities, stocking densities and fly control can all impact on the animal external physical heat load. Buffaloes are more prone to heat stress than cattle due to scarcely located sweat glands, black color and sparse hair on body surface. The sweat glands of buffalo skin have a low blood supply, number of sweat glands per unit area of skin is about one third of that of cattle and the thickness of corneum layer and epidermis is about double that of cattle.

The thickness and the black pigment of the buffalo skin help in absorption of more heat and leads to disproportionate convective and radiative heat losses from the extremities during exposure to solar radiation.As mentioned earlier, heat load will increase as temperature, humidity and solar radiation increase and air movement decreases.

Effect of heat stress on animals

Under heat stress, a number of physiological and behavioral responses vary in intensity and duration in relation to the animal genetic makeup and environmental factors. The degree to which an animal resists rise in temperature varies with species because of difference in their heat regulation mechanism. When animals are exposed to rising air temperature, the first response observed was increase in respiration rate. Air temperature up to around 300C has little effect on respiration rate and rectal temperature. At higher temperature above 410C, rectal temperature of animal will increase rapidly, while the respiration rate rises rapidly to about 3-4 times the normal values. Under thermal stress, animal employs moderate level of sweating and resort to open mouth panting. Thermal stress lowers feed intake of animal which in turn reduces their productivity in terms of their milk yield, body weight and reproductive performance. Under thermoneutral environmental conditions, most of the large domestic animals are able to maintain equilibrium between heat production and heat loss. High heat loads may lead to energy deficit, even when they do not induce a marked reduction of feed intake in animals.

Strategies for ameliorating heat stress

The effects of heat stress are costly to dairy farmers, but there are opportunities to recover some of the losses to hot weather. Physical modifications of environment, genetic development of breeds that are less sensitive to heat and nutritional management are the three major key components to sustain production in hot environment.

1. Shelter management

With the help of managemental tools, it is possible to modify the microenvironment to enhance heat dissipation mechanism to relieve heat stress.

(a)Scientific construction of animal shed so the air movement will not be hampered

(b) Provide comfortable micro-environment to animals.

(c) Use of cooling ponds, water sprinkler system and whole body bathing.

(d) Use of cooler for cooling of animal sheds.

There is no doubt that shading is one of the cheapest ways to modify an animal's environment during hot weather. Although shade reduces heat accumulation, there is no effect on air temperature or relative humidity and additional cooling is necessary for farm animals in a hot humid climate.

2. Nutritional management

It has been documented that both low and high ambient temperature cause oxidative stress. Oxidative damage, as a result of heat stress may be minimized by antioxidant defense mechanisms that protect the cells against cellular oxidants and repair system that prevent the accumulation of oxidatively damaged molecules. Antioxidants, both enzymatic and non-enzymatic, provide necessary defense against oxidative stress as a result of thermal stress.

I.Non enzymatic antioxidants in reducing oxidative stress

a)Vitamins

Both vitamin C and vitamin E have antioxidant properties. Antioxidant vitamins have proved to protect the biological membranes against the damage of ROS and the role of vitamin E as an inhibitor –“chain blocker”- of lipid peroxidation has been well established. Like vitamin E,ascorbate is also a chain breaking antioxidant. It prevents lipid peroxidation due to peroxyl radicals. It also recycles vitamin E. It protects against DNA damage induced by H O radical. Vitamin C has a paradoxical effect as it can also produce ROS by its action on transition metal ions. Both ascorbate and zinc are known to scavenge reactive oxygen species (ROS) during oxidative stress. Vitamin C was found to assist in absorption of folic acid by reducing it to tetrahydrofolate, the latter again acts as an antioxidant. Use of folic acid is impaired when vitamin C is deficient.

b)Minerals and trace elements

Zinc and other trace elements like copper and chromium act as typical antioxidants as they work indirectly. Zinc is a catalytic cofactor for Cu/Zn SOD and catalyzes dismutation of superoxide anion, producing molecular oxygen and H2O2, the latter product is usually metabolized by GPx and CAT. The activity of Cu/Zn SOD, CAT and GPx is decreased in copper deficient animals. It is also reported that normal copper levels are necessary to maintain the structural integrity of DNA during oxidative stress. Supplementation of electrolytes is one among the nutritional strategies to combat heat stress in animals. Addition of Na+, K+ and Cl- is benefited in heat stressed dairy cows in terms of milk yield, acid base balance and altered temperature. Supplementation of sodium and potassium in the form of bicarbonate/carbonate also help in better regulation of acid-base balance in the blood.

3.Amelioration through immunomodulation by dietary supplement

The immunostimulant effect of antioxidant depends on age and immune state of organisms.The effect of heat stress can be neutralized by complex antioxidant system that can organism develops. The antioxidant system can be booked by supplementing antioxidants in diet. Vitamin C and trace minerals like zinc have proved to play a vital role as modulators of antibody response and enhances of wound healing in domestic animals.

Ajeet Kumar & Anil Gattani, Assistant Professor,

Department of Veterinary Biochemistry, Bihar Veterinary College, Patna

MASTITIS: CHALLENGES AND SOLUTIONS

Introduction

One of the reasons for low productivity is poor animal health, particularly, mastitis which is single largest problem in dairy animal in terms of economic losses in India as well as all over world.

Bovine Mastitis

 mastitis is an inflammation of the mammary gland in response to injury for the purpose of "destroying or neutralizing the infectious agents and to prepare the way for healing and return to normal function.

Inflammation

can be caused by many types of injury including infectious agents and their toxins, physical trauma or chemical irritants. In the dairy cow, mastitis is nearly always caused by microorganisms; usually bacteria, that invade the udder, multiply in the milk-producing tissues, and produce toxins that are the immediate cause of injury." The teat end serves as the body's first line of defense against infection. A smooth muscled sphincter, which surrounds the teat canal, functions to keep the teat canal closed, prevent milk from escaping, and prevents bacteria from entering the teat. The cells lining the teat canal

produce keratin, a fibrous protein with lipid components (long chain fatty acids) that have bacteriostatic properties. This keratin forms a barrier against bacteria. During milking, bacteria may be present near the opening of the teat canal, either through dirty and wet conditions at the teat end, through teat end lesions or colonization, on contaminated surfaces of milking units. Trauma to the teat renders it more susceptible to bacterial invasion, colonization, and infection because of damage to keratin or mucous membranes lining the teat sinus. The canal of a damaged teat may remain partially open. Conditions that are associated with high impact force against the teat end propel bacteria through healthy teat ends. This includes liner slips caused by excessive temporary vacuum losses, low vacuum reserve or level, and abrupt milking unit removal without shutting off vacuum, as well as vacuum fluctuations caused by inefficient vacuum regulation, blocked air vents, restrictions in the short milk tube, poor cluster alignment, or poor liner condition. After milking, the sphincter muscle in the teat canal remains dilated for 1-2 hours and bacteria present during this time can enter the teat canal. Examples would be dirty housing or environment, or failure to use teat dipping properly. An inflammatory response is initiated when bacteria enter the mammary gland and this is the body's second line of defense. These bacteria multiply and produce toxins, enzymes, and cell-wall components which stimulate the production of numerous mediators of inflammation by inflammatory cells. The magnitude of the inflammatory response may be influenced by the causative pathogen, stage of lactation, age, immune status of the cow, genetics , and nutritional status. Polymorphonuclear neutrophil (PMN) leukocytes and phagocytes move from bone marrow towards the invading bacteria and are attracted in large numbers by chemical  messengers or chemotactic agents from damaged tissues. Masses of PMN may pass between milk producing cells into the lumen of the alveolus, thus increasing the somatic cell count (SCC) as well as damaging secretory cells. Somatic cells consist mainly of PMN or white blood cells. At the infection site, PMN surround the bacteria and release enzymes which can destroy the organisms. The leukocytes in milk may also release specific substances that attract more leukocytes to the area to fight the infection. Numbers of somatic cells remain in large concentrations after bacteria are eliminated until healing of the gland occurs. Clots formed by the aggregation of leukocytes and blood clotting factors may block small ducts and prevent complete milk removal. Damage to epithelial cells and blockage of small ducts can result in the formation of scar tissue in some cases, with a permanent loss of function of that portion of the gland. In other cases, inflammation may subside, tissue repair may occur, and function may return in that lactation or the subsequent one.

Mastitis Causing Bacteria

Disease causing bacteria are often referred to as pathogens. The most common mastitis pathogens are

found either in the udder (contagious pathogens) or the cow's surroundings (environmental pathogens), such as bedding, manure, soil, etc. Contagious mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae) are spread from infected udders to "clean" udders during the milking process through contaminated teatcup liners, milkers' hands, paper or cloth towels used to wash or dry more than one cow, and possibly by flies. Although new infections by environmental pathogens

(other streptococci such as Str. uberis and Str. Dysgalactiae and coliforms such as Escherichia coli and Klebsiella) can occur during milking, primary exposure appears to be between milkings. Coliform infections are usually associated with an unsanitary environment (manure and/or dirty, wet conditions), while Klebsiella are found in sawdust. About 50% of environmental streptococci infections display clinical symptoms. Sixty to 70% of environmental pathogen infections exist for less than 30 days and are not easily detected. Subclinical infections are those in which no visible changes occur in the appearance of the milk or the udder, but milk production decreases, bacteria are present in the secretion, and composition is altered. There exits a negative relationship between SCC and milk yield. Many of the cows with SCC over 200,000 may have subclinical mastitis.

Effect on Milk Composition

Mastitis resulting from major pathogens causes considerable compositional changes in milk, including

increases in SCC. The types of proteins present change dramatically. Casein, the major milk protein of high nutritional quality, declines and lower quality whey proteins increase which adversely impacts dairy product quality, such as cheese yield, flavour and quality. Serum albumin, immunoglobulins, transferrin, and other serum proteins pass into milk because vascular permeability changes. Lactoferrin, the major antibacterial iron-binding protein in mammary secretions, increases in concentration, likely because of increased output by the mammary tissue and a minor contribution from PMN. Milk protein breakdown can occur in milk from cows with clinical or subclinical mastitis due to presence of proteolytic enzymes. Plasmin increases proteolytic activity by more than 2-fold during mastitis. Plasmin and enzymes derived from somatic cells can cause extensive damage to casein in the udder before milk removal. Deterioration of milk protein as a result of mastitis may continue during processing and storage. Mastitis increases the conductivity of milk and sodium and chloride concentrations are elevated. Potassium, normally the predominant mineral in milk, declines. Because most calcium in milk is associated with casein, the disruption of casein synthesis contributes to lowered calcium in milk.

Effect on dairy industry

Mastitis is responsible for heavy economic losses due to reduced milk yield ( up to 70%), milk discard after treatment (9%), treatment costs (75), premature culling (14%), decrease in milk quality and price due to high bacterial / somatic cell count, increased risk of subsequent mastitis, herd replacement, antibiotics residue in milk and its products and rejection by processor and consumer. Though cows with clinical mastitis have more dramatic changes in milk yield and composition than cows with subclinical mastitis, the losses due to latter are more severe than those due to the former. The Indian diary industry suffers and annual loss of approximately 526 millions dollars due to mastitis, 70% of which is due to subclinical  mastitis.

           

Diagnosis

While acute clinical mastitis is easily suspected/recognized While acute clinical mastitis is easily suspected/recognized even by farmers and is readily diagnosed due to udder swelling, pain and drastic decrease in milk production, the sub-clinical mastitis has neither visual abnormalities in the mammary gland (swelling, hotness, cracks etc.) nor in the milk (blood, clots, flakes etc.). Therefore, routine physical examination of udder and diagnostic screening tests for early detection of mastitis and proper treatment of affected animal are of paramount importance in order to minimize losses due to sub-clinical and clinical mastitis.

Treatment and control: The treatment of the Mastitis is definitely more expensive than its control. Needless to mention in Clinical Mastitis parenteral and intra-mammary antibiotics are used. The word of caution is the judicious use. The intra-mammary use of antibiotics should be avoided to the best possible extent as this is likely to create more damage to udder.

Some of the control measures are as mentioned below:

1. The best possible way is to regularly examine the udder milk for possibility of Sub-Clinical Mastitis.

2. The udder and the teats should be washed pre and post milking with clean water.

3. Herbal teat-dip should be used for cleaning and disinfecting the udder.

4. Post diagnosis of Sub-Clinical Mastitis. Mastilep should  be applied with gentle hand on udder during post milking.

5. The Veterinarian should be consulted for farm management, prevention/control and treatment of mastitis.

Conclusion

Mastitis not only reduces the productive capacity of the cows, it is also expensive to treat. Therefore, its prevention should be the prime concern of each farmer. Effective mastitis control strategies including prudent use of antibiotics, adequate strategies including prudent use of antibiotics, adequate housing with proper sanitation and regular screening for early detection and treatment, follow up of chronic case, culling of older cows with repeated attacks, avoiding consecutive milking and susceptibility testing of the mastitis pathogens before treatment are recommended to alleviate the problem.

Bovine Mastitis: An Important Dairy Cattle Disease

by Anita Tiwari

Ph.D. Scholar, School of Public Health & Zoonoses, GADVASU, Ludhiana – 141004

Mastitis involves an inflammation of the mammary gland through bacterial infection, trauma, or injury to the udder. One of the most common diseases incurring huge losses to the diary industry, it not only reduces the productive capacity of the cows but is also expensive to treat. Mastitis, mainly of tow types – sub-clinical and

clinical, is responsible for heavy economic losses due to reduced milk yield, milk discard after treatment, treatment costs and premature culling.

Mastitis an inflammation of the mammary gland caused by bacterial infection, trauma, or injury to the udder, remains the most common and expensive disease affecting dairy

cattle throughout the world. Mastitis is caused by several different bacteria that can invade the udder, multiply there and produce harmful substances that result in inflammation.

It reduces the productivity of the cow as well as the quality of  milk causing enormous losses for breeders and consequently, to the national income of the country.

Etiology

This disease can be caused by an infectious or non-infectious etiological agent. The infectious type of mastitis is the most important one that frequently occurs due to infection by one and / or the other pathogens, such as bacteria, viruses, mycoplasma, yeasts and algae (DaRong et al, 2010). Classically, the mastitis pathogens may either be contagious or environmental. The contagious pathogens are the organisms which are adapted to survive

within the host, in particular within the mammary gland, and are capable of establishing sub-clinical infections, which are typically spread from cow to cow at or around the time of milking (e.g. Staphylococcus aureus, Streptococcus agalactiae, Str. Dysgalactiae) (Bradley 2002). The environmental pathogens are opportunistic invaders of the mammary gland which typically invade, multiply, engender a host immune response and are rapidly eliminated (e.g. Escherichia coli, Klebsiella species, Enterobacter aerogees, Streptococcus uberis,  Corynebacterium bovis, Mycoplasma species, Serratia, Pseudomonas, Proteus species, environmental Streptococci) (Bedada and Hiko, 2011). Despite intensive research, the etiology of around 20-35% of clinical cases of bovine mastitis cannot be established readily.

Types of mastitis

Mastitis is mainly of two types. It may be Sub-clinical type in which although there are no visible changes in the appearance of the milk and / or the udder, milk production decreases by 10% to 20% with undesirable effect on its constituents and nutritional value rendering it of low quality and unfit for processing (Rady and Sayed, 2009). Sub-clinical mastitis is the most common and economically most harmful; and gradual decline in milk production is its characteristic feature although there are no visible or palpable external changes inspite of the presence of infection and inflammation in the udder. The milk has a normal or slightly increased somatic cell count. Normally the bacterial count of herd milk is not affected and will remain below 50,000 per ml. It is estimated that 50% of all cows have subclinical mastitis in one quarter of their udder. The other type is Clinical Mastitis in which there is an

inflammatory reaction characterized by heat, pain, swelling and redness of the udder, along with reduced as well as an abnormal nature of milk yield. It is usually accompanied by a mild fever and the animal is depressed. The affected quarter is sensitive to

touch and painful to the animal. If acute mastitis is not attended and the inflammatory process persists for long, it gets converted into chronic mastitis which may further lead to a progressive fibrosis (hardness) of the gland thereby rendering the milk secreting tissue unable to produce any more milk. These changes are generally incurable and permanent. Often one or more quarters or even the whole udder may become permanently dysfunctional.

Effect on dairy industry

Mastitis is responsible for heavy economic losses due to reduced milk yield (up to 70%), milk discard after treatment (9%), treatment costs (75), premature culling (14%) (Bhikane and Kawitkar, 2000), decrease in milk quality and price due to high bacterial / somatic cell count,

increased risk of subsequent mastitis, herd replacement, antibiotics residue in milk and its products and rejection by processor and consumer (Harmon, 1994). Though cows with clinical mastitis have more dramatic changes in milk yield and composition than cows with subclinical mastitis, the losses due to latter are more severe than those due to the former (Muhamed et al, 2011). The Indian diary industry suffers and annual loss of approximately 526 millions dollars due to mastitis, 70% of which is due to subclinical mastitis (Rady and Sayed, 2009).

Diagnosis

While acute clinical mastitis is easily suspected/recognized even by farmers and is readily diagnosed due to udder swelling, pain and drastic decrease in milk production, the sub-clinical mastitis has neither visual abnormalities in the mammary gland (swelling, hotness, cracks etc.) nor in the milk (blood, clots, flakes etc.). Therefore, routine physical examination of udder and diagnostic screening tests for early detection of mastitis and proper treatment

of affected animal are of paramount importance in order to minimize losses due to sub-clinical and clinical mastitis. Physical examination of udder: It can be done by visual

observation and digital palpation. Physical examination of each gland must be made immediately after milking when the hormone stimulation has ceased and the udder is

completely relaxed and empty (Sharma et al, 2009).

Milk examination

The visible abnormalities like presence of flakes or clots in the milk, changes in the consistency and colour of milk (which may be thin or watery and at times yellow in color)

are noted (Sharma et al, 2009). For convenience milk examination tests may be divided into two groups, viz: — Direct or cultural test: These are the standard tests for determining the presence and identity of mastitis organisms in the milk, but are time consuming and

require technical skill and laboratory facilities. — Indirect Tests: These depend upon the development of palpable lesions in the udder or changes in the composition of milk. Indirect tests (e.g. Somatic cell count, California Mastitis Test, Strip cup test etc.) are useful in determining the quality of milk in the absence of laboratory facilities. These are simple,

economical, fast and easy to use as a cow-side test.

Treatment

The treatment of clinical mastitis is generally based on clinical signs, number of episodes and the likelihood of response. It should include supportive therapy, milk-out, and observation until culture results are available the following day. In case of contagious pathogen, all 4 quarters should be treated to ensure elimination of pathogen and to prevent possible cross-infection of a non infected quarter. Drug manufacturer's instructions

regarding frequency, duration and level of treatment should be precisely followed. Udder balm may be applied on the udder to reduce inflammation. For anti bacterial treatment, the drug (usually an antibiotic) must reach the causative bacteria in the udder. Therefore, an intra-mammary treatment is by far the most common method for all forms of mastitis. The antibiotic must be administered into the teat of the affected quarter after it has been emptied of milk.

Antibiotic therapy

a)Parenteral administration-Severe mastitis is usually treated systemically, although intra-mammary therapy will often be used adjunctively.

b)Intra-mammary administration-This route is accepted as the route of choice in the treatment of subclinical, chronic or mild clinical mastitis and as prevention during dry clinical mastitis and as prevention during dry cow therapy. It permits delivery of the antibiotic directly intothe mammary gland.

Hygiene and management:

The infection easily spreads from one cow to the other during milking via contaminated milk, hands of the milker, and udder cloths (in case of milking machine). Infection may also occur

during the interval between milking. Possible routes are contaminated beddings, licking of teats and udder, contact of the udder with the tail and legs and files. Therefore strict

hygiene has to be maintained. Cows with a high cell count can be separated from healthy

cows with a low cell count. Disinfection of the entire teats immediately after milking in a safe and effective teat dip is perhaps the most important single measure a dairy farmers

can take to reduce new infections in a herd. Most commercially available teat dips will reduce new infections by atleast 50%.

Control and prevention

Cows suffering from mastitis may recover spontaneously, but usually drug therapy is required to maintain productivity. It is a good practice to empty the affected quarters as often as possible by stripping the concerned teats several times per day. Improved animal husbandry, hygiene and good management are the only practical methods of prevention and disease control. To prevent cows from damaging their teats barbed wires should be

removed from the premises.In conclusion the most effective measures to prevent

mastitis are:

— Maintaining a consistent high standard of management and hygiene before, during and after milking;

— Using a good milking technique or an adequately functioning milking machine;

— Use of teat-dip with a disinfectant on all cows after every milking;

— Treating all cows with evidence of clinical mastitis promptly;

— Applying the somatic cell count monthly to monitor the health status of the herd;

— Applying antibiotics to all cows after the last milking at the time they are dried off;

— Attending immediately to any minor injury to the teat or udder tissue;

— Culling of cows suffering from recurrent clinical mastitis.

— Providing adequate nutrition to preclude increased susceptibility to mastitis.

Conclusion

Mastitis not only reduces the productive capacity of the cows, it is also expensive to treat. Therefore, its prevention should be the prime concern of each farmer. Effective mastitis control strategies including prudent use of antibiotics, adequate strategies including prudent

use of antibiotics, adequate housing with proper sanitation and regular screening for early detection and treatment, follow up of chronic case, culling of older cows with repeated attacks, avoiding consecutive milking and susceptibility testing of the mastitis pathogens before treatment are recommended to alleviate the problem.