Section 5

Calf Health Management Programme

Calf rearing is an important activity in a dairy farm as these calves bring advantage of improved genetics to the farmers. Compared to management of milking animals calf rearing requires different set of skills knowledge and infrastructure. Many farmers who breed and milk adult cows and buffaloes do not have time and infrastructure to rear calves. As a result superior genetic buffalo calves are lost. Small or medium hold farmers in rural areas are also not generally inclined to rear calves because of low productivity in dam which necessitates marketing of milk for cash and non-affording of offering milk to young calves. Thus calf rearing in India poses complex systemic constraints that need to be addressed in organised way. One possible solution could be to encourage few farmers to take up calf rearing up to pregnant heifer stage. Male buffalo calf rearing for beef purpose could also be an alternate business for wiling farmers since majority of male buffalo calves are left to die. Thus female or male, calf rearing offers novel business model for Indian farmers.

The concept of herd health management can also be extended to calf rearing. In this system also the primary objective is to set up performance data management and the analysed information is used to implement preventive calf health and productivity programme. The important components of calf health management programmes are here.

Post-birth neonate management

Immediately after birth of a calf, the umbilical cord should be severed with a clean knife and dressed with Tr. Iodine. The head should be cleaned, especially the nostrils, eye, ears, mouth with a towel and wrapped for drying of the body. Colostrum (the milk secreted by cow/buffalo during first three days after parturition) should be fed as early as possible within 4-6 hours. When a calf is born the gastrointestinal tract (GI) is sterile and within hours after birth billions of environment bacteria (including bacteria found on the body of the mother cow) including pathogens enter the GI tract and colonise.

The golden rule is that colostrum should be fed before environmental bacteria can multiply and colonise in the GI epithelium. Experiments have demonstrated that the antibodies present in colostrum inhibit multiplication and colonisation of these bacteria. There is also confusion about when the cow/buffalo should be first milked for colostrum. As a general principle, colostrum should be removed only after the birth of the calf since with removal of colostrum there is also loss of body calcium, which otherwise may affect calf birth. But in case there is excessive letting down prior to actual parturition and the udder is swollen, red and has become painful, then colostrum can also be milked earlier. In such cases, make sure that you do not remove all colostrum just enough to relieve the udder of pressure and painful induration. The removed colostrum can be saved for feeding of the calf.

 Colostrum feeding methods

Unlike infants, bovine calf at birth is devoid of any antibodies due to trans-placental barriers to crossing of protein molecules. The maternal antibodies can be transferred only after feeding of colostrum. This is a unique phenomenon in which large quantities of colostrum proteins are absorbed through intestinal tract. Colostrum is rich in antibodies against many bacteria, protozoa and viruses and it contains important proteins and growth factors. Ingestion of sufficient quantity of good quality colostrum at optimum time after birth is the single most crucial factor that can ensure calf health.

More than 50 per cent of the health and growth problems in calves can be prevented if sufficient quantity of good quality colostrum is fed to the calf immediately after birth and subsequently for three days. Experienced dairy farmers always prefer manual feeding over suckling as it ensures feeding of right quantity of colostrum.

It is a general observation that more than 50 per cent of the calves when born are unable to suckle enough quantities up to 6-8 hours. As a result in such calves severe enteric infections with systemic signs are common due to failure of passive transfer of antibodies. These calves also lag behind in growth compared to healthy calves in the farm.

Best management practice is to feed neonate calves measured quantities of colostrum through nipple bottle. In case weak and unthrifty calves are unable to suckle, colostrum should be fed through stomach tube. Colsotrum is also extremely good supplement to treat enteric infections in calves.

Excess colostrum therefore should be saved and stored. Orphan calves and calves born to mother suffering from mastitis at birth can be fed pooled colostrum. Organised farms rearing sufficient number of calves should have colostrum bank. Even fermeted colostrum has also been found to be useful supplement in calf diarrhea.

 Housing and hygiene key to calf health

When a calf is born it is free from any pathogen, but within minutes after birth it is threatened with variety of pathogens. These are contracted from cow environment, such as mother itself, bedding, floor, wall, pen and other sick animals, especially calves suffering from diarrhea. Any negligence in cleanliness and feeding practice leads to enteric or lung infection. Implementing biosecurity measures in calf pen is a sure way to prevent enteric or respiratory diseases.

Calves should be housed separately from adults. At least for first one month, calves should be kept in individual pen and a dedicated labor should be assigned for calf management. Calf mortality is higher in units of large herd size because of high population density, especially different age group calves being housed together. In calf rearing first week is important as up to 55-60 per cent mortality could occur at this age, whereas 20-30 per cent mortality can occur in second week. Calves kept indoors along with adult animals or higher age group calves have higher morbidity and mortality, which is because of poor sanitation and air quality.

It is better practice to rear calves on elevated stalls than on ground and individual pens are more preferred. Metal pens are more suitable than wooden because these can be cleaned easily. Calf hutches of size 4 x 4x 8 ft with opening facing south and detachable feeding utensil holder are preferred and have been found to reduce enteric and lung infection.

Giving access to water immediately after feeding of milk is important as it hastens development of rumeno-reticulum which would be delayed if only milk is fed. Maintaining sanitation in calf pen is critical but care should be taken that the floor is not wet as wetness with faulty ventilation expose animals to respiratory diseases. After one month calves should be housed in group of 4-6. Even in calves open hose with corner shed for protection from sun and earth floor has been found to reduce morbidity and mortality.

Health and growth programmes

Commercial farms should develop targeted calf health and growth targets. The target should focus on calf mortality in first month <3-5 per cent of live calves born. Keeping records is important to monitor health and growth. The ‘Herdman’ software has a separate calf module wherein calf file is created with entry of calving of the mother and subsequently in this file growth and treatment records can be updated periodically, once the calf has been assigned unique identification number. The programme also communicates actions and alerts on all aspects of calf management and the farmer can generate calf performance reports and growth curves periodically. This aids in evaluating the existing programme and detecting problem areas.

Another advantage of having records is that when heifer is sold it will fetch better price as authentic genetics and other life-data of health can be shared with the buyers. Crossbred/buffalo calves should have a daily gain in weight of around 500 grams per day in first three months. Calves being highly susceptible to endemic diseases must be vaccinated regularly (please see details earlier).

If calf growth is not as per target, investigations should be done to evaluate quality of feed, feed intake and if there is parasite load. Regular medication for worm infestation is also critical.

 Management of calf diarrhea

In calves the major health problem in first four weeks is diarrhea. It is an acute syndrome in newborn calves caused by one or more organisms involving E. coli, rota virus, corona virus, cryptosporidia, or Salmonella. Calf diarrhea is a management-related problem and with better practices it can be prevented. Two important factors associated with the problem are: (a) failure to feed sufficient quantity of good quality colostrum; and, (b) sudden change in weather or feed. Feeding of milk replacer with contaminated nipple or low quality milk replacer is an important source of infection. The disease is more common in calves born to mothers that were undernourished during dry period possibly due to low quality and quantity of colostrum secreted by such animals. The disease is more common in organised farms especially when stocking density is high compared to low holding farmers. The box provides a guide to provisionally diagnose the infectious cause, based on age of occurrence.

Enteric infection in calves invariably leads to profuse diarrhea, dehydration and anorexia. Since it is dietary in origin, many calves in the age group would show varying degree of diarrhea. Untreated calves become unthrifty and lose weight rapidly and do not gain weight for considerable period after the attack. Death occurs due to dehydration and shock. Although mixed infection may be common, primary infectious cause mostly depends on the age of the calf and could be a good diagnostic key.

 Treatment

All affected calves should be separated and treated. Individual evaluation of the clinical status of each calf is important, especially when dehydration is severe. Administration of fluids, oral or parenteral, is very critical. The treatment should be ensured at the earliest and before arrival of the veterinarian, the oral rehydration treatment (ORT) should be started. ORT is the hallmark of the treatment approach and since this can be started before the veterinarians visit this can play important role in reducing mortality due to calf diarrhea.

The role of antibiotics in treating calf diarrhea is still a debated issue. A number of clinical trials have demonstrated no advantage of giving antibiotics. On the contrary, it has been shown that antibiotics causes more harm by killing even the ‘good bacteria’ in intestine and hence recovery is delayed. Evidence based antibiotic on rectal swab culture has been found to be inaccurate as the results may not reflect the small intestinal flora which is the site of infection hence the veterinarian may be misled. Presence of bacteraemia is considered as an important condition to choose therapy but it is difficult to demonstrate in blood culture. Hence the only guiding rules to rely upon is clinical presentation. The following box gives broad clinical grading of calf diarrhea and possible approaches to therapy. Colostrum either fresh or frozen thawed around 50 ml has been found to be a good supplement to reduce pathogen load. However, care should be taken to avoid administering large quantities of colostrum for fear of fermentation and toxemia.

Management of respiratory diseases in calves

Respiratory illnesses are another major source of morbidity and mortality in young calves. Calf pneumonia also called enzootic pneumonia is the most common disease complex affecting calves as young as 2-3 weeks and common up to 6 months of age. The problem is common in calves that are housed in the barn rather than those housed outside. Inadequate ventilation, failure of passive transfer of immunity through colostrum, group density and proximity to adult animals are critical associated factors. It is a disease complex caused by bovine respiratory viruses and bacteria such as, Pastuerella multocida, Mannheimia haemolytica and Mycoplasma bovis. The symptoms include loss of appetite, scum at nostrils and sometime watery secretion through nostrils, coughing and respiratory distress. The calves lose weight rapidly and if left untreated deaths are common. Recovered calves grow slow and recurrent attacks are common. It is very difficult to eliminate the disease but through sound husbandry practices the disease can be brought under control by lowering the severity. Use of individual calf hutches has been shown to improve calf respiratory health. The key to treatment of such calves is rapid detection of sick calves and immediate treatment administration (which requires observation of calves at least twice a day).