«Dairy cattle husbandry Agrodok 14 - Dairy cattle husbandry More milk through better management Agrodok 14 Dairy cattle husbandry More milk through ...»
? Body temperature. Adult cattle have a normal body temperature of between 38 - 39◦C and calves up to 1 year 38.5 - 40.5 ◦C. A higher temperature does not necessarily mean fever. Fever is usually accompanied by shivering, rapid breathing and an increased pulse rate, and possibly, diarrhoea. Often the ears, horns and legs of the animal are cold to the touch while the body is too warm. Check the temperature of the animal by inserting a thermometer into the anus for one Figure 9: The place of the minute; for calves, insert the blood vessel to feel the pulse Animal health thermometer one third of its length, and two thirds for adults.
? Coat, skin, hooves and horns. A healthy animal has a shining, smooth and even coat, as well as shiny horns and hooves. Its eyes should be normal, without any discharge or tears, and the muzzle moist.
Health problems can be caused by:
? Infections from internal or external parasites like worms and ticks, or microorganisms such as protozoa, bacteria, rickettsia, viruses and fungi.
? Nutritional deficiencies of energy, protein, minerals or vitamins.
? Digestive disturbances due to improper feeding or lack of water.
? Being too fat at calving, a body score above 3.5.
? Genetics: the animal may inherit abnormalities from its parents.
? Accidents and predators.
Hygiene everyday helps to keep the vet away.
There are many cattle diseases, though some are only of significance in certain areas (e.g. Trypanosomiasis) or under specific conditions.
Unfortunately describing all the diseases with recommended treatments is clearly impossible within the confines of this Agrodok. Disease identification and proper treatment require specialist knowledge and skills. If your animals are not in good health, you must seek veterinary assistance. A few diseases are described below, with the emphasis on prevention.
5.1 Vaccinations Vaccinations against the following diseases may be relevant for dairy
? Rinderpest. Compulsory in many parts of Africa. Can be combined with vaccination against contagious bovine pleuropneumonia once in a lifetime.
? Haemorrhagic septicaemia prevails in humid areas. Quite often a combination of vaccinations is administered annually, which also protects against anthrax and black quarter.
? Foot and mouth disease in areas where this disease is common. Repeated each year.
? Brucellosis. Female animals of about 9 months are vaccinated once.
5.2 Diarrhoea and pneumonia in calves Diarrhoea, or scouring, is the main cause of death of young calves in the first 2 - 3 weeks of their lives. It is easy to detect: the dung is liquid, white in colour and has a very bad smell. The calf looks ill and does not drink well.
Diseases and prevention To prevent scouring it is most important to provide the calf with colostrum within 2 hours of its birth; hygiene is essential. Clean buckets for feeding and clean housing are really necessary. A clean and dry floor with bedding or a slatted floor is important too. As treatment, the first step is to give the calf boiled water to prevent dehydration. Add one teaspoon of kitchen salt and two tablespoons of sugar per litre of water. Once the calf has recovered start milk feeding again gradually. If after some days the diarrhoea has not disappeared, treatment with antibiotics will be necessary.
Figure 10: Signs of health and disease in the calf. A: Healthy, alert, clean eyes, shining coat and pricked ears. B: Diarrhoea, dirty hind legs and tail, drooping ears and sunken eyes. C: Pneumonia, Runny eyes and nose, difficult breathing, open mouth and neck stretched out Pneumonia is an important cause of poor growth and death in the first four months of a calf’s life. Symptoms are coughing, high fever, watery eyes and a runny nose. Calves are mainly affected after two months of age.
38 Dairy cattle husbandry For prevention, feeding of colostrum immediately after birth and clean open housing, with good ventilation and a dry floor are important.
Calves should be protected against large variations in environmental temperature. Vaccination at an age of three months is possible.
If a calf suffers from pneumonia, treatment with a broad-spectrum antibiotic for at least five days will generally be successful.
5.3 Worm prevention An animal suffering from a worm infection will lose weight and become ill and frequently will also have a “pot-belly”. Young animals are particularly susceptible to gastrointestinal worm infestation from grazing. Worms develop well under humid and hot conditions.
Regular cleaning and keeping the stable floor dry will help prevent infection. Stall-feeding instead of grazing will help reduce the risk of infection. Avoid grazing in humid areas or use mobile pens in clean pasture plots instead. De-worming is common practice for young animals, starting from the age of two months and repeating treatment every 3-4 months until about 2 years of age. As most infections occur during the rainy season, de-worming before and after this season is useful in many areas.
5.4 Tick control Ticks can be a real problem, especially under grazing conditions. They suck blood and infect cattle with nasty so-called tick-borne diseases.
There are many kinds of ticks and although not all of them transmit diseases, they weaken the animal by causing blood loss. They make wounds that allow bacteria to enter the skin resulting in loss of value of hides. Ticks can also attack the udder causing the loss of a teat, thus making the cow less productive.
Farmers should find out which combination of tick and tick-borne disease control measures will be the most suitable. This will depend on Diseases and prevention the kinds of ticks in the region, the farm situation (breed of cattle, feeding system), the costs and benefits of the measures and on the veterinary services available.
Figure 11: Tick control If an animal has only a few ticks, they can be removed by hand.
Nowadays there is also a drug “pour-on” that can be easily applied to control ticks. In most situations, however, special chemicals called acaricides have to be used. But because acaricides not only kill ticks but also are toxic to humans and cattle, careful handling and following of the provider’s instructions is most important. Acaricides can be used in dip baths or with sprays or sponges. If the animal does not have many ticks, apply acaricides or pye-grease to the parts of the body preferred by ticks, especially the folds of the skin. Use the correct mix of chemical and water for each purpose.
The frequency of treatment depends on the type of ticks, the breed of animal and the season. It varies from twice a week for exotic cattle like Friesians in regions with East Coast Fever to once every three weeks to control Boophilus (blue) ticks that transmit babesiasis and anaplasmosis. It also depends on the feeding system and the contacts 40 Dairy cattle husbandry of the animals with other cattle in the village. If an animal suffers from a tick-borne disease, seek veterinary assistance.
5.5 Trypanosomiasis control Trypanosomiasis or sleeping sickness is a disease caused by protozoa transmitted by tsetse flies. It is characterized by anaemia (lack of red blood cells), loss of condition, abortion, infertility and, if left untreated, high mortality.
Trypanosomiasis prevention and control is partly dependent on national measures, including elimination of tsetse flies and limiting contact between cattle, wild animals and the flies. In a region with a risk of trypanosomiasis, a drug can be administered that prevents the animals from becoming ill. Timing and dosing of the drug are very important, so follow the instructions carefully. The same type of drug can be used to treat animals already suffering from trypanosomiasis. If necessary, seek help from an expert.
5.6 Hoof problems Besides lameness, cows with hoof problems may present a serious drop in milk production. Hoof problems can be caused by infections or by hoofs growing out of shape.
Prevention consists of the following measures:
? Hygienic housing. Clean and dry, well-levelled floors are required.
Floors should not be slippery, so the surface should not be too smooth.
? Nutrition. Well-balanced feeding with sufficient roughage and no drastic changes is recommended. Zinc deficiencies may cause hoof problems.
? Hoof trimming. Hoofs grown out of shape need trimming. This job requires special skills and should be done by an experienced person.
? Footbath. When problems occur frequently, a footbath with a disinfectant could be considered.
Diseases and prevention
5.7 Mastitis Mastitis or infection of the udder is a common problem on dairy farms. It can be chronic or acute. Signs of acute mastitis are: abnormal milk with flakes, different colour, watery appearance and a foul smell.
The area of the udder that is affected will be painful and hard, sometimes swollen and reddish. The cow will be difficult to milk and its milk production decreases. Infection most often occurs just after milking when the teat is still open and bacteria can enter easily.
For early detection of chronic mastitis a strip cup with a dark bottom in which the first milk is collected is useful. The first squirts of milk from a cow suffering from chronic mastitis are watery and contain small flakes (see Figure 12).
Figure 12: For early detection of chronic mastitis a strip cup with a dark bottom in which the first milk is collected is useful. The first squirts of milk from a cow suffering with chronic mastitis are watery and contain small flakes.
Try to prevent mastitis by taking the following measures:
? Cleanliness of the milker, building, equipment and cow is of the utmost importance, at all times.
42 Dairy cattle husbandry ? Milkers should wear clean clothes, wash their hands and have short nails.
? Keep udders as clean as possible by shaving them and providing clean bedding.
? If the udder is not very dirty, just use a dry cloth to wipe off any loose dirt.
? If water is necessary for udder cleaning, add a mild disinfectant, change water and cloths frequently and dry udders well, preferably with paper towels.
? Disinfect teats after milking with a dip or spray.
? Feed the cows after milking so they will not lay down in the first hour.
? A long-lasting antibiotic can be used to treat all quarters at drying off on farms with serious mastitis problems.
If a cow has mastitis:
? Milk and massage the affected part as often as possible, for example every two hours. Washing the udder alternately with warm and cold water and massaging with ointment will also help.
? Consult a veterinary officer and apply antibiotics to the infected area. Milk from treated cows is not suitable for consumption!
? Milk infected cows last and bury the infected milk.
? Clean your hands carefully after milking the affected quarter.
? Check the other cows carefully for signs of mastitis by using a strip cup.
? Cull cows with chronic or incurable mastitis.
5.8 Milk fever Milk fever is the most common digestive disorder in older cows. It occurs at the time around calving. When a cow has milk fever, it does not eat, it lies down with its head to one side and cannot stand up. It has staring eyes, cold ears and a dry muzzle. If not treated, it may die.
The main cause is improper feeding with relation to the mineral calcium. This occurs when the cow is fed too much concentrate during Diseases and prevention the dry period before calving. She should be fed as if producing 5 kg milk per day and not be allowed to become fat. If a cow has a milk fever history, do not milk her out completely at first.
Take immediate action if a cow has milk fever. She will need additional calcium, preferably injected into the bloodstream by an experienced person.
5.9 Retained placenta Normally the afterbirth or placenta will be expelled within 12 hours after a calf’s birth. If not, part of the membranes can be seen hanging from the vulva and this causes a foul smelling discharge. At first, the cow may seem all right but after a few days, she will eat less and her milk production will drop. The cause of placenta retention is not yet known. Infections play a role, but also feeding.
To reduce the incidence, avoid letting the cows get too fat at calving.
Be very careful with interventions during calving. Milking or suckling of the calf just after calving helps too. Vaccinations against diseases like brucellosis can be useful. Do not remove the placenta by force. A special pill with antibiotics can be put into the uterus to treat infections.
5.10 Wounds Accidents occur. Besides treating the wound itself, it is very important to identify the cause and eliminate it. The building, equipment, fences, other animals, predators and parasites, may be the cause of wounds.
Cleanliness and protection against flies are the most important factors in wound treatment. Equipment, clothing, hands and housing should be clean. Hairs around the wound should be clipped and dirt removed.
Wash out with a weak disinfectant and try to stop bleeding. Apply iodine tincture, methylene blue or wound spray. If the problem is serious, call in an expert.
Without reproduction there is no production.
A cow has to give birth to a calf before she can start a new lactation.
Pregnancy only occurs after effective service during heat. The length of the calving interval is determined by the time between calving and the next conception. This affects the length of lactation, which together with the age at first calving has a significant effect on the lifetime production of the cow.
6.1 Heat detection Signs A cow in heat indicates that she is ready for breeding and that with an
effective service she is ready to become pregnant. Heat signs are:
? The cow becomes restless, bellows and tries to attract attention of other animals.
? She tries to mount other animals, she sniffs them and invites being mounted and sniffed at.
? During standing heat, she will allow mounting and will stand still.
This is the most reliable indication of heat and the appropriate moment for (natural) service.
? She may have mud on her flanks from having been mounted before.