The approach of winter means it is time to wean calves. Weaning, associated with significant stress for calves and their dams, can have a profound influence on calf health.
Flip Prinsloo of Pribio Animal Health says respiratory diseases are a common problem in calves at the beginning of winter, with pneumonia a leading cause of calf mortality. A harsh environment, inadequate management and compromised immunity in the calf may lead to pneumonia, usually caused by viral and bacterial infections.
Management factors that can predispose calves to pneumonia include:
- Poor ventilation: Viruses and bacteria that cause pneumonia thrive in moist, damp environments with inadequate air flow.
- Wind: Young calves exposed to cold and windy conditions use excessive amounts of energy to stay warm, compromising their immunity and increasing the risk of contracting pneumonia.
- Cold stress: Exposure to low temperatures may cause stress in young animals.
- Malnutrition: Coping mechanisms to deal with the cold are dependent on decent intakes of milk and feed.
- Weaning: Gradual weaning with increased dry feed intake before separation from the dam, reduces stress.
- Mixing age groups: This may encourage the spread of disease from older to younger calves.
Prevention through vaccination
Dr Ian Jonker of the Leeudoringstad Veterinary Clinic advises farmers to vaccinate calves against the pathogens that cause respiratory disease. He also recommends a multi-strain clostridial vaccination.
According to Flip, pneumonia may have long-term effects on the calf. It can cause permanent damage to the respiratory system, lead to poor growth, underperformance and higher treatment costs. “Even fully recovered animals may perform poorly in the first lactation. It has a long-term impact on the weight and carcass of beef cattle,” says Flip.
Diarrhoea in calves
Diarrhoea is another problem during winter. Insufficient intake of colostrum, poor quality colostrum and the presence of pathogens all cause calf diarrhoea, explains Ian. High standards of hygiene and fresh, clean water supplies are absolutely critical if diarrhoea is to be avoided.
Diarrhoea is the most common cause of calf mortality in South Africa, says Flip. Crowding, underfeeding, mixing of age groups and dirty milking equipment all contribute to the spread of pathogens, he adds.
Tips to prevent calf diarrhoea:
- Test colostrum quality and ensure that calves are getting enough colostrum.
- Maintain a clean environment in the calving camps.
- Maintain high standards of hygiene in the calf pens, disinfecting after each group moves out.
- Avoid contact between younger and older calf groups.
- Ensure sufficient calorie intake to boost the immune system.
Weaning and separation stress
Because calves in beef cattle herds are usually weaned during March and April, weaning stress has an additional impact on calf health. Weaning stress occurs during the first two to three days after separation from the mother. Weaning stress includes nutritional stress and separation stress. Farmers generally use a supplementary creep feed ration three weeks prior to weaning and three weeks after weaning, to limit nutritional stress.
Using a nose ring or weaning by fence-line separation that allows visual contact, can limit separation stress. Ian believes nose rings are a good method of reducing weaning stress as it also helps prevent weight loss in cows.
- Place the bull calves with the heifer calf mothers and the heifers with the bull calf mothers. Use a robust boundary to separate the groups.
- Teach the calves to feed from troughs and offer them good quality feed before and after weaning.
- Do not dehorn, castrate or vaccinate immediately before or after weaning.
- Do not wean calves in extreme weather.
The secret to ensuring calf health is to keep calves free of gut and respiratory diseases by immunising with the appropriate vaccines.
Ian recommends vaccinating cows as this provides calves with passive immunity for the first three months after birth, and following the veterinarian’s vaccination protocol for calves. Adequate shelter, good quality veld and licks must also be provided to reduce nutritional stress.
For more information, contact Flip Prinsloo on 056 217 1114 or Dr Ian Jonker on 082 925 7273. – Koos du Pisanie, Stockfarm