Winter months are usually when calves are under the most stress and when diseases, like coccidiosis, can take advantage of depressed calf immune systems.
Coccidia are parasites in the intestinal tracks of cattle. Eggs are produced and shed via manure. “From the moment a calf is born she is very likely to get oocysts in her mouth,” says Sam Leadley with Attica Veterinary Associates in Attica, N.Y. Leadley offers some advice on reducing shedding rates in older animals:
- Create clean, well-bedded resting space for calves.
- Optimize ventilation in the barn and calf or heifer pens.
- Provide adequate feed space per animal.
- Minimize weight and age variation between animals in the group.
- Avoid feeding on the ground unless it is at a bunk.
- Provide 12" of linear water space per 10 animals.
- Treat infected animals.
- Maximize time between successive occupants of the same pen.
“On nearly all dairies, all animals will eventually be exposed to coccidia. Through natural exposure, they will build immunity that suppresses infection,” Leadley says. “If the exposure of young calves can be managed to maintain a low level of infection, they can build immunity without excessive damage to their gut and loss of normal growth.”
If natural exposure rates are high, Leadley recommends using a feed additive labeled to control coccidia activity in exposed calves. Preclinical use of the additives is recommended, he says.
“Damage in the gut due to uncontrolled growth of coccidia will occur as early as five days after coccidia exposure,” Leadley says. “Thus, don’t wait until clinical symptoms are present to begin using the additive that you and your veterinarian [believe] is best for your situation.”