Calves with Sam

 Coccidiosis and Shedding

 

In a presentation about coccidiosis at the Dairy Calf and Heifer Association meetings Dr. Sheila McGuirk talked about shedding. That's the process where an infected heifer passes eggs (sporulated oocysts) in her feces.

The significance of her remarks about shedding is in the close connection between shedding rates and infection levels. When the infection level is high, so is shedding. And, high rates of shedding in a pen of heifers leads to even higher rates of infection among more animals.

Thus, the action called for in controlling coccidiosis, therefore, is to adopt practices that reduce shedding. Her short list includes:

• 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. 

It's all a numbers game. Controlling shedding, even in a pen of heifers that seem "healthy," cuts exposure. Lower exposure levels mean better feed conversion rates.