There is no magic bullet or secret formula for keeping young, preweaned calves healthy, according to North Carolina State University professor of veterinary medicine Geof Smith.
Smith told the audience of a recent DairExnet seminar on "Avoiding Diseases in Dairy Calves" that disease prevent comes down to four time-testing fundamentals:
- Removing the source of infection from the calf's environment
- Removing the calf from the contaminated environment
- Increasing immunity; and
- Decreasing stress
Smith said timely delivery of clean, high-quality colostrum still should be the number-one priority to prevent disease in young calves. He advised delivering 3 to 4 quarts of high-quality colostrum within 2 to 4 hours of birth. He also advised against pooling colostrum, and recommended that dairies always have some frozen colostrum, or high-quality colostrum replacer, on hand.
Housing, ventilation and nutrition also play important roles in preventing the three major disease conditions that cause calf mortality: diarrhea, pneumonia and septicemia. His advice to protect calves from these conditions included:
- Don't expose calves to manure from older animals. There are many organisms in adult-animal manure that calves' immature immune system cannot handle.
- Don't overcrowd calves. In group housing, 30 to 40 square feet of resting space is advised. And just because calves may be housed in individual hutches doesn't mean they should be stacked together like cordwood. Allow at least one hutch-width of space between hutches.
- As a general rule, sickness in the first week of life usually is due to unsanitary calving conditions and/or poor colostrum delivery. Sickness that occurs later tends to be the result of contamination from the calf housing environment or feeding equipment.
- Air quality in indoor barns should be evaluated at the calf level, not the human caretaker level. Retrofitted swine and poultry barns with low ceilings tend to have the most ventilation and air quality issues.
- Calves can tolerate cold, open ventilation (producing better air quality) if they have dry, deep straw bedding that allows them to nest deeply enough that their legs are hidden.
- Feeding at higher levels of liquid nutrients has been shown to help calves resist disease. If you're still feeding a gallon of 20:20 milk replacer a day, that's probably not enough.
- Work to minimize stress for young calves, as studies in other young animal species have shown that diarrhea-causing organisms can lie dormant in the gut, but become clinical when animals are under stress.
- Work with your veterinarian to develop written disease treatment protocols. Use records to evaluate management practices and treatment outcomes. Stick to the prescribed treatment instead of bouncing from one drug to another.
"If your preweaned calf mortality is 4% or higher, and/or you have a treatment rate of more than 25%, there is room for improvement in your disease-prevention management," said Smith. "Sometimes even small changes can make a big difference in keeping calves healthy."
You can view the full webinar, including Smith's answers to calf-rearing questions, here.