Ask the Expert: How Has Calf Raising Changed During Your Career? – Dr. Ken Nordlund, University of Wisconsin-Madison
Question: How has calf raising changed during your career?
Answer: I worked as a dairy veterinarian in private practice in Minnesota for 12 years then as a professor in the School of Veterinary Medicine at the University of Wisconsin-Madison for 25 years. While lots of things have come and gone, three items that have big impacts for the good of dairy calves are more milk, fresher air, and better drainage.
I began my veterinary career when most of the nursing dairy heifers were housed in a warm corner of a tie-stall barn within view of their mothers. Those were the days of 2 quarts of milk or replacer twice a day and non-stop exposure to polluted air. And many of those Holstein heifers were barely 800 pounds at a 15-month breeding age.
Those poor little dairy heifers looked incredibly small and weak compared to their beef heifer cousins. At another farm just down the road, you’d see Simmental-cross heifers that were raised outdoors with deep straw, windbreaks and ad-lib access to their dams, and they weighed 700 pounds at seven months of age.
The old idea was that, by limiting milk, the calf would shift to solid feeds at a younger age and reduce the cost of raising her. But the reality was that they actually didn’t consume much more solid feed. Instead, they grew less, were sick more and died more easily. The recent understanding that improved early growth translates into adult cow milk yield is part of the story. Rather than trying to grow them at a lower cost, we should have been trying to grow them better.
We started moving heifers out of cow barns in the 1970s and worked with negative pressure calf barns. That was a modest improvement. By the 1980s, adventurous dairy farmers in the upper Midwest reported that calves could survive our winters in hutches. In fact, those heifers did really well and those hutches were as cold inside as outside.
But dairy herds expanded in the 1990s. Suddenly, delivering milk to 100 nursing calves on a bitter January morning became intolerable and we saw the construction of naturally ventilated individual pen barns. Based on a field trial in the winter of 2005, we developed the positive pressure ventilation tubes to supplement natural ventilation. The goal was to deliver a small quantity of fresh air into the microenvironment of the calf without a draft. This technique has had a substantial impact on heifer rearing.
Most of the calves in hutches did well, especially those in deep straw on top of a gravel pad. However, the move back into calf barns usually meant modest bedding over a concrete floor – a step backward.
In our 2005 field trial in calf barns, the average dry matter of core bedding samples from calf pens was 48 percent, which meant calves were dealing with cold stress while lying on a bed that was 52 percent water. And liquids drain from the bed onto the floor, increasing the risks of Salmonella and other causes of nursing calf diarrhea. By removing the solid concrete base and providing drainage below deep straw, disease risk is reduced, growth rates are improved, and bedding costs are lowered.
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Calf and heifer nutrition
Starting Strong - Calf Care