Fall is in the air, and so is the reminder that day-to-night temperature swings are becoming more extreme. They pose a health threat to calves that makes it important to carefully reexamine the quality and quantity of the nutrition they receive.
"Rains and cooler weather mean more moisture that can create nasty conditions for the calves' environment," says Tom Earlywine, director of nutritional services for Land O'Lakes Animal Milk Products. "Both can be major health challenges that make it tougher to keep calves growing, so we need to look pretty hard at the plane of nutrition that is provided in fall."
This starts with remembering that dry cows that suffered summer heat stress tend to produce terrible quality colostrum, so calves that receive it in the fall start out at a disadvantage. Cool fall nights bring more moisture to bedding, which spurs faster bacteria growth and poses a greater challenge to calves' immune systems. These alone are stresses, so the addition of anything else can dramatically boost calves' nutrition needs.
"Maintenance nutrient needs of calves go up by an additional 150 to 200 percent when there's any kind of stress at all," says Earlywine. "All it takes is just a moderate level of stress and even a calf that's receiving 3 quarts twice a day will start losing weight and eventually be at risk of starving to death."
Rather than increasing the nutrient density of milk or replacer that is fed, he recommends keeping the same mix and feeding more of it.
"A lot of people are feeding 4 quarts or more per twice-a-day feeding," says Earlywine. "In fact, there are some who have stepped up to 6 quarts per feeding or 4 quarts three times per day. The fun part about that is calves aren't getting fat; they're putting on frame length and height. And when subfreezing temperatures do happen, those calves won't all of a sudden be back to a starvation diet level; they'll actually be able to maintain some growth."