Smart Calf Management
Smart Calf Management is an ongoing series providing information and pointers to help dairy producers manage their calves more effectively and efficiently. Look for additional installments in future issues of Bovine Health Watch.
Cold Weather Calf Management
Sound management practices help calves thrive in cold weather.
Cold weather can cause young calves to use excessive energy. It is stressful and puts their health at risk. But, by thinking ahead and using sound management practices, producers can minimize those risks and help their calves thrive.
Calves, especially young ones, are using lots of energy growing, fighting off disease threats and building body mass during their first few months of life. When cold weather comes along, they have another demand on that energy: staying warm. If calves don’t have enough energy reserve, the cold will rob the energy that should have gone for growth or disease resistance.
The average body core temperature of a calf is approximately 102 degrees Fahrenheit. Their “thermal neutral zone’ is bounded by 60 at the bottom and 75 or 80 at the top, according to Sam Leadley, Ph.D., P.A.S., Calf/Heifer Management Specialist at Attica Veterinary Associates in Attica, NY. and editor of Calving Ease, a monthly newsletter for calf raisers. So, for them, it starts feeling cold—and energy starts being diverted away from growing and staying healthy —when the mercury drops below 60 degrees. And, the colder the weather gets, the more energy a calf has to use maintaining that body temperature.
How quickly their energy is depleted depends on how effective the producer’s calf management strategies are. And, that can make the difference between health and sickness … even life and death.
There are basically two avenues for minimizing the drain on energy during cold weather months: (1) bolstering the calf ’s energy reserves and (2) shielding the calf from the cold that is draining energy. Here are a few easy ways to accomplish both.
Rev up their energy.
Set the stage for a high energy start by making sure each calf ’s dam has had good nutrition. “That translates into more brown fat, which converts directly to heat and helps calves during the first few days of life warm their bodies during the cold weather,” Leadley explained. It also yields better quality colostrum for the newborn calf. He added that calf energy can be stimulated as much as fourfold in newborns simply by making sure they stand up quickly after birth.
Feed more energy during the colder months. The amount increased depends on how cold the weather gets. Leadley says he generally recommends a 50 percent increase for Western New York winters. In everyday terms, that correlates to feeding three quarts of replacer or milk per feeding twice daily instead of two quarts per feeding. He and many other experts in the field recommend adding grain to the calf ’s diet—as early as day two. That also provides a rich source of energy and heat.
“Grain ferments in the rumen, and after about five or six weeks of age, that fermentation is generating a fair amount of heat,” said Leadley.
Shield them from the cold.
Protect calves from wind or strong drafts that can compound cold temperatures and further deplete energy. Provide places for the calf to escape the wind, especially where they can lie down. Lying down exposes less of their body to the wind than standing up, so it consumes less energy.
Make sure their bedding insulates them from the cold. Earth and concrete are both very cold in winter months, so provide an adequate amount of dry, comfortable bedding material that has good insulating properties. Be certain the bedding is thick enough to provide a three-inch base, when compressed. If the bedding material accommodates “nesting,” that will further shield calves from the cold. If a calf has enough straw bedding for winter you should not be able to see her feet when she lies down, Leadley said. Or, you can test the effectiveness of the bedding yourself by kneeling down on it. If your knees feel cold after a few minutes, you can be sure that a calf will, too. If bedding materials are less than desirable or don’t allow nesting, you can even purchase calf blankets to keep them warm.
Warming their milk and water is one more way to keep the cold from depleting their energy stores. We don’t often think about it, but when calves drink cold milk, replacer or water, their body has to warm it to 102 degrees. By feeding the liquids in their diets at close to body temperature, you can reduce that drain on their energy. Leadley says it is important to monitor feeding temperatures, especially for milk. An inexpensive rapid-read thermometer can be used to quickly check to see that “as-fed” milk is not too much cooler than 102 degrees even under winter conditions.
These are just a few ways that producers can more effectively manage the health of their calves during cold weather. Sound management practices such as these can help prevent the cold from robbing calves of their energy—and producers of their profits.