November 14, 2002

Taking the Cold out of Feeding Calves During Winter Months

Feeding dairy calves in winter can be tricky in North Dakota. During periods of severe or prolonged cold, feeding adjustments must be made or calves can be suddenly lost, according to J.W. Schroeder, North Dakota State University Extension dairy specialist.

"Calves are most comfortable at 50 to 60 degrees," Schroeder says. "Lower temperatures and wind chill factors result in ‘cold stress’. Energy to generate body heat comes from food or stored body fat. If calves are not fed more during periods of cold weather, they will burn body fat and lose weight. Once body fat stores are consumed, the calf can become hypothermic. Signs of hypothermia include depression, weakness, loss of appetite, and cold extremities. These calves will die if not warmed and fed."

According to Schroeder, most young calves are capable of consuming milk at approximately 25 percent of their body weight per day in six to eight feedings. However, calves are often fed only twice a day. If milk is provided at a volume of 25 percent body weight in only two feedings, calves may reduce intake or develop bowel disorders. Consequently, each feeding should equal about five percent of the calf’s body weight. Thus, feeding twice a day will result in a daily intake of 10 percent body weight.

"With this regimen, the calf is not consuming to appetite and so begins to eat dry feed early in life," Schroeder says. " Ultimately, this allows lower feeding costs and earlier weaning. This earlier development of rumen function ultimately benefits the calf."

Unfortunately, Schroeder notes, there are a few potential problems with this program. For the first several weeks calves are underfed because dry feed intake is not yet substantial. In cold weather, calves are at an increased risk of inadequate energy intake. This threat is complemented by the standard practice of feeding two quarts per feeding, which amounts to approximately 8 pounds per day. This is adequate for an 80-pound calf, but is only 8 percent body weight for 100-pound calves. In addition, many milk replacers incorporate only 10 percent fat, equivalent to 2 percent milk fat when reconstituted.

Steps to a Successful Program

• Use High-Fat Milk Replacers

Use milk replacers with 20 percent fat to provide calves with extra energy, especially during winter months. Reconstituted by label directions, this will equate to 4 percent milk fat.

• Increase Feed Intake

Increase dry matter intake by 10 percent for every 10 degrees that the daytime high is below 32 F. When daytime highs are below 7 F, feed the excess in a third feeding to help prevent digestive upsets.

• Increase Fat Intake

Add a commercial fat supplement to increase milk or milk replacer energy levels. There are dried supplements specifically made to mix with liquids. Tallow or liquid vegetable oil doesn’t mix well with liquids. The fat should complement the starter, not replace it.

• Keep Clean, Dry, and Draft-Free

Use plenty of bedding in hutches. Deep, clean, dry straw in a tight hutch will help keep well-fed calves warm. Sand, sawdust, or shavings are good bedding bases, but should be supplemented with straw in cold weather.

• Encourage Starter

Get calves to eat a well-balanced starter as soon as possible. Ruminating calves are not as easily cold-stressed as calves consuming only liquid feed. Starters are more effective than hay at developing the rumen and providing energy for warmth and growth. Calves should be eating at least 2 to 3 pounds of starter each day at weaning.

• Offer Plenty of Water

Offer calves water at least once a day during winter months. Water is necessary to promote starter intake and rumen development. It also helps maximize the benefits of nutrients in extra milk replacer.

• Minimize Changes

Once a calf is on a high-energy liquid diet, continue this diet until weaning. Feeding changes can cause digestive problems.

"Calf raising techniques do vary from these recommendations, and new research is suggesting diets specific to management style and heifer growth rate," Schroeder says. "Nonetheless, these procedures are key to maintaining a healthy calf, especially during cold weather."

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Source: J W Schroeder, (701) 231-7663, allen.schroeder@ndsu.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu