Calves' needs go up during winter
by Mid-Maryland Dairy Veterinarians
Mid-Maryland Dairy Veterinarians is a seven-man practice located at Hagerstown, Md.
Each winter, we start to receive this call, "Hey Doc, I have 10- to 14-day-old calves that are dying and nothing I treat them with works."
When we visit the farm, we see thin, weak calves that are scouring, depressed, and about to die. When we ask what has changed, we usually hear, "Nothing. We are feeding them the same way we always have."
Why is this happening? Calves are born with only 3 to 4 percent body fat . . . much less than most other species. This means they are not very well insulated, and they have very little energy stored. Calves were meant to be able to eat small meals as often as they want in order to provide the energy they need to keep warm and grow.
Instead, we give them only two meals a day, and then we limit the amount of milk so we can get them on grain as soon as possible.
The standard milk replacer diet (8 ounces of 20:20 milk replacer in 2 quarts of water twice a day) provides only enough energy to meet the calf's maintenance needs plus 0.5 pound of gain per day at 68°F. However, at 15°F, that same calf requires 12.5 ounces of milk replacer twice daily just to survive.
The amount of milk that we got by with during warmer times doesn't even meet the calf's basic needs below 50°. As a result, the calf loses weight from day one. In a starvation mode, the body quickly uses up the fat stores and begins using muscle for energy. All systems are shut down to preserve energy, and one of the first to go is the immune system.
Fortunately, the cure for starving calves is easy . . . just feed them more milk! Mix two 8-ounce cups of milk replacer in 4 quarts of water, and feed them 1 gallon twice a day. If you feed whole milk, give them 3 quarts twice daily. Most calves will drink a gallon from day one.
It also is important to feed calves as close to every 12 hours as possible. Allowing a longer interval between feedings at night makes it harder for them to keep their body temperature up. This diet provides enough protein and energy to meet maintenance all the way down to -20°F. At 15°F, it meets maintenance plus provides for 1 pound of gain per day.
Buckets are the easiest way to feed this, and calves perform just as well on buckets as they do on bottles. Start calves with 1 gallon of colostrum at birth; then wait 24 hours for the next feeding. Most will drink a gallon of milk replacer from the bucket on the first feeding.
Here are some frequently asked questions about stepped-up feeding:
How about feeding more powder in 2 quarts of water like the label says? Boosting the concentration of the milk replacer works if the calf drinks plenty of extra water. But that can be difficult to provide in the winter. Problems occur if the milk is too cool when it is fed or if the calf can't get enough water.
Won't too much milk make calves scour? Diarrhea is a healthy body's natural defense against intestinal pathogens. Calves live in a contaminated world so scours are normal. With plenty of energy available, the calf's body can defend itself easily and keep eating and growing.
Won't more milk keep calves from eating grain? During the first three weeks, these calves don't eat much grain. However, they are growing much faster than your regular calves. By 4 to 5 weeks of age, they are eating enough grain to begin weaning.
Here are some additional incentives to feed more milk. Calves that get the energy and protein they need are not just heavier; they are taller at 2 months of age. Bigger, stronger heifers wean better, have less treatment costs, and breed sooner.
At least seven different studies (see table) have shown that calves on a higher plane of nutrition for the first 60 days of life gave about 2,000 pounds more milk in their first lactation.
Using a milk replacer that is higher in protein will add to the benefits by more closely meeting the calf's requirements. Feeding more milk is not just a cold-weather survival tactic . . . it's a way to lower costs and end up with a better milk cow.