Sounds like something from an old almanac, but I just made it up.
While some calves seemingly do get a long and fluffy hair coat overnight, the more important cue of that chill for calf feeders is to feed baby calves more.
Requirements. How do we need to adjust nutrition for calves less than three weeks old in cold weather? Using the Nutrient Requirements of Dairy Cattle program, let’s look at maintenance requirements first.
With a 90-pound calf (Holstein heifer) and a 60-pound calf (Jersey heifer) as examples, we see a critical need for additional milk or milk replacer occurs as temperatures drop toward freezing.
These pounds of dry matter are the milk replacer powder, or equivalent amounts of fresh milk (one, 2-quart bottle of milk contains about a half pound of dry matter).
Traditional milk replacer feeding recommendations of 1 pound of dry matter per day, (usually fed as two bottles with 8 ounces of powder each) will allow a calf to gain a half pound per day in warm weather. But at 32 degrees, both calves need 50 percent more milk replacer dry matter to meet maintenance requirements (neither gaining or losing weight).
Additional milk replacer must be fed beyond that if we expect the calf to grow.
Changes. How must nutrition change in cold weather? Quite simply, the calf has to eat more. If she isn’t offered nutrients, she simply won’t get them.
In calves less than three weeks old, starter consumption is minimal and will not provide significant nutrients. Even though it doesn’t provide significant nutrients, the consumption is important because digestion of those mouthfuls of starter initiate rumen development.
How much more milk or milk replacer these calves need is a function of temperature and our target rates of gain.
The following tables show dry matter requirements for our 60-pound and 90-pound calves receiving a 20:20 milk replacement diet:
Getting calves fed well day in and day out, especially if multiple people are doing the feeding, is an important factor in overall calf health. Changing amounts fed each day depending on the temperature is both impractical and not likely to happen.
Goals. Set a goal for rate of gain. If we feed for 1.5 pounds gain per day for a Holstein at 60 degrees (2.2 pounds dry matter), our potential rate of gain will drop to 1 pound per day in extreme cold.
If we feed 1.6 pounds of dry matter for 1 pound of gain, we will drop to no gain in extremely cold conditions.
We never, ever, want to drop below maintenance requirements. Calves will lose weight and their immune system will be challenged.
Some farms feed fresh milk. The exact test of this milk will vary from day to day and farm to farm. See the latest issue of the Buckeye Dairy News at http://dairy.osu.edu for a chart and discussion for feeding whole milk.
How should additional milk be fed to calves? Healthy calves can easily eat more than the typical bottle or half-gallon of milk or milk replacement fed at 12.5 percent dry matter per feeding.
Actually, they would like to eat more than that. Large calves can and will eat a gallon per feeding. Small-breed calves can handle a half to 3/4 of a gallon with no adverse effects.
If they have eaten most of their diet, but do not care to finish, do not force feed an otherwise healthy calf.
Calves are designed to handle 12.5 percent dry matter liquid diets (equivalent to fresh milk). Keeping diets close to this concentration is less likely to cause digestive issues than trying to concentrate more powder in a given volume of water.
There is some suspicion that very concentrated dry matter in liquid diets can contribute to the incidence of acute bloat syndrome, an infrequent, but usually fatal disease in neonatal calves.
Loose manure. Additional liquid intake will result in loose manure, which should not be mistaken for scours. While calves can still contract scours, when their manure is simply loose from a higher liquid intake, they will maintain a good appetite.
Feeding calves to gain does not decrease the need for good housing – clean, dry, fluffy bedding that calves can nestle down in and top-quality care.
Invest time and adequate nutrition in these calves. They are the future of your dairy farm business.