The nutrition of the early weaned (90-120 days of age) calf is not greatly different than that of the normal age (~205 days) calf; however, there are several key factors to consider.
Whether or not you've ever fed calves, you’re more qualified to wean your calves than anyone else, provided you’ve got some quality feedstuffs and appropriate facilities. The reason? If you can simply move the calves or cows to an adjacent pen or pasture from one another, the stress of weaning is nearly eliminated. And this greatly reduces the risk of subsequent disease.
Many ranchers have instituted fenceline weaning, in which the calves are placed in a pen or pasture adjacent to their mothers, and can have nose-to-nose contact with them. Or the cows are placed in a pen and the calves are allowed to graze in an adjacent pasture. These systems have proven highly effective at reducing stress on calves. Oftentimes the cows create more noise after weaning than the calves. After a few days, the calves can be completely separated without additional stress. This speaks volumes about the nutritional needs of the calf; it needs only some occasional, shortterm contact and proximity from the dam, but nutritionally, the calf is ready to be on it’s own.
When the calf nurses, a groove closes, shunting milk from the esophagus, bypassing the reticulum, rumen, and omasum, straight to the abomasum. But, when a calf either grazes or eats solid feed from a bunk, feed enters the reticulo-rumen and begins fermentation. Once the rumen has been ‘inoculated’ (usually very soon after birth) with bacteria and protozoa from it’s environment, and has been ‘fed’ through grazing, the calf is a functional ruminant---this is the normal scenario for beef calves.
The rumen and the calf are both accustomed to grass and the rate of energy release from forages. So the first feed offered to the calf during it’s weaning transition should resemble what they’ve been consuming up to this point--that is, good quality forage. Good quality hay from either grass, grass/legume mix, or annual grains work well. This hay should be spread out, either long-stemmed or very coarsely chopped, in the very same bunks where the calves will be fed. Provide all the hay the calves will eat in a day, which will normally be about 10-15 pounds per head per day.
It is counter-productive to train the calves to eat from a bale feeder only to later try to retrain them to a bunk, and the attraction of good quality, loose, long-stemmed hay in the bunk is the best way to accomplish this. Also, on either the first or second day after weaning, place about 2-3 pounds per head of a nutrient dense starter ration on top of the loose hay. This ration should be a mix of 25-35 percent ground hay, and the remainder made up of a blend of cracked or ground grain and a source of protein, vitamins, and minerals. Byproducts such as dry distillers grains, wheat midds, corn gluten feed, and soy hulls work well to provide both energy and protein, and can be used to replace all or a portion of the grain in the diet. With the inclusion of byproduct feeds to supply all needed protein, a commercial source of vitamins and minerals can be used to balance the diet.
If the calves are healthy, vigorous, and eating well, the loose hay can be reduced and eliminated over a period of 3-4 days, but if health and intake of the ration are poor, continue to place 3-4 pounds of loose hay in the bunk until health and intake improve.
Economic return from early weaning is driven primarily by ensuring future productivity of the cow herd, but proper management of the calves can contribute as well. Plan to have feed and space for these calves for at least 30 days, and 45-60 days may be even better. That will give the calves time to recover any lost weight from the weaning transition, recover from any respiratory disease they may have endured, and fully respond to the vaccination protocol given at weaning time.
Another benefit of feeding these calves for a time is that given their young age and lean stage of growth, these calves convert feed to gain very efficiently (often in the range of 4:1); therefore, the cost of gain can be very economical, compared to commercial feeding, depending on the cost of your local feedstuffs.
Based on current estimated Kansas costs of alfalfa hay, cracked corn, dried distillers grains, and a medicated mineral/vitamin supplement, calves can be fed for approximately $1/day (not including yardage or labor). If no major health challenges occur, we should expect the calves to gain at or above 2 lb/day. This results in a feed cost of gain of about 50¢/lb, while current commercial feedyards are experiencing feed costs of gain of about 80¢/lb for finishing cattle.
There are many ways to effectively manage these special calves. The most important thing is to get them the needed nutrition, preserve the cow, and preserve the range.
Source: Chris Reinhardt, extension feedlot specialist, Kansas State University