When are calves ready to wean?
The obvious answer is when she can digest and absorb nutrients from solid feeds rather than milk replacer.
Not so obvious is the amount of nutrients that need to come from solid feeds such as calf starter grain. How much is enough?
Is there anyone that does not know what has happened to the price of milk replacer recently? The increases are enough to drive anyone to ask, “How can we use less milk replacer?” One of several ways is to wean calves earlier. When are calves ready to wean?
The obvious answer is when she can digest and absorb nutrients from solid feeds rather than milk replacer. Not so obvious is the amount of nutrients that need to come from solid feeds such as calf starter grain. How much is enough?
In a recent Hoard’s Dairyman article (May 10, 2007) Dr. Al Kertz explained how starter intake is the key factor to consider when weaning calves. He points out that if starter intake is not adequate during the two weeks before and after weaning (he refers to these four weeks as “weaning transition”) the rate of gain among calves will “slump.” He adds, “Calves may actually lose weight.”
His observations imply that our goals for calves during the “weaning transition” should be:
- To avoid weight loss (in my experience, many of these calves will have to be treated for pneumonia within seven to fourteen days post weaning)
- To maintain a desirable rate of gain.
I translate “enough nutrients” from solid feed into volume of calf starter grain consumed. Thus, amount of grain is a proxy measure for nutrients available to meet maintenance and growth needs. This proxy, grain consumed = available nutrients, works quite well as long as the calf has been eating a cup or more of calf starter grain for about three weeks.
Successful weaning can start when calves have been eating grain for three weeks and have arrived at regular daily consumption of one quart. If you want to check the weight:volume ratio of your starter, fill a ten-quart or five-gallon pail with starter and weigh it. Most calf starter grains have a ratio of one quart = one pound.
I think you should consider beginning the weaning process by dropping one of the two daily feedings of milk replacer. If you are feeding two quarts of 20-20 milk replacer and one quart of calf starter grain with 18 percent crude protein and an energy value of 3.7 Mcal/kg a one-hundred twenty pound calf should be able to continue gaining about one pound a day. With more intensive milk replacer feeding programs the estimated rate of gain will be higher.
Several years ago I compared two methods of cutting back on milk replacer. I wanted to reduce the amount fed by one-half. Half of my calves were cut back to one-half fed in two feedings while the other half were fed the same amount in one feeding. The rate at which the calf starter grain consumption increased was much faster among the calves fed once a day versus twice a day even
though all of them received the same amount of milk replacer. Expect starter intake to double within three days after you drop back to once a day feeding. Caution. Remember that for this to work the calves must have both free choice water and free choice grain.
As calves increase grain consumption we may run the risk of bloat. When we add five or more pounds of calf starter grain at one time to an empty bucket a hungry calf may eat the entire amount at one time. This kind of slug feeding under the right conditions may result in bloat. However, in most situations with which I am familiar when the grain feeding pails are not allowed to get empty very little slug feeding takes place. If the farm’s growth goals dictate limit feeding starter, then I recommend not feeding in excess of two to two and one-half pounds at a time.
Completing the weaning process
A popular rule-of-thumb is to drop all milk replacer feeding when the calf is regularly eating three pounds of starter per day. That is based on a summer environment, a 150 pound calf with an expected gain of one pound a day. If your growth goal is closer to two pounds a day, then calves need to be
eating about five pounds a day. Further, if your calves weigh closer to 170 pounds at this point you need to add about another one-half pound.
Do remember that as the environment gets colder more energy is used for maintenance and less is available for gains. For example, at 20 degrees, calves need about one and one-half pounds extra calf starter to achieve the same gains compared to summer conditions. When the popular “3 pounds a day for 3 days in a row” rule is applied in the winter calves often experience a slump in gains and sometimes break with pneumonia.
More details on colder conditions in this article >>
Finally, observe grain intake rates during the week after weaning. I like to keep calves in individual housing for this first post-weaning week so I can watch grain consumption. You should expect grain intake to go up another twenty-five percent or more in this first week off milk replacer.