How much an animal eats can be simplified down to a handful of basic factors. Some, like frame size or maturity (does the animal still need to grow or has it reached its full potential size), we can only manipulate slowly over time through genetic selection. Others like demands from maintenance energy, lactation, and pregnancy can be a quicker reacting lever to utilize. This time of year, producers with limited forage resources may consider leaning on the lactation lever a bit by weaning calves from their spring calving herd early.
Typically, spring calving herds won’t wean until later this fall, but doing so earlier rather than later has the potential for some positive outcomes when grazing is tight, if managed correctly. Research suggests that spring born calves on pasture begin consuming significant amounts of forage at 45 days of age, showing that rumen function has begun. Weaning beef calves as early as 45 days of age is early enough to encourage the cows to cycle and rebreed. Weaning calves this early is used as a "last resort" management strategy when cows are thin prior to the start of the breeding season. Weaning at 3 to 5 months of age is too late to cause early cycling; therefore, it doesn't contribute to the improvement of reproduction but may be a viable alternative if forages are scarce in the latter part of the grazing season.
Early weaning the calf significantly reduces the nutrient demands placed on the cow and more closely matches her requirements to nutrients supplied under drought or poor range conditions. Spring calving cows need to be in adequate body condition (BCS 5) prior to calving. Removing the calf early helps to improve body condition which has the potential to carry-over through the winter causing increase body condition at calving that is also evident during the next breeding season.
Early weaning of calves from 2-year-old, first-calf-females reduces the stress of nursing and raising a calf. As a result, these females will be in better body condition at calving that should result in cows that cycle and breed back earlier in the breeding season. For heifers bred for higher milk production, early weaning takes on greater importance. The greater the milk output, the greater the nutrient demands, the more difficult it is to keep young females in adequate body condition on a limited forage base.
Ultimately, early weaning, due to decreased nutrient demands from the cow, can stretch forage resources. By removing grazing pressure from the calf and reducing that from the cow, less forage is consumed and pastures can be grazed for longer periods without overgrazing occurring. When paired with proper supplemental feeding, cow condition and pasture health can be maintained under even the driest conditions.
To early wean successfully, managing calf stress is critical. Two stage weaning practices like fence-line weaning can be one way to reduce stress by easing the calf into the transition away from the cow by maintaining social and visual contact while preventing nursing. Before weaning, make sure that calves are ready for the new feed they will be consuming. Introduce feeds 3-4 weeks prior to weaning that are palatable with adequate levels of protein and energy to meet your desired performance goals. Having a familiar feed available at weaning limits the time calves may be off feed and further reduces stress on the calf.
In certain areas, strategic mineral supplementation when the calves are with their dams prior to weaning may be beneficial for getting good immune response. Minerals such as copper, zinc, cobalt, and manganese are important to immune system function. A lack of these minerals in feed sources or high levels of other minerals, such as sulfur which can inhibit absorption of minerals, can impact immune response.
Early weaning to deal with forage limitations, is a viable strategies if planed for and managed correctly. Success hinges on minimizing stress by taking steps like introducing feeds early and using a two-step approach like fence line weaning. By reducing the pressure from lactation and calf grazing on pastures, animal condition may be easier to maintain and grazing resources stretched.
-Ben Beckman is a beef systems Extension Educator serving the counties of Antelope, Cedar, Knox, Madison and Pierce. He is based out of the Cedar County Extension office in Hartington. You can reach him by phone: (402) 254-6821 or email: ben.beckman@unl.edu