During normal precipitation years, calves in Northern Nevada are weaned at six to seven months of age. In typical spring calving herds, this is usually September through November. However, during drought, forages are generally limited, and early weaning should be considered as a management tool. Time of weaning will have impacts on cow and calf performance as well as health and productivity of the native range or pasture.
The rumen of a newborn calf lacks the microbial population that enables adult cattle to process forage fiber. However, rumen development proceeds rapidly once solid food consumption begins. Research suggests spring-born calves consume significant amounts of native range forage at 45 days of age. 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. Weaning calves at 45 to 60 days of age may be a management strategy included in a drought plan. Weaning calves at 3 to 5 months of age may also be a viable alternative if forages are scarce in the latter part of the grazing season.
There are several items to consider prior to early weaning calves. Calves can adapt quickly to the change in environment and diet if a management plan has been carefully developed. Regardless of weaning age, calves that start eating dry feed immediately after separation from their dam have fewer incidences of morbidity and mortality than calves that do not eat for 24 to 48 hours after separation. Offering a creep feed three to four weeks prior to weaning will help calves adjust to eating processed feeds and make the weaning transition period less stressful. Using creep feeding in this manner will bunk break the calves and will teach them to eat. Be sure that bunk and water heights will accommodate the smaller calf.
Early weaning is one management option, which should be considered during drought. Early weaned calves achieve adequate rates of growth if given access to high quality ration. By the time calves are 3 to 4 months of age, they are consuming significant amounts of forage. At 6 to 7 months of age, calves will consume approximately half the amount of forage as a mature cow. Following weaning, dry cows will eat less forage than lactating cows, further reducing demand placed on the pasture. By removing the demands of lactation, acceptable pregnancy rate and calving season length can usually be maintained.
When forage production is low and it becomes necessary for producers to make management adjustments to reduce forage needed for the cow-calf enterprise, some additional options that can be employed are: Sell cows, Lease additional pasture, and/or Feed additional energy to reduce grazing. A good reference to help with this planning is, “Evaluating an Early Weaning Drought Management Strategy” By Paul H Gutierrez, Extension Economist, at New Mexico State University. This publication includes budgets for different rations and costs/return analysis for early weaning vs. traditional weaning of calves. Also, an “Early Wean Ration Calculator Plus” spreadsheet can be found at; http://aces.nmsu.edu/drought/index.html.
Just remember, production benefits from early weaning must lead to economic rewards for the individual operation for early weaning to be profitable. A breakeven rate of gain can be calculated based on partial budgeting data. The success of early-weaning programs will depend on forage and feeding programs, when and how calves are marketed and individual ranch management.