Gerald Hauer, DVM
Bison Production Specialist
Alberta Agriculture, Food and Rural Development
Bison Centre of Excellence, Leduc, Alberta.
Phone: (780) 986-4100
Reprinted from The Tracker, volume 3, issue 10, November 1999
Weaning can be a stressful time for calves and this can make them more susceptible to diseases and slow down their growth. Minimizing stress can decrease the level of illness and encourage optimum growth in your calves.
It is time to think about weaning this year's calves. There are several things that must be considered when deciding how and when calves should be separated from the cows. In this article I will offer some tips for weaning elk and bison calves so that the process goes as smoothly as possible.
What is the best time to wean? The optimum time to wean depends on both your animals and your feeding practices. Calves that are weaned too early lose the nutritional benefit of their mother's milk and are forced to meet their high energy and protein requirements with solid feeds. Unless these calves are fed extremely well they will not grow as quickly as their counterparts that remain with their mothers. Calves that are weaned too late lose the nutritional benefit of milk as their mother's supply dries up and they are forced to compete with adults for feed. If the feed is not abundant and very good quality, these calves will grow slowly.
Another factor to consider is that the longer the calves are left with the cows, the thinner the cows will become due to the increased demands of lactating. Depending on how fat your cows are this may or may not be detrimental and it can often be offset with supplemental feeding.
The best time to wean bison calves seems to be late fall or early winter. At this age they are usually old enough to meet their nutritional needs with feed and generally do quite well. The best time to wean elk calves is a little more complicated because the rut is in the fall. Weaning before the rut will give you smaller calves but the cows will tend to have a higher fertility rate because they will be in better body condition. If you are going to pre-rut wean, you must consider the age of your calves. Late born calves should probably stay with their mothers until late fall or early winter. Weaning after the rut will give you larger calves but your calf crop next year may be reduced.
Prior to weaning you should be sure that your herd health program is in order. If your calves aren't healthy the stress of weaning may be enough to cause significant disease. It is wise to deworm and vaccinate them 1-2 weeks before weaning so that they have the maximum resistance to disease.
Weaning can be a stressful time for both the calves and the cows. The traditional method involves removing all the calves at one time, putting them in a pen out of sight (and out of hearing range) from their mothers, and then letting them settle down over the next few days. This is called hard weaning. It works but it is stressful for both the cows and the calves. Another approach is called soft weaning where calves are removed from the cow herd a few at a time and allowed to stay in an adjacent pen where they are in full view of the cow herd. Separation can be accomplished by quietly allowing a few cows or calves through an open gate and closing it behind them, or by creep feeding calves in a different pen and then closing the gate behind them. Once they are separated the cow and calf will often lay together on different sides of the fence and be much more relaxed than if they were completely separated. After a few days you can do the same thing with a few more cows or calves. It takes longer to wean the whole herd but it seems to be less stressful for everyone involved.
You should also think about the safety of your newly weaned calves. I have seen situations where newly weaned calves have been killed by predators that have entered the pen. The calves' distress calls seem to notify the wild animals where there may be an easy lunch. It may be wise to leave an older cow in with the group to act as a protector should they be in danger.
How and when you wean your calves depends on your management system. Several different ways can be used successfully. Remember to keep the process as stress free as possible and your results should be good.