The Impact of Weaning Calves

— Written By and last updated by JoAnne Gryder

Weaning time for many fall-born calves has already started. We all know that weaning isCalf-nursing the removal of a suckling calf from the cow. But, what might not be so obvious are all the stressors and impacts associated with weaning, both for the calf and the cow. Weaning can also be stressful for the owner of the animals, especially if the weaned calves are placed in a pen near a person’s bedroom window. As animal managers, we should try and make weaning as stress-free as we can, while keeping productivity and profitability in line with our goals.

Time of Weaning

Several factors can influence time of weaning, including loss of dam, forage resources and cow body condition, sale time, other farm activities. Calves can be weaned any time after their rumens become functional, that is, when their digestive system can process whole feeds. Bottle-fed calves can be weaned after one month of age, while calves nursing cows are weaned between 3 and 8 months of age. It is usually best to wean at the older age. For comparing weight of calves weaned at different ages, a 205-day weaning weight is sometimes calculated. This “205-day WW” is the calf weight adjusted for birth date and weaning date, and does not infer that calves should necessarily be weaned at that age. If forage is in short supply or cow body condition is low, calves can be weaned early (before 8 mo). This preserves cow energy reserves to allow for development of the new calf inside her and keep her in good shape for timely re-breeding after that calf is born. Studies have shown, that in times of forage shortages, it can be economical to wean calves early. In those cases, the cost of feeding early-weaned calves was more than offset with improved reproductive performance of cows that were kept in a body condition that favored efficient reproductive performance. Another option available that many people use is weaning based on the Moon phases / signs. One “rule” for weaning is to do it when the Moon is the signs of Sagittarius, Capricorn, Aquarius and Pisces. These signs rule the thighs, knees, ankles, and feet, and the dates listed in the Farmers’ Almanac are based on this rule.

Preparation for Weaning

Preparing calves well in advance to actual weaning time has benefits well worth the effort.

Because immune function and response is lower in times of stress, and weaning can be stressful, many veterinarians suggest that vaccinations be given 3-4 weeks prior to weaning and that deworming be done after weaning. This not only lessens the stress at weaning, but also improves immune response to the vaccines. Other management procedures, such as castration and dehorning should be done well in advance of weaning. Also, it is a good idea to make sure that, before weaning, calves are used to eating the intended post-weaning diet. You can feed that diet to both cows and calves for a short period of time, about two-weeks, or provide it in a creep feeder – narrow passages into a feeding area are set up so the calves creep in, but larger cows cannot. Although creep feeding can be used to acclimate calves to a post-weaning diet, it’s primary use is to provide supplemental feed to nursing calves in order to increase weaning weight. Make sure that the post-weaning diet is appropriate for the age of calf, including forage quantity and quality, and contains a vitamin/mineral mix and plenty of fresh, accessible water. For the very young calf, this means a special calf starter diet, either bagged or specially formulated feed. For older calves, good quality forage (fall pasture regrowth, irrigated summer pasture, or very good quality hay/silage) will suffice, depending on target performance. Make sure they can safely reach water and know how to drink it.

Weaning Method

Whether your weaning consists of total separation of cows and calves or the relatively new, low stress technique of fence-line weaning, make sure you address nutrition and health measures. Total separation weaning can be accomplished with good success if preweaning and postweaning management address stress, health, and nutritional management sufficiently. For traditional weaning, it is best to have cows and calves together in the place where calves will stay. Remove cows to a new location out of sight and sound from calves. Leave calves in familiar surroundings. It is normal for cattle to bawl for several days. In fence-line weaning, cows and calves are placed on opposite sides of a strong fence (woven wire or multiple-strand, high-tensile wire). As with total separation weaning, cows are moved and calves remain in the initial pasture. Although the cattle are seldom seen challenging the fence, they have some nose-to-nose contact, but spend the majority of time grazing away from the fence. Fenceline visits gradually decrease over the first five days and the weaning process is complete within a week. Studies have shown these calves bawled less and gained more weight during the weaning process than with complete separation weaning.


Oregon State University