Weaning winning replacement heifers

Raising replacement heifers takes a lot of time, labor and re­sources. However, the investment is worth it. According to the Dairy Calf and Heifer Association, the first six months of a dairy calf’s life account for 50% of lifetime stature growth and 25% of lifetime weight gain. The transition to weaning is particularly critical as a slump during this time will impact the calf’s longterm health and productivity.

Here are some practices that will help avoid the post-weaning slump, adapted from an article in Bovine Veterinarian:

Don’t change everything at once

Making changes incrementally will reduce the stress of weaning. For instance, instead of removing liquid rations all at once, drop them back to once per day for a few days or re­duce the auto feeder volumes before removing them entirely. Similarly, don’t change housing and feed at the same time. Many producers success­fully keep calves in their pre-wean­ing housing for a week after wean­ing, while others keep calves on their pre-weaning grain mixture when they enter new housing. The order of changes can be adjusted to suit operational needs. The goal is to allow calves to adjust to one change before making another.

Transition diets gradually

Going abruptly from a milk-based diet to a grain and forage ration disrupts the microbes living in the calf’s digestive tract. There are many ways to ease into the transition. For instance, you can feed MFA Stand­out Calf Starter ad lib (available at all times) for the first 12 weeks of life or until the calves are eating 10 pounds of daily intake, and then transition to MFA Trendsetter as the grower feed with free-choice hay for another 12 weeks.

Rumen volumes increase dramat­ically in the first 24 weeks of life. Feeding starter early—offering it by day 3 after birth—will trigger chem­ical reactions that drive papillae development on the rumen wall and improve overall rumen development. However, switching immediately to a mostly forage diet at weaning can disrupt this development. If you have to feed forage at weaning, limit it to no more than 15% of the diet. The calf’s rumen will fully devel­op by 6 months of age, and that is when heifers are ready to transition to an all-they-can-eat fermented forage buffet.

House calves in small groups

The first post-weaning grouping of calves should be six head or less. This lets heifers learn how to interact in a group, access the feed bunk, and find the water source without stressful competition. Similarly, calves raised in auto feeder pens should be kept together for their first post-weaning grouping.

Make it easy for the calves

Give the 2- to 4-month-old dairy heifers 12 to 18 inches of feed bunk space per head, making sure that the height allows all animals to reach the trough. Ensure ample air movement without creating a draft. Keep bedding dry and the walking surface clear of mud, snow and ice. Comfortable conditions keep heifers from diverting extra energy to staying warm or getting feed, thus reducing the risk of slump.

Feed for their needs

When feeding young heifers, con­sider what they need rather than what feed is the most convenient. During this stage, it is important to pay attention to the total protein content of their ration. Consider that lower-protein grain mixes—12% to 14% crude protein when paired with forages testing less than 18% to 20% crude protein—don’t allow adequate protein intake for skeletal growth. We recommend MFA Trendsetter Developer R-54, which improves protein utilization to balance a feed­ing program for better performance, faster growth and healthier calves. This ration also covers the animal’s mineral requirements and aids in coccidiosis control with the addition of Rumensin.

Control coccidiosis

Using a post-weaning feed medicated with a coccidiocide, such as the ionophores Rumensin or Bovatec, is important to overall calf growth and health. This is especially important if Deccox, a common coccidiostat used in feed, was in the pre-weaning starter ration. If this medication is removed from the diet after weaning, you can have a break in coccidiosis protection, allowing the coccidia protozoa to complete their life cycle. The parasite can cause diarrhea in calves and young growing stock, often decreasing production. An ion­ophore also improves feed efficiency and helps calves put on weight, lowering cost of gain.

For more information on avoiding the post-weaning slump with replacement heifers, including feed recommendations for your specific operation, visit with the livestock experts at your MFA location.

READ MORE from the June/July 2023 Today’s Farmer’s Magazine, the MFA Incorporated member magazine.