Do not let heifers fall into transition slump

Many times, weaned calves are considered the main group to experience transition slumps. This age group is certainly at high risk, but older calves and heifers may also experience transition issues.

Regarding the preweaning calf, it is important to remember that the process of rumen development takes approximately one month. If we wean a calf without adequate rumen development, she will not be able to digest her nonmilk diet correctly and will transition poorly. This means our weaning-aged calf will have to be consuming somewhat significant amounts of starter 3-4 weeks before she is weaned from milk. If the calf doesn’t achieve this, you will likely observe poor growth rates, possibly even weight loss, and health challenges.

I recommend the following tips for prepping the preweaning calf:

— Begin offering starter during the first week of life. It is not necessary to offer large amounts, but just enough for the calf to discover and nibble at it.

— Keep starter fresh in the buckets daily. Don’t dump new starter over days-old starter or wet starter. If the old starter is not moldy or too wet, you can feed it to older calves to avoid waste.

— Consider shallow dishes, such as dog dishes, set inside the buckets to start calves on calf starter. This will make it easier for calves to find the starter and reach the bottom when they eat, which calves like.

— Offer water year-round. Calves require water to digest calf starter, so if you skip water, you will automatically limit starter intakes. I recommend feeding warm water right after milk feeding. If the weather is particularly cold, you can still give water, but remove it 1-2 hours after providing it to avoid the massive ice blocks that form.

— Periodically measure your starter intakes during the last four weeks of the milk phase.

— Dehorning should be performed before 8 weeks old. Additionally, I avoid injectable vaccines at times of transition, such as weaning. If possible, give vaccines 1-2 weeks ahead of transitions so the immune system can respond properly.

Weaning should be a planned process. Create a step-down process that encourages grain intake to increase as the calf nears weaning. I recommend using 3% of the calf’s body weight as the grain intake goal at the time of weaning. This translates to 3-4 pounds of grain per day for a calf at weaning. In my experience, weaning calves off milk can take some time to fine-tune and normally takes 10-14 days at a minimum.

Grouping animals can also have a huge impact on transition. Consider pairing or creating small groups for the first grouping, ideally 4-8 head. Additionally, pay attention to the total square footage per calf. The Dairy Calf and Heifer Association recommends a total area of 35 square feet per calf in group pens. In my experience, groups of calves with less than 35 square feet have more respiratory disease and are difficult to keep clean. Giving calves more space (such as 40 square feet) can make a huge improvement in respiratory health.

Gradually make groups larger, combining groups of similar-aged calves. If calves are moved to a pen with head slats or locks, consider putting some type of trough on the inside of the pen for a week or two, so that feed is easier for them to find. There should be room for every animal to eat at the same time during these initial groupings. It also is not a bad idea to push calves up to waterers on the first day to make sure they know where water is. These young calves’ waterers should be some of the cleanest on the farm to help encourage as much water intake as possible.

Up until around 3-4 months of age, nearly 100% of a calf’s diet should be grain. These calves can be on a grower feed. Small amounts of hay can be offered within a month after weaning so that they can learn what it is and encourage rumen health. Note that this should be good-quality hay in limited quantities. Total mixed ration should be introduced slowly, and if possible, not before 5 months old. Since these calves have never been fed fermented feed before, it will take a little time for their digestive system to figure out how to utilize these feed types. Start by putting some TMR down, then putting grain and/or hay over the top of it.

These diet transitions can be a real challenge for coccidia control as well. There are several products that can be fed for coccidia prevention, but each has different mechanisms and requires a specific intake level to work. I recommend staying on the same coccidiostat to reduce the odds of a coccidia break if possible. In addition, if you utilize some sort of refusal from cows or other animals, make sure to properly balance the mineral and coccidiostat so heifers get high enough levels to be effective. Keep in mind, TMR refusal tends to heat in the summer and can have contaminants from dirt and older animals, so it may not be a good choice for younger heifers.

Megan Weisenbeck is one of five veterinarians at Northern Valley Livestock Services in Plainview, Minnesota. She practices primarily dairy production medicine in Minnesota and Wisconsin. Megan can be reached at meganweisenbeck.dvm@gmail.com.