The author is a partner in the Maria Stein Animal Clinic, Maria Stein, Ohio.

Mark Hardesty, D.V.M.
My predecessor started the concept of herd health checks in our area over 50 years ago. Cows and heifers were checked for their reproductive status on a schedule. Later, we added dehorning of calves, and for a time we did official calfhood vaccination at those scheduled visits.

Dairy managers learned they could dehorn their own calves, and Brucella became a disease of historic significance in most of the United States. Over time, us veterinarians spent less scheduled time in the calf barn than we should have.

The calves still need care, and veterinary care is part of that. Calves are the future of the dairy, and time spent there has significant rewards, both financially and looking forward to our future.

A look into the lungs

Lung ultrasound has gotten veterinarians back in the calf barn at herd check time. Some use the ultrasound scores as a way to determine which calves to treat, raise, or cull. That thought process is valid, but I also see it as a way to modify our vaccination and prevention protocols while monitoring the results.

I like to scan six to 10 calves at each week of age from 1 week old to weaning. This gives me a picture of when calves are getting respiratory disease. We then adjust vaccination and ventilation to improve the calf’s ability to resist respiratory disease.

The procedure is noninvasive with the ultrasound on the outside of the chest. This is obvious to those who have seen us do this, but one dairyman thought we passed the probe down the calf’s throat and that we raised the rate of respiratory disease by scanning them. That would probably be the case, but it is not what we do. We don’t make respiratory disease, we just find it.

One of the benefits of lung ultrasound is just looking at the calves to see what is going on. I had two herd checks last Wednesday that are made of the stuff that make veterinarians happy to do their job.

Fresh air needed

At the first herd check, we had recently redone the positive pressure tubes (PPT) in one calf barn. While ultrasounding lungs a few months ago, we discovered that one tube installed years ago did not have any holes on one side of a tube, leaving one row of calves without the fresh air that tubes provide.

I used my hot wire anemometer to measure air speeds and found other deficits. This installation is an example of a PPT designed by someone who does not actually visit the farm to take the measurements and review the situation. These mail order PPTs do the dairy a disservice. I reworked the recommendations and the calf barn was fitted with a new positive pressure tube, including a different fan.

When we finished the most recent reproduction exams, I was asked to check the tubes. Using my anemometer, I found 1,200 feet per minute at discharge from the tube and 60 feet per minute at the calf level. It was consistent throughout the barn, and I was very pleased with the improvement. These were the best numbers I have ever seen. The lung scores should respond to the improved air.

Keep the pens dry

On another farm where I do herd checks, we have periodically walked the calves and made improvements. One day when we got done checking cows and heifers, the boss man asked if I could look at the calves. As I walked the calves, they looked good except one. We saw liquid in the aisles that I had noticed before, but this was more.

The discussion turned to where there could be a water leak, but there was no leak. I was assured that they were not in the bad habit of dumping water buckets in the calf space. They are dumped into a large bucket and the water is taken outside as it should be.

The liquid was seeping out of the calf pens. Our progression of calf focus had moved from feeding milk in buckets to feeding 3 quarts in bottles twice a day. The extra milk feeding meant more liquid in the pens.

I entered the calf pens and heard the familiar “squish, squish” of bedding that is saturated. This is a prime breeding ground for coccidia and other health threatening organisms. Coccidia are protozoa that live in the intestines, creating soft stool and nutrient malabsorption. Coccidia also create immunosuppression, often leading to respiratory disease.

Some address this issue by changing the bedding as frequently as once a week. This is the preferred approach of the few autofeeder barns we have in the area.

With individual pens, we prefer to install a drainage system. Years ago, it was popular to put slope in the pens out of the back or the front to get rid of liquid. None of these systems worked very well, and we especially don’t want contaminated liquid coming out of the front of pens where it gets tromped into other pens. We lose some of the advantage of individual pens for calves when we contaminate them.

The solution is a drainage tube. We cut a 12-inch slot in the middle of the row of pens. We scooped out 1 foot of depth with a mini excavator and installed a 4-inch drainage tile in the slot and covered it with coarse gravel. The tube can discharge into a catch tank or run onto a filter strip. We designed the tube at this dairy and decided the best place to plant pumpkins for the growth contest is right at the end of the filter strip.

Take care of the future

Calves on milk aren’t the only animals that could use another set of eyes. Weaned heifers are commonly found with lice, ringworm, and respiratory disease. Some farms struggle with parasite control, and Salmonella dublin is a constant challenge on others.

Converting dairies to total mixed ration (TMR) feeding of heifers with on-farm feeds is an opportunity, and ventilation is important here, too. Observations are about everything that could be better, but the focus is on respiratory.

We use the University of Wisconsin-Madison system of evaluation to give calf caretakers guidance to look for cough, nasal and ocular discharge, and abnormal breathing. The caretaker can then auscultate the lungs and take temperatures. I especially focus on ocular discharge as an early respiratory sign where treatment is very rewarding.

Creating a list of calves that need attention helps caretakers gain skills, and they soon do this on their own, much like they took over dehorning decades ago. My job is to find the next thing to do. I don’t walk calves every visit, but knowing what is going on and making constant improvement is how we create the future of our dairies.