Veterinarian View | August 2025

Less is More

contributed article by Dr. Vince Collison, Collison Embryo and Veterinary Services,

Rockwell City, Iowa

collisonembryoservices.com 

Recently I have found myself using the statement “Less is More” much more frequently. Bovine Respiratory Disease (BRD) continues to be a challenge for many even when implementing a full vaccination program. The wet weather this spring was also a challenge for early calving herds leading to many cases of BRD. With many of the affected herds using a comprehensive vaccine program, I am fairly convinced that failure of passive transfer is a larger problem in these herds than many realize.

Passive Transfer Through Colostrum

Good passive transfer of antibodies at birth through colostrum is paramount to early calf health and leads to better health and performance of the calf as it grows out. To achieve the level needed, a calf should consume 300 grams of IGG antibodies as soon after birth as possible. The best absorption of antibodies is in the first two hours of birth.

It’s very critical for the calf to consume at least 100 to 200 grams of IGG within the first two hours to achieve the levels needed for good health. After two hours, the ability to absorb antibodies will rapidly diminish and it will be much harder to reach the levels needed to maintain the calf’s health and will likely lead to failure of passive transfer. This is one area where I would not hesitate to intervene if the calf is not getting up and nursing soon after birth.

If you have to tube a calf, go ahead and give it the full dose of colostrum. Many producers worry that the calf will not nurse if they give the full two quarts of colostrum. My experience is that calves are programmed to nurse at birth and most of the calves will be up and nursing soon after receiving a full dose of colostrum. And if they don’t get up right away, they will have received what they need for a good start.

Winter Calving Impact

Earlier calving in the winter months can also contribute to many of the problems associated with failure of passive transfer. When calves get chilled out, they will often lose their sucking reflex and have a harder time getting started. Also, if a calf gets chilled out, its ability to absorb colostrum is reduced. If a calf can consume colostrum right away or if the producer intervenes and tubes the calf with colostrum, the fats in colostrum will activate the calf’s brown fat and make it easier for it to thermoregulate itself in the colder temperature.

Vaccinations at Birth

One other thing I have observed is that everyone wants to vaccinate the calf right at birth and I wonder if this contributed to the calf not nursing as much in the first 24 hours as it would have had it not been vaccinated right away. The fact that many of these calves will still get sick even after receiving vaccinations has us always looking for more answers, and observations in other herds has led to the conclusion that we need to really ensure that these calves get full passive transfer through colostrum at birth.

Additional Colostrum

This past spring we had a client who was telling me that he routinely gives every calf that is born a half dose of commercial whole colostrum at birth. Which I found interesting, as his newborn calves don’t typically have any health issues.

In another client herd that calves through January and February, the owner had also tried giving a half dose of the same commercial whole colostrum to every calf at birth. He also stated that the calf health was as good as he’d ever had and will probably do it again. In both cases, they had stated that it is fairly expensive to do, but that they had been able cut out some of the other things they were doing plus had the added health benefits.

Illnesses in Calves

Most of what we see for pneumonia in the younger calves is bacterial, mostly being Histophilis somnus and Mycoplasma bovis. We also will see Pasteurella multocida and M. hemolytica as well, and all four bacteria usually in some combination. Viral infections have been less common in younger calves, but Corona virus seems to be the most common and is usually in some combination with a bacterial component.

The two most common bacteria that we see, Histophilus and Mycoplasma are fairly hard to vaccinate against. Vaccines that are available for both organisms are whole cell bacterins that won’t stimulate cell mediated immunity very well, thus making it harder to protect against them. Both of these organisms are slow growing and that makes treatment more difficult since antibiotics work to disrupt cell division.

Because these two bacteria grow slowly, the therapeutic levels of antibiotics won’t last long enough to fully treat in these cases and relapses are common. For these reasons, colostrum intake is critical to help keep the health at its highest and help prevent these infections naturally.

Management Practices

Another management thing to do includes getting pairs spread out once they are calved to reduce the spread of disease. This can be hard to do when calving in the winter and pairs often stay in a dry lot situation, but calves will do better if they aren’t in as tight of quarters.

As far as vaccinating to prevent pneumonia in neonatal calves, we think it is important to focus on just using the vaccines necessary to control the issues that affect your herd. It’s pretty easy to get caught up in trying to vaccinate for every possible disease, but we need to remember that vaccination is not a non-event.

Vaccination can cause stress, and it takes energy for the calves to build immunity from the vaccinations. Also, we need to be careful not to blitz their immune system so severely that they don’t respond to any of the vaccines very well. It has been shown with infrared technology that Clostridial vaccines can really heat up at the injection site and calves vaccinated for Clostridium will lay around a lot more than non-vaccinated calves over the next three days.

These examples are the main reason we don’t like to give vaccinations in the first 24 hours after birth, so that vaccination stress is not compromising the calf’s ability to suckle frequently in the first day of life. After that first day it is important to tailor your program to prevent only the issues that affect your herd. Your herd veterinarian is best suited to help you develop a management and vaccination program for the targeted prevention of the issues you deal with most often.

learn more www.collisonembryoservices.com 

Dr. Vince Collison is co-owner of Collison Embryo and Veterinary Services PAC

in Rockwell City, Iowa.