Kenny Barrett: Vaccinate with a Purpose, mental fodder when administering vaccines

Have you ever stopped to consider why we vaccinate calves, yearlings, heifers, cows and bulls? It would seem like an obvious answer. But dig a little deeper and we start to peel away layers of confusion we didn’t know existed. What we are left with is sound science and evidence-based medicine tailored to each individual ranch.

No matter which species or stage of production, we vaccinate animals to stimulate an immune response that produces safety or confers immunity for an animal to a specific pathogen(s). I can think of five broad reasons to vaccinate a cow; to protect the cow, to protect the fetus, to protect nursing calves at side, to produce colostrum, and regulatory purposes. Many vaccines may needle into numerous categories at the same time.

Some vaccines are designed to help protect the cow directly. Examples include footrot, pinkeye, and respiratory vaccines. Respiratory vaccine can be used to reduce asymptomatic carriers to reduce pathogen shedding to suckling calves and respiratory vaccines can be timed to protect the fetus and reduce abortion from IBR and BVDV. Brucellosis or “Bangs”, “vibrio” or campylobacter, and leptospira are additional vaccines given to protect the developing fetus or a future pregnancy from abortion.

Scours vaccines are administered with the aim of reducing calf diarrhea. These vaccines include E.coli, Salmonella, various types of Clostidium Perfringens, Rotavirus, and Coronavirus. Occasionally these vaccines are given to neonatal calves but the majority are administered to cows. Beef cows are rarely affected by these pathogens but the goal is to stimulate the cow to produce high levels of protective antibodies, or immunoglobulins, which can then be secreted into the colostrum. The immune response is somewhat short lived but titers will eventually wane. The amount of antibodies secreted in colostrum is proportional to the amount of antibodies circulating in the blood stream. Therefore, it is important to time the vaccination so the titer will be high during the period when colostrum is produced.

Vaccines need to be strategically timed and also specifically chosen to enhance the immune response for the challenges ahead. Some vaccines produce a local immunity on a mucosal surface. These vaccines are good at protecting animals from pathogens that invade through mucosal barriers. For example, intranasal vaccines are effective at limiting respiratory disease but will not produce a large titer increase for good colostrum production.

This winter or spring, plan to administer any necessary scour vaccines with colostrum in mind. Work with your local veterinarian to develop a vaccine program and discussing timing of the vaccines. Steps taken now can improve vaccine response and favorable outcomes. I hate to wish mud on anyone during calving but we surely need the moisture. May your overshoes get lost in route to the calving shed and hot box rarely needed.

Nerd Word

Dysentery – any of a number of disorders marked by inflammation of the intestine, especially the colon, with abdominal pain, tenesmus, and frequent stools often containing blood and mucus. The causative agent may be chemical irritants, bacteria, protozoa, viruses, or parasitic worms.

Correction – An astute reader caught an error in the previous column “The Unofficial Ink on Brucellosis”. The nerd fact suggested BT in BT-corn came from Brucella thuringiensis when it should have read Bacillus thuringiensis.