Every autumn, cow/calf producers reach for magic vaccines which will prevent their calves from getting sick. Calves’ immune systems are capable of protecting against the majority of disease threats. Our husbandry practices, such as providing balanced nutrition, abundant clean water, adequate bunk space, and dry comfortable places in which to live, help support calves’ immunity. However, as every cattle producer can tell you, despite excellent conditions provided every day, calves may still succumb to infections.

Feedyards prefer calves graduate from preconditioning programs that include vaccination so they don’t arrive shedding virus. For years, calf death loss upon entering feed yards stands at 10 percent.

Vaccines alone are not making this better. We need to take a magnifying glass to our management to determine why our vaccine protocol is failing.

It’s a constant battle; us against the pathogens. Pathogens are determined to survive. So we reach for the vaccines in order to stimulate the calf’s acquired immunity against a particular pathogen, vaccinating for the pathogens of most concern for our herd.

Producers must work with their veterinarian to establishing manageable vaccination protocols. Vaccines must be stored, handled, injected correctly and boostered appropriately; the vast majority of vaccine failure is due to human error. Producers need to choose between using Modified Live Vaccines (MLV) and killed products. MLV vaccine does cause a mild, controlled infection. When the healthy calf is growing under sound husbandry practices, the risk of MLV induced disease is minimal.

Recently, you may have heard reports of reproductive failure in dairy herds using approved MLV IBR protocols. IBR is involved in nearly every bovine respiratory disease complex and this virus has deleterious effects on the ovary: arresting follicular and on early embryonic development.

Presence of IBR in naïve animals will prevent failure of conception when these cattle are bred or abortion in pregnant cattle. Because IBR is a virus, you will get better immune response from MLV IBR vaccine.

Viral infection and viral MLV, which mimics infection, are recognized by both the humoral and cell-mediated aspects of immunity; a more complete picture of what that pathogen looks like develops, so that the next time the pathogen presents itself, the complete immune system responds.

Read the label for how to safely use MLV IBR. MLV IBR must first be used in non-pregnant cattle. Wait 30 days after vaccinating with MLV IBR to breed cattle.

Once vaccinated, the animal’s immune memory is primed, and the deleterious effects on the ovary, embryo and fetus are no longer seen. So this 30 day rule will no longer apply to subsequent vaccinations.

Make sure the cow has been previously exposed to MLV before using MLV IBR in nursing calves. When using MLV IBR in nursing calves of un-primed mammas, IBR shedding from these calves may prevent the cow’s next pregnancy or cause her to abort an early pregnancy.

Shedding from viral vaccines especially happens when the calf is vaccinated while under stress. Do not wean, change environment (new pen, new feed, unfamiliar waterer) castrate, dehorn and deworm all on the same day. Piling on tasks because it fits our schedule may overwhelm the immune system; the calf will get sick or begin shedding virus.

When we ‘vaccinate once and truck wean’ because we don’t have preconditioning facilities, we create viral shedding calves. With nearly every product, the first primary dose must be boostered. If you don’t plan to booster the primary dose, then don’t bother to give it. £

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