WILLIAMS LAKE, B.C. — When it comes to successful beef production, veterinarian Cheryl Waldner recommends the four Bs: body condition scores, balanced mineral programs, biosecurity and bulls.
“Nutrition is probably the most important determinant of reproductive performance,” she said at the recent British Columbia Cattlemen’s Association annual meeting in Williams Lake.
Waldner, based at Saskatoon’s Western College of Veterinary Medicine, participated in the western cow -calf productivity surveillance network that has now expanded to 175 herds across Canada.
Body condition score
Body condition score is directly related to pregnancy rates.
The Canadian system rates animals from one to five with the lower number being emaciated and the higher being obese.
A cow with a score of two has ribs that can be seen, indicating it is too thin, while the fat ones are at four or more. It is recommended that producers manually feel the cows’ fat cover but that may not be feasible for everyone.
“It is better to visually body condition score your cows than to not score them at all,” Waldner said.
A score of three is good but 3.5 is better. Cows with a bit more fat cover are more likely to get pregnant.
“You don’t lose anything from that cow being a bit heavier,” she said.
Thin cows are more likely to abort or have a stillborn calf. They are also likely to have difficulty calving.
Skinny animals are more likely to be first and second calvers or cows older than 10. If they are thin in the spring, calving and at breeding, they are not likely to catch up. Their calves may also have more struggles to thrive.
Waldner said drought can also affect the calf crop.
Stillbirths happen almost twice as often in cows from herds living in areas that received less than 200 millilitres of rain. Their condition may be adequate but Waldner speculates the problem could also be linked to vitamin A deficiency because it is found in green grass.
Trace minerals such as copper govern pregnancy.
Lower serum copper is associated with higher open rates in young cows. Slightly older females might show slight effects and mature cows do not seem to be affected. The young ones that suffered from being mineral deficient fail to get pregnant and end up being culled.
Producers are urged to watch water sulfate levels in standing water because it ties up copper.
Force feeding cows copper helps when it is mixed in with silage or grain to encourage them to eat it at a consistent level.
Free choice minerals do not help because some take in too much and others do not eat it.
“Loose mineral is better than blocks if you can manage it. They do consume more,” Waldner said.
Surveys show many producers give selenium and vitamin E injections at birth. These supplements help lower death losses.
Producers should talk with a local veterinarian about mineral deficiencies because it varies by region.
More biosecurity is needed when herds consolidate because newcomers may bring in new diseases or get exposed to something in the new home they have not experienced before.
“Biosecurity is one of the cheapest things you can do to improve the infectious status of your herd,” she said.
She also suggests setting up separate shelters for calves away from cows, as well as segregated systems where pairs are separated from those that have not yet calved.
Depending how they are managed, community pastures may present many disease risks but modern vaccines help.
Vaccination is part of a good health plan because bovine viral diarrhea and other diseases still exist.
“It is probably not as bad as it was before we started vaccinating, but it is still there and still causing problems,” she said.
The latest production survey showed 93 percent of calves are getting vaccinated with at least one product before going to pasture. Most receive at least one dose but only one-third receive a booster.
More producers vaccinate, citing economic benefits of lower infections, more pregnant cows and fewer abortions.
Most people do it before breeding, which is the best time.
More cows and bulls are vaccinated for clostridial diseases like blackleg. About half of producers vaccinate cows for scours depending on their herd management.
Before unweaned calves go to pasture, clostridial vaccine and a tetanus shot is recommended, especially if males are not castrated right away.
More people are using intranasal vaccines on newborn calves for protection against respiratory diseases.
Bulls need a full vaccine regime but are sometimes forgotten.
They also need semen tests.
More cases of the sexually transmitted bacteria vibrio are appearing so tests must be done.
Depending on how much cattle interact with other herds, tests for vibrio and trichomoniasis are recommended.
“We are seeing positives. I have had a vibrio positive herd that had pregnancy rates that are 30 percent,” she said.
Cows may get pregnant again but it may take months to clear the infection from their systems.
There is an effective vaccine but it has to be used pre-breeding and does not last long. Talk to a veterinarian about local cases and potential risk.