Going to Pasture

By: Dr. Tanya Anderson, DVM Gladstone Vet Clinic

Spring has finally come and, while many are still calving or just getting started, other cow/calf producers are winding down calving and will soon be into breeding season if not already. Now is the time to sit back and reflect on how the last year panned out. What went well and what didn’t? Decisions made now as the cows go out to pasture will impact on outcomes at weaning in the fall and calving again next spring.

Calving season is equivalent to the harvest season for grain producers. Poor planning and management will produce poor yields. Numerous studies have shown that the most profitable beef operations have a short calving season (1 ½ to 2 months) and a uniform calf crop. It is critical that cows get bred within the first two cycles (goal –70% cows bred at first cycle). Cows must be cycling at the start of the breeding season and the bulls must be breeding.

The “textbook” gives a benchmark of <10% open cows at preg testing but in reality, well-managed operations should easily achieve <5% opens. If you routinely cull high numbers of open cows in the fall, look at your nutrition/vaccination programs and bull management.

Cattle with high growth and lactation demands require better nutrition.

Replacement heifers, first calf heifers and thin or high milking cows should be placed on the better pastures. These same animals should receive energy supplementation post-calving to ensure that they are on a rising plane of nutrition

(maintaining/gaining weight) and cycling at the start of the breeding season. If you find that the whole herd is coming through the winter in poor condition, assess your winter-feeding program. Shortcuts to feeding and weight loss over the winter will haunt you next year! The “benchmark” is a BCS of 5, which represents an average, moderately fleshed cow with fat evident over the ribs and alongside the tailhead. In general, cows should calve at BCS 4-6 and then gain slightly to breeding. This past year was a good example of why feed testing should be done. Feed was plentiful and looked quite good, but test results showed inferiority…that showed up as failure of cows to keep in condition.

Mineral supplementation also affects cyclicity, fertility and embryo viability. Deficiencies of selenium, copper, zinc, manganese, cobalt, and iodine have been associated with decreased/ irregular cycling and poorer conception. Vitamin deficiencies (esp. Vit A and E) can also affect fertility and cause weakened immune systems Look at your vitamin and mineral program if you have high numbers of cows with uterine infections post-calving, retained placentas, low levels of cycling or lameness issues

Bull management is also critical to ensure you have a calf crop next spring. Check out the BCRC website for info re: breeding soundness evaluation of bulls. Be sure to check your pastures regularly and ensure the bull that passed the BSE with flying colors is actually breeding the cows! Bull/cow ratios vary depending on pasture size, bull age and fertility. Mature bull ratios vary from 1:30-50. Yearling ratios should be no greater than 1:15-20. Don’t forget that the bull is half the herd – look after him! Ensure the bull is in good shape with no foot or eye problems. Vaccinate against pinkeye and foot rot - do while in the chute for semen evaluation Vibrio vaccination and Trich testing may be necessary in certain situations – check with your veterinarian continued on page 16