Get late-calving cows cycling sooner
There are several things you can try to get late-calving cows rebreeding sooner, says Jim Kranz, South Dakota State University Extension cow-calf specialist at Mitchell, S.D., and George Perry, SDSU beef reproduction specialist, Brookings, S.D.
Removing calves to reduce suckling, treating cows with a progestin prior to the breeding season, and boosting protein and energy in rations after calving are options.
• Several things can be done to help late-calving cows rebreed soon.
• Reducing suckling will reduce the postpartum interval.
• Treatments and adequate nutrition will help.
According to researchers at Texas A&M, a calf suckling a cow will extend the postpartum interval, Kranz says. Management strategies that reduce suckling frequency can be used to reduce postpartum interval and facilitate rebreeding.
These include early weaning, once-daily sucking and temporary calf removal.
Early weaning. Early weaning is normally only used in conditions such as drought, overgrazing or inadequate feed quality. Research over the past few decades shows that weaning calves between 45 and 80 days of age resulted in increased conception rates. However, increased costs and the increased labor and management associated with early-weaned calves must be carefully considered.
Once-daily suckling: Calves are only allowed to suckle once a day beginning at 30 to 40 days of age. Cows are introduced to their calves once a day for approximately 30 minutes. This strategy requires daily sorting of cows and calves; however, once a cow has initiated estrous cycles and has been inseminated, her calf can be returned. Normally, this strategy should not last more than 40 days, and calves need to be provided proper shelter and nutrition. Calf weights may decrease during this period, but previous research in Texas has reported no reduction in weaning weights.
Short-term calf removal: This is the least-aggressive method of reducing suckling frequency and requires less labor than the two previous methods. Short-term calf removal normally only lasts for 48 hours; calves should be at least 40 to 45 days of age. Be sure to provide the calves sufficient water, high-quality hay and a creep feed that is approximately 14% crude protein.
Treatment with a progestin prior to the breeding season will simulate a short cycle and initiate normal estrous cycles, Kranz says.
The only progestin legal for use in postpartum beef cows is the CIDR (Controlled Internal Drug Release). Research from the USDA Research Center in Miles City, Mont., shows that treatment with a CIDR for six days induces estrous cycling in 90% of short postpartum animals that were in good body condition (BCS >5), and 100% of the animals that ovulated following CIDR removal had a normal-length estrous cycle.
Source: SDSU Extension Service
This article published in the May, 2012 edition of DAKOTA FARMER.