Photo Courtesy Sara Bauder, SDSU Extension

If heifers are not able to be bred early due to mud, breeding at the same time as the mature cows will work but rebreeding as a 2 year old may be more challenging.
Photo Courtesy Sara Bauder, SDSU Extension If heifers are not able to be bred early due to mud, breeding at the same time as the mature cows will work but rebreeding as a 2 year old may be more challenging.

By Taylor Grussing, SDSU Extension Cow/Calf Field Specialist



April is here, and as the saying goes, “April showers, bring May flowers”. Those April showers, coupled with continued melting snow across South Dakota, will also prolong flooding and muddy pens and pastures. Early calving spring cow herds have wrapped up calving and are preparing for breeding season. If you are having flashbacks to breeding in the mud of 2018; try approaching this year with an open mind and review breeding season protocols with a “mud” backup plan.

Heifers should be bred between 12 and 14 months of age, so to calve at 24 months of age. If possible, plan to breed replacement heifers 20 – 30 days ahead of the mature cow herd. This will provide ample space and resources to assist them during calving and a longer postpartum period to resume cylicity. However, if heifers are not able to be bred early due to mud, breeding at the same time as the mature cows will work but rebreeding as a 2 year old may be more challenging. Heifers that conceive early in the breeding season are more likely to continue breeding early in life and also return more value to the herd by raising older, heavier calves. Therefore, select the oldest replacement heifers for breeding, as they have likely reached puberty and are more likely to conceive early in the breeding season.

Observe heifers for visual signs of estrus (riding, ruffed up tail heads, licking, grouping up) prior to the breeding season. Muddy pens can sometimes suppress estrus and make it difficult to determine if heifers have reached puberty. Puberty is controlled by genetics, hormones, environment and nutrition. While genetics can’t be changed at this point, exposing heifers to estrus synchronization, a social environment of cows that are in estrus, or fence line contact with a bull can help induce estrus. Also, having heifers on an increasing plane of nutrition going into the breeding season can help heifers express estrus also.


Utilization of Synchronization

Reproductive technology, such as estrus synchronization, is available to assist producers in getting more heifers and cows bred within a short period of time. With the use of exogenous hormones, the natural estrous cycle of cattle can be shifted to a concentrated period of time for mass breeding programs to be implemented. The 2019 beef cow and heifer protocols are available online.

Protocols are available in heat detection, heat detect and Time- AI, and fixed-time AI, with separate plans for heifers and cows ranging from 8 to 36 days in length. Within these three protocol groups, plans can often be altered during muddy times when running cattle through a chute multiple times a day is not feasible, cattle go off feed or heat detecting and breeding is interrupted by rain or snow storms. Moreover, long protocols (such as MGA or 14-CIDR protocols) may be able to be shortened if mud challenges plan implementation. Example alterations include: using a CIDR protocol and turning cattle out to grass instead of feeding MGA in a muddy feedlot setting, pulling a CIDR early or late due to incoming weather and adjust breeding time accordingly or breeding once a day vs. twice a day. Consult a reproductive management expert within SDSU Extension or industry representative who can review breeding season plans and provide alternative strategies if needed, rather than scrap an entire breeding program.