When the breeding season starts, there is an implied contract between shepherd and ewe. Your commitment to keep her around for another production cycle means her commitment to return her annual costs plus some in lamb production. To do this, she must get pregnant, lamb, and wean a litter that is a relatively high percentage of her own body weight. Getting pregnant is the first step.

Ewes that breed and conceive early in the season have a greater chance of weaning a heavier litter. They also contribute to a shorter lambing season, improve lamb crop uniformity, and reduce shepherd fatigue. While this is a relatively lowly heritable trait, long-term, intense selection offers opportunity for improvement.

There is no excuse for a ewe to take more than two heat cycles (34 days) to conceive. Ewes that take longer are only increasing costs while being less likely to return anything substantial. Therefore, keep your breeding season to 34 days or less by removing rams at this time point. As discussed in the Spring 2024 newsletter, CIDRs may be used to shorten this even more. If additional selection pressure for fertility is desired, switch out rams after the first heat cycle and introduce a terminal sire. These terminal-sired lambs should be easy to identify, can be marketed as higher value slaughter lambs, and will help resist the urge to retain females born later in the season. Pregnancy detection should be used 30-45 days after ram removal to confirm pregnancies and make culling decisions. Short-term, higher culling rates may be needed, but in the long-term, a greater proportion of your flock should breed and lamb early, thus improving flock productivity.

By: Dr. Andrew Weaver, NCSU Small Ruminant Specialist