printStock Journal Feature, August 2022
Author: Dr Colin Trengove, Pro Ag Consulting
There has been much emphasis on managing ewes to optimise lamb survival in recent years but relatively little attention is paid to rams in the quest for good lambing outcomes. It is generally assumed that rams will be ready for work at joining but that is often not the case.
Reproductive surveys reveal that on average one in five flock rams have fertility-limiting conditions. This not the case where ram health check is conducted routinely pre-joining by an experienced operator.
Rams should be checked at least two months before ram sales and/or joining. Checking rams before ram-sales provides an opportunity to determine replacement ram needs, while a pre-joining exam is to ensure they are in good order to fulfill their task.
Common fertility-limiting conditions in rams include arthritis, foot abscess, too low (<3.0) or high (>3.5) body condition, poor testicular tone and/or lumps and diseases reducing or preventing semen production and quality. Semen takes two months to mature and so a ram needs to be examined at least two months before joining to allow sufficient time to identify and rectify limitations.
It is oft said that any sire is essentially two semen canisters and a delivery system and so it is necessary to ensure that both are functional to optimise joining potential. This requires at least an annual preventative health check by an experienced person of both the reproductive organs and locomotory system to minimize the risk of infertility at joining.
Additional considerations such as the genetic merit of a ram with respect to his intended purpose is equally important but beyond the scope of this article. Pre-purchase checks should include a full review of both the physical attributes and Australian sheep breeding values (ASBVs) in the quest to optimize both fertility and breeding outcomes.
The bottom line is don’t assume the rams in your flock or the ones you purchase are “match-fit”. Get them vet-checked with adequate time to undertake culling and replacement or management adjustments before joining.