Schoenian: Culling ewes is a powerful tool for sheep producers to improve
When the time comes to decide which sheep need to go and which need to stay, producers can cull ewes for multiple reasons.
In a webinar titled, “Replacement Ewe Selection and Culling of Underperforming Ewes,” Susan Schoenian, University of Maryland Extension sheep and goat specialist, discussed different culling factors for ewes.
“Sometimes, it’s easier for producers to get rid of the worst sheep in a flock, which then helps identify the best sheep to improve future flocks,” says Schoenian.
Schoenian specifies age as the number one reason to cull an ewe, especially for flocks on the range where it’s difficult for producers to provide individual attention.
“Overall, ewes between the ages of three and six are the most productive, so after six years, on average, older ewes give birth to fewer lambs and produce less milk,” notes Schoenian.
Another major reason to cull is health, she says. Hard bag and mastitis are the two main health issues producers use to determine which ewes need culled.
“Only ewes with sound, healthy udders should be retained in a producer’s flock. The udders should be free of scar tissue, lumps, fibrous tissue and have normally sized teats with equally functioning halves,” states Schoenian.
According to Schoenian, foot rot is also a major factor when culling because the disease is difficult to get rid of once introduced to an area.
“Ewes chronically infected with foot rot that don’t respond to treatment should be removed, along with ewes that have excessive or abnormal hoof growth,” she explains.
Schoenian says producers may also want to consider removing ewes with poor body condition, prolapse issues, internal parasites and give birth to poor performing lambs or reject their lambs.
“Producers can create easy care flocks by culling ewes with problematic issues,” she adds.
Culling single birth ewes is also an option for producers, she says. Ewes with single lambs of poor quality should definitely be removed.
“Every producer should maximize lambing percentages, relative to their environment and production system. Production systems have cost structures, which require higher lambing percentages to be profitable, making culling for single births necessary,” Schoenian states.
“The bottom line is, producers can’t make money with ewes that don’t raise lambs,” she adds.
Ewe performance is another factor for producers to look at when selecting ewes for removal, Schoenian mentions, especially if producers want to rapidly improve genetics and increase their replacement rates.
She says records should be kept, so producers can rank ewe productivity to determine the most productive ewes.
Schoenian also discussed why producers should keep accurate and up-to-date records on their flocks.
“Keeping records allows producers to identify the most productive ewes and, therefore, which ewe lambs should be saved by selecting from the most productive ewes in the flock,” she explains.
Records help producers cull the least productive sheep in the flock, increase genetic improvement rates and select young replacement ewes that are genetically superior, Schoenian notes.
“If producers don’t think their ewe lambs or replacement ewes are the best sheep on the farm, then they’re not doing something right. The whole idea is to select females better than the previous generation,” she states.
The Let’s Grow Committee of the American Sheep Industry Association presented the “Replacement Ewe Selection and Culling of Underperforming Ewes” on Oct. 3, 2017.
Heather Loraas is assistant editor of the Wyoming Livestock Roundup and can be reached at firstname.lastname@example.org