Sheep producer finds a high heritability for resistance to parasites in the breed


WOOSTER, Ohio — In Wooster, a producer of Katahdin sheep is working with producers from two other states on the heritability of parasite resistance. The group is investigating methods of identifying ewes with a reduced periparturient rise.

They are comparing the fecal egg count of sheep selected for their low fecal egg counts as lambs to determine how it relates to their adult parasite resistance and that of their offspring.


Prior to 2000, Kathy and Jeff Bielek of Misty Oaks Farm wanted to diversify their tree farm and incorporate some livestock. After attending Ohio Sheep Day in Wooster in 2000, they decided on sheep.

They started with Shetlands, but then switched to Katahdins in 2001, and grew to love the breed. Katahdins are a hair sheep raised for their meat.

The Bieleks, along with a group of 10 Katahdin producers, submitted a proposal to the North Central Region Sustainable Research and Education Program’s Farmer Rancher Grant Program in 2005 and were awarded $17,950 for their project, Selecting Sheep for Parasite Resistance.


In 2007, they applied for another grant to continue their work with three producers from three states, and were awarded a subsequent grant from the Farmer Rancher Grant Program for $14,215 for their project, Building on Parasite Resistance Selection in Sheep.

In their current project, David Coplen of Birch Cove Farm in Missouri, Donna Stoneback of Wade Jean Farm in Pennsylvania, and the Bieleks are raising registered Katahdin hair sheep.

All are forage based, and all are using rotational grazing and selective deworming strategies. Flock sizes range from 25 to 32 ewes.

Each farm uses at least two rams, some closely related to rams used on other farms.

“As we were monitoring the parasite levels in our flock over two years we noticed distinct differences in the resistance to parasites between offspring of different sires. We really wanted to see if these differences in the parasite resistance in lambs of different sires that we had identified on our farm could be duplicated on other Katahdin farms,” said Bielek.

Data collected on 10 farms as part of the initial Sustainable Agriculture Research and Education grant was submitted to David Notter, professor of animal science at Virginia Tech and head of the National Sheep Improvement Program, for analysis and for use in his work on developing a fecal egg count measure of expected progeny differences in Katahdin sheep.


Notter reported a fairly high heritability for resistance to parasites in the Katahdin breed. In addition, the group was able to learn and demonstrate the effects management had on parasite levels in their flocks.

All three couples learned methods they could use to better manage parasites in addition to selecting more resistant sheep.

“In our project we were able to demonstrate how different management strategies, like managed grazing, time of lambing, nutrition and genetics can impact parasite management on our farms,” said Bielek. “This will enable farmers to lessen the use of expensive and increasingly ineffective dewormers while still maintaining healthy, productive sheep.”

Read more about the Bielek’s project online at

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