Breeding / Genetics
Sustainable agricultrual enterprises are those that match the genetic potential of the animal to the natural resources of the farm. Our climate, soil and land grow abundant cool season grasses and legumes from mid April until October. The quality of our pastures is capable of supporting ewes nursing twins and even triplets. Sheep that perform well on grass is a priority for us. Stockpiled grass extends the grazing season into December. Hardiness to withstand winter on hay and snow is equally important.
Most breeds of sheep (source: Oklahoma State University) are known for a specific trait or two. The black-faced “Down” breeds are known for growth and muscling, Merino, Rambouliett and others for wool, dairy breeds for milk. While there are some dual purpose sheep that might fit our enviroment, we have opted to utilize crossbreeding to create sheep that flourish on our resources. Heterosis, or hybrid vigor, is the productivity boost achieved from crossbreeding. The crossbred indivual is better than the average of the two parent purebreds. Crossbreeding increases animal vigor and survivability. Combining breeds of sheep with distinctly complientary traits increases heterosis.
Our breeding program is a rotational crossbreeding scheme. We maximize the use of heterosis as a tool to optimize ewe productivity. Producing lambs off grass that are desirable as feeder lambs, locker lambs or replacement ewe lambs is our goal.
To achieve the ewe productive goal of two lambs weaned per ewe we introduced the Booroola gene into our flock in 1988. The Booroola gene is a single gene that when carried by a ewe, will deliver an extra lamb. (To learn more about the Booroola gene, click here to see the articles that Bob wrote for The Shepherd in 2009). The Booroola gene has helped us reach our goal of achieving 2 lambs weaned per ewe, which means we have a significant number of ewes nursing more than twins.
Good milk production is essential for ewes that nurse more than two lambs. To boost the milk production of our flock we utilize the East Friesian breed in our crossbreeding program. We like to maintain one quarter to one eighth (25-12.5%) East Friesian blood in our ewes. Attentive, quiet mothering is another desirable trait for highly productive ewes. We use old fashioned production focused Dorsets in our crossbreeding scheme for this. East Friesian/Dorset F1 rams are an important maternal sire that we use in our breeding program.
Lamb growth and muscling are two important traits of high quality lambs. We started our flock in 1987 with old fashioned Oxfords, a “Down” breed orginally from England, that were well muscled and fast growing. We currently use production orientated Hampshires or Shropshires in our crossbreeding scheme for these traits. We do not use the “Frame Type” black-faced sheep that are popular in today’s show ring. The “modern” show ring type sheep are not very efficient living off our grass and their size (height) is makes working with them troublesome.
Recently we introduced the South African Meat Merino (SAMM) into our crossbreeding scheme. The SAMM has given us growth, muscling and frame as well as improved wool quality.
The parent gene pools for our crossbreeding rotation are distinctly different from each other. This generation rotation of complimentary breeds has given us a flock of ewes that are excellent convertors of grass into highly desirable lamb. Our ewes average 175 pounds; have generally quiet dispostions, good milk production and good mothering instincts that produce fast growing well muscled lambs.