The longevity issue is more than just genetic, and the cow man has the same problem with bulls. It is as much how they are raised before they are purchased. In the past I have purchased rams from farms that did a lot of corn and alfalfa that nearly starved the first year, with a full bunk of hay while my home raised rams thrived. It was not that they were not genetically fit, as their offspring did swell. Its just that it can take up to several years for a sheep to learn how to survive in a tougher environment. It took the purchase of several rams, over a period of years, all of which were walking skeletons their first year here, for me to realize that our environment must be tough and that it is touch and go for the first 18 months here.
I have argued with many a producer from the corn belt who just does not understand that not all pasture is the same, and that feeding heavy levels of corn and alfalfa to breeding stock that are destined to go to pasture operations is doing no one any favors.
Some bull producers are taking the lead and producing what they call range ready bulls, meaning they have remained on a grazing program and supplementation has been minimal or in a few willing to bite the bullet, none at all.
But as any bull or ram seedstock producer can tell you, the buyer IS part of the problem. I can't tell you how many producers who are accustomed to buying those BIG sleek corn fed rams have a hard time adjusting their vision of what the ram should look like when they are looking at a pen of 100% forage fed rams from native pastures. Now don't get me wrong, the right genetics should be expressing full muscle, be thrifty, and in great condition, BUT they won't be nearly as large as their corn fed contemporaries as lambs or at one year of age. Basically they finish their growth much slower, achieving full potential around 3 years old, rather than 1.5 years old. But then those rams are going to live to what, 6, 8, 10 years old?
I've visited with plenty of pasture seedstock producers who were tempted to go back to corn feeding just to make the rams look the way the buyer wants them to look.
It does amaze me how much the sheep and cattle business spins its wheels doing self defeating things like this!
Tamarack Prolific and Ile de France crosses