Starting a cross breeding program

[cugrad]

Hello again,

Hope I am not being a little bit redundant, but I have another question regarding breeding programs. If you decided you wanted to utilize dorper/kat crosses, how would you start? What are some common techniques for tweaking the percentages. I only have reading to go off of, but it seems like the hobby folks did not like 50/50 dorper/kat. So as a personal hobby, if I want to play around with Kat-dorper crosses until I get the mix I want whats the best way to do that? Would you breed a dorper ram to a kat ewe, and then cross the offspring back to a kat to dilute the dorper?

Feel free to point me towards literature if you know of any! I don't mind scientific based sources.

Sorry, I'm a bit of a nerd, and genetics have always interested me. Add in that I have always held a deep respect and interest for farmers and I am just hooked on this sheep thing. I really wish I had some local sheep gurus so I could pick their brain. I wish I would have found out how awesome sheep are earlier, but I suppose at 22 I still have plenty of time!

 

[SheepGirl]

I'm not really sure what question you're asking.

There are different types of crossbreeding--most should be done with a purpose, to get a specific trait, not just willy nilly. The most common one is terminal crossbreeding, which is where you cross a terminal sire onto a flock of maternal ewes (ie Dorper ram on Katahdin ewes). For more information you can read this article: http://www.ansci.wisc.edu/extension-new copy/sheep/wisline_09/Useable Crossbreeding Systems.pdf

But...

If you breed a Katahdin to a Dorper, you will get a 1/2 Katahdin x 1/2 Dorper cross. If you were to breed that cross to a Katahdin, you will have 3/4 Katahdin x 1/4 Dorper. If you bred that cross to a Dorper instead, you will have 3/4 Dorper x 1/4 Katahdin.

You can even breed crosses to other crosses. Like breed a 3/4 Katahdin x 1/4 Dorper to a 1/2 Katahdin x 1/2 Dorper and you have 5/8 Katahdin x 3/8 Dorper.

You can play with the crosses, and see what you like best in terms of production (prolificacy, growthiness, hardiness, etc) and then continue breeding for that specific cross. You will probably require a lot of different breeding groups to be able to produce more parent stock to produce your desired cross.

 

[cugrad]

you answered some of it, sorry for being scattered brained. Your example and the article were what I was looking for.


If this makes sense maybe you can help me, if not just ignore it lol.
Suppose I have two rams, A and B. And six ewes. So I breed the six ewes with ram A. Then breed the offspring of Ram A to Ram B. In my limited experience, the offspring of ram B will still be genetically similar to each other since they all come from the same females for two generations. The only thing I changed were the rams genetics. So how long can I continue that type of breeding without running into inbreeding issues? I really hope that made sense.

 

[SheepGirl]

you answered some of it, sorry for being scattered brained. Your example and the article were what I was looking for.


If this makes sense maybe you can help me, if not just ignore it lol.
Suppose I have two rams, A and B. And six ewes. So I breed the six ewes with ram A. Then breed the offspring of Ram A to Ram B. In my limited experience, the offspring of ram B will still be genetically similar to each other since they all come from the same females for two generations. The only thing I changed were the rams genetics. So how long can I continue that type of breeding without running into inbreeding issues? I really hope that made sense.

If you breed Ram A's daughters to Ram B, then you wouldn't have any inbreeding unless the rams were related to each other. The fact that the females are all related does not matter if you use an unrelated ram to breed them to. In fact, having a very closely related ewe flock (daughters/mothers/sisters) is probably BETTER because they are genetically similar and they tend to have similar traits, ie gestation length, heat cycles, growth, milkability, and other important traits. It will probably also be easier to find a ram with the traits you need to improve in your flock AND your lambs will be more consistent and predictable in their performance.

IMO inbreeding isn't that bad and doesn't cause much issues (if any). Many people make it out to be something bad (because it is not socially acceptable for humans), but for animals it enables you to emphasize the good traits in your stock with little to no side effects.

But what I would do is I would get one ram to start, sell him after breeding, and then buy a new ram the next breeding season. Or split up the ewes to each ram so you aren't wasting money feeding a ram for a year that isn't breeding.

 

[cugrad]

You are very helpful! Thanks for the explanation and advice. I'm chewing on the article you linked. I think it covers many of the questions I have.


Basically, I want a sheep that has Katadhin mothering and shedding, with Dorper size, weight gain, and standard color. Not sure if its an attainable goal. I doubt I will hurt myself much by tweaking my flock to get to an ideal cross. Especially since both breeds are good meat sheep anyway. Sounds like a fun project to me.