Labels

Thursday, November 12, 2009

Hybrid Vigor?


Well, not exactly. But I think that I am seeing something analogous to it in the few foals that resulted from breeding Corolla stallions to mustang and one modern mare. Hybrid vigor is the result of crossing two species and often creating off spring that are superior to either parent in several attributes. for example, the mule, produced by crossing a male donkey and a female horse is pound for pound stronger than either parent, often lives longer, and has fewer health problems. The mule, of course, is sterile.

The Corollas have been isolated for so long that their DNA contains fewer alleles than modern breeds. However, they are still horses and the offspring produced by breeding a Corolla stallion to a mare of another breed is not a hybrid and is not sterile.

That being said, all of the 1/2 Corollas produced from these crosses (who are now about 15-17 months old) are significantly larger than previous foals that those same mares had produced. For example, a thirteen hand Corolla stallion bred to a 13 hand mare of Chincoteage and mustang extraction is now taller than her parents and much heavier than her mother although she will not turn two until next summer.

These crosses will never be part of the Corolla off site breeding program but I expect them to be superior horses because of their lineage.

The real test will come next year. Persa, a Shackleford mare, has never had a foal though she had been with a stallion before I obtained her. She may be sterile. I hope not. In the early fall I kept her with Tradewind, a beautiful Corolla stallion. The Corollas and the Shacklefords are the only Colonial Spanish horses left in the wild on the east coast. The live on opposite ends of the Outer Banks of North Carolina and have for centuries. Perhaps the same phenomenon of larger foals will result from this cross.

We will see next summer.

(Her is a picture of Persa from a few months ago.)

4 comments:

Priscilla said...

That's one fine looking horse you got there....

Anonymous said...

I agree that limited gene pools need to be expanded, and I agree with hybrid vigor as a concept. But do keep in mind that horses who spend their first years in the wild probably do not have access to the nutrition they need to reach optimal growth.

My CSH stallion is 13.2 and I breed him to mares not much bigger, but all their offspring are larger than either parent. There is no hybrid vigor involved, as all come from the same gene pool. Nutrition alone can make the difference.

My stallion was captured at age 4, so he had only scrub vegetation to eat for the first 4 years. If he had been raised on the good feed his babies are getting, he probably would have been 1-2 hands taller by age 4.

Rancho Californio

Steve Edwards said...

So far, with the pure Corollas raised in captivity from very early age it seems that post natal nutrition is not as significant a determinant of growth as is prenatal nutrition. Those removed prior to or at weaning age are not significantly larger than those raised wild, but it appears that those born domestically have significantly higher birth weight than those born in the wild.

To date the 1/2 Corollas that we have bred, which will enter their second year this summer, were each larger than any foals previously born to the mares, regardless of stallion size.

This is going to be a fascinating thing to watch as the program continues. We certainly are not going to be breeding these horses with an eye towards selectively increasing their size. I have seen two in the wild that I believe were over 14 hands and I have a great one, Red Feather who is 12.2.

What strain is your stallion? Could you post a picture of him on this blog or send it to me so I could do so.

Thank you for your input.

Anonymous said...

You can see a photo of our stallion at www.californio.us

I just updated the website for the first time in two years. It's been a busy time! Moving onto a 100-year old farm that had been woefully neglected for several generations, trying to bring everything up to speed while maintaining a full-time job elsewhere... Not easy.

I appreciate your distinction about pre-natal nutrition. Of course the fact that his wild mother was living on scrub vegetation while carrying him would also have had a profound influence on our stallion's development. Since all our foals were conceived, carried to term and raised with benefit of good nutrition for dams and foals alike, I have not had opportunity to compare their growth to a weanling from the wild. Thanks for that insight.

Deb
info@californio.us