Fw: [Jacob-list] Fw: What is lilac?

[Grose]

Here is additional communication with Dr. Sponenberg. I often make the mistake of assuming that the things that I observe should hold true in the general case and that those things that are most probable are the general rule. Don't bet the farm on it.                          Neal Grose
----- Original Message ----- 
From: Phil Sponenberg 
To: Grose 
Sent: Monday, August 13, 2001 11:17 AM
Subject: Re: [Jacob-list] Fw: What is lilac?


  I don't know that I am losing sleep over this, but it sure is confusing. When in doubt, assume that life is confusing.


yes, it is.


  One thing that I had put in the catagory of "spotting gene" but may actually be relevent here is the odd observations that we have made through the years. 15 years ago, we started out with 3 Corridale ewes [1 white and 2 colored] and 2 Jacob rams for the purpose of producing colored wool for handspinning. The linebred Hescock ram always threw black lambs, but the inbred Tramutola ram always threw spotted lambs. At the time, the conventional wisdom was that REAL Jacob rams always would throw black lambs when cross-bred. ...sooo.. How come the less "real" Jacob has the more dominant spotting gene?


don't know. I suspect that maybe this points to different spotting genes, which could happen.


  And, why when we bred a black 1/2 Jacob ewe out of a black Corriedale ewe to a black Cotswold/Finn ram did we get an all white lamb.


crossed dominant black to a recessive black, and the white can pop out again.


  In receent years, we have noticed that outcrossed Jacobs have more freckling than the inbred ones. This is almost the opposite of what we might expect, since increasing heterozygousity tends to make the offspring more average.Could the culprit here be the spotting genes? Does the spotting gene/s act only on "E"? 


no, any background color.


  Do we know that the recessive black genes come from fence jumpers, when these genes could be hid in the authentic population for years?


no, we don't know that at all! The recessive black may well be in several of the breed, and not imply past crossing.



  In playing around with the Windows paint program, I have come up with a color reasonably close to our lilac. It is : red 37 green 37 blue 29 hue 41 saturation 34 lum 31. Of course it's not that simple, there are fibers in there that have a distinctively lavender hue. Of course we also have a shade darker [more charcoal] color that came in with the ram that we purchased from Robert Johnson that was from Painter and Barraclough stock.

  Crossbreeding. I have seen JacobXDorset lambs that were white, and the same rams crossed on longwool ewes that produced black and spotted lambs. 


this is odd, unless some of the white ones were just big spots.


  We have had lilac sheep from the beginning. They have the same attributes as the black and whites [leg coloration, rate of greying, etc] except they are a diferent color. 



This is not totally surprising. I suspect your lilacs are moorits, but can't be sure. other lilacs are probably an agouti phenomenon.

is this clear as mud?

Phil



D. Phillip Sponenberg, DVM, PhD
Director of Student Affairs
Professor, Pathology and Genetics
Virginia-Maryland Regional College of Veterinary Medicine
Virginia Tech
Blacksburg, VA 24061
USA

e-mail: dpsponen at vt.edu
phone: 1-540-231-4805
fax: 1-540-231-6033 
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