Judging Fleeces Based on the Lambs Tail?
I recently purchased an old book called Hammond's Farm Animals 4th ed. 1971 by Sir John Hammond which told of an experiment on selection and inbreeding where Romney sheep were inbred based on selection for woolly tails or hairy tails in lambs. The book states that hairy tails are associated with coarse britch wool and woolly tails with fine britch wool.
There was a wide variation in hairy and woolly tails in the original outbred (non-inbred) purebred flock used in this experiment.
This photo from the book shows lambs resulting from selection for woolly tails (top) and hairy tails (bottom). Note the halo hairs on the backs and britch of the hairy tailed lambs, while the wooly tailed lambs appear to have a tight curl and smooth look to the fleece.
The book discussed how selection for different traits and inbreeding the selected animals could be used to separate out characteristics and reduce the variation, causing the sheep to breed true for the selected trait, in this case hairy or wooly tails.
What interested me the most was the idea that I might be able to better judge the fleeces of my sheep at a young age. I have been rating this year’s lambs based in the amount of hairiness in their tails, roughly by quarter percentage. 100% is vey hairy tails, 50% is hair halfway up the tail from the tip, and so on. I am finding that the white sheep in general have less hairiness than the natural colored, though one set of twins- one white and one (Extension dominant) black are both very hairy in the tail and the entire body. Interestingly, the black lamb seems to have a more normal crimpy fleece at 8 weeks, while the white lamb has a long fleece with relatively straight fibers. It also seems that those with very hairy tails also have halo hairs at the britch and hairy polls, rather than tight curls on the top of the head. Some of the hairy tailed lambs also have hairy fleece on the front of the neck.
On the right are photos of tails from two of our 2010 lambs. You can see that the lighter silver blue is woolly to the tip, while the darker lamb is hairy from the tip to about 75% up to the base of the tail.
I did a google search on this subject and found the abstract for an article; The lamb's tail in relation to wool type in British breeds and crosses of sheep By P. Bhattacharya and John Hammond The Journal of Agricultural Science, Volume 42, Issue 1-2, January 1952, pp 180-183 Published Online by Cambridge University Press 27 Mar 2009
The abstract states;