[Jacob-list] Generations

[Gary Anderson]

I know of no reputable Jacob sheep breeder whose primary goal is to move at
an accelerated pace through JSBA's lettered generations; such an approach
would be.well, sheep-headed.  Equally so, in my view, would be complete
disregard for registration status in favor of selecting a breeding ram
solely based on his looks.

 

Advanced generations in our flock are a consequence of our breeding
strategy, not a goal.  Our breeding strategy is based on a fundamental
principle of animal breeding (that's "animal breeding" as an organized
field, not the physical act of breeding) that parents can be improved upon
in their offspring.  A number of criteria are included in our selection
program; among them are wool quality and hardiness.  Our flock tends to be
young with older girls and boys giving way to their younger generations.
This approach tends to produce lambs eligible for JSBA registration in the
higher-lettered generations, compared with an approach where breeding
animals are kept for various reasons to ripe, old ages.

 

Breeders who register their sheep through JSBA apparently see value in the
registration process, including inspection at each generation to evaluate
their animals against the breed standard.  I believe the registration and
inspection process can have additive value in sheep with multiple
generations of registered ancestors.  As an organization, JSBA seems to
agree.  Some old-timers will recall that originally registered sheep fell
into a uniform category called "JSBA" after the B generation; sometime
during the early 1990s generations C, D, on so on were added.

 

The Jacob Wool Project was conducted using wool samples and pedigree
information from JSBA-registered sheep.  Results showed that average fiber
diameter significantly decreased (i.e., toward finer wool) with time (i.e.,
since 1989, JSBA's first year of registration) and with generation.
Moreover, analysis including pedigree information showed that this decrease
in average fiber diameter was accompanied by genetic change (i.e., not due
solely to changes in management, feed, etc.).  Personal preferences and
contrary opinions not withstanding, as populations, JSBA-registered sheep in
advanced generations (e.g., C and D) were shown to be genetically different
from sheep in less-advanced generations (e.g., FF and A) for the single
trait that has been quantitatively studied in JSBA-registered sheep.

 

BTW, Hillside Jacobs has a good selection of 2009 ewe lambs eligible for
registration in JSBA's E and F generations and available for sale at
reasonable prices.  The ewe lambs are bred to lamb in April as yearlings.
Alas, they were sent slumming with D-generation rams, albeit very nice ram
lambs picked up at last summer's AGM from two respected breeders and that we
are pleased to have as new sires in our flock. 

 

Gary Anderson

Sparta, MI

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.pairlist.net/pipermail/jacob-list/attachments/20091207/02df3dfa/attachment.htm>