[Jacob-list] Breeding -Rams

[Jacobflock at aol.com]

In a message dated 9/30/02 8:54:36 AM Central Daylight Time, RnS1260 at aol.com 
writes:


> Jacob List, 
>     It is my understanding that our ewes will cycle twice about 14 days 
> apart. Is there a time when I can put the other ram in with all of them, or 
> is it best to remove the ram I am currently breeding with this year from 
> the flock? What are the practices used for breeding? Need help! Thanks 
> again. 
> Cheryl  (Rise "N" Shine)  ( : 

Estrous cycle is from 14-20 days.  

St. Jude's is probably odd man out.  We try to maintain diversity by using 
multiple rams (eight to twelve) over groups of ewes and each group is 
reviewed for pedigree and inbreeding.  Inbreeding coefficients are 
"pre-calculated" for each offspring.  

We use about a forty five to sixty day exposure for each group.  If we remove 
a ram we wait for approximately ten days (half a period and the length of 
normal variation in the gestation period 140-150 days).

We never have placed two rams together in a breeding group. Our first and 
primary reason is loss of pedigree integrity.  The second is fear of male 
fighting.  We have left a ram with his bred ewes, even thru birth and 
lactating.  But ram behavior in a "multiple ram single ewe flock" breeding 
situation, in our view, is too unpredictable to consider.

If you have multiple rams on pasture/forage only, there may be less risk of 
lethal fighting.  We have observed, and this is very limited and has a number 
of variables, that over the course of the past five years, multiple rams 
(eight to fifteeen) kept in a separate field and fed absolutely no grain, 
tend to fight less than a group of six kept on an acre out back that has poor 
forage.  They were augmented with hay and grain and tended to fight.  We 
reduced the six rams to four (to reduce pasture demand) and have kept these 
four on pasture the past two years (no grain) and the fighting stopped ... 
and then maybe they know where the other two rams went!

A final note on breeding.  The USDA recently completed its initial review of 
inbreeding and effective population for about 1200 Jacobs.  The average 
current inbreeding level seems to be about 5% and increasing on a regression 
line about 0.25% per year.  If, collectively, the level of inbreeding can be 
kept at these levels for another ten years it would represent a significant 
accomplishment. 

Fred Horak
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