- Running Multiple Jacks With a Herd
The Brayer, May-June 1997
We have seen this problem more with miniatures than other
breeds. Due to the more quiet nature of the smaller jacks, we
have heard of letting several jacks run with the jenny herd.
We do not recommend this procedure for several reasons.
First, not all jacks will respond the same way to newborns. Some
may be fine and ignore them, younger jacks nay want to play with
them and accidentally injure them, or they may see them as small
predators and attack them. This has to been taken on a case-by
case-basis. However, it will make things much easier on the jenny
if she is not constantly being pursued by a lovesick jack while
she is also being trailed by a demanding youngster.
Secondly, and just as important, in a mixed-herd situation, unless
you are running one jack only, there is no way short of blood-and
DNA- testing to be absolutely certain which jack sired which
foals. This problem can also arise if a jennet is exposed to
two different jacks within a short time period. If the time is
less than two months apart on the breeding, it cannot be told
for certain which jack is the sire. Jennies usually carry their
foals for 12 months, but any are, whether the first-time mother
or the most experienced brood jennet, can be off on their timing.
Weather, condition ~f the female, her age, number of previous
foals, all can have an effect on the length of gestation. Some
studies also show that male foals are carried a slightly different
length of time than females.
Third, the jacks will establish a dominance (pecking order) pattern
among themselves. Bigger, older, more experienced jacks may injure
or kill smaller, quieter, or shy jacks. Serious injury could
also occur to any animal that got n the middle.
Don't believe that keeping a yearling jack in with a herd is
safe just because he is less than one year old. Young males have
been known to sire foals when they were only 8 or 9 months old.
Although it is far less detrimental to the young jack than to
the jennet or mare that is bred too young, it is still not a
sound breeding practice. Some animal registries will in fact
refuse to register animals if either parent is below a certain
set age limit. Although this is not our practice at the ADMS,
since we do require a breeders certificate on foals of any registered
sire. the paperwork could look quite strange and embarrassing...
Separate your jacks early, keep close records on brood stock,
and geld excess males (especially any that do not meet up to
breeding-quality standards) as soon as possible! |
