The female ferret normally starts a estrus cycle when the days start
getting longer after the winter solstice.  The males go into their rut
cycle at the same time.  After the breedingjills deliver a litter in 42
days.  Kits are normally weaned some 5 to 7 weeks later - this varies a
lot on litter size and the specific kits.  If for some reason the litter
sdoesn't happen or something happens to the kits, the jill will go back
into season.  Sometimes it happens without a problem in the litter as well.
 
Since light was the primary trigger the timing of this can be adjusted
based on artificially adjusted light cycles.  With an adjusted diet the
cycle can be brought on more readily for a second breeding.
 
With combinations of diet and light cycle adjustment a ranch can so
confuse the yearly cycle to permit three breedings in some jills in a
given year.  Basically you confuse the ferret into think it is early
spring/late winter more often.  A real good diet is needed because the
nursing of the kits is very hard on a jill.  A poorly fed jill might not
go into season at all.
 
None of the hobbiest breeders that I am aware of would try to do this.  They
aren't as interested in volume reproduction.  The 'backyard breeders /
ferret mills' would love to be able to do this but the costs are usually
beyond their means.  The outdoor ranches usually try for a second breeding
but are at the mercy of natural sunlight.  A larger ranch with the ferrets
in buildings are trying to run a business.  The more offspring produced the
better for their bottom line.  THey'd have to replace the breeding jills
more often as nursing really tires them out.  The hobs that are kept in
season too long also get worn out faster from the stresses of their own
hormones.
 
In a lab situation it was possible to have a jill have 4 litters in a year
but only if the jill started that 'year' from the time of her very first
pregnancy.
 
Ferrets have a tendancy to have 'false' preganancies.  Many of the east
coast breeders are having big problems with their jills being unable to get
pregnant at all.  A purely speculative theory of mine is due to the
coincidental timing of the ECE epidemic.  These jills are having problems
getting pregnant and if they do get pregnant they are unable to have normal
sized litters or to carry the litters to term.  I've wondered if the damage
that ECE has done to their intestines has reduced their ability to absorb
foods and without the required nutrients are unable to go through a normal
reproductive cycle.  No testing of this has been done nor does everyone
agree.  I've just been working with the other ocal breeders to solve these
problems.  Fortunately for me, we've not seen any of these problems in our
breeding program and have been blessed with 8 of our own litters this year
and one we took over for another breeder.
 
bill killian
zen and the art of ferrets
[Posted in FML issue 1307]