CAMELID MATING
cycle
 The female has no heat cycle because llamas are copulation-induced ovulators.  In simple terms, this means that they generally have several eggs in various stages of maturation, and will release one when stimulated by the male.  Each ovary in turn ripens an egg every eight to ten days, so there is generally one available; on some occasions a receptive female will be between eggs and will need additional exposure to the male.  Some "hard to settle" females require a very aggressive male or many repeat breedings to stimulate ovulation.  Because llamas use up from six to eight eggs every month that they are open (unbred), and are born with a finite supply, the surest way to insure the fertility of a doe intended for breeding is to keep her pregnant.  Females who have not regularly produced offspring are not likely to be successful doing so after age 7 -10 because their ovaries have been depleted.
pre-mating
The male llama will rarely mate until he is secure in his surroundings.  This is because the process takes anywhere from ten to thirty minutes, during which time he is completely absorbed and vulnerable to hostile males.  (We use the mating period to trim toenails!) If he is new in an enclosure, he will first go to the poop pile and exhibit "flamen" behavior.  You will see him lip the pellets several times, then raise his head (the neck is often still down; it looks funny, and the first time you see it you wonder if something is wrong with him.) With his mouth open, he will inhale.  We speculate that in this way he is able to detect by taste or smell if there is an open female using that pile, or if any rival males have been around.
foreplay
 Once the stud has checked out the enclosure and satisfied himself that no rivals will interfere when he is mating and that an open female is present, he will begin to "orgle", an industry term for the male mating noise, which sounds like a cross between a gargle and a snort, and goes on continuously throughout mating.  If the female is interested, she will cluck upon seeing him, "fan" her tail back and forth, and begin to run.  The male will pursue her, orgling the while.  During the chase, the prepuce (penile sheath) on the stud, which normally faces to the rear for urination, has been pulled forward by the contraction of the muscles.
mating
After a chase which can last up to ten minutes, the male will get on top of the female to attempt to force her down, or she will stop running and sit.  The male then sits on top of her, hitching forward until he makes contact. Only after the male has settled on the female and positioned himself properly does he extend his penis, a delicate, pencil-thin organ about fourteen inches long with a "hook" of cartilage on the end.  But contact alone will not stimulate the female to ovulate.  The male llama must penetrate the corkscrew-shaped opening of the cervix (hence the 'hook', which is just for this purpose), and extend himself all the way into the fallopian tube, where a small amount of semen is deposited.  He does each side, then withdraws.  This is why the whole affair takes so long.  It should also explain something of the difficulties which make artificial insemination impractical for this livestock.
refusal
 A female who is bred will refuse to sit for the male; if he insists, she will spit! More aggressive females will actually chase the male away.  (Some young studs won't take "no" for an answer and will be covered with smelly green slime before they give up.) The female seems to know that she is pregnant within a week of being bred, so if she is brought back to the stud after that time, the success of the breeding will be manifest.  After one month, a blood sample can be sent for progesterone testing to determine if the pregnancy has held.  As a rule, it is best to leave the mating pair together for a few days for two reasons: first, because the female may be "between" ripened eggs; and also because some females will not ovulate unless stimulated by repeat matings.
 gestation
The length of the llama pregnancy is around 11-1/2 months.  Normal pregnancies may vary from one month early to one month late.  The dam is normally lactating during the first five months of her pregnancy.  Females should not be bred until they have reached 60% of their adult weight, which can be anywhere from twelve to thirty months, depending on genetic and nutritional factors.  The female is most fertile ten to twenty days after giving birth; in their native environment they must be re-bred at this time if they are to produce at the proper time of year (the only time there is enough food available).
productive life
A typical breeding female will produce eight to ten offspring over her lifetime if kept continuously with a fertile male. Births are single; although there are recorded cases of twins, most twin fetuses are spontaneously aborted late in the pregnancy or stillborn, so it is not a particularly desirable trait.  (Twinning is hereditary; and as the production of animals with this tendency is lower than single-birth llamas, it should be considered as a negative in a breeding program.) Most fertile llama females produce until the age of fourteen, and can continue pregnancies right on into old age if they have been well managed.  Llamas can live up to thirty years for a very old individual, but by sixteen an average llama is getting elderly.