THE INDUCED OVULATION OF LLAMAS

Cows sheep, goats, or horses reproductions are very different then the Llama, unlike all of the other species, female llamas do not have a regular estrous cycle. Camellias are induced ovulates, they do not come in heat at regular intervals. This means that the female does not ovulate any eggs until the male has bred her. The act of breeding stimulates hormonal events inside the female, which result in ovulation and hopefully conception.

Estrous Cycles - Is a period of receptivity to the male and a period of definite non- - receptivity to the male. Estrogen is produced by follicles and is the predominant hormone in a receptive female. After ovulation the follicle stops producing estrogen and the remaining cells develop into a corpus lutetium. Progesterone is produced by the corpus lutetium and is the predominant hormone in a non- - receptive female. After a period of time, the corpus lutetium regresses in response to prostaglandin's, this is another group of Harmones and a new follicle begin to develop. When pregnancy begins the fetus tells the corpus luteum to remain for part or all of the pregnancy. If the female does not get pregnant she will go thru the whole cycle again. This is the scenario for cows, sheep, goats and horses that ovulate spontaneously.

The llama does not have an estrous cycle with definite periods of receptivity and non- - receptivity; there is still cyclic activity on the ovaries. Some follicles are stimulated to develop and mature together in "waves" on the ovary. The waves of stimulated follicles develop from primordial follicles to primary follicles and then to secondary follicles, which contain some fluid and are capable of producing estrogen. Only one single follicle which dominates and continues developing to become a tertiary or Graffian follicle which is larger and able to ovulate. This follicle also produces estrogen and is the follicle which will ovulate if the llama is bred at the appropriate time. Follicles which do not ovulate will regress and shrink. Each egg can only be stimulated to develop once and then is not used again. Females cannot produce more eggs than what was already present in the ovaries at birth. Despite this and despite the fact that several eggs are stimulated to develop and then never used with each follicular wave, there is still plenty of eggs for the lifetime of the female.

Each follicular wave is composed of three stages of growth, maturity, and regression. Each of these stages takes an average of 4 days, but the entire follicular wave takes 11 to 12 days. This means while the follicles are at the mature stage the llama is more receptive to the male and breeding should result in ovulation. During the foUicular growth stage or regression stage breeding is much less likely to result in ovulation, the female is usually less receptive during this time. The mature stage occurs 3 to 4 out of every 12 days of a folllcular wave. Follicular waves will occur on both ovaries and often the waves don't coincide. This example will explain, as one ovary eaters the regression stage, the other ovary will begin the growth stage and have a mature follicle ready within a few days. This will maintain the follicles which are ready to ovulate more often than without the overlap or lack of synchronization between the ovaries.

The overlap of these follicular waves keeps the estrogen circulating in the female. Estrogen contributes to making her receptive to the male at almost any point during the follicular wave. A non-pregnant female may appear to be receptive all the time. Even though the female will accept the male does not mean that there is a follicle ready to ovulate. Some smaller follicles in the growth or regression stage may be the cause of a non- pregnancy. A breeding, which does not result in ovulation, could easily occur.

Once ovulation does occur and the corpus luteum is formed, it will remain for only 14 days if a pregnancy did not result from the breeding. The corpus luteum remains throughout the entire pregnancy if a pregnancy has resulted. If the female becomes receptive to the male again in 5 to 7 days, then no corpus luteum formed to produce progesterone because the female did not ovulate during breeding. In a female who becomes receptive again two weeks to 16 days after breeding, ovulation occurred but did not result in a pregnancy.

Llamas can be checked for pregnancy by a rectal palpation. Depending on the size of the female and the size of the veterinarian's hand, this may be difficult to impossible. It is usually easier in females who. tww already had at least one cria. In 35 to 40 days a pregnancy can be determined, but it is more i"diaMeitt45 days. After 90 days the uterus will extend past the brim of the pelvis making palpation for pregnaacy fliore difficult Any kind of rectal palpation always carries the risk or rectal tears or perforations. Llamas and alpacas e not as susceptible to rectal trauma during palpation as the mare, but are more susceptible than the cow. If this is done gently and with the proper restraints of the female and the use of plenty of lubrication, the-~ are minimized enough to make the procedure worthwhile. The females which jump up and lay donma Mfette riskiest to palpate or ultrasound rectal. Sometimes sedation maybe necessary to perform this proeeduMi Epidural anesthesia may be necessary to relax the anus if there is excessive anal sphincter to relax the law.

No single method of pregnancy detection is 100% accurate, but all methods that follow are accurate to a usefUl degree. Combining detection methods leads to the most accurate determination of pregnancy. Experience from consistent use of any detection method makes knowledge of the results easier and mace accurate. Any test that easily fits your management system you should continue to practice it and iDalciuU use of it. Behavior testing or progesterone testing is important to understand what is happening to the overica. lfmd when ovulation occurred from breeding, progesterone will be produced by a corpus luteum (CL) wittatti 14- 17 days making her unreceptive. The CL will regress if the female is not pregnant, or it will remain ifll is. lfovuiation did not occur during breeding, no CL will be formed and the female will be receptive lgftia in 5 to 7 days when the next wave of follicles will develop. You need to get more detailed informatioa oa induced ovulation and breeding physiology to better understand these important details.

BEHAVIOR TESTING Whether or not a female is pregnant behavior testing is very commonly used as an initial indication. Females are not receptive to the males while under the influence of progesterone. The female with progesterone as the dominant hormone will reject or spit off the male. When he approaches her and smtib underneath her tail to check her receptivity, a pregnant female will tiy to move away or she may put her ears back and spit. A non-pregnant female will not spit and she will tolerate the male's advances witlxmt moving away or lay down to breeding. As an experienced male can also assist in behavior testily for pregnancy. After smelling a pregnant female he will often not be interested and may just walk away. lfthc female is not pregnant he will begin to orgle, and be very interested in her and will try to breed her if he can. All animals do not behave the same under similar conditions.

PROGESTERONE ASSAY A progesterone testing can be used to determine if progesterone is still present. The level ofprogeaterone is greater then 2 ng/mL. Daily variation in progesterone levels also occurs. This is one of the most accurate types of testing for pregnancy. This test comes from using serum of the blood. This requires a veterinariM to draw the blood and to send it to a diagnostic lab. Some breeders draw their own blood and to do the tM them selves. If you are comfortable with that then you can do it yourself. Progesterone testing is vciy coatty and time consuming and invasive than other methods. These results are more objective, more accuntewd can provide a more definitive proof of a pregnancy. Keep in mind that there are other much less commob ways that a CL could be present without a pregnancy. If you have any reason to question a positive progesterone test, confirm the pregnancy with other methods.