Alpacas and llamas are South American Camelids. Both species are native to high altitudes in various areas of the Andes and Alto Plano of South America. The fiber that is yielded from the alpaca and the growing popularity of both species as pets has resulted in both alpacas and llamas being raised in many countries throughout the world. To support the growing market, animal management and production systems are developed in order to optimize reproductive capabilities and increase the efficiency and success of breeding. (Cortez 114) A limitation in raising camelid livestock has to do with their reproductive physiology. Both alpacas and llamas have a long gestational period (approx. 350 days) and the females are uniparous, which means that they only give birth to a single offspring. Females are also induced ovulators, that is when the cervix is stimulated, there is a surge in LH (lutenizing-hormone), which causes ovulation. This differs from cattle, horses, sheep, gaots, and people all of whom are spontaneous ovulators, that is these species ovulated evertime cycle. Thus, camelids show ovarian activity throughout the year and are capable of breeding, conceiving, and giving birth at any time of the year. An advantage to this is that mating can be timed so that parturition will occur during the season in which pasture is most nutritionally sound. In South America, "Spring matings are carried out from mid-October to mid-December to ensure that the subsequent births and lactation are timed to coincide with peak pasture growth". In North America, spring breedings might occur in March through May. Research at Ohio State University has shown that spring crias have the fewest problems with disease during the period from birth to weaning. The mechanisms for controlling parturition are not well understood in alpacas and llamas. In several South American studies, it was shown that births almost always occur during the day, frequently in the morning and usually in calm weather. This suggests that alpacas and llamas can delay giving birth in order to avoid unfavorable conditions. (Bruce 297, 300) Follicle wave generation can recommence within 24 hours of giving birth in South American Camelids. However, fertile matings are not usually possible for at least 2 weeks after parturition. Ovulatory follicles are sometimes seen as soon as 7 days postpartum, but uterine involution isn't completed until 15-18 days after conceiving. Therefore, it is said that alpacas and llamas are able to successfully breed by 15 days postpartum, but that conception rates are improved at 21 and 30 days postpartum as compared to those at 2 weeks postpartum. This leaves a very small window of opportunity between conceiving and mating in order to maintain a 12-month reproductive cycle. (Gorden 195) Three basic breeding techniques are used in camelids: natural service pastrure-breeding, natural service pen-breeding, and natural service paddock-mating. Natural service refers to the fact that the male is actually breeding the female as opposed to artificial service where semen is collected from a male and deposited at the desired time in the desired female. Each method has advantages and disadvantages. (Purdy 2000) Field-Breeding: Concept One male is placed in a pasture with several females. Advantages Most natural method Limited labor Optimal conception rates (esp for novice breeder owners) Disadvantages Behavior and receptivity often not observed. Uncertainty about breeding dates. Disruption of breeding program if stud male not fertile. Pen-Breeding: Concept One male and one fermale are placed in a pen for a period of time (1 to 7 days). Advantages - Breeding dates can be more accurately determined. Disadvantages - Males have more aggressive libido Females may be over bred, resulting in decreased fertility or infection. Paddock-Mating: Concept Each female is introduced to the stud male individually for short periods of time and breeding is only allowed to take place if the female is receptive to the male. Advantages - Behavior and receptivity easily observed. Breeding dates are known. Duration of breeding activity is known. Disadvantage - Male has very dominant, aggressive libido and may cause more severe bruising, etc in reproductive tract which can lower conception rates Observation of receptive behavior of female may give "false positives" because female "submits" to dominering male In a study performed at Tara Hills High Country Research Station in 1996, pen-breeding was more successful in terms of the numbers of pregnancies with respect to the number of matings. (Bruce 299) Obviously, there are endless combinations and modifications of these breeding regimens. Experienced breeders have often developed methods that are extremely successful and unique to their farm. Artificial insemination (A.I.), in vitro fertilization (I.V.F.), and embryo transfer (E.T.) are not commonly used in alpacas and llamas. The reason that A.I. isn't usually done is mostly due to the difficulty of semen collection. Male alpacas will breed a female for an average of 25 minutes. They are "dribble ejaculators" and deposit a relatively small amount of semen into the female. Semen deposition is intracornual, with the female in a ventral recumbent position ("cushed"). Some methods that have been employed to collect semen from alpacas have included condoms or vaginal sacs, electro-ejaculation, vaginal sponges and cannulation of the male's urethra. However, the most reliable samples have been collected via a "dummy" female with an artificial vagina heated to the appropriate temperature and equipped with a stricture that is made to resemble a natural cervix. According to a study conducted in Peru in 1993, pregnancy rates were higher when the collected semen was deposited directly through the cervix, into the left uterine horn, rather than via the intracornual deposition by laparoscopy. (Bravo 619, 624) In vitro fertilization is a technique by which eggs are collected from a donor female and are matured and fertilized in a laboratory for subsequent implantation into a recipient female. (Safely 2001) Compared with ruminant species, llamas have an accelerated rate of embryonic development, but it takes longer for their oocytes to mature. According to Gorden, the accelerated development may have something to do with the early maternal recognition of pregnancy that has to occur. During this period of time, there is a transient decrease and then a recovery in progesterone concentrations and a muted pulsatile release of prostaglandin (as compared with non-pregnant animals). (Aba 88) In an experiment done by Del Campo in 1994, scientists concluded that the I.V.F system could be employed with llamas using "abattoir material"(slaughter-house tissue) and that llama oocytes could "be fertilized in the presence of heparin and epididymal sperm". (Gordon 203) The text did not specifically discuss the success rate of such a procedure, only that it was possible. Embryo transfer is a technique that has been developed to, among other things, increase the number of offspring born. In a study conducted by Mr. & Mrs. Paul Taylor and published in the Alpaca Registry Journal, a protocol for this was established. First, a donor female was super-ovulated with injections of FSH (follicle-stimulating-hormone). The super-ovulated female was then bred to a stud male, producing several embryos at the same time. The embryos were then collected and transferred to recipient females. The recipient females subsequently gave birth to fraternal triplets. (As previously discussed, this is relatively un-heard of in New World camelids.) As you can imagine, different producers tend to have favorite methods in which to run his or her farm. Breeding management is one of the most important functions of a breeding farm manager. To avoid reproductive failures in camelids, producers should seek out as much information as possible before employing their breeding programs. References: Gorden, Ian (1997) Controlled Reproduction in Horses, Deer & Camelids. New York: CAB INTERNATIONAL Aba, M.A., Auza, N., Forsberg, M., Kindahl, H. & M. Quiroga Levels of Progesterone and changes in PGF2 alpha release during luteolysis and early pregnancy in llamas and the effect of treatment with flunixin meglumine. Animal Reproduction Science, 59: 88 Bravo, P.W, Flores, U., Garnica, J. & C. Ordonez. Collection of Semen Artificial Insemination of Alpacas.. Theriogenology, 47: 619 Bruce, G.D., Davis, G.H., Dodds, K.G & G.H Moore. Seasonal effects of Gestation length and birth weight in alpacas. Animal Reproduction Science, 46: 297-303 Cortez, Sandra, Ferrando, German, Gazitua, Francisca J., Parraguez, Victor H. & Luis A. Raggi. Early pregnancy diagnosis in Alpaca (Lama pacos) and llama (Lama glama) by Ultrasound. Animal Reproduction Science, 47: 113-121 Taylor, Paul. Embryo Transfer in South American Camelids. Alpaca Registry Journal. Spring 2000. Web-sites: http://www.purdyvet.com/ Author: Stephen R. Purdy, D.V.M http://www.alpacas.com/ Author: Michael Safely http://www.internationalcamelidinstitute.org/ David E Anderson, DVM, MS Diplomate, American College of Veterinary Surgeons Associate Professor of Surgery, Food Animal 601 Vernon L Tharp Street College of Veterinary Medicine The Ohio State University Columbus, Ohio 43210 Anderson.670@osu.edu Phone: 614-292-6661 Fax: 614-292-3530
VISIT OUR WEB-SITES: http://www.vet.ohio-state.edu/docs/ClinSci/bovine/index.htm http://www.vet.ohio-state.edu/docs/ClinSci/camelid/index.html http://www.internationalcamelidinstitute.org/ |