Reproduction in South American Camelids

South American camelids have many unique reproductive characteristics that differ from other domestic species. Females, for example, show waves of ovarian follicular growth and regression as induced ovulators requiring mating to trigger the ovulatory process. More recently, it was suggested that ovulation occurs not only by mechanical stimulation, but also in the presence of an ovulation inducing factor, characterized as beta nerve growth factor. After ovulation, a short life-span corpus luteum is developed and most pregnancies are carried out in the left uterine horn, although both ovaries collaborate with oocytes in equal proportion. The duration of copulation is variable and ejaculation occurs during the entire copulatory process. Semen in these species also has some particularities as low volume, high viscosity, and low sperm concentrations.

These characteristics of camelids reproduction are likely involved in the causes of their low reproductive rates. It has been reported that many matings are infertile due to ovulatory failure and a high rate of embryonic loss, most of them before day 30 of pregnancy. Thus, additional research is needed to provide a complete understanding of the different aspects of their endocrinology and reproduction in order to generate new strategies to improve reproductive rates.

Moreover, the application of biotechnologies such as artificial insemination and embryo transfer that are routinely used in other domestic species are still not completely applicable in camelids. New information regarding these biotechnologies, including techniques to freeze semen or improve pregnancy rates after embryo transfer are required to boost production of camelids products as fiber and meat. This knowledge is also relevant for its application in the conservation of endangered South American camelids, such as vicunas.