During copulation the stud will “orgle.” Orgling is a low, humming sound with an occasional grunt. Once the stud has adequately positioned himself, he will then begin to insert his penis and thrust. These thrusts are named “ejaculating thrusts.” The penis will physically penetrate the hembra’s cervix. Semen is deposited in both the left and right uterine horns. The semen is viscous and needs to liquefy prior to entering the oviducts. Within 6 hours of deposition, semen can be found near the utero-tubal junction. These cells can remain in the oviduct for up to 30 hours to fertilize an ovum. It is believed that the act of mounting and positioning of the stud on the female’s back act as neurohormonal stimuli for ovulation. These neurohormonal stimuli initiate a cascade of events that culminate in the ovulation of a follicle. Copulation is expected to occur over a 15- to 20-minute period but can range from 10 to 60 minutes.

In llamas and alpacas, embryos predominantly implant in the endometrium of the left uterine horn (about 90% left horn pregnancies and 10% right horn pregnancies). These pregnancies occur from ovulations from either the left or right ovary. Embryotaxis to the left horn occurs for unknown reasons. Placental development in llamas and alpacas occurs with diffuse epitheliochorial placentation. Pregnancy is CL dependent throughout gestation.

Congenital defects are relatively common among camelids. This may have been caused by narrowing of the genetic base upon which the thriving camelid industry in South America of today is based. Congenital refers to a trait that an animal is born with (existing at the time of birth). These defects are not necessarily genetically programmed and may have resulted from problems encountered during organogenesis or fetal development in utero (e.g., flexural limb deformity). Heritable defects are genetically programmed in that animal and can be passed on from the affected animal. A common misconception is that a trait may not be heritable because the dam or sire has produced multiple progeny that were normal. Heritable defects are complex and usually do not result in a high frequency of abnormal neonates. These defects may be passed on to progeny and may surface many generations distant from the affected dam or sire. The most common body systems to be affected by congenital defects are the reproductive, musculoskeletal, and cardiovascular.

The most common congenital defects affecting the reproductive tract are segmental aplasia, cryptorchidism, and pseudohermaphroditism. Affected camelids should be removed from the breeding pool by neutering. Segmental aplasia has been seen in many forms including uterus unicornous, cervix aplasia, aplasia of the uterine body, aplasia of the oviduct, and ovarian hypoplasia. Little information is available regarding heritability from the dam or sire, but the breeding combination should not be repeated. Cryptorchidism is uncommon in camelids, and few cases have been reported. Based on breeding studies from other livestock species, cryptorchidism should be considered heritable and affected males gelded. The mode of inheritance is unknown, but the breeding combination should not be repeated. Pseudohermaphroditism also is uncommon. Most affected camelids have female external genitalia but with an enlarged clitoris. Histopathology of the ovaries reveals the presence of ovotestis.

Stay updated, free articles. Join our Telegram channel

Join