Skoči na glavni sadržaj

Pregledni rad

https://doi.org/10.46419/vs.51.5.1

Physiology of reproduction in camelids - Assisted reproductive technologies, pregnancy, and parturition. Part II.

Dražen Đuričić orcid id orcid.org/0000-0002-8013-2091 ; Veterinarska stanica Đurđevac, Hrvatska
Iva Kilvain ; Hrvatski veterinarski institut, Veterinarski zavod Rijeka, Hrvatska
Marko Samardžija ; Veterinarski fakultet, Sveučilišta u Zagrebu, Hrvatska


Puni tekst: hrvatski pdf 497 Kb

str. 477-486

preuzimanja: 305

citiraj


Sažetak

Although camelids are not representedand economically significant animals in Croatia, they represent an attraction and there is a growing trend of breeding these animals as pets, especially the South American camelids, llamas and alpacas. In natural conditions, the reproductive efficiency of camelids is relatively low. Camelids are seasonally polyoestrous animals. Ovulation in the female is induced by copulation. Semen collection consists of the use of an artificial vagina (with stricture) placed in a female wooden dummy in the sitting position. Use of assisted reproductive technologies, such as Artificial Insemination (AI) and Multiple Ovulations and Embryo Transfer (MOET), in vitro (maturation, fertilization, culture) embryo production or other biotechnologies (cloning and transgenesis) are not widely used as routine breeding procedures in camels. AI and MOET are technologies applied in breeding programmes to improve the production characteristics of various domestic animal species. These techniques are not directly applicable in camelids, a the reproductive physiology differs compared to other domestic animals. Today, the most commonly used combination for the multiple ovulation of ovaries in camels is a combination of porcine FSH (pFSH) and equine chorionic gonadothropine (eCG). A better pregnancy rate is achieved with recipients ovulating 24 h after the donor. Recipients must be prepared from a group of females with follicles 13 - 17 mm in diameter, and are injected with GnRH or hCG 24 h after mating with the donor. Embryos are flushed transcervically on day 7 after ovulation. After selecting the embryos based on morphological characteristics, the embryos are aspired in the paillette and transferred to the prepared recipients (on day 6 after ovulation), usually in the left horn of the uterus. The generational interval is relatively long because of the late sexual maturity, long gestation period and they have only one newborn. Gestation length is 365 to 410 days in dromedary camels, 345±15 days in llamas, and 330±10 days in alpacas. Pregnancies usually occur in the left uterine horn. The embryonic signal for maternal recognition is important for embryo survival. Parturition is divided into three stages: preparation for birth (2 - 6 hours), the passage of foetus (10 - 45 minutes), and expulsion of the placenta. Because of the relatively long neck and limbs and the fact that almost all foetuses are born in the anterior longitudinal presentation, neck or/and limb flexion is often present. With good management and controlled breeding, it is possible to increase the reproductive efficiency of camelids. The caul (placenta) of camelids (according to the layers) is the placenta epitheliochorialis (microcotyledonaria), and according to the schedule between placenta materna and placenta fetalis is the placenta diffusa. Due to the long generation interval, more attention should be directed at improving assisted reproductive technologies and early ultrasound pregnancy recognition.

Ključne riječi

camelids, assisted reproductive technologies, pregnancy, parturition

Hrčak ID:

238131

URI

https://hrcak.srce.hr/238131

Podaci na drugim jezicima: hrvatski

Posjeta: 691 *