- With the adaptation and refinement of Embryo Transfer (ET) techniques for alpacas, breeders are increasingly turning to this technology to accelerate genetic gain in their herds. Put simply, ET takes a fertilised egg from one female alpaca (the donor), and implants it into another female alpaca (the recipient). The recipient then carries the pregnancy, delivers the cria, and raises it as her own, whilst the donor can be mated again, either to carry her own cria, or to be used again as a donor.
- Alpaca reproduction is a complicated business. Unlike other farm animal species, the use of artificial insemination and other assisted reproductive techniques poses a great challenge for veterinarians working with these animals. And the gestation period is a lengthy 11 months. How then, can a breeder reproduce multiple crias from the most valuable animals in a relatively short period? Through embryo transfer, a technique now being perfected by the reproduction specialists at The Ohio State University Veterinary Medical Center.
- Embryo transfer offers great advantages to South American camelid farmers to reach their breeding goals but the technology still plays a relatively minor role in comparison to other domestic farm animals like cattle. The aim of the present study was to analyse a data set of 5547 single or multiple ovulation embryo transfers performed in commercial alpaca farms in Australia to determine the factors that influence number and quality of embryos produced, embryo transfer success (percentage of crias born) and gestation length following transfer. Logistic binary regression identified the variables day of flushing after mating, embryo diameter, embryo quality, day of transfer after GnRH, and the age of the recipient to have significant impact on the outcome measure embryo transfer success. Transfer of smaller embryos or lower quality embryos resulted in decreased transfer success rates. Optimal days for obtaining embryos from donors were Days 8 and 9 after mating, optimal days for transfer into recipients were Days 7 and 8 after GnRH treatment. Age (>15 years) and body condition of recipients
- Embryo transfer is a method used to maximise a female’s reproductive potential. Under normal circumstances, a female alpaca is capable of only having one cria annually. Using embryo transfer technology, you can allow her to breed multiple times in a single year and have her embryos harvested for transfer into less valuable females that have poorer genetics that you wouldn’t necessarily think were worth breeding on their own merit. This increases the number of potential offspring that a single female is able to produce in her reproductive life. The embryos from your best females are carried by the “recipient” females and subsequently raised by those females, although their genetics is of much higher value.
- An assessment was made of the risk of transmission of foot and mouth disease (FMD), vesicular stomatitis, bluetongue, tuberculosis and brucellosis by llama embryos. The study suggests that embryo transfer is a safe method for the international movement of llama embryos despite the special characteristics of these embryos, such as the absence of a zona pellucida, and despite the lack of data onpathogen-embryo interactions. For acute viral diseases such as FMD, vesicular stomatitis or bluetongue, embryo transfer reduces the risk of international embryo movement by a factor of 104. Therefore, if favourable epidemiological or ecological conditions exist in the region of origin of the embryos, the risk of contamination of a batch of llama embryos with the above agents is close to zero. The risk of contamination with Mycobacterium or Brucella depends on the incidence of these diseases, but under the most unfavourable prevalence levels, the risk does not exceed 10-3.3, given that the results of diagnostic tests of the herd and of donor animals are negative before and after collection of the embryos. This study demonstrates that risk assessment can be a valuable tool to facilitate international movement of embryos, particularly for those species for which little or no data are available regarding embryo-pathogen interactions.