Embryo Transfer (ET)

  • Alpaca Cria Birth Signifies Successful Embryo Transfer

    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.More »
  • Buying the Best Oven

    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.More »
  • Development of a Large Commercial Camel Embryo Transfer Program: 20 Years of Scientific Research

    Embryo transfer in camels was initiated to respond to demand from the camel industry particularly in the United Arab Emirates since 1990. This paper reviews the research performed in critical areas of reproductive physiology and reproductive function evaluation that constitute a pre-requisite for a successful embryo transfer program. A description of donor and recipient management as well as a retrospective evaluation of calf production in the embryo transfer program at Sweihan, UAE is provided. The program utilized two management systems for donors, with and without ovarian superstimulation. Non-stimulated donors are flushed every 14–15 days with a mean embryo production per year per female of 8.5 ± 3.1 (mean ± SEM). Response to gonadotropin stimulation is extremely variable. FSH doses and frequency of administration is often adjusted to a specific female. In the period of 1990–2010, 11,477 embryos were transferred to recipients. Transfers from 1990 to 2009 (n = 10,600) resulted in 2858 weaned calves, representing an overall efficiency (% weaned calves/transfer) of 27%. Pregnancy rates at 60 days post transfer varied from 19 to 44%. Pregnancy length following transfer is extremely variable. A major challenge in a large embryo transfer program is finding good quality recipients. Causes of pregnancy and neonatal losses are under study.More »
  • Embryo Production by Superovulation and Dual Siring in Alpacas (Vicugna pacos)

    Alpacas can only produce one offspring per year. In order to accelerate the genetic gain of a herd, superovulation and embryo transfer can be used to produce multiple embryos from superior females. We hypothesized that the use of dual siring with superovulation would result in the production of multiple embryos sired by different males. After administration of the superovulation protocol, receptive females were bred to two proven males (A and B) 8–12 h apart and ovulation was induced by gonadotropin at the time of the first breeding. Growth of multiple dominant follicles was successfully achieved in 95% of cycles. Females that were receptive after FSH treatment and were bred with both males (order A–B or B–A). Embryo collections were performed 8–9 days post-breeding on 15 cycles and 73% of collections recovered ≥1 embryo. A total of 46 embryos, were recovered for an average of 3.13 ±3.1 (range 0–10) embryos/flush. Parentage analysis was performed for 23 embryos (6 from A to B, 17 from B to A). Twenty-two of the 23 embryos were determined to be sired by male B, being six embryos from breeding A-B and 16 embryos from breeding B-A. A single embryo from breeding B-A was sired by male A. In conclusion, FSH administered at decreasing doses can be used to promote superovulation resulting in collection of multiple embryos per cycle. However, slight differences in male fertility may affect the frequency of embryos sired by each male.More »
  • Embryo Transfer

    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.More »
  • Embryo Transfer - A Breeders Perspective

    The use of embryo transfer (ET) technologies has been a relatively recent advance in breeding technology for alpacas in Australia. The reasoning behind the development of the technology was to increase the use and allow great availability of genetically superior animals both locally and internationally. With long gestation periods for alpacas (11 months), conventional breeding results in slow genetic gain. Also information gained from these breedings is less reliable as it is difficult to compare results over various years due to the variations in season etc also influencing the results.More »
  • Embryo Transfer in the South American Camelids

    In the summer of 1998 a man named Bob Godke phoned our ranch in Montana. He said he had heard we knew how to do embryo transfer in the South American camelids. Godke, it turned out, was Dr. Robert Godke, Professor of Reproductive Physiology at LSU and world famous authority on advanced reproduction techniques. He was in Montana for a fly fishing holiday and decided to track down the rumor he heard at a meeting of the International Embryo Transfer Society (of which he is a past President). Godke came to the Taylor Ranch for an afternoon of conversation which led to demonstrations and eventually to a full-blown cooperative project between LSU and the Taylors. He was quick to admit that he simply had not believed reports that an unpublished layman llama breeder, without any formal training in advanced reproduction, was doing embryo transfer in llamas with a high rate of success. Nobody else in the world had recorded more than a few successful embryo transfers in the lamas (less than 10 in total) and we were claiming more than one hundred live births. The success of our llama embryo transfer program is due to a team effort. My wife, Sally, does most of the actual palpations, ultrasound scans and embryo flushes and transfers while I assist and take notes. Bob Godke realized the importance of this and began to refer to Sally as my "secret weapon". Teamwork, at least two people working closely together to manage the animals, do the technical work and keep accurate records, is essential for successful embryo transfer in camelids. Luckily for me, Sally enjoys this work and is very good at it.More »
  • Factors Influencing Embryo Transfer Success in Alpacas: A Retrospective Study

    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 recipientsMore »
  • Facts About Embryo Transfer in Alpacas

    This article intends to answer questions about the application of embryo transfer in alpacas as a powerful tool to genetically improve herds. Its main purpose is to present the information available in an objective and simple manner to inform breeders of the advantages and limitations of the technique.More »
  • Reflections on Multiple Embryo Transfer Programmes in Alpacas

    Late in 2004 we decided to experiment with the advanced reproductive technique of embryo transfer . It was a big decision to make for our small stud as the technique has only recently evolved from an experimental research challenge in alpaca breeding to a potentially useful commercial breeding tool. As the results can vary dramatically between ET programmes and across different studs, the following discussion highlights some of the issues and challenges that we had to face as novice users of this technology.More »
  • Risk of Disease Transmission by Llama Embryos

    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.More »
  • Who's Afraid of ET?

    What are we afraid of? - Is the procedure safe for the animals? - Is doing ET ethical? - Do the costs and difficulty of the technology make it only practical for the larger, wealthier farms? - And if so, is it fair? - Does using ET decrease the variability of the gene pool and is it going to increase inbreeding? - If ET improves the fiber quality across the national herd, do alpacas become just a fiber industry? If so, where is the value in breeding the animals? - Isn’t ET going to flood the market with alpacas? The answers for many of these questions can be found by observing what has happened with other livestock industries that utilize ET, and by instituting some important guidelines.More »