1:00 pm - 2:00 pm
4-10C Agriculture/Forestry Centre, University of Alberta, Edmonton AB
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Mikayla Ewasiuk. This seminar is open to the general public to attend.
MSc with Drs. Michael Dyck and Richard Uweira
Zoom Link: https://ualberta-ca.zoom.us/j/94126127960?pwd=9fXnMYM3Tjr6qQbajMdWAu5HX35HnA.1
Thesis Topic: The use of uterine horn resection surgery to optimize non-surgical embryo collection in gilts and sows
Abstract:
Non-surgical embryo collection (nsEC) and transfer have proven to be financially beneficial practices across a multitude of livestock sectors, justifying their demand in the swine industry. Currently, the conventional methods for collecting pig embryos involve either a costly and invasive surgical procedure or a terminal post-slaughter collection. Over the last several decades, the pursuit to standardize the techniques of swine nsEC has encountered significant challenges. The impediments limiting the widespread adoption of nsEC include the narrow cervical canal and convoluted structure of uterine horns (UHs), as well as the requirement for a specialized catheter to traverse through the uterus.
The objectives of this study were to explore a transitional surgical model involving an ipsilateral resection to enhance access to the utero-tubal junction and better facilitate embryo retrieval upon implementing a transcervical catheter procedure. A contralateral ovariectomy was performed to evaluate the ovarian response of a single ovary. Optimizing nsEC would support the evaluation of embryo survival, quality, and interactions within the uterus. When combined with embryo transfer, these methods would offer a superior and cost-effective means of disseminating swine genetics and safeguarding herd health from pathological agents while concurrently addressing animal welfare concerns associated with live animal transport by reducing the use of this convention.
During this research investigation, purebred dam- and sire-line gilts (parity zero; n = 15) and sows (parities one through five; n = 8) underwent a multi-step UH resection surgery to shorten the UH tissue, excise the contralateral ovary, and ligate the contralateral horn to produce an ipsilateral 40 cm UH. The three subsequent estrous cycles following the surgical procedure were reserved for uterine healing and recovery. After the recovery period, a series of nsECs involving uterine flushing were conducted between days 4 and 8 of the estrous cycle, following the onset of estrus (day 0) and cervical artificial insemination. In the gilt group, across 50 nsECs, the mean embryo media recovery was 57.8 ± 26.8% (mean ± sd), while in the sow group, across 49 nsECs, it was 76.0 ± 17.0%. Collectively, between the gilts and sows, 140 oocytes and embryos were retrieved using transcervical catheterization, gleaning that the application of non-surgical techniques is a feasible approach to harvesting embryos in pigs. Additionally, superovulatory ovarian hypertrophy was observed between the surgical procedure and post-slaughter assessment in the dam- and sire-line pigs. This was demonstrated by an increase in the number of corpora lutea (13.4 and 3.0 vs 27.2 and 12.0, P < 0.05) and intact ovary weight (11.9 and 7.7 vs 25.9 and 38.7 g, P < 0.05), respectively.
Our efforts focused on attaining consistently elevated embryo media recovery rates and potential embryos using nsEC procedures. We envision that a refined catheter design and the use of second parity maternal breed sows will serve as pivotal components in streamlining embryo recovery procedures, representing a noteworthy advancement in the quest to improve the efficiency of swine reproduction. This pioneering approach is anticipated to be fundamental in propelling the broader field of assisted reproductive technologies within swine breeding and the industry as a whole.
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