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Zwiefelhofer ML, Shury T, Zwiefelhofer EM, Singh J, Mastromonaco GF, Adams GP. Strategies for oocyte collection and in vitro embryo production in free-roaming bison herds. CONSERVATION PHYSIOLOGY 2022; 10:coac058. [PMID: 35966755 PMCID: PMC9368820 DOI: 10.1093/conphys/coac058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/19/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
The study was conducted to test the feasibility of protocols for field collection of cumulus-oocyte complexes (COC) for in vitro embryo production (IVP) in wild bison. The study was done with captive wood bison during the anovulatory season. In Experiment 1, the efficiency of transvaginal ultrasound-guided COC collection was compared between bison restrained in a squeeze chute without sedation vs in lateral recumbency after chemical immobilization using a dart gun (n = 8/group). In Experiment 2, a 2 × 2 design was used to examine the effects of superstimulation treatment [single dose of equine chorionic gonodotrophin (eCG) vs multiple doses of follicle stimulating hormone (FSH)] and method of drug administration (manual injection vs field darting) on COC collection and IVP. In Experiment 1, no difference was detected between chute-restrained vs chemically immobilized groups in the time required to complete COC collections, the number of follicles aspirated (11.5 ± 1.9 vs 9.3 ± 1.8; P = 0.4) or the COC recovery rate [COC recovered/follicle aspirated; 58/92 (63%) vs 44/69 (64%); P = 0.9]. In Experiment 2, no differences were detected between superstimulation treatments (eCG vs FSH). The total number of follicles available for aspiration did not differ between manual injection and field darting (23.9 ± 2.7 vs 21.6 ± 1.9; P = 0.4). Compared with the random start unstimulated group, the embryo production rate was higher [18/132 (14%) vs 53/189 (28%); P = 0.04] after wave synchronization and superstimulation. Results suggest that COC collection is equally feasible in a recumbent position after chemical immobilization as those bison restrained in a standing position in a hydraulic chute. Ovarian superstimulation with a single-dose eCG protocol is as effective as a multiple-dose FSH protocol, and field darting is as effective as chute-side administration of superstimulation treatments. The strategies in the present study are ready to be incorporated into field collections in free-roaming bison herds.
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Affiliation(s)
- Miranda L Zwiefelhofer
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Todd Shury
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
- Parks Canada Agency, Government of Canada, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Eric M Zwiefelhofer
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Jaswant Singh
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Gabriela F Mastromonaco
- Department of Reproductive Sciences, Toronto Zoo, 361A Old Finch Avenue, Toronto, Ontario, M1B 5K7, Canada
| | - Gregg P Adams
- Corresponding author: Veterinary Biomedical Sciences, 52 Campus Drive, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B4, Canada. Primary: 306-966-7411; Fax: 306-966-7376.
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Zwiefelhofer ML, Singh J, Zwiefelhofer EM, Mastromonaco G, Adams GP. Influence of ovarian follicular wave synchronization and single-dose eCG superstimulation on oocyte collection and in vitro embryo production in bison during the ovulatory and anovulatory seasons. Theriogenology 2022; 187:238-246. [DOI: 10.1016/j.theriogenology.2022.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/08/2022] [Accepted: 04/23/2022] [Indexed: 10/18/2022]
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Embryo production by in vitro fertilization in wild ungulates: progress and perspectives. ANNALS OF ANIMAL SCIENCE 2022. [DOI: 10.2478/aoas-2022-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Wild ungulates are of fundamental importance for balancing ecosystems, as well as being the species of economic interest. Increasing concern over the accelerated population reduction of these species has resulted in the development of assisted reproduction techniques, such as in vitro fertilization (IVF), as a tool for conservation and multiplication. In the present scenario, IVF protocols were developed based on the methodologies used for domestic ungulates. Nevertheless, owing to the physiological and reproductive differences among the species, several factors associated with IVF and its relationship with the characteristics of the species of interest require clarification. In vitro conditions for the collection and selection of female and male gametes, oocyte maturation, sperm capacitation, co-incubation of gametes, and embryonic development can influence IVF results. Therefore, the present review considers the main advances in the methodologies already used for wild ungulates, emphasizing the strategies for improving the protocols to obtain better efficiency rates. Additionally, we discuss the conditions of each IVF stage, with emphasis on aspects related to in vitro manipulation and comparability with the protocols for domestic ungulates.
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