Developing embryo technologies for the eland antelope (Taurotragus oryx)
Assisted reproductive technologies developed in domestic cattle serve as a starting point in similar studies on nondomestic bovids. The common eland is a useful model species for studies on rare tragelaphine antelopes. In Chapter 3 of the present study, effects of components/attributes of protein-free embryo culture media on the in vitro development of in vitro-derived bovine embryos were evaluated. A 2 x 2 factorial study comparing effects of groups of amino acids (20aa or 11aa) in two base media (modified KSOM or BM-3) demonstrated that amino acids and base medium affected embryonic development. A subsequent 7 x 2 factorial experiment to evaluate effects of osmotic pressure and supplement type in BM-3-20aa showed that embryonic development was largely affected by supplements and identified glucose (0.2 mM) as a crucial supplement. In Chapter 4, the use of behavioral training and handling of elands in a hydraulic chute to perform transvaginal ultrasound-guided oocyte retrieval without inducing general anesthesia were evaluated. Nine of 10 females associated specific sound cues with food treats. Females varied in their response interval to audio cues and to training for voluntary entry into the chute. Handling elands for oocyte retrieval required sedation and increased blood glucose levels. In Chapter 5, type of estrous synchronization or ovarian stimulation protocol did not affect ovarian response. Animals, but not month of the year, affected ovarian response. In 37 oocyte retrieval procedures using seven females, an average of 12.8 follicles yielded 9.8 oocytes, of which up to 73% matured to metaphase II. In vitro fertilization, intracytoplasmic sperm injection and nuclear transfer resulted in embryonic development. In conclusion, the bovine embryo culture study suggests that the beneficial effects of amino acids are influenced by the base medium and glucose plays more important roles in non-ATP producing pathways. Behavioral training and handling of sedated females in a hydraulic chute is a reliable method for collecting eland oocytes, which can undergo in vitro maturation and some in vitro embryonic development.
embryo, in vitro fertilization, eland antelope, oocyte, nuclear transfer, behavioral training, in vitro culture
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Veterinary Physiology, Pharmacology, and Toxicology (Veterinary Medical Sciences)