149 AN INEXPENSIVE LABORATORY PRACTICE TO TEACH EMBRYO COLLECTION AND TRANSFER

Abstract

The objective of this work is to describe a hands-on laboratory session for surgical embryo collection and transfer using rabbits as a model. Rabbits are characterised for their low purchase price, easy handling, and low maintenance, thus allowing their use as a tool for embryo transfer teaching and for its potential application in other species, such as the bovine, ovine, and caprine. These are important reasons in countries where the use of low-cost techniques and animal models is a must. Two females of the New Zealand breed were used as donors and one female of the Chinchilla breed was used as recipient. All females were healthy and multiparous. Three days after receiving natural service by a male, the donors were anesthetized (by injection of xylazine hydrochloride, 1.1 mg kg^–1 IM, then sodium pentobarbital, 30 mg kg^–1 IV), and ovariohysterectomy surgery was performed on each one. Each uterine horn was flushed 3 times with Ringer’s lactate (Hartmann) solution. Using a stereoscopic microscope, we searched for embryos and then placed them in a Petri dish for evaluation and selection. Once selected, embryos were moved to a 6-well dish containing 0.5 mL of a commercially available holding solution and washed 3 times. Twenty-one grades 1, 2, and 3 embryos were recovered and evaluated, showing developmental stages 1 to 6, according to IETS. The recipient female was anesthetized, and by laparotomy, her uterine horns were exteriorized to transfer a total of 15 grade 1 embryos with development stages 4 to 6. Pregnancy diagnosis was performed by real-time ultrasound on Days 10 and 20 post-transfer, with positive results. The transferred embryos induced a 34-day pregnancy, including 3 days of embryo development within the donors. Parturition was normal and without problems; 2 live offspring were born, with normal weight and size. The technique, used for teaching purposes, was successfully performed by 3 graduate students directed by 2 professors. The use of rabbits as a teaching model was efficient and the total cost of the laboratory practice was low, as compared with the use of other domestic species. The handling of the females and their offspring was easy, the feeding costs were low, and the practical laboratory session was fulfilled. It is proposed that the rabbit species be used for teaching surgical embryo collection and transfer to graduate and undergraduate students in underdeveloped and developing countries, where low-cost teaching models are of the utmost importance.