Acta Vet. Brno 2020, 89: 11-17
Intrafollicular oocyte transfer in cattle – a technical report
The aim of the study was to develop and evaluate the functionality of a new equipment for intrafollicular oocyte transfer (IFOT) in dairy cattle. The new system for IFOT is composed of the applicator, the aspirator, and the injector. After aspiration of oocytes, the IFOT set is inserted into the working tube of the ultrasound transducer holder, the content of the applicator can be injected into the preovulatory follicle via transvaginal ultrasonography by one operator. The function of instruments used for IFOT was firstly verified in laboratory conditions. Slaughterhouse oocytes filled into the instruments were injected into Petri dishes. The highest recovery rates in vitro (97.5%) were achieved when the applicator was stored with the needle in a downward position. Synchronized Holstein heifers were used for in vivo test. Intrafollicular injection of saline (n = 9) was performed to find whether ovulation is affected by the injection. Then IFOTs of phosphate buffered saline with 20 oocytes (n = 21) were performed into the preovulatory follicles followed by 7-day-old embryo collection. Total ovulation rates were 86.7% (26/30). Total recovery rates (oocytes + embryos) were 23.1%, embryo recovery rates were 10.1%. The new instrument allows for the loading of oocytes and easy transportation to recipients, and also allows IFOT to be performed by one person in field conditions. The method does, however, need further investigation.
Keywords
Heifer, in vitro embryo production, ovarian transvaginal ultrasonography, intraovarian injection.
Funding
The study was supported by Internal Grant Agency (119/2017/FVL) of UVPS Brno. The authors thank U. Besenfelder and V. Havlicek (Reproduction Centre – Wieselburg, University of Veterinary Medicine, Vienna, Austria) for their support during the experiments and for endoscopic embryo collection.
