143 COMPARISON OF COMMERCIAL IN VITRO EMBRYO PRODUCTION AND PREGNANCY RATES OF BRAHMAN DONORS IN PANAMA VERSUS DOMINICAN REPUBLIC

Abstract

It has been previously demonstrated (IETS 2011) that Panama is applying the biotechnology of in vitro embryo production (IVP) to their bovine reproduction management systems. The present work demonstrates the ability to apply the IVP technology across 2 distant country borders. Herein, we demonstrate that a country (Dominican Republic; DR) that does not have a bovine IVP laboratory can take advantage of fresh bovine IVP embryos for transfer using distant IVP facilities in another country (Panama; ~1500 km away). The objective of this study was to demonstrate that a model system for large-scale commercial in vitro bovine embryo production for beef and dairy producers, that do not have IVP technology in their home country, could be developed producing comparable results. As the same laboratory provides IVP services to the both countries, a special sanitary protocol was developed in order to legalize the exchange of biological materials (oocytes or embryos). The data obtained in DR was compared to Panamanian client data because identical conditions were utilised for IVP. Cattle production systems were similar, as Brahman (a Zebu type of cattle) is the most popular breed in both countries. Oocytes were collected from 10 different herds in Panama and 4 different herds in DR. The oocytes were transported in an oocyte transporter in both instances. However, oocytes from DR were transported in InVitro Brasil™ maturation medium from 12 to 18 h and in Panama from 6 to 12 h before they were placed in a standard CO₂ incubator. In both cases, the oocytes were matured for 24 h before fertilization with conventionally frozen Brahman semen in InVitro Brasil™ fertilization medium, followed by culture for up to 7 days in InVitro Brasil™ embryo culture medium. The embryos were transferred on Day 7, either in Panama or DR. They were transported by car in Panama and via airplane back to DR. A comparison of oocyte number and quality, cleavage, embryo production, and pregnancy rate, was made using the same in vitro production system for Brahman donors from September 2012 until May 2013. The difference between sites in the relative number of viable oocytes, relative number of cleaved oocytes among viable oocytes, relative number of embryos produced among cleaved oocytes, and relative number of embryos produced among viable oocytes was tested using Fisher's exact test. Pregnancy rate was analysed with chi-squared. We realise these results represent field data; however, we believe the present work is a significant step in demonstrating the potential for wide commercial-scale dissemination of IVP technology between distant countries. The number of embryos produced in Panama was slightly, but significantly, higher than those produced in DR; this is likely due to the larger number of donors and oocytes from the Panamanian herds. However, the pregnancy rate was higher in DR, likely due to the health status of DR recipients. These data illustrate that IVP using Brahman donors could be used as a tool to improve and spread superior genetics. Furthermore, this technique can serve as a model for other Central American and Caribbean countries under similar management systems.

Table 1.  Panama and the Dominican Republic in vitro Brahman embryo production and pregnancy (September 2012 through May 2013)