Experiences in the use of embryo transfer for the creation of a Girolando herd in Pococí, Costa Rica

Abstract

During the years 2012-2017 Multiovulation and Embryo Transfer (MOET) technique was applied in Holstein and Girolando F1 animals at the Animal Reproduction Unit (URA), of the Escuela de Zootecnia of the University of Costa Rica, with the aim to create and evaluate a Girolando herd in the Costa Rican Atlantic. Female embryo donors were selected at external farms and URA. Selection in external farms was done through the information of breed herd books and farm records, while in URA, through the data of lactation and performance of the offspring. In addition, an estimation of partial costs of embryo production was obtained. URA evaluated animals, as part of the embryo donors selection, showed an average daily milk production of 11.1 kg, with an average lactation length of 296 days, on a single daily milking and with a calf at the cow side. The weaning was carried out at 7 months of age, with an average weight of 255 kg (244 kg for females and 262 kg for males). Overall, in both URA and external farms, 38 collections were done in 24 selected donors, from which 381 structures were collected, 73.5% fertilized and 26.5% unfertilized. From those fertilized structures (embryos), 47.3% were considered transferable (quality 1 and 2 according to the International Society of Embryo Transfer, IETS), for an overall average of 4.8 transferable embryos per collection. 83 fresh embryo transfers and 34 frozen embryo transfers were performed, from which 33.7% (28/83) and 5.9% (2/34) pregnancy rates were obtained, respectively. The low pregnancy rates obtained, compared to literature reports, are not normal results, but are related to this particular study. The production cost of an embryo,  due to consumables, hormones and semen was US$62.5 dollars. Production and embryo transfer technique collaborated in the creation and development of the Girolando herd of the Animal Reproduction Unit of the University of Costa Rica.