Comparative productive performance of cows born through embryo transfer, artificial insemination and natural mating in dairy and dual-purpose herds raised in tropical conditions

Abstract

A populational, observational and longitudinal-retrospective study with records of 28 dairy-specialized and dual-purpose farms was carried out to compare the productive performance of cows born by embryo transfer (ET), artificial insemination (AI) and natural mating (NM), using the database of Centro Regional de Investigación para la Producción Animal Sostenible (CRIPAS) of cattle herds in Costa Rica. Herds (system × altitude), conception method (ET, AI and NM), genetic background (DSpB: specialized dairy breeds [Bos taurus] and crosses, GYR × HOL: Gyr × Holstein Crossbred and DSpB × BI: crosses between dairy breeds and Bos indicus), year of birth (or at calving), lactation number and days in milk were evaluated for the productive parameters age at first calving (AFC), calving to conception interval (CCI) and lactation milk yield (LMY) using a GLIMMIX procedure on SAS. The AFC, CCI and LMY were affected (p .05). The higher LMY (p