Effect of bilateral uterine horn insemination on first service fertility in dual purpose crossbred cows

The effect of site of inseminate deposition on first service fertility was determined from 333 cornual and 433 uterine body Al in dual purpose crossbred cows. Three farms located in an area of dry tropical forest in Zulia State, Venezuela, were involved in this study. Data was analyzed by chi-square procedure of SAS. From the total cows (n=766) considered, 227 uterine body (52,0%) and 236 cornual (71,0%) were diagnosed pregnant with a significant higher percentage (P<0,01) for the cornual technique, When the farm-inseminator effect (A,B,C) was evaluated the following first service fertility percentage for uterine body and cornual semen deposition were found: A: 54 vs 67% (P>0,01), 13: 51,3 vs 74,3% (P<0,01), C: 53 vs 71% (P<0,01), respectively. Although there are controversial results in the literature regarding the cornual technique, our data indicated that it is a valid option to increase efficiency in technicians with low or moderate records under tropical conditions.