Objective.

To assess the effects of body condition, female category, reproductive status and inseminator technician on the conception rate with a fixed-time insemination protocol in beef crossbreed cows.

Methods:

711 beef crossbred cows were treated (day 0) with an intravaginal device of progesterone + estradiol benzoate, on day 8 removal of the device + estradiol cypionate + eCG + PgF2α, IATF at 46-50 h later and diagnosis of pregnancy (ultrasonography) at 30 days’ post insemination. The effects (category of the female, body condition, ovarian cyclicity and inseminator technician) in the conception rate at the first service, were evaluated with the Chi Square test and comparisons by pairs of proportions with the Bonferroni correction, with a level of P <0.05 and validated by binary logistic regression by steps (Wald forward) with simple contrast.

Results:

The conception rate at the first service was only significantly influenced by the inseminator technician with odds ratio of 3.35; 4.62 and 1.94 for inseminator technicians 2, 3 and 4 respectively compared to the reference.

Conclusions:

The efficiency of the inseminator technician (measured by the gestation rate at the first service and the odds ratio) was decisive in the results achieved with significant differences between them. It is recommended to use the methodology used for the systematic evaluation of insemination technicians in the efficiency of the results of the IATF programs.