DESEMPENHO REPRODUTIVO DE FÊMEAS NELORE E F1 ANGUS × NELORE NA REGIÃO DO OESTE GOIANO

Abstract

The Western region of Goiás has a great potential to increase the reproductive efficiency of beef cattle females through genetic improvement and appropriate management techniques. The objective of this experiment was to evaluate the reproductive performance of beef cattle females of two genetic groups (Nelore and F1 Angus × Nelore) in three different categories (nulliparous, primiparous and multiparous). The experiment was carried out at São Lucas II Farm, (Arenópolis/GO), 75 km away from Iporá. A breeding season and fixed-time artificial insemination (AI) were adopted as reproductive management strategies. Upon the end of the breeding season at the end of 2018 and beginning of 2019, data were recorded relative to age of first calving in nulliparous females, service period in primiparous and multiparous cows, as well as the number of fixed-time AI needed to confirm pregnancy on the three female categories. The experimental design was a completely randomized in a 2×3 factorial scheme (two genetic groups and three categories of females). Data were analyzed by R software in a mixed model and, for significant effects, Tukey test was used at 5% probability. The results indicated a greater reproductive efficiency (P<0.05) in females belonged to the F1 Angus × Nelore genetic group.