Reproductive characteristics of Japanese quail hatched from eggs incubated at different temperatures

The objective of this study was to evaluate the influence of different incubation temperatures (ITs) on the posthatch reproductive characteristics of Japanese quails (Coturnix japonica). A total of 1332 fertile eggs were incubated at different temperatures: 36.0, 37.5 and 39.0 °C. After hatching, the birds were transferred to rearing cages until 35 days of age and, later, to production cages in groups of nine females and three males. The experimental design was a randomized block with three treatments and six replications. IT did not influence (P > 0.05) birth weight or hatch window; however, higher hatchability was observed (P < 0.05) in eggs incubated at 37.5 °C. There was no effect (P > 0.05) of IT on the relative weight of organs at 35 and 60 days of age or on the male growth curve. In females, body weight at growth maturity was higher (P < 0.01) when the IT was 39.0 °C. The characteristics of the semen were not influenced (P > 0.05) by IT, except for sperm viability, which was higher (P < 0.05) when temperatures of 37.5 and 39.0 °C were used. There was no effect (P < 0.05) of IT on egg fertility or on the morphological characteristics of female reproductive organs. However, a lower age at first egg were observed (P < 0.05) when the IT was 39.0 °C. There was no effect (P > 0.05) of IT on egg quality, except for yolk height, which was higher (P < 0.01) at 36.0 and 39.0 °C. It is concluded that a temperature of 37.5 °C should be used during the incubation of Japanese quail eggs.