Duration and recovery of fertility in Japanese quail <i>(Coturnix coturnix japonica)</i>

Abstract

Synopsis Duration and recovery of fertility were investigated in the course of a long‐term project concerning inbreeding depression of fitness and other traits in Japanese quail. In two trials pair matings were made in the four possible combinations between mature random bred (R) and inbred (I) males and females. Analysis of both trials was limited to (i) birds that were fertile in at least one previous hatch and (ii) matings that produced at least one fertile egg on or after the second day following removal of males. With these restrictions differences between mating types were not statistically significant. R×R matings had a longer duration and a faster recovery of fertility than the other mating types. Slower recovery of fertility in matings involving inbred birds may in part be due to reduced mating frequency, especially of inbred males. Mean duration of fertility in all data analysed was 6.3 days after removal of males from pair cages. Upon remating the first fertile egg was laid after an average of 3.5 days. Ageing effects of sperm significantly decreased hatchability of fertile eggs. Comparison with other species of birds shows the mean duration of fertility in Japanese quail to be about as short as that of ducks and geese, and about one‐half and one‐fourth as long as that of chickens and turkeys, respectively.