Production, hatchability and fertility of eggs from breeding Japanese quail (Coturnix coturnix japonica) fed diets containing furazolidone.

1. Breeding Japanese quail were allocated to 8 groups, each group consisting of 20 females and males. The birds were fed one of 4 diets for up to 33 d: a control diet or a diet containing 200 mg/kg, 400 mg/kg or 1000 mg/kg furazolidone. Subsequently, quails were fed a furazolidone-free diet for up to 21 d. Egg production, quality, hatchability and fertility of the groups were measured. 2. Significant reduction in egg production occurred in birds fed 400 mg/kg and 1000 mg/kg furazolidone, the effect being more pronounced at the higher concentration. 3. Hatchability was reduced significantly for all groups of birds fed furazolidone and this effect was both dose and time dependent. The reduction in hatchability was attributable to an increase in infertile eggs rather than an increase in embryonic mortality. 4. Egg quality was affected, with more small eggs being produced by birds fed 1000 mg/kg furazolidone. 5. After removal of the experimental diets egg production of the affected groups returned to control values. Hatchability and fertility of affected groups also returned toward control values, but had generally not attained these values 21 d after the cessation of the experimental diets. 6. It was concluded that standard recommendations for the therapeutic dosage of poultry with furazolidone may not be appropriate for breeding Japanese quail.