In the present work, the effects of Habfuginone hydrobromide and Maduramicin ammonium mixed with ration for 120 days were studied in Bovans laying hens. Serum levels of estradiol and progesterone and egg quality, besides histop athologbal changes of the ovaries were also studied. Results revealed that serum estradbl and progesterone levels were significantly decreased In Maduramicin treated groups. Egg quality and age of start laying were also significantly decreased in the latter groups. No significant changes of the ovaries were observed in both groups. It could be concluded from the present study that Halofuginone hydrobromide (1.5 or 3 p.p.m.) can be given to Bovans laying hens during the rearing period, but not recommended during the period of egg production as it has significant effect on egg quality. Maduramicin ammonium cannot be used safely in Bovans laying hens as it delays sexual maturity and stops the egg production until 21 days post drug withdrawal.