The study was carried out to evaluate the effect of dried mixture of four herbal plant seeds as feed additives and some environmental factors on growth performance, milk yield and its composition of Rahmani and Chios sheep. Fifty four pregnant Rahmani and Chios ewes, during the last periods of pregnancy were divided into 3 groups (8 Rahmani and 10 Chios ewes each) using complete random block design. Group2 (G2) and group3 (G3) were supplemented with polyherbal combination at the rate of 3 and 6 g/100kg-1 LBW, respectively. Ewes without polyherbal combination served as a control (CTR). Body weight and ADG of G2 lambs was significantly (P<0.05) higher than G1 and control. Variations among genetic groups regarding body weights, TG and ADG were highly significant (P<0.01). Male lambs were significantly heavier (P<0.05 or P<0.01) than female except at birth, male lambs have attained TG heavier (P<0.01) than female lambs. There was a significant (P<0.01) effect of medical and aromatic plant seeds on colostrum yield at birth, 12, 24 and 36 hours, TMY and ADMY was affected significantly. There were significant difference between the two breeds in the production of milk per week, TMY and ADMY. Sex of lambs had a significant (p<0.05) effect on milk produced at the 2nd, 6th, 7th, 8th and 9th weeks of lactation. TMY and ADMY was affected significantly by sex of lambs. TMY and ADMY was (P<0.01) greater in ewes rearing twin lambs compared with ewes rearing singles. Colostrum fat and energy was affected (P<0.05) by treatments. As well as, milk components except lactose are (P<0.01) affected. Colostrum ingredient, except TS were not significantly affected by breed of ewes. TS level significantly increased in colostrum of Chios than Rahmani ewes. The ewe breed had a significant (P<0.01) effect on fat, TS, ash, SNF and milk energy. All colostrum components were not significantly affected by age of ewes. But, TS, ash and energy of milk were affected (P<0.01) by age of ewes. Milk constituents were affected significantly (P<0.01) by different lactation stages. The results of this study indicated that the inclusion of some medical and aromatic plant seeds as feed additives in Rahmani and Chios diet improves growth performance, feed intake and milk yield.