Akkaraman ve İvesi ırklarından oluşan 3581 koyunda gebelik oranı (GO), doğuran koyun başına doğan kuzu (DKDK) oram ve sürü verimliliği (SV) iîe kuzularda yaşama gücü (YG) hesaplanmış, GO, DKDK oraaı ve S V üzerine ana yaşı, yıl ve ırkın; YG özerine ise ana yaşı, yıl ve ırk ile kuzuların doğum tipi ve cinsiyetlerinin etkisi aras/ınlnuştır. Sürüde GO, DKDK oranı, SV ve YG için en küçük kareler ortalamalan sırasıyla % 91.65 ± 0.80, %127.74 ± 1.26, % 110.06 ± 1.57 ve % 95.56 ± 0.48 olarak bulunmuştur. Ana yaşının GO dışındaki ölçütler üzerine etkisi önemlidir (p

In this study, 3581 Akkaraman and Awassi ewes were used in order to determine the effects of age, year and breed on the conception rate, prolificacy, viability and productivity. In addition, the effects of sex of lamb and birth type on viability were also studied. The least-squares means for these parameters of all flock were found as follows; 91.65 ± 0.80 %, 127.74 ± 1.26 %, 95.56 ± 0.48 % and 110.06 ± 1.57 %, respectively. Except for conception rate, effects of the age on these parameters were found to be statistically significant (p<0.01). The maximum productivity was obtained with 5-years old ewes. Effect of breed was significaat only on the prolificacy (p<0.05). With regard to prolificacy, Awassi ewes were superior to Akkaraman (12S.27 % vs 126.21 %). The year factor had a significant effect on all parameters (p<0.01). Sex effect on the viability was not significant, but birth type effected viability significantly single lambs being superior to twin ones.