Bu araflt›rmada, Marmara Bölgesi’nin hakim ›rk› olan K›v›rc›k, bölgenin prolifik ›rk› olan Sak›z ve yap›lan adaptasyon çal›flmalar›nda Marmara Bölgesi koflullar›na en iyi uyum gösterdi¤i tespit edilen etçi kültür ›rk› Alman Siyah Bafll› Etçi (ASB) Koyun ›rklar› aras›nda yap›lan ikili ve üçlü melezlemelerin dölverimi, melez kesim kuzular›n›n büyüme ve yaflama gücü yönünden karfl›laflt›r›lmas› amaçlanmaktad›r. Araflt›rmada, K›v›rc›k, ASB x K›v›rc›k ve ASB x F1 (Sak›z x K›v›rc›k) genotiplerinin önemli dölverimi özelliklerinden gebelik ve do¤um oranlar› s›ras›yla %76,66, %81,13 ve %85,29; bir do¤uma düflen kuzu say›s› 1,17, 1,25 ve 1,66; kuzu verimi ise 0,90, 1,02, 1,41 olarak saptanm›flt›r. K›v›rc›k, ASB x K›v›rc›k ve ASB x F1 melezi kuzular›n sütten kesimdeki yaflama gücü oranlar› % 96,3, %98,1 ve %89,6 olmufltur. Ayn› genotip s›ras› içinde kuzular›n do¤um a¤›rl›klar› 3,58 kg, 4,27 kg ve 3,77 kg ve sütten kesim a¤›rl›klar› 21,21 kg, 24,98 kg ve 28,30 kg olarak belirlenmifltir. Bu çal›flma ile Sak›z genotipinin melezlemeler yolu ile say›sal olarak kuzu verimini art›rabilece¤i, ikili ve üçlü melezlemeler ile elde edilen kuzular›n yaflama gücü yönünden önemli sorunlar yaflamad›klar› ve melez kuzular›n K›v›rc›k kuzulara k›yasla sütten kesime kadar geçen sürede daha h›zl› büyüme gösterdikleri sonucuna var›lm›flt›r.

The aim of this study was to compare the fertility of ewes and the survival and growth traits of lambs which were produced by two-way and three-way crossbreeding with Kıvırcık sheep, the predominant breed in the Marmara region, Chios sheep, the most prolific breed in the region and German Black-Headed Mutton (GBM), the mutton breed which exhibits the best adaptation to the environmental conditions of the region. In the study, it was determined that the fertility of the Kıvırcık, GBM x Kıvırcık and GBM x F1 (Chios x Kıvırcık) genotypes were 76.66%, 81.13% and 85.29% for pregnancy and birth rates; 1.17, 1.25 and 1.66 for litter size; and 0.90, 1.02 and 1.41 for lamb production, respectively. The lamb survival rates of Kıvırcık, GBM x Kıvırcık and GBM x F1 crossbred lambs at weaning were 96.3%, 98.1% and 89.6%, respectively. The birth and weaning weights of the lambs were found to be 3.58 kg and 21.21 kg for Kıvırcık lambs, 4.27 kg and 24.98 kg for two-way crossbred lambs and 3.77 kg and 28.30 kg for three-way crossbred lambs. The results of the study showed that crossbreeding with the Chios genotype could lead to a rise in lamb production. Lambs produced by two-way and three-way crossbreeding did not have significant survival problems, and when compared to the Kıvırcık lambs, the crossbred lambs exhibited better growth performance up to weaning.