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 Kivircik 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 Kivircik, GBM x Kivircik and GBM x F-1 (Chios x Kivircik) 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 Kivircik. GBM x Kivircik 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 Kivircik 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 Kivircik lambs, the crossbred lambs exhibited better growth performance up to weaning.
