Improvement studies on mutton sheep for Marmara region conditions: I. fertility, lamb survival, and growth traits of lambs [Marmara bölgesi şartlarina uygun etçi tip koyun geliştirme çalişmalari: I. dölverimi, kuzularda yaşama gücü ve büyüme performasi]

Th e present study was conducted to compare the fertility of ewes, the survival rates, and the growth performance of lambs that were crossbred by mating German Black-Headed Mutton (GBM) rams with Ki{dotless}vi{dotless}rci{dotless}k ewes. Th e average lambing rates of the GBM × K(F1), Bandi{dotless}rma-I and Bandi{dotless}rma-II genotype, and Ki{dotless}vi{dotless}rci{dotless}k ewes were 80.00%, 75.73%, 76.78%, and 83.72%, respectively. Th e diff erences in lambing rates between the genotypes were signifi cant (P < 0.01). Th e genotypes had a signifi cant eff ect on litter size at birth, but not on fecundity. Th e diff erences in lambs' survival rates between the genotypes were signifi cant (P < 0.05). Th e birth weight (BW), weaning weight (WW), and yearling live weight (YLW) of the lambs were 3.77 kg, 34.11 kg, and 43.71 kg for the GBM × K (F1); 3.74 kg, 32.98 kg, and 44.91 kg for the Bandi{dotless}rma-I; 3.73 kg, 33.18 kg, and 45.71 kg for the Bandi{dotless}rma-II; and 3.45 kg, 30.92 kg, and 42.22 kg for the Ki{dotless}vi{dotless}rci{dotless}k lambs. Th e results of this study showed that crossbreeding between the GBM and Ki{dotless}vi{dotless}rci{dotless}k breed did not signifi cantly increase lamb production. However, crossbred lambs did not have signifi cant survival problems when compared to native Ki{dotless}vi{dotless}rci{dotless}k lambs and had higher growth performance than purebred Ki{dotless}vi{dotless}rci{dotless}k lambs. © TÜBİTAK