Turkish Journal of Veterinary and Animal Sciences

Yazarlar: Mehmet Emin TEKİN

Konular:-

Anahtar Kelimeler:Mutton sheep breed,Crossbreeding,Performance test,Selection,Fixing new types

Özet: This study was conducted to evaluate the fattening performance of Hasmer (31.25% Hampshire Down (HD) + 31.25% German Black Headed Mutton (GBM) + 37.50% Merino), Hasak (31.25% HD + 31.25% GBM + 37.50% Akkaraman), Hasiv (31.25% HD + 31.25% GBM + 37.50% Awassi) and Linmer (50% Lincoln + 50% Merino) types. The research was performed between 1997 and 1999. Potential sires were selected based on their performance test results. The general linear model and Tukey's honestly significant difference test were used for statistical analyses. Year and genotype were introduced into the model as fixed factors and initial weight was introduced as a covariate along with year x genotype interaction. The year, genotype, year x genotype interaction and initial weight factors statistically affected the weight performance of ram lambs tested at 150 days. The live weights of lambs at 150 days were 40.7, 41.0, 44.0 and 41.7 kg in 1997; 42.6, 44.3, 46.1 and 41.1 kg in 1998; and 41.6, 42.8, 41.7 and 40.5 kg in 1999 for the Hasmer, Hasak, Hasiv and Linmer types, respectively. The differences between genotypes were statistically significant in all 3 years, and the differences between years were also significant in all genotypes, except for the Linmer group. The values obtained in 1998 were generally higher than those for 1997 and 1999. The superiority of genotypes over others varied year by year, but the Linmer registered the lowest value in all 3 years. The same statistical results were obtained for daily gains, the values being 258, 263, 302 and 272 g in 1997; 284, 307, 330 and 264 g in 1998; and 270, 287, 272 and 255 g in 1999 for the genotypes in the same order as above (P < 0.05 in all 3 years). The feed efficiencies were 4.38, 5.00, 5.03 and 4.22 kg in 1997 (P < 0.05); 4.28, 4.17, 4.14 and 4.06 kg in 1998 (P > 0.05); and 4.30, 4.28, 4.09 and 4.76 kg in 1999 (P < 0.05) for these genotypes, respectively. The differences between years were significant in all genotypes except for the Hasmer group. The 150-day live weight averages of the selected ram lambs were 42.1, 49.4, 51.9 and 46.0 kg in 1997; 50.3, 54.3, 51.5 and 44.9 kg in 1998; and 50.9, 53.8, 48.9 and 47.2 kg in 1999 (P < 0.05 in all 3 years). The relative superiority of the selected rams to others was 10-17.3% in 1997; 13.7-19.5% in 1998; and 14.0-22.0% in 1999 in all 4 genotypes. A moderate level of mean daily live weight gain was thus obtained in this study. However, the Linmer group had generally lower values. Although the Hasiv group had relatively higher values, the limited number of animals in this genotype could be considered a disadvantage for the selection procedure. We recommend that Hasmer and Hasak crossbreeds in particular be reared and improved; however, Hasiv and Linmer crossbreeds may be reared or culled. Performance test and selection studies should be continued.

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