Livestock Studies 2001, Vol 41, Num, 2     (Pages: 039-050)

Some Important Production Traits of Central Anatolian Merino Sheep and possibilities of improving through selection of these traits II. Phenotypic and Genetic Parameters and Selection Index

Necmettin ÜNAL 1 ,Halil AKÇAPINAR 1

1 Ankara Üniversitesi Veteriner Fakültesi Zootekni Anabilim Dalı Dışkapı Ankara Viewed : 129 - Downloaded : 64 This study was carried out to investigate the possibilities of improving through selection of the some important production traits in Central Anatolian Merino Sheep kept at Konya Central Animal Research Institute. For this purpose, the present performance levels and the effects of some measurable environmental factors on the some production traits have been determined and the phenotypic and genetic parameters of these traits have been estimated and also a selection index has been constructed. In this part of the study, phenotypic and genetic parameters of production traits and constructing of a selection index have been considered.

The heritability values estimated by paternal half - sib correlation method were 0.18, 0.09, 0.15, 0.21 and 0.19 for birth weight, 45th, 75th, 105th and 180th day weights, respectively, and those for body weight after shearing and greasy wool production of hoggets were 0.42 and 0.25. Positive genetic correlation coefficients were found that lamb birth weight and lamb weight at different ages ranged from 0.11 to 0.64. Positive genetic correlation coefficients between hogget body weights after shearing and lamb weight at different ages were found ranging from 0.10 to 0.48 and greasy wool production ranging from 0.13 to 0.31. Genetic correlation coefficient between hogget body weights after shearing and greasy wool production was 0.65 (P<0.01). The selection index constructed using by weaning weight of lambs at 105 days (X1 ) and greasy wool production of hoggets (X2 ) was as follows: I = 0.212 X1 + 0.079 X2 . The estimated correlation coefficient between selection, index and aggregate breeding value was 0.45. The results of the study showed that there was no antogonism to genetic improvements through selection between production traits, and they were in the desired direction. Keywords : Sheep, heritability, genetic correlation, phenotypic correlation, selection index