An Estimation of the Genetic, Phenotypic and Environmental Trends for as Related to Growth Traits, and Pelt Score in Karakul Sheep

Hasani, Saeed; Emam Verdi, Omid; Zerehdaran, Saeed; Ahani Azari, Mojtaba; Farhangfar, Homayoun

An Estimation of the Genetic, Phenotypic and Environmental Trends for as Related to Growth Traits, and Pelt Score in Karakul Sheep

Authors

Saeed Hasani

Omid Emam Verdi

Saeed Zerehdaran

Mojtaba Ahani Azari

Homayoun Farhangfar

Abstract

Thriteen thousand, seven hundred and fifty two (13752) records on growth tarits (birth weight, 1, 3, 6, 9 and 12 month weights) as well as pelt scores, collected during 1996-2002 as Karakul Sheep Breeding Station, Sarakhs, Iran were employed in this study. Best Liner Unbiased Prediction (BLUP) of breeding values, genetic and phenotypic trends of the traits were estimated as the regression of average predicted breeding values and phenotypic values over birth year, respectively. Environmental trends were assessed as the difference between phenotypic and genetic trends. Estimates of genetic trends were found as: 0.013±0.001, 0.034±0.004, 0.119±0.010, 0.087±0.013, 0.127±0.018, 0.119±0.019 kg/year and 0.257±0.019 score/year, respectively. Phenotypic trend for the above traits were -0.151±0.005, -0.116±0.023, 0.268±0.035, 0.185±0.052, 0.443±0.065, 0.559±0.078 kg/year and -0.235±0.048 score/year, respectively. Environmental trend for the same traits were respectively estimated as -0.164±0.004, -0.151±0.019, 0.149±0.025, 0.098±0.039, 0.316±0.047, 0.440±0.059 kg/year, and -0.492±0.029 score/year.

Keywords

Economic traits

Genetic change

selection

sheep