Estimated genetic trends for weaning weight in three Dorper lines with different selection criteria

Abstract

A study was undertakent o compare the effectivenesso f threed ifferent selections trategiesin increasingw eaning weight of a Dorper flock under natural conditions. Data were analysed by mixed model procedures. Direct selection for weaning weight under natural conditionsp roved to be effective.S electiono n breeds tandardsa nd selectiono n weaning weight under natural conditions combined with feedlot performancew ere not successfuli n increasingw earungw eight. Only direct selection for weaning weight under natural condrtions is therefore recommended. 

'n Studie is onderneemo m die doeltreffendheidv an drie verskillendes eleksieprosedurevsi r die verhoging van speenmassa in 'n Dorperkudde onder ekstensiewet oestande,t e ondersoek.G emengdem odelproseduresis gebruik vir die vergelyking van die verskillende seleksiemetodesD. irekte seleksiev tr speenmassao nder ekstensiewet oestandew as die effektiefste metode om speenmassate verhoog.S eleksieo p grond van rasstandaarden seleksiev ir speenmassao nder ekstensiewet oestandeg ekombineerm et voerkraalprestasiew as nie suksesvolm e. Slegsd irekte seleksiev ir speenmassao nder natuurlike toestande word dus aanbeveel.

Keywords: Dorper sheep, selection, mixed model procedures, weaning weight.