The effect of some factors on growth performance of Lori Bakhtiari lambs

摘要

ThepresentstudywasconductedtoanalyzetheeffectofsexandtypeofbirthongrowthcurveofLoriBakhtiarilambs.Thedatawerecollectedfrom3081maleandfemalelambsfromthebirthtoone-yearold.Inordertoestimatethegrowthparameters,bodyweightoflambswasfittedtoGompertzmodel.Malelambswereheavierthanfemalesoverthegrowthperiod(P0.05).Moreover,single-bornlambswereheavierthantwinones(P0.05).Growthparametersweresignificantlyaffectedbysex(P0.05).Therewasasignificantdifferenceamongthegrowthparametersfortypeofbirth,excepttheweightatmaturity(A)andweightatinflectionpoint(y)(P0.05).Inaddition,single-bornlambshadhigherK(rateofmaturity)thantwinones(P0.05).Malelambshadahighergrowthratethanthefemaleones(P0.05).Theresultsshowedmalelambshadafastergrowthandreachedlargermatureweightthanfemalealso,sexandtypeofbirtharethemainfactoraffectingonthegrowthofLoriBakhtiarilambs.