Effect of time of initiation of feeding after hatching and influence of dietary lysine supplementation on productivity and carcass characteristics of Ross 308 broiler chickens in South Africa

摘要

nbsp;Anexperimentwasconductedtoevaluatetheeffectoftimeofinitiationoffeedingafterhatchingandinfluenceofdietarylysinesupplementationduringrealimentationonproductivity,carcasscharacteristicsandmortalityofRoss308broilerchickens.Thestudywasafactorialarrangementinacompleterandomizeddesign.ThreehundredandsixtyunsexeddayoldRoss308broilerchickswithaninitialweightof30±2gperbirdwereassignedto12treatmentsina4(timesofinitiationoffeeding)x3(lysinesupplementallevels)factorialarrangementwiththreereplications,eachhavingtenbirds.Theexperimentaldietswereisocaloricandisonitrogenousbutwithdifferentlysinesupplementationlevels.Lysinesupplementationstartedthreedaysafterhatching.nbsp;Lysinesupplementationduringrealimentationonlyreducedthenumberofdaysof#8216;catch-up#8217;irrespectiveoftimeofinitiationoffeedingafterhatchingandthereafterhadnoeffect(P0.05)onproductivityandmortalityofthebirds.However,thebirds#8216;caught-up#8217;withineightdaysofrealimentation.Thiscompensatorygrowthcouldbeexplainedintermsofhigherintakes.Generally,morethan50%ofthebirdsdiedbetween1and3daysofagewheninitiationoffeedingafterhatchingwasabove36hours.nbsp;Itisconcludedthattimeofinitiationoffeedingabove36hoursafterhatchingisnotdesirable,mainlybecauseofitsnegativeeffectonmortality.Beneficialeffectoflysinesupplementationinthedietofbroilerchickenssubjectedtodelayedinitiationoffeedingafterhatchingcouldbeexploitedinacceleratingtherateof#8216;catch-up#8217;growthresponse.