Oregano, Rosemary and Vitamin E dietary supplementation in growing rabbits: effect on growth performance, carcass traits, bone development and meat chemical composition

The studyaimedtoevaluatetheeffectofdietarysupplementationwithdifferentnatural dditives(aqueousextracts)ontheperformanceofgrowingrabbits,thenutritional compositionandoxidativestabilityoftheirmeatandontheirhindlegbonetraits.For this experiment,200NewZealandWhiterabbitsweanedat30daysofagewererandomly allocatedintofivedietarygroups(n¼40 rabbits/group)until80daysofage,whenthey weresacrificed.Dietarygroupswere:S(standarddietwithnosupplementation),E (standarddietþ150ppmvitaminEpositivecontrol),O(standarddietþ0.2% oregano, Origanumvulgare, aqueousextract),R(standarddietþ0.2% rosemary, Rosmarinus offici- nalis, aqueousextract)andOR(standarddietþ0.1%oreganoextractþ0.1%rosemary extract).Anadditional50ppmvitaminEwasaddedtoeachdiet.RabbitsintheOand OR groupsshowedthehighestfinalliveweightandcarcassweight(Po0.001).Oregano supplementedanimalsalsohadthebestfeedconversionratio. Longissimusdorsi (LD) meat of EandRrabbitshadhigherproteincontentcomparedtoOandOR(Po0.001)whichhad a highermoisturecontentthanErabbits(Po0.005).Alldietarytreatmentsimprovedthe oxidativestabilityoftheLDmeatcomparedtotheSgroup.TreatmentsOandEwerethe most effectiveindelayingthelipidoxidationofLDmeat,followedbytheORandRdiets (Po0.005).Nosignificantdifferencesamonggroupsincompositionofthehindlegmeat (HL) wereobserved.TheOrabbitshadahigherboneweight(Po0.05)thanEanimalsand this differencewasmainlyascribabletofemurweight(Po0.01).Inconclusion,thestudy showedthatsupplementationwith0.2%oreganocanhaveapositiveeffectonproductive performanceandmeatqualityofrabbits.