Reproductive characteristics of the female grasscutter (Thryonomys swinderianus) and formulation of colony breeding strategies

摘要

Thereproductivecharacteristicsof34femalegrasscutters(ThryonomysSwinderianus)wereinvestigatedtoidentifycommonfeaturesthatcouldbeusedtoformulatebreedingstrategiesforgrasscuttersincaptivity.Thefemale'sabilitytomanifestanoestrouscycle,mate,conceive,deliverandweanitsyoungincaptivity,aswellaselicitsignsofsuccessfulmating,conceptionandimminentparturitionwereinvestigated.Thirty-one(91.2%)femalescyclederraticallyandmatedwithin2weeksofpairingwiththemale,irrespectiveoftheoestrousphase.Twenty-seven(87.1%)conceived,2abortedand25(92.6%)gavebirthafter148-157daysto2-6pupsperlitter,totalling98neonates,whichincluded9stillborn.Theremaining89pupsweresuccessfullyweanedat6weeksofage.Allmatedfemalespresentedpost-matingvulvalcongestion,whilethosethatbecamepregnantbledintermittentlyonthe32nd-38thdayaftermating,Eleven(44%)ofthepregnantfemalesadoptedthe'penguinposture'2-3daysbeforedelivery.Thevariationsamongthegrasscutterswithrespecttoalltheparametersinvestigated(excepttheoestrouscyclelength)werestatisticallynotsignificant;suggestingthatacommonbreedingprogrammecouldbeputinplaceformanagementofgrasscuttersincaptivity.Furthermore,sincemating,pregnancyandimminentparturitionwereaccompaniedbyvisiblecues,theycouldbeusedtoenhancethepracticalmanagementofthebreedingcolonies.Inconclusion,theoverallfindingsofthisstudyshowedthatthoughthegrasscuttersofthestudyarestillundergoingdomestication,theyexhibitfairlyuniformcharacteristicsandthereforetheformulationofacommonbreedingprogrammeispracticable.