Effect of tannins on in vitro ruminal protein degradability of various tree forages

摘要

Thepresentstudieswereundertakentoevaluatetheeffectofhydrolysable(HT)andcondensedtannins(CT)(attherateof1mgper26mgcrudeprotein)onruminaldegradabilityofproteininlocallyavailabletreeforagesusinginvitrogasandammonia(NH3)productionmethod.nbsp;TheNH3-Ncontentafter24hincubationdecreasedwithaddedstarch.Gasproduction(24h)decreasedwithaddedHTandCTforallforagesexceptinAlbiziastipulata.Invitroruminaldisappearanceofnitrogen(IVRDN)calculatedbylinearregressioninuntreatedforageswasobservedtobehighest(63.2%)forGrewiaoptivaandlowest0%)forQuercusincana.Withaddedtannins,IVRDNvaluesvariedfrom4.8%(Acacialakoocha)to33.2%(Grewiaoptiva).AdditionofHTresultedinincreaseinIVRDNvaluesofAcaciacatechu,Albiziastipulata,Bauhiniavariegata,Dendrocalamushamiltonii,Ficusroxburghii,Leucaenaleucocephala,MorusalbaandQuercusincana.Comparatively,additionofHTwasmoreeffectiveinincreasingIVRDNthanCT.However,theIVRDNvalueswhencalculatedwithblankforNH3-NwithoutaddedHTdecreasedwithadditionofHTinalltheforagesamples.TreeforageswithaddedCTexhibitedaninconsistentresponseforIVRDNvalues.Thevaluesweremaximum(34.4%)forMorusalbaandminimum(6.5%)forQuercusincana.ThecorrelationbetweenIVRDNandfiberboundtanninswasnon-significantbutpositiveandsignificant(P0.02)betweenIVRDNandCPcontentoftheforages.Ahigherslopeintheregressionequationsobservedinpresenceoftanninsindicatedhigheruptakeofammoniabyruminalmicrobesandpossiblytoincreasedmicrobialproteinsynthesis.