Effects of season on potential nutritive value, methane production and condensed tannin content of Astragalus gombo

摘要

Inthiswork,wewereinterestedtoassesstheeffectofthecollectionseasononthenutritionalvalue,condensedtanninsandmethaneproductionbythesheepmicrobiotainthepresenceofAstragalusgombo,takenfromasemi-arideregioninAlgeria.Significantvariationswereobserved(p0.05)betweenthethreeseasonsinallthechemicalcomponentsofASGOexceptcondensedtanninboundproteins.Theplantstudiedhereinhascrudeproteinvalues#8203;#8203;(CP)widelydifferent.ThelowestratewasnotedinCPofASGOcollectedduringthesummerwithavalueof165,5g/kgDM,whilethehighestvalueisrecordedinASGOtakeninwinter(284.7g/kgDM).Lowtotalcondensedtanninscontentsarerecordedwithsmallvariationsfromoneseasontoanother.Overall,thetanninsvaryfrom19.0to24.2(g/kgDM).TheASGOcollectedduringwinterandsummeristhehighgasproducer,with68.5and70.3ml/gDM,respectively.ItisfollowedbythespringASGOwith50.8ml/kgDM.ASGObyitshighcrudeproteinandlowlignincontent,showsgoodpotentialnutrientforruminantsinaridareas,eitherbyfreegrazingonrangelands,orsupplementationofdietshighinfiber.ItcanbeseenthatdespitetheexceptionalfeaturesofadaptationofthenativefloraSaharanAfricatoharshclimaticconditionsofthedesertenvironment,itisclearthattheirsurvival,developmentandchemicalcompositionarehighlydependentonclimaticvariations.