Studies on the nutritive value for pigs of New Cocoyam (Xanthosoma sagittifolium); digestibility and nitrogen balance with different levels of ensiled leaves in a basal diet of sugar cane juice

摘要

Fourcrossbred(Yorkshire*Landrace*Pietran)castratedmalepigswithinitialweightof18.7±3.2kg(mean±SD)receivedvaryingproportionsofensiledNewCocoyam(Xanthosomasagittifolium)leaves(ENCL)andfreshsugarcanejuiceintwoconsecutiveperiodstoprovidedifferentlevelsofcrudeproteinintherangeof80to160g/kgofdietDM.Inperiod1,theplannedlevelswere:100,120,140and160g/kgDM;inperiod2thesewerechangedto90,110,130and150g/kgDM.Thefreshsugarcanejuicecontained20to21%totalsugars.TheCocoyamleavesweremaceratedinahigh-speedmechanicalchoppingmachineandensiledwithadditionof10%(freshbasis)ofsugarcanejuice.TheleafsilagewasofexcellentqualityasjudgedbysmellandcolourandtherapidfallinpH(4)within3daysofensilingtheleaves.RecordedproportionsofENCLindietDMwere0.49,0.56,0.67and0.76inperiod1and0.46,0.48,0.57and0.67inperiod2.DMintakewashighonalldiets(rangefrom32to53g/kgLW)andshowedacurvilinearresponsetoincreasingproportionsofENCLinthediet,withamaximumvalueat0.55ofENCLindietDM.ApparentdigestibilityofDMdecreased,andthatofcrudeproteinincreased,astheproportionofENCLinthedietDMincreased.NretentionincreasedwithincreasingproportionofENCLinthediet,therelationshipbeingcurvilinearwiththemaximumvalueat0.67ENCL,equivalentto130gcrudeproteinperkgofdietDM.