The nutritive value of ensiled cassava leaves for young Mong Cai pigs fed high levels of protein

摘要

EightMongCaicastratemalepigsofmeaninitialweight12.3kgwerefeddietscontainingsugarpalm(Borassusflabellifer)syrupanddryfishsubstitutedornotwithensiledcassavaleaves(0and50%ofthedailyrationindrybasis)accordingtoachangeoverdesign.Thesilagewasmadefromsun-dried,wilted,choppedleavesandpetiolesinasinglebatchofcassavafoliageharvestedafter8weeksofregrowth.ThepHwas4.39,DM41.2%,NDF66.7%,N2.87%andcyanide120mg/kgindrybasis.Meanenvironmentaltemperaturewas34.5oCatmidday(12:00)duringthetrialinMay2001.Thepatternoffeedintakewascharacterizedbyaveryfastintakeofthesyrupandaslowingestionofsolidmaterials.Therewerenosilagerefusals.Voluntaryfeedintakewas36.6gDM/kgbodyweightperday.Theanimalswereinapositivebodyweightbalancewhentheywerefedtheensiledcassavaleaf-baseddietandaveraged140gbodyweightgainduringthetrial.Nutrientdigestibilityofthesilageaspredictedbydifference(n=8)wasDM77.7%,organicmatter79.8%,NDF82.5%and?N74.2%.ThereappearedtobeapositiveresponseinNretentionduetoincorporationofcassavaleafsilageinthediet,eitherrelatedtoNintake(improvementof10.6%)ortoNdigested(improvementof19.2%;P0.10).ItappearsthatyoungMongCaipigshaveahighcapacityfordigestionofcellwallmaterials,furthersupportedbylowerfaecalpHvalues(P0.05)andDMconcentration(P0.01)inthedietcontainingcassavaleafsilage(6.74and29.3%)ascomparedtothebasaldiet?(7.26and39.1%).ItisconcludedthattotalNdigestibilitybypigsofensiledcassavaleavescanbehighwhenthedietary?proteinsupplyishighandrichinsulphuraminoacids.