Performance traits of pigs fed sweet potato (Ipomoea batatas L.) foliage ad libitum and graded levels of protein

摘要

Agrowthtrialwasconductedwithatotalof40crossbredcastratemalesandfemalepigs(1:1)of29.3kgmeaninitialliveweightdistributedatrandomintofivetreatmentstostudytheeffectoffeedingadlibitumfreshfoliagefromsweetpotato(IpomoeabatatasL.)andgradedlevelsofprotein.From30to60kgtheanimalsreceived1.6kg/dayofafeedmix(20.7MJ/kg)containing25.1,23.7,17.0or13.2%protein.From60to90kgthepigswerefedwith1.8kg/dayofafeedmix(22.0MJ/g)containing23.0,20.6,14.5and9.9%protein.Inbothperiodstheanimalswerefedfreshsweetpotatofoliage(SPF)adlibitum.Inbothperiodsfeedintakedecreased(P0.05)withlessproteininthefeed.IntakeofSPFshowedanonlinearresponse(P0.10)withlowervaluesforintermediatelevelsofproteininthefeed.Therewasnotreatmenteffectoncarcasstraitsoftheanimals.Fortheoverallgrowthandfinishingperiods,themeandailygain(721g)andfeedconversion(2.40kgDM/kggain)werethebestwithacombinationof23.7/20.6%proteininthefeedsupplement(1.6/1.8kgperday).Itissuggestedthatitispossibletoobtaingoodperformancetraitsinpigsfedfreshsweetpotatofoliageadlibitum,providedafeedsupplementisgivenwhichcontainseither23.7and20.6%or17.0and14.5%proteinduringthegrowingandfinishingperiods,respectively.