Study On The Optimum Particle Size Of Soybean Meal To Weaned Piglets Pellets

Three experiments were to investigate grinding particle size of soybean meal on the feedquality，productivity，electricity consμmption per unit，the nutrition digestibility of diet inweaned piglets and digestibility in vitro to confirm optimum particle size．The first experiment was conducted to study the effects of grinding particle sizes ofsoybean meal on feed quality of piglet and product cost by long sampling and testing infeed stuff process corporation．Grounding soybean meal to particle sizes of450,540，683or827μm with1.0+1.0，1.5+1.5，1.5+2.0or2.0+2.0mm screen combination for pellets. Theexperiment sample were collected in ingress and exit of crusher and pellet mill，then labelingfor use. Recording production time，production,electrical power consμmption during grindprocessing and pellet processing for production efficiency and electricity consumption perunit calculation．The result of this experiment indicated：The homogeneity（CV）was increased linearlyas particle size increased and450μm or540μm supported the lowest CV（P <0.05）. Theparticle size addition increased（P <0.05）pellet hardness and pellet durability index(PDI).However，the proportion of fine was unaffected（P>0.05）. The electricity consμmptionper unit increased （P <0.05）and productivity decreased（P <0.05）in grind processing withthe increased of soybean meal particle size．A digestion experience was conducted to study effects of feed particle size onperformance and digestibility of nutrients in weaned piglets.Thirty twoDuroc×Landrace×Yorkshire weaned piglets with an average initial weight of （18.5±0.7）kgwere randomly allocated into8treatments with4replicates，and each replicate contained1piglet．Feed diet was based on soybean meals that was ground to particle sizes of432，505，637，717or805μm to compare the effects of feed particle size on performance anddigestibility of nutrients in weaned piglets．The result of this experiment indicated： The experiment showed that nutrients digestibility was increased as particle size increased．However，there no effect on pelletnutrients digestibility of DM(dry matter) and OM(organic matter）.The performance increasedand DM，nitrogen content decreased with the increased of soybean meal particle size.Available data clearly suggest that nutrients digestibility was higher in pellet feeds than inmash feeds，but feed gain ratio and daily gain was exact opposite when particle sizes of683or827μm．A experiment was conducted to study the effects of feed particle size on digestibility ofnutrients of feed differing in type(soybean meal，mash and pellet) with Enzyme by apepsin-trypsin in two-step vitro method and explore relationship between in vivo digestibilityand in vitro digestibility．Soybean meals that was ground to particle sizes of450、540、683、827、1241μm and mash diets and pellted diets that was based on soybean meals to study on effects of feedparticle size on digestibility of nutrients and relationship between in vivo digestibility and invitro digestibility．The result of this experiment indicated：The dry matter (DM)，crude protein (CP)digestibility of soybean meals linearly increased （P>0.05） as particlesizedecreased．However，digestibility of mash was unaffected（P>0.05） by particlesizes．The CP digestibility of pellet increased（P>0.05）as particle size decreased，and it wasremarkably highe（rP <0.05）that was grinded to450μm than others．The DM digestibility ofpellet was highest（P <0.05）as particle sizes of540μm．Digestibility in vivo linearlyincreased（P <0.01）as digestibility in vitro increased．In conclusion：The particle size reduction improved feed quality，increased electricityconsμmption per unit and decreased productivity．However，particle size of soybean meal hadno effect in pellet processing；The performance increased and dry matter，nitrogen content decreasedwith the increased of soybean meal particle size；The particle size had no effect in feed digestibility invitro and digestibility of soybean meals linearly increased as particle size decreased．...