Effect Of Bentonite And Attapulgite On The Efifciency Of Slow-release Of Urea Of Starea

Thanks to the advantage of slowing the speed of urea-releasing and synchronizing rumen Navailable with carbohydrate fermentation, Starea is widely used as Non-protein Nitrogen inruminant nutrition. Used mainly as binder, bentonite and attapulgite have relatively strongadsorptivity, so this research emphasized the effect of using them on the efficiency of slow-releaseof urea of Starea, and had3main experiments: effect of bentonite and attapulgite on the efficiencyof slow-release of Starea, effect of different types and grades of purity of bentonite on theefficiency of slow-release of Starea and evaluating the quality of Starea manufactured in theprevious experiments. This study aims to provide the scientific basis for the use of bentonite andattapulgite in Starea so as to produce high quality Starea.Experiment1using the method of in vitro thermostatic urease enzymatic hydrolysis studiedthe effect of bentonite and attapulgite on the efficiency of slow-release of urea of Starea whichwere made by DSE-25twin-screw extrusion machine in the same specifications. A3×3factorialexperiment design was adopted and the two factors were3types of binder and3levels of bindersadded.3types of binder were Na-bentonite, Ca-bentonite and attapulgite.3levels of bindersadded were5%,10%,15%. Results indicated that: the effect of different types of binder ongelatinization degrees had no significant difference （P>0.05）,while the effect of different levels ofbinder on gelatinization degrees had significant difference （P<0.01）; the effect of different types ofbinder on the efficiency of slow-release of urea of starea had no significant （P>0.05）,while theeffect of different levels of binder on the efficiency of slow-release of urea of starea hadsignificant difference （P<0.01）.The conclusion were that utilizing10%binder in Staera had thebest effect on the efficiency of slow-release of urea of Starea, and the type of binder had onsignificant effect.Experiment2using the same method as experiment1studied the effect of different types andgrades of purity of bentonite on the efficiency of slow-release of urea of Starea. The meas ofmanufacturing starea was also same to experiment1. A2×2×3factorial experiment design wasadopted and the3factors were2types and2grades of purity of bentonite and3levels of bentonitadded.2types were Na-bentonite and Ca-bentonite,2grades of purity were70%and90%, and3levels were5%,10%,15%. Results indicated that: the effect of different types and grades of purityof bentonite on gelatinization degrees had no significant difference （P>0.05）, while the effect ofdifferent levels on gelatinization degrees had significant difference （P<0.01）; the effect of differenttypes and grades of purity of bentonite on the efficiency of slow-release of urea of starea had nosignificant （P>0.05）, while the effect of different levels on the efficiency of slow-release of urea ofstarea had significant difference （P<0.01）. The conclusion were that utilizing10%binder in Staerahad the best effect on the efficiency of slow-release of urea of Starea, and the type and the grades of purity of binder had on significant effect.Experiment3using the method of in vitro cumulative gas production studied the effectof the4kinds starea selected by their relatively slow-release speed based on previous experiments on themetabolism of artificial rumen by some fermented parameters, dry matter disappearance（DMD）and48total gas production（TDP）. A completely randomized design was adopted and the dietswere formulated to be iso-energy and iso-nitrogen. Results indicated that: at4different fermentingtimes the effect of4kinds of Starea on pH, concentrations of NH₃-N and microorganism protein,DMD and TDP had no significant difference（P>0.05）. The conclusion were that utilizing10%and5%of binder in Starea had no difference on rumen fermentation.