title: Soaking increases the efficacy of supplemental microbial phytase in a low-phosphorus corn-soybean meal diet for growing pigs.
abstract: Sixty-three crossbred barrows averaging 18.7 kg initial BW were used in a 6-wk study of the effects of soaking on the efficacy of supplemental microbial phytase (Natuphos, BASF) in a low-P corn-soybean meal diet. The basal corn-soybean meal diet contained .06% available P, .32% total P, and .55% Ca with no added inorganic P. The basal diet was supplemented with 0, 250, or 500 phytase units (PU)/kg of diet. The diet was fed dry or soaked (2 parts water:1 part diet and mixed for 2 h at 30 degrees C before feeding) in a 3 x 2 factorial arrangement. A positive control diet was supplemented with inorganic P and provided .23% available P, .48% total P, and .60% Ca. Pigs were individually penned and fed their respective diets to appetite in four equal meals daily. There were no soaking x phytase interactions (P > .1 to .6) for growth performance criteria. Daily gain and gain/feed ratio were increased (P < .01) by soaking and increased linearly (P < .01) by phytase. Daily feed intake was increased linearly (P < .01) by phytase. There were soaking x phytase quadratic interactions (P < .01) for apparent P absorption criteria because soaking the 250 PU/kg diet increased P absorption similar to that obtained with the 500 PU/kg diet fed dry. Apparent P absorption criteria were increased by soaking (P < .01) and were increased linearly (P < .001) and quadratically (P < .03) by phytase. Phytase reduced fecal P excretion 37 to 40% with dry feeding (P < .03) and 48 to 49% with soaking (P < .01).
authors.affiliation: Department of Animal Sciences, University of Missouri, Columbia 65211, USA.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: D W
authors.initials: DW
authors.lastname: Bollinger
authors.forename: D R
authors.initials: DR
authors.lastname: Ledoux
authors.forename: M R
authors.initials: MR
authors.lastname: Ellersieck
authors.forename: T L
authors.initials: TL
authors.lastname: Veum
mesh_terms: D010832:6-Phytase / Q000494:pharmacology*; D000135:Acid Phosphatase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D001234:Aspergillus niger / Q000201:enzymology; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002136:Calcium, Dietary / Q000378:metabolism / Q000494:pharmacology; D004032:Diet / Q000592:standards / Q000662:veterinary*; D005243:Feces / Q000737:chemistry; D005511:Food Handling / Q000379:methods*; D005527:Food, Fortified / Q000592:standards*; D008297:Male; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D016226:Phosphorus, Dietary / Q000378:metabolism / Q000494:pharmacology*; D013025:Glycine max / Q000592:standards*; D013552:Swine / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D003313:Zea mays / Q000592:standards*
chemical_list: D002136:Calcium, Dietary; D016226:Phosphorus, Dietary; D010758:Phosphorus; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D010832:6-Phytase; D002118:Calcium