A method to determine and factors that influence in vivo solubilization of phosphates in commercial Leghorn hens.
Experiments 1 and 2 were conducted to establish a technique for the recovery of dietary phosphates from commercial layer manure. Solutions of ethanol, 60% ethanol:40% water (vol/vol), 50% ethanol:50% water, 40% ethanol:60% water, and 100% water were tested to determine the efficacy of dicalcium phosphate recovery. Solutions containing 50% or greater ethanol were found to be most effective. Experiments 3 and 4 were conducted to determine factors that influence in vivo phosphate solubilization in commercial Leghorn hens. In Experiment 3, mono-dicalcium phosphate (Biofos), di-monocalcium phosphate (Dynafos), and tricalcium phosphate (Multifos) were fed to layers at 1.67 and 3.3 g hen/d levels. In vivo phosphate solubilization was higher (P < or = .05) for Biofos and Dynafos than for Multifos. Dietary phosphate level did not consistently influence in vivo phosphate solubilization in hens. In Experiment 4, a 3 x 2 x 2 factorial arrangement consisting of three types of phosphates (Biofos, Dynafos, and Multifos), two dietary levels of added P (.3 and .6%), and two levels of dietary Ca (.88 and 3.75%) were used. In vivo phosphate solubilization decreased as Ca level was increased. In vivo solubilization of Multifos was lower than Biofos or Dynafos at both dietary Ca levels tested. These results indicate that phosphate source and calcium level, but not phosphorus level, consistently influence in vivo solubilization of phosphates.
Rao
S K
SK
Department of Poultry Science, Alabama Agricultural Experiment Station, Auburn University 36849, USA.
Roland
D A
DA
Gordon
R W
RW
D000818:Animals; D002136:Calcium, Dietary / Q000494:pharmacology*; D002645:Chickens / Q000378:metabolism; D005260:Female; D008372:Manure / Q000032:analysis*; D010758:Phosphorus / Q000737:chemistry*; D016226:Phosphorus, Dietary / Q000008:administration & dosage / Q000302:isolation & purification* / Q000493:pharmacokinetics*; D012995:Solubility / Q000187:drug effects
D002136:Calcium, Dietary; D008372:Manure; D016226:Phosphorus, Dietary; D010758:Phosphorus