BIOLOGICAL AVAILABILITY OF PHOSPHORUS IN DEFLUORINATED PHOSPHATES WITH DIFFERENT PHOSPHORUS SOLUBILITIES IN NEUTRAL AMMONIUM CITRATE FOR CHICKS AND PIGS
Rd. Coffey et al., BIOLOGICAL AVAILABILITY OF PHOSPHORUS IN DEFLUORINATED PHOSPHATES WITH DIFFERENT PHOSPHORUS SOLUBILITIES IN NEUTRAL AMMONIUM CITRATE FOR CHICKS AND PIGS, Journal of animal science, 72(10), 1994, pp. 2653-2660
Two experiments were conducted to assess the bioavailability of P in f
ive sources of defluorinated phosphate (DFP) that differed in P solubi
lity in neutral ammonium citrate (NAC). In Exp. 1, 384 2-d-old male ch
icks were fed a corn-cornstarch-dextrose-soybean meal basal diet (1.22
% lysine, 1.00% Ca, .45% P) or the basal with .05 or .10% P from monos
odium phosphate (MSP), or .10% P from DFP with 60, 70, 75, 82, or 91%
NAC soluble P. Each diet was fed to six pen replicates of eight chicks
per pen for 14 d (58 to 402 g). Growth rate, feed/gain, and tibia bre
aking strength and ash concentration were improved (P < .001) by P sup
plementation, regardless of P source. Tibia strength and ash were regr
essed on P intake, and slope-ratios were calculated to assess the rela
tive bioavailability of P in the DFP sources. The bioavailabilities of
P in the 60, 70, 75, 82, and 91% NAC soluble DFP sources, relative to
MSP (given a value of 100), were 81, 75, 84, 84, and 98%, respectivel
y (linear, P < .08): In Exp. 2, 35 individually penned pigs were fed a
corn-soybean meal basal diet (.95% lysine, .75% Ca, .33% P) or the ba
sal with .15% P from MSP or from the five DFP sources. Each diet was f
ed to five pigs for 33 d (15.0 to 35.9 kg). Growth rate, feed/gain, an
d breaking strength of the metacarpals, metatarsals, and femurs were i
mproved (P < .001) by MSP and DFP. The bioavailabilities of P in the 6
0, 70, 75, 82, and 91% NAC soluble DFP sources were 90, 80, 82, 90, an
d 87%, respectively (P > .25). From these results, a slight positive r
elationship exists between the NAC solubility of P and the bioavailabi
lity of P in DFP for chicks, but not for pigs.