Research Note: delay in sampling influences the profile of phytate in gizzard digesta and ileal digestibility of P in broilers

作者：H.X. Zhai; A.J. Cowieson; M. Lehmann; J.W. Wilson

来源：Poultry Science, 2020.

DOI：10.1016/j.psj.2020.06.049

• broiler
• digestibility
• phosphorus
• phytase
• phytate
• sampling

ABSTRACT

The objective of this study was to investigate the effect of different durations of time delay when sampling digesta from the gizzard and ileum of broilers on the degradation of myo-inositol hexakisphosphate (InsP6) and digestibility of phosphorus (P). There was 1 experimental diet with a supplemental phytase activity of 1,212 FYT/kg feed, which was provided to birds from day 13 to 18 post hatching. The diet was formulated to provide 6.6 g/kg Ca and 1.9 g/kg non-phytate P and fed to 24 cages of 6 birds. The 24 cages of birds were further randomly divided into 6 sub-groups of 4 cages from which the digesta samples in gizzard and ileum were collected at 0, 5, 10, or 20 min post-mortem. The results showed that the concentration of InsP6 decreased linearly (P = 0.002), InsP5 decreased quadratically (P = 0.038), and the summation of concentrations of P in InsP6-4 decreased linearly (P = 0.028) in the gizzard digesta with the increasing delay of sampling. In the ileum, the digestibility of phytate P tended to decrease linearly (P = 0.087) and the digestibility of total P decreased linearly (P = 0.026) with prolonged delay. In conclusion, delay in sampling could alter the measured profile of InsP esters in gizzard digesta probably due to a continued effect of supplemental phytase, while the ileal digestibility of total P could diminish. Therefore, standard sampling procedures should be implemented to minimize variance.