Effects of dietary Ca/P ratio, P level and microbial phytase supplementation on nutrient digestibilities in growing pigs: precaecal, post-ileal and total tract disappearances of OM, P and Ca
M. Seynaeve et al., Effects of dietary Ca/P ratio, P level and microbial phytase supplementation on nutrient digestibilities in growing pigs: precaecal, post-ileal and total tract disappearances of OM, P and Ca, J ANIM PHYS, 83(1), 2000, pp. 36-48
Citations number
55
Categorie Soggetti
Veterinary Medicine/Animal Health
Journal title
JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION-ZEITSCHRIFT FUR TIERPHYSIOLOGIE TIERERNAHRUNG UND FUTTERMITTELKUNDE
Eight female pigs (26-61 kg) provided with a simple T-cannula about 10 cm p
roximal to the ileo-caecal valve, were used in two experiments to investiga
te the effects of Ca/P ratio, P level and supplementation with phytase (500
FTU/kg) on precaecal, post-ileal and total tract disappearances of organic
matter (OM), phosphorus (P) and calcium (Ca). In experiment 1, two Ca/P ra
tios and two P levels were tested according to a 2 x 2 factorial arrangemen
t within a Latin square design. In experiment 2, the diets of experiment I
were supplemented with phytase (500 FTU/kg). There was a substantial absorp
tion of OM, P and Ca in the post-ileal tract for all diets. Precaecal and t
otal tract disappearances of OM were reduced by phytase addition (-4.1 and
-0.8%, respectively). Supplementation with phytase resulted in an improveme
nt of total tract and post-ileal P disappearances by 10.3 and 12.1%, respec
tively, without affecting precaecal P disappearance. Addition of feed phosp
hate resulted in a higher precaecal disappearance of P (+10.8%), resulting
in a higher total tract disappearance of P (+5.9%). Addition of limestone h
ad little effect on disappearances of OM, P and Ca, bur reduced activity of
supplemental phytase and had a negative influence on growth performance. P
recaecal, post-ileal and total tract Ca disappearances were hardly affected
by the examined dietary factors. The results might indicate that P from fe
ed phosphate is absorbed primarily prececally and that P From phytate, libe
rated by microbial phytases, is dominantly absorbed post-illeally.