Phytase effects on the efficiency of utilisation and blood concentrations of phosphorus and calcium in Pekin ducks

M. Rodehutscord, R. Hempel, P. Wendt
2006 British Poultry Science  
1. The objective was to study the effects of a supplementation of a 6-phytase 1 derived from the Peniophora lycii gene in the White Pekin duck. 2 2. In two balance studies, low-phosphorus (P) diets consisting mainly of maize, solvent 3 extracted soybean meal and solvent extracted sunflower meal were supplemented with 4 phytase up to concentrations of 1500 U/kg (Study 1) or 2000 U/kg (Study 2). Each diet 5 (phytase level) was fed to 8-10 individually penned ducks. The intake and excretion of
more » ... nd excretion of each 6 animal was measured for 5 consecutive d when ducks were in their third week of life. 7 Responses were described by nonlinear regression. 8 3. Although the basal diets from the two studies were similar in ingredient composition, 9 efficiencies of P utilisation (P accretion/P intake × 100) for the unsupplemented basal diets 10 were 39% in Study 1 and 30% in Study 2. Phytase supplementation significantly improved P 11 utilisation up to levels of about 55% in both studies. A plateau in P utilisation with an increase 12 in phytase supplementation was achieved in Study 2, but not in Study 1. The enzyme was 13 more efficient in Study 2 than in Study 1 at low rates of supplementation. Utilisation of 14 calcium (Ca) was significantly improved by phytase supplementation. Accretions of P and Ca 15 increased at a constant ratio. 16 4. In a 5-week growth study, diets with an intentionally marginal P level were used. Diets 17 were fed either unsupplemented or supplemented with 1000 or 10000 U/kg of phytase. Eight 18 pens of 10 sex-separated ducks each (4 pens per sex) were allocated to each dietary treatment. 19 5. Phytase significantly improved the growth of ducks of both sexes between d 1 and 21, but 20 not between d 22 and 35. Feed conversion rate was not affected by treatment. Blood serum 21 phosphate concentrations, but not calcium, were significantly increased by phytase 22 supplementation. Blood concentrations of creatinine, aspartate aminotransferase, and lactate 23 dehydrogenase remained unaffected while alanine aminotransferase was significantly reduced 24 by phytase supplementation. 25
doi:10.1080/00071660600732353 pmid:16787855 fatcat:orc26uw5nfakdkml6kk5qpsbay