Effects of administration of four different doses of Escherichia coli phytase on femur properties of 16-week-old turkeys

Effect of supplemental phytase and xylanase in wheat-based diets on prececal phosphorus digestibility and phytate degradation in young turkeys

This study aimed to investigate the effect of phytase and a combination of phytase and xylanase on the prececal phosphorus digestibility (pcdP) of wheat-based diets in turkeys. A low-P basal diet (BD) based on cornstarch and soybean meal, and 2 diets containing 43% of different wheat genotypes (genotype diets GD₆ or GD₇) were fed to turkeys from 20 to 27 d of age. Diets were fed either without enzyme supplementation or supplemented with phytase (500 FTU/kg) or a combination of phytase and xylanase (16,000 BXU/kg). At 27 d of age, digesta were sampled from the lower ileum of animals to determine pcdP and pc myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP₆) disappearance, and to analyze the concentrations of lower inositol phosphate isomers. Similar pcdP was observed in non-supplemented BD and GD (∼36%). Phytase alone increased the pcdP in all diets by 8 to 12%, but a beneficial effect of xylanase was found only for BD. Similar results were found for pc InsP₆ disappearance, although xylanase addition compared to phytase alone decreased pc InsP₆ disappearance in GD₇ compared to phytase alone. Animals fed GD₇ performed better than those fed GD₆; however, these differences could not be linked to the pcdP. The pattern of lower inositol phosphates in digesta also changed with enzyme supplementation, resulting in lower proportions of InsP₅ and higher proportions of InsP₄. Phytase alone decreased Ins(1,2,3,4,6)P₅ but increased D-Ins(1,2,3,4,5)P₅ and D-Ins(1,2,5,6)P₄ concentrations. An additional increase in D-Ins(1,2,3,4,5)P₅ and D-Ins(1,2,5,6)P₄ concentrations was achieved with xylanase, although for the former isomer, this was observed only with GD. These results indicate that enzyme supplementation alters the pc degradation of InsP₆, and that combining both enzymes had a minor additional effect on the pcdP from wheat-based diets when compared to phytase alone.

Dose-dependent effects of probiotic supplementation on bone characteristics and mineralisation in meat-type female turkeys

To evaluate the influence of the probiotic on bone tissue in female turkeys, bone mineral density and geometrical and mechanical properties of the tibia and femur were determined in a dose-dependent manner (107 colony-forming units (cfu)/g, 108 cfu/g, 109 cfu/g). No effect of the treatments on bone mass and wall thickness of femur was observed, but the administration of the probiotic resulted in the elongation and the reduction of both strengths. The increase in the cross-sectional area of the femur was dose-dependent. Probiotic supplementation at a concentration of 108 cfu/g resulted in a reduction in ultimate strength, but at a concentration of 107 cfu/g, it resulted in the enhancement of the maximum elastic strength of the tibia compared with other groups. The influence of the probiotic administration on tibia geometry was dose-dependent. No effect of the treatments on the relative bone weight and the ratio of mass to length was observed. In general, the influence of the probiotic administration on bone mineral density, bone mineral concentration, bone tissue density, and bone ash, calcium and phosphorus concentrations was dose-dependent. The investigated properties of long bones in female turkeys are affected through probiotic-supplemented diets in a dose-dependent manner. However, on the basis of densitometry, it seems that the administration of the probiotic at a higher concentration of cells is more beneficial for bone development in turkeys.