background: old laying hens are more prone to dietary calcium (ca) and phosphorus (p) deficiencies as  they absorb ca and p less efficiently than younger hens. objectives: in a 2×2 factorial design, the influence of diets with two levels of available phosphorus (ap) and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2nd producti...

abstract the increasing of yield per unit area is usually achievable by improving the soil fertility level through using (chemical) fertilizers. the purpose of the present research was to evaluate the 6 extraction methods including olsen, morgan, ammonium bicarbonate-dtpa, colwel, bray and mehlich 3 in order to specify a suitable extractant(s) for estimating available phosphorus through using 2...

Background: Old laying hens are more prone to dietary calcium (Ca) and phosphorus (P) deficiencies as  they absorb Ca and P less efficiently than younger hens. OBJECTIVES: In a 2×2 factorial design, the influence of diets with two levels of available phosphorus (AP) and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2nd producti...

Unwanted microbial interference in samples used for biological assays of P availability has routinely been eliminated by autoclaving samples before inoculation with algae. Twenty-three soils were selected to evaluate the relationship between algal growth in P-deficient solutions containing small quantities of soil and the level of P determined by a variety of tests used to evaluate P availabili...