Non-phytin phosphorus requirements of commercial broilers and White Leghorn layers

Abstract

Experiments were conducted to determine the optimum requirements of non-phytin phosphorus (NPP) in commercial broilers and White Leghorn layers. Five levels of NPP (2.5, 3.0, 3.5, 4.0 and 4.5 g kg −1 diet) were tested to assess the NPP requirement of commercial broilers (3–30 days of age) fed maize–soya diets containing 10 g Ca kg −1. Each level of NPP was fed to quadruplicate groups of ten chicks each. Inclusion of graded levels of NPP significantly ( P < 0.01) influenced body weight gain, feed intake, tibia ash content, phosphorus content in serum, tibia ash and phosphorus retention. The predicted NPP requirements for body weight gain, P content in serum and tibia ash were 4.4, 4.48 and 4.1 g kg −1 diet, respectively. The NPP requirement for tibia ash was the highest (7.4 g kg −1 diet). Similarly, four levels of NPP (2.0, 2.5, 3.0 and 3.5 g kg −1 diet) were tested with maize–soya diets containing 35 g Ca kg −1 for White Leghorn layers (266–350 days of age). Each diet was tested on four groups of 12 hens in each. Egg production was not influenced by the variation in dietary NPP levels. The predicted NPP requirements for better egg weight and shell thickness were 2.6 and 2.4 g kg −1 diet, respectively, while for the serum inorganic P level the value was 3.42 g kg −1 diet. Therefore, it can be concluded that commercial broilers need about 4.4 g NPP kg −1 diet for better performance, whereas, White Leghorn layers need not more than 2.0 g NPP kg −1 diet for better egg production. However, layers require 2.6 g NPP kg −1 diet to produce eggs with better egg size and shell quality.