Utilisation of different phosphorus sources in relation to their fluorine content for broilers and layers

Abstract

1. The relative utilisation of different phosphorus sources in relation to their fluorine (F) content was studied in commercial broilers (5 to 40 d) and White Leghorn layers (252 to 364 d). The phosphorus (P) sources tested were bonemeal (BM), low fluorine (LFRP) and high fluorine (HFRP) rock phosphates and a commercial mineral mixture (CMM). The P sources were incorporated in broiler and layer diets by replacing dicalcium phosphate (DCP) on a P basis. 2. The F contents of diets based on BM, LFRP, CMM and HFRP were 53, 365, 622 and 1383 mg/kg in the broiler experiment and 34, 242, 437 and 967 mg/kg in the layer experiment, respectively. F was not detected in DCP based diets. 3. In broilers, body weight gain, food intake, gain: food, P retention and serum inorganic P content on P sources (BM and LFRP) containing F up to 365 mg/kg diet were similar to those on DCP. Body weight gain, food intake, serum calcium and inorganic P contents and retention of P were depressed in groups fed on CMM and HFRP, which may have been due to the toxic effects of F (622 and 1383 mg/kg) present in diets based on these P sources. 4. Bone ash and its P content were not affected by feeding diets containing F up to 1383 mg/kg from various P sources. The amount of F deposited in tibia increased significantly with increases in dietary F concentration. 5. In layers, egg production and food intake were not affected by F up to 437 mg/kg in diets containing BM, LFRP or CMM as the sole source of supplemental P. Egg production and food intake were depressed significantly in layers given the diet containing 967 mg F/kg from HFRP. 6. Egg mass: food, egg weight, shell quality (shell thickness and shell weight) and serum calcium and inorganic P levels were not affected by F up to 967 mg/kg in diets containing different P sources. 7. It may be concluded that the performance of broilers and layers was not affected by feeding various P supplements with dietary levels of F up to 365 and 437 mg/kg, respectively. The reduced performance in broilers and layers observed with some of the P sources may have been due to poor availability of P and/or toxic effects of F (622 and 967 mg/kg, respectively).

Evaluation of an indigenous source of rock phosphate as a supplement for broiler chickens

“…The growth performance in the present study was maximized at 205 mg of F/kg and its presence in poultry feed above this limit leads to reduced growth performance. However, the safe level of F reported for broilers is not consistent (Weber et al, 1969;Suttie et al, 1984;Huyghebaert et al, 1988;Rama Rao and Reddy, 2001). The variations observed in the levels of F tolerance seem to be attributed to differences in the strain of birds, age, and types of rock phosphate used.…”

Safety assessment of antibiotic and probiotic feed additives for Gallus gallus domesticus

“…In short, tibias placed in porcelain cubicles were, dried at 100 °C for 24 h, cooled down for 30 min in a desiccator and then weighed. The tibia were then broken in half, defatted in petroleum for 48 h 115 , dried at 100 °C for 24 h and weighed. Lastly, the tibias were exposed to 600 °C for 24 h and the ash weighed.…”