Nutritional and Metabolic Parameters in Laying Hens Fed with Different Levels of Calcium, Phosphorus and Phytases

The experiment was made on a Lohmann Brown classic hybrid from 32 to 42 weeks of age. There were used feeds containing various levels of Ca, P or phytase: NC1 and NC2 were commercial recipes, NC3 was supplemented with Phyzyme (500 TFU/kg), NC4 was supplemented with monosodium phosphate and NC5 with dicalcium phosphate according to nutrient requirements (NRC 1998). There was tested the possibility to use the phytase included at a level of 0.12%nPP to make available enough phytic phosphorous to satisfy the birds requirements. (0.25% nPP). When included at a level of 500 FTU/kg feed, Phyzyme hydrolyzed 75% of the phytic phosphorous contributing to a 0.30% aP in the feed. The biological value of the phosphorous in NC3 was of 91.19% and it did not influence either the eggs production or the eggs’ quality.