Phytase in diets for broilers from 1 to 21 days housed in environments with different HVAC systems

Abstract

The experiment was conducted to evaluate effect of different inclusion levels of phytase in diets of broilers housed in environments with and without fogging on performance variables, incorporation of crude protein, calcium and phosphorus in carcass and contents of nitrogen, calcium and phosphorus in litter of birds during 1-21 days of age. Day-old chicks (640) were housed in cages uniformly distributed in two sheds, both equipped with ventilators and only one had nebulizers. The experimental design was completely randomized, factorial 5 x 2, five levels of phytase: 0, 1000, 2000, 3000 and 4000 FTU/kg diet, associated with two environments (shed with ventilation and fogging and shed with ventilation without fogging), four replicates and 16 birds per experimental unit. The birds were isonutritives based on corn and soybean meal, formulated to meet nutritional requirements, except available phosphorus, which was reduced in 20% of requirement diets. Room with ventilation and fogging improves weight gain, feasibility and productive efficiency, and increase incorporation of crude protein and phosphorus in carcass. Phytase supplementation to 4000 FTU/kg in diets with 20% reduction of available phosphorus increases weight gains, productive efficiency and incorporation of crude protein in carcass, and reduces levels of phosphorus in bed.