FIELD EVALUATI ON OF A SPRINKLING SYSTEM FOR COOLING COMMERCIAL LAYI NG HENS IN IOWA

Abstract

An economical, lowpressure (276 kPa, 40 psi) sprinkling system was tested for its efficacy of cooling laying hensin a commercial highrise layer house [14 130 m (46 426 ft)] in Iowa. The sprinklers, rated at 2.1 mL/s (2 gal/h) each,were equally spaced at 3 m (10 ft) apart and 2.4 m (8 ft) above the floor in each cage aisle of the layer house. They werecontrolled to operate 10 s every 10 min when the inside temperature exceeded 32_C (90_F). The system was shown to improveegg production by 2.6% overall and 5.6% for the top deck (P < 0.01). There was no sign of sprinkling damage to eggshellintegrity. Autocorrelation analysis has the potential to quantify the impact of heat stress history on subsequent egg productionresponse of the hen. Work is needed to optimize the layout of the sprinklers for uniform water distribution and waterapplication rate as a function of environmental conditions.