Field evaluation of a sprinkling system for cooling commercial laying hensin Iowa

An economical, low-pressure (276 kPa, 40 psi) sprinkling system was tested for its efficacy, of cooling laying hens in a commercial high-rise layer ho use [14 x 130 m (46 x 426ft)] in Iowa. The sprinklers, rated at 2.1 mL/s (2 gal/h) each, were equally spaced at 3 m (10ft) apart and 2.4 m (8ft) above the floor in each cage aisle of the layer house. They were controlled to o perate 10 s every 10 min when the inside temperature exceeded 32 degreesC ( 90 degreesF). The system was shown to improve egg production by 2.6% overal l and 5.6% for the top deck (P < 0.01). There was no sign of sprinkling dam age to eggshell integrity. Autocorrelation analysis has the potential to qu antify the impact of heat stress history on subsequent egg production respo nse of the hen. Work is needed to optimize the layout of the sprinklers for uniform water distribution and water application rate as a function of env ironmental conditions.