A comparison of bone strengths from broilers reared under various conditions in coops and floor pens.

A series of four trials was conducted to compare the influence of several design variables on the strength of bones from coop and floor-reared broilers. So that the activity of coop-reared broilers would increase, a fan system intermittently forced air up through the bottom of the coops. Because the broilers became accustomed to the intermittent force of air, the induced extra activity decreased after the first 7 days of fan use. No differences in bone strength were observed in broilers reared in the control and fan-treated coops. Broilers reared in floor pens with a screen covering placed at a height equal to the height of the coops (29 cm) had significantly (P less than .01) weaker wing bones than floor-reared controls. When the height of the screen was increased to 46 cm, no significant difference was observed in the strength of wing bones of broilers in the screened and control pens.