Performance of Broilers in Cages

Four tiers of cages were built with two cages per tier. Each cage measured 0.61×0.91 m. The top three tiers of cages were floored with rubber-covered nylon with holes of 0.95 cm. punched into the fabric every 0.64 cm. The bottom tier of cages was floored with 1.27×12.7 cm. plastic mesh. The droppings were allowed to fall through each cage tier and were collected under the bottom cages. Broilers were placed in the cages at a density of 3.7 dm.2 per broiler, and in two floor pens with rice hull litter at a density of 9.3 dm.2 per broiler. No significant differences were found for 8-week live body weights among the floor and cage reared broilers although the cage reared broilers were heavier than those grown on the floor. At 9 weeks of age, the caged broilers were heavier (P < 0.05) than broilers grown on the floor. The occurrence of breast blisters was higher (P < 0.05) on broilers grown on plastic mesh than on birds grown on litter or rubber-covered nylon. There was no difference among the cage and the floor reared broilers as to tibia breakage strength as measured by an Allo-Kramer shear press. No significant difference was found among the cage and floor reared broilers for feed efficiency. The floor reared broilers had fewer broken wings (P < 0.05) than cage reared broilers when processed in a commercial processing plant. After the broilers were processed, there was a greater (P < 0.05) number of downgrades due to breast blisters for broilers grown on plastic mesh and on the floor when compared with broilers grown on rubber-covered nylon. Floor reared broilers had a stronger humerus (P < 0.05) than did broilers reared in cages when measured by an Allo Kramer shear press.