Effects of flock size in boiler reared by f floor system and cage housing systems on performence, some stress parameters and bone mineralization

This study was planned as three experimental designs. In the first experimental design effect of flock size in floor housing system (FH) containing 15.000 (I), 25.000 (II) and 35.000 (III) broilers; in the second experimental design, effect of flock size in cage housing system (FH) containing 25.000 (IV), 40.000 (V) broilers on performance, some blood parameters, bone quality and pH level of Musculus pectoralis were examined. In the third experimental stage, effect of floor and cage housing systems containing 25.000 broilers capacity (group II and IV) on some blood parameters, bone quality and pH level of Musculus pectoralis were investigated. For this purpose, to determine the performance parameters, four different flocks from each capacity were simultaneously observed throughout summer and autumn seasons. A total of 20 broilers (10 males and 10 females) per different flock size, having stable live weight were selected on 32nd day of growing period. Broiler chickens were slaughtered via beheading method and the blood samples were collected into special tubes. The pH level of Musculus pectoralis pH measurement was measured within ten minutes later following the slaughter. Bones were eviscrated from meat and analyzed. The bone analyses were performed for 10 broilers (5 males and 5 females). Effect of flock size on the live weights of groups on 1st, 7th, 14th, 21st, 28th and on the day of slaughter was similar to per groups in both floor and cage housing systems (P>0.05). The mortality rate was lower in group I of FH (P≤0.01). Serum glucose and uric acid levels were high in group III of FH (P≤0.01). In addition, these parameters were higher in CH compare with FH (P≤0.01). Effect of flock size in CH on blood parameters were found insignificant (P>0.05). Serum total cholesterol, very-low-density lipoprotein (VLDL cholesterol), triglycerides, protein levels and enzyme activities of alkaline phosphatase and creatine kinase were statistically insignificant in the all research groups grown in FH and CH. (P>0.05). Physical properties of tibio-tarsal and femur bones were detected as similar in the all research groups (P>0.05). Flock size didn't significantly affect on bone quality in FH and CH (P>0.05). Bone ash ratio and mineral content (BMC) of tibio-tarsal bone were higher in FH than CH (P≤0.05). pH level of Musculus pectoralis was measured higher in group III of FH (P≤0.05). It was significantly increased in CH compare with FH (P≤0.01). Consequently, housing system and flock size in floor housing system have been found to significantly affect broiler performance and some welfare criteria. Key Words: Broiler, floor housing, cage housing, flock size, performance, welfare.