EUROPEAN POULTRY SCIENCE, cilt.78, 2014 (SCI-Expanded)
The aim of this study was to determine the effects of rosehip fruit (Rosa canina) which is used as a source of vitamin C in broilers under cold stress on performance, some blood parameters (total antioxidant capacity, total antioxidant status level, paraoxinase enzyme activity), rectal temperature and carcass parameters. In total, 240 one day old male broiler chicks (Ross 308) were used in the trial. Four treatment groups were formed at the beginning of the trial each including three subgroups (n = 20) with similar live weights. In order to prepare cold stress conditions, starting from the third week and onwards, the temperature of the trial room was set to 14 degrees C for 12 hours and to 24 degrees C for the following 12 hours. The main ration containing corn and soybean meal was used as control and other rations with 10, 20, 30 g/kg doses of rosehip supplementation formed the treatment groups. The highest live weight was measured in the groups supplemented with 10 and 20 g/kg rosehip. Increased dose of rosehip (30 g/kg) was observed to significantly decreased live weight (P < 0.01). The highest rectal temperatures (41.1 degrees C and 41.0 degrees C, respectively) before cold stress were recorded in the groups supplemented with 10 and 20 g/kg rosehip while the lowest temperature after cold stress was recorded in the group supplemented with 30 g/kg rosehip (P < 0.05). The use of rosehip in the rations of cold-stressed broilers significantly affected the levels of T3 hormone, Na, cholesterol, RBC, HCT and HGB (P < 0.05). T3 hormone level significantly increased in the group with 20 g/kg rosehip supplementation. Cholesterol level significantly decreased in the groups supplemented with 10 and 20 g/kg rosehip compared to the group with 30 g/kg rosehip supplementation. Similarly, the levels of blood hematocrit parameters RBC, HCT and HGB were detected to be lower in the groups with rosehip supplementation (P < 0.05). With respect to color parameters, a*, b* (P < 0.001), H and C values of thigh meat and L* (P < 0.001), b* (P < 0.001), H and C values of breast meat were significantly affected by the treatments (P < 0.05). The findings of the current study revealed that oxidative stress in broilers induced by cold weather conditions can be reduced by use of rosehip in broiler rations.