A research on some production characteristics and synthesis of Hsp70 in Denizli genotype hens at high temperatures

The aim of this study was to determine the synthesis of HSP70 (heat shock protein), some biochemical changes in blood and also some production characteristics in Denizli genotype hens at different ambient temperatures. In the research, 196 Denizli genotype hens were used as animal material. Chickens were divided into 4 groups at 20th week and kept at normal rearing conditions until 40 weeks of age. All hens were kept in individual cages up to age of 44 weeks and performance data were recorded. Chickens in control group (I. group) were kept at 22°C and heat exposure was 34, 37 and 40°C at the II, III and IVth experimental groups respectively between 40-44 weeks. Feed consumption, feed conversion ratio, egg production, egg weight, shell weight, shell thickness, shell ratio were decreased significantly by increasing ambient temperature. Blood samples were taken from jugular vein of 3 hens from each group at several times of heat exposure (0, 30, 60, 90, and 120. minutes) to determine hematocrit, T3 hormone, total cholesterol and HSP70 levels. Mononuclear blood cells were isolated and HSP70 concentrations were determined by Western Blot analysis with a monoclonal anti-Hsp70 antibody. By increasing ambient temperature, T3 hormone and hematocrit levels decreased whereas total cholesterol level was increased significantly (P<0.05). Thermal stress caused induction of HSP70 in all experimental groups except control group and level of HSP70 induction was both temperature and time-dependent. Individual variations were observed in synthesis of HSP70 at serum and mononuclear blood cells either. According to our results, HSP70 and T3 levels may be use as a selection criterion in breeding programmes for choosing the heat-tolerant individuals in Denizli genotype chickens.