The effect of propolis on HSP27 and HSP70 gene expression profile and some physiological stress parameters in goat kids in different seasons

Objective: This study, it was aimed to determine the effect of propolis at the cellular level against temperature stress and physiological response to temperature stress by comparing HSP27 and HSP70 gene expressions and some stress parameters in different seasons in goat kids with and without propolis treatment. Material and Methods: After receiving colostrum, 20 goat kids at an average age of one week were divided into two groups the control group which was given only mother's milk, and the experimental group which was given mother's milk + 0.4 cc propolis supplementation. In the feeding of the goat kids, milk from all mothers was mixed homogeneously and given to t twice a day at body temperature by the bottle. The daily amount of milk given was adjusted to correspond to 10% of the live weight of the goat kid. In the second week of the experiment, 50 g of concentrate feed was given to the goat kids and the amount of feed was increased in parallel with the live weight gain of the goat kids after weaning. In all groups, the live weights of the kids, rectal temperature measurements, pulse rate, and respiratory rate of the animals were determined twice a day, in the morning and the evening, for a total of 16 weeks. After the beginning of the experiment, blood samples were taken and analyzed twice a month in April and July, 4 times in total, and the expression levels of HSP27 and HSP70 genes of the experimental and control groups were determined by qRT-PCR and the fold changes (2-ΔΔCT) were calculated by comparing the Ct values obtained with the gene expressions between the groups. At the end of the study, all data were collected and statistically analysed and the results were interpreted. Results: During the experiment, there was no significant difference between the two groups in terms of feed consumption, but when the intra-group averages were analyzed, it was found that the live weight gain of the experimental group was higher than that of the control group despite the equal amount of feed consumption (average live weight gain was 9.49 kg in the control group and 12.24 kg in the experimental group during the experiment). When the rectal temperature values between the groups were compared, it was observed that the rectal temperature values of the experimental group were higher than the control group. The pulse and respiration rates of the experimental group were lower than the control group. When the values normalised according to actin were examined, the expression level of the HSP70 gene in the control group increased with the increase in temperature, but the HSP70 expression levels of the experimental group remained constant at high temperatures. While the HSP27 gene was expressed less in the control group compared to the experimental group in the spring, the HSP27 gene was expressed less in the experimental group compared to the control group in July when the temperature increased. Conclusion: In the weeks when the air temperature started to increase, body weight gain was observed in the experimental group and although rectal temperature values were higher in the experimental group, pulse and respiratory rate of the experimental group were lower than the control group. Propolis increased the body temperature of the goat kids but positively affected the response of the goat kids to heat stress. Propolis, stabilised HSP70 values and ensured that the expression values in the hot summer months were at the same level as the spring expression values. HSP27 expressions were higher in the spring period in the experimental group compared to the control but were less expressed in the summer period compared to the control. In line with these results, we can say that propolis positively affects the response of goat kids to heat stress, prevents the decrease in appetite levels observed in animals in hot weather, and especially positively affects feed utilization. Keywords:Goat Kid, Propolis, Heat Stress, HSP, Gene Expression