Amin Allahverdi,Adel Feizi, Mohammad Ashrafzadeh Takhtfooladi and Saeed Shabani
High environmental temperature can influence the acid-base balance in poultry. Among sodium (Na) and potassium (K), the monovalent ions are the key minerals involved in acid-base balance of the body fluids. The aim of this study was to determine the effect of high environmental temperature on plasma Na and K concentration in commercial layers. In this study two hundred laying hens (Hy-Line) 40 weeks age were divided randomly into two groups, each group contains 100 hens (control group and purpose group). Every 4 hens were kept in a cage with water and same basal and supplemental diets ad libitum. During the experiments hen houses received 16h of light per day. Hen house’s temperature was measured four times a day (06.00, 12.00, 18.00 and 24.00). The average minimum and maximum daily temperature respectively were 22°C and 36°C that recorded in hot season of year. The length of the experiment was 90 days. The control group was kept in the same experimental situation and average minimum and maximum temperature were 20°C and 26°C respectively. Blood samples were taken weekly, concentration of plasma Na and K measured by the flame photometer. Differences between groups were evaluated by t-tests. P-values <0.05 were considered statistically significant. Average Na concentration in purpose and control groups was 140 mmol/L and 123 mmol/L respectively. Average k concentration in purpose and control groups was 6.53 mmol/L and 8.61 mmol/L respectively. Results of present study showed significant (P = 0.001) changes in Na and K plasma concentrations during heat stress period. Our results can be recommended that dietary minerals supplementation be helpful for maximum performance in laying hen under hot climate conditions, especially during the summer months when birds are most susceptible to heat stress.
