Changes of blood Mg²⁺ and K⁺ after starvation during molting in laying hens

Either the fasting during natural molting or the starvation in induced molting would be a severe metabolic stress to laying hens. The metabolic stress during starvation and subsequent refeeding syndrome could lead to unbalance of mineral homeostasis, including Mg²⁺, K⁺ and P required by ATP synthesis. Since Mg²⁺ is a fundamental ion for normal metabolic processes and stress may not only increase in demands of Mg²⁺ but also produce consequence of Mg²⁺ deficiency, we investigated the changes of blood ionized and total ions related to starvation during molting in laying hens. We founded the significant decrease in blood Mg²⁺ and K⁺ accompanied by the changes of biochemical parameters relating to increased metabolic stress after molting. These results suggested that appropriate Mg²⁺ and K⁺ supplements to laying hens could have beneficial effects during molting and subsequent refeeding that could produce a severe hypomagnesemia and hypokalcemia.