Why is a high dEB (dietary Electrolyte Balance of 250 mEq/kg) essential during hot summer months in Multan to prevent egg drop in brown layers?

Dietary Electrolyte Balance (dEB) is calculated using the milliequivalent equation of monovalent ions: $Na^+ + K^+ - Cl^-$. Under thermoneutral conditions, a dEB of 180 to 200 mEq/kg is standard. However, during the intense summer heatwaves in places like Multan and Sahiwal, hens suffer from severe heat stress and pant continuously. Excessive panting drives off carbon dioxide ($CO_2$) from the lungs, shifting the blood pH to alkaline (respiratory alkalosis). This alkaline shift prevents the ionization of calcium and depletes blood bicarbonate ($HCO_3^-$), which is the primary substrate needed for calcium carbonate ($CaCO_3$) shell matrix deposition. To counter this, nutritionists formulate a high dEB of 230 to 250 mEq/kg by replacing sodium chloride ($NaCl$) with sodium bicarbonate ($NaHCO_3$) and adding potassium chloride ($KCl$). This high dEB restores blood bicarbonate levels, stabilizes blood pH, and replenishes potassium ions lost in urine, preventing summer egg drops and thin-shelled, brittle brown eggs. Farmers can study electrolyte balance formulas in the Poultry Encyclopedia, buy feed-grade sodium bicarbonate on Poultry Plaza, check daily rate sheets on Poultry Rates, and trade on Murghi Mandi.