Dietary electrolyte balance for broiler chickens exposed to thermoneutral or heat-stress environments

• Published in: Poultry science 2003-03, Vol.82 (3), p.428-435
• Main Authors: Borges, S A, Fischer da Silva, A V, Ariki, J, Hooge, D M, Cummings, K R
• Format: Article
• Language: English
• Subjects: Ammonium Chloride - administration & dosage; Animals; Bicarbonates - administration & dosage; Chickens - physiology; Chlorides - administration & dosage; Diet; Eating; Electrolytes - administration & dosage; Energy Metabolism; Glycine max; Hot Temperature; Humidity; Hydrogen-Ion Concentration; Male; Potassium Compounds - administration & dosage; Potassium, Dietary - administration & dosage; Regression Analysis; Sodium Bicarbonate - administration & dosage; Sodium, Dietary - administration & dosage; Stress, Physiological; Weight Gain; Zea mays
• ISSN: 0032-5791
• DOI: 10.1093/ps/82.3.428

Ross male broiler chicks (n = 480) on new litter were used in a randomized block design with two blocks (environmental rooms) and four treatments having four replicate pens (1.0 x 2.5 m; 15 chicks) each to evaluate dietary electrolyte balance (DEB; P < 0.05). Two rooms were 1) thermoneutral (Weeks 1 through 6, with decreasing maximum from 32 to 25 degrees C and minimum from 28 to 19 degrees C; relative humidity 49 to 58%) and 2) cyclic daily heat stress (Weeks 1 and 2, thermoneutral; Weeks 2 through 6, maximum temperatures 35, 35, 33, and 33 degrees C, respectively; and minimum temperatures 23, 20, 19, and 19 degrees C, respectively; relative humidity 51 to 54%). The DEB treatments (0, 140, 240, or 340 mEq Na + K - Cl/kg) had NaHCO3 plus NH4Cl, or KHCO3, or both added to corn-soybean meal mash basal diets with 0.30% salt (NaCl). In the thermoneutral room, DEB 240 increased 42-d weight gain and 44-d lymphocyte percentage and decreased heterophil percentage and heterophil to lymphocyte ratio compared to the DEB 40 treatment. The DEB 240 diets had 0.35 and 0.35% Na and 0.37% and 0.29% Cl in starter (0.75% K) and grower (0.67% K) diets, respectively. No DEB treatment differences were found in the heat stress room. For combined rooms, 42-d feed intake was higher for DEB 240 than for DEB 40. The 21-d weight gain was higher for DEB 240 than for DEB 40 or 140; and 21-d feed/gain was lower for DEB 40 than for DEB 340. The predicted maximum point of inflection for 21- and 42-d weight gains were DEB 250 and 201, with highest 42-d feed intake at 220.