title: Potassium chloride improves the thermotolerance of chickens exposed to acute heat stress.
abstract: Experiments were designed to test the hypothesis that chicks that drank an electrolyte solution containing K prior to and during an acute exposure to heat would have greater thermotolerance than chicks that consumed only water. In three experiments, 5- or 7-wk-old male chickens drank distilled water (control), or .3, .6, or .9% KCl solutions (Experiments 1 and 2), and .6 or .9% KCl or .8% KHCO3 solutions (Experiment 3) for 48 h before acute heat stress (HS) and during HS. Body temperature (Tb), blood pH, partial pressure of blood carbon dioxide (pCO2), ionized Ca (Ca2+), plasma Na, K, Cl, total Ca, inorganic P (Pi), and osmolality (Osm), and water consumption were determined. Water intake increased with the concentration of KCl. Before HS, .6% KCl increased plasma K and Ca2+, whereas .9% KCl resulted in a marked increase in K, Ca2+, Na, Cl, and Osm and a decrease in pH. During HS, .6% KCl-birds had lower hyperthermic Tb and pH values and higher Ca2+ and K concentrations than controls. Plasma Na and Osm of .6% KCl birds decreased whereas those of the control birds remained unchanged. Providing K as KHCO3 aggravated respiratory alkalosis and failed to influence either Tb or plasma electrolytes, suggesting that the beneficial effect of .6% KCl may in part be attributed to the accompanying Cl. Hyperthermic Tb and Ca2+ values were highly correlated. The results showed that .6% KCl solution reduced HS-related responses and indicated a relationship among supplemental KCl, blood Ca2+, and Tb.
authors.affiliation: Department of Poultry Science, North Carolina State University, Raleigh 27695-7608.
authors.forename: A
authors.initials: A
authors.lastname: Ait-Boulahsen
authors.forename: J D
authors.initials: JD
authors.lastname: Garlich
authors.forename: F W
authors.initials: FW
authors.lastname: Edens
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects; D000208:Acute Disease; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002645:Chickens / Q000502:physiology*; D004573:Electrolytes / Q000097:blood; D006358:Hot Temperature / Q000009:adverse effects*; D008297:Male; D011189:Potassium Chloride / Q000494:pharmacology*; D011201:Poultry Diseases / Q000503:physiopathology; D013312:Stress, Physiological / Q000503:physiopathology / Q000662:veterinary
chemical_list: D004573:Electrolytes; D011189:Potassium Chloride