Changing dietary electrolyte balance for dairy cows in cool and hot environments

• Published in: Journal of dairy science Vol. 74; no. 5; pp. 1662 - 1674
• Main Authors: West, J.W. (University of Georgia, Tifton), Mullinix, B.G, Sandifer, T.G
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Dairy Sci Assoc 01.05.1991; American Dairy Science Association
• Subjects: Acid-Base Equilibrium; AGOTAMIENTO POR EL CALOR; Animal Feed; Animals; Bicarbonates - blood; Biological and medical sciences; Body Temperature; Calcium - blood; Carbon Dioxide - blood; Cattle - metabolism; Cattle - physiology; Chlorides - administration & dosage; CHLORURE; CLORUROS; COUP DE CHALEUR; Eating; EFFICACITE ALIMENTAIRE; EFICIENCIA DE CONVERSION DEL PIENSO; ELECTROLITOS; ELECTROLYTE; Electrolytes - administration & dosage; EQUILIBRE ACIDOBASIQUE; EQUILIBRIO ACIDO-BASE; Feed and pet food industries; Female; Food industries; Fundamental and applied biological sciences. Psychology; INGESTION DE PIENSO; Lactation; Milk - secretion; POTASIO; POTASSIUM; Potassium - administration & dosage; PRISE ALIMENTAIRE (ANIMAUX); RENDEMENT LAITIER; RENDIMIENTO LECHERO; SERUM SANGUIN; SODIO; SODIUM; Sodium - administration & dosage; SUERO SANGUINEO; TEMPERATURA AMBIENTE; TEMPERATURA DEL CUERPO; Temperature; TEMPERATURE AMBIANTE; TEMPERATURE CORPORELLE; VACAS LECHERAS; VACHE LAITIERE; Temperature; Lactation; Ox; Environmental factor; Cow; Metabolism; Inorganic element; Vertebrata; Mammalia; Electrolyte; Artiodactyla; Ungulata; Milk
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(91)78329-X

Two Latin square studies, each containing eight primiparous cows (four Holstein, four Jersey), were conducted to determine the effect of changing dietary electrolyte balance during cool and hot environmental conditions on performance of lactating dairy cows. Electrolyte balance, expressed as Na + K - Cl in milli-equivalents per kilogram of diet, was altered by changing K and Cl content in the diet using potassium bicarbonate or calcium chloride. Maximum and minimum temperatures averaged 26.7 and 15.0 degrees C during the cool phase and 32.3 and 22.5 degrees C during the hot phase of the study. Milk yield improved linearly with increasing electrolyte balance with nonsignificant treatment by phase interaction, whereas DMI of cows improved quadratically with increasing dietary electrolyte balance. A treatment by phase interaction for DMI was detected, although intake of DM reached a plateau at a similar dietary electrolyte balance during die cool and hot phases. Body (milk) temperature of cows appeared to be related to the level of feed consumed and varied by treatment within phase. Body (milk) temperature was higher during the hot phase of the experiment. Blood bicarbonate and pH were lowest in cows offered the low electrolyte balance (high Cl) diet, and blood d urinary Na + K - Cl increased linearly with increasing dietary electrolyte balance. The response to dietary electrolyte balance appeared to be mediated through blood buffering and the impact on physiologic systems of the cow