Effects of Dietary Sodium Bicarbonate and Calcium Chloride on Physiological Responses of Lactating Dairy Cows in Hot Weather

• Published in: Journal of dairy science 1984-03, Vol.67 (3), p.574-584
• Main Authors: Escobosa, A., Coppock, C.E., Rowe, L.D., Jenkins, W.L., Gates, C.E.
• Format: Article
• Language: English
• Subjects: Animals; Bicarbonates - administration & dosage; Body Temperature; Body Weight; Calcium Chloride - administration & dosage; Cattle - blood; Cattle - physiology; Female; Hot Temperature; Lactation; Milk - secretion; Pregnancy; Sodium Bicarbonate
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(84)81341-7

Twenty-four lactating cows were assigned randomly to three treatments to evaluate responses to large differences of dietary sodium and chloride. Treatments were corn-cottonseed meal-corn silage based complete rations with either: 1) .23% sodium chloride (control), 2) control plus 2.28% calcium chloride, or 3) control plus 1.70% sodium bicarbonate. Treatment effects were significant for urine pH (7.96, 5.41, 8.18), blood pH (7.50, 7.39, 7.49), partial pressure of oxygen (91.2, 99.4, 86.3mm Hg), partial pressure of carbon dioxide (34.60, 30.57, 32.98mm Hg), bicarbonate (26.20, 18.06, 24.64 meq/liter), total carbon dioxide (27.51, 19.18, 25.88 mM/liter), base excess (4.50, −4.31, 3.13 meq/liter), plasma chloride (93.4, 102.8, 95.7 meq/liter), serum potassium (3.26, 4.24, 4.14 meq/liter), and inorganic phosphorus (7.11, 5.61, 6.80 mg/100ml). Blood glucose (45.1, 43.0, 55.5 mg/dl) and blood urea nitrogen (11.8, 8.7, 11.9 mg/dl) exhibited treatment effects. Respiration rates, 84.8, 61.8, 89.9 per min, and body temperatures, 39.7, 39.0, and 40.0°C were significantly different. Lower intake of the high chloride diet and higher intake of the bicarbonate diet were probably responsible for some of the effects. Dietary electrolytes should receive attention in formulation because acid-base status of the animal is determined, in part, by ionic concentration and balance of the diet.