Dietary Fermented Ammoniated Condensed Whey and Postprandial Effects on Blood and Urine Acid-Base Metabolites in Lactating Cows

Abstract

Effects of a fermented whey product containing 38% lactic acid, time post-feeding, and temperature on acid-base metabolism were studied with four lactating Jersey cows in a 4 × 4 Latin square. Treatments included 0, 33, 66, and 100% replacement of soybean meal with fermented whey in a 60% corn silage, 40% concentrate diet (dry basis). Increasing fermented whey to 100% reduced intake and milk production, 27 and 32% compared to animals fed 0 and 33% fermented whey diets. Fermented whey had no effect on blood pH, carbon dioxide tension, bicarbonate, and potassium whereas increasing fermented whey above 33% replacement reduced glucose and sodium in plasma 15 and 40mg/100 ml from controls. Increasing consumption of fermented whey to 100% replacement increased urinary ammonium excretion 1365/meq per day and slightly decreased urine pH, which suggested changes in acid excretion. Effects of time postfeeding on blood traits were measured from samples taken at 0, 1, 2, 3, 4, 6, and 8 h. Blood pH was higher at 1 to 3 h as compared with 4 to 8 h postfeeding, whereas carbon dioxide tension and bicarbonate increased 10.6 mm mercury and 6.3 meq/liter at 1 h and declined afterward. Period effects for blood acid-based characteristics showed decreasing blood carbon dioxide tension with increasing ambient temperature. © 1981, American Dairy Science Association. All rights reserved.