title: The relationship among dietary undetermined anion, acid-base balance, and nutrient metabolism in swine.
abstract: Dietary undetermined anion (dUA) reflects, in part, the net acid load contributed by the diet. Although dUA is known to influence performance and nutrient metabolism of swine, a lack of knowledge impairs its application to diet formulation. This study was undertaken to separate the effects of dUA from the individual electrolytes that constitute its calculation. Eighteen 35-kg pigs were fitted with indwelling venous catheters and fed one of three barley and soybean meal-based diets: a control diet (C), an acidogenic diet containing calcium chloride (A), or a compensated acidogenic diet containing alkaline salts of sodium and potassium, as well as calcium chloride (CA). Compared with diet C, diet A lowered (P < .05) blood pH, bicarbonate, and base excess and increased (P < .05) urinary ammonium, titratable acid (TA), and net acid excretion (NAE). Diet CA returned blood acid-base values to normal and reduced urinary ammonium, TA, and NAE relative to diet A. Total nitrogen balance was unaffected by diet. Diet CA increased (P < .05) water intake and urine output. Diet A, but not CA, increased (P < .05) serum ionized Ca and C1. Apparent Ca and S digestibility and retention were reduced by diet A, but not by CA. Sodium retention was enhanced (P < .05) by diets A and CA; potassium retention was impaired (P < .05) by CA. Dietary UA altered systemic and renal acid-base balance in pigs. Mineral, but not nitrogen, metabolism was affected by both dUA and specific ion effects.
authors.affiliation: Prairie Swine Centre Inc., Saskatoon, Saskatchewan, Canada. patience@sask.usask.ca
authors.forename: J F
authors.initials: JF
authors.lastname: Patience
authors.forename: R K
authors.initials: RK
authors.lastname: Chaplin
mesh_terms: D000136:Acid-Base Equilibrium; D000641:Ammonia / Q000652:urine; D000704:Analysis of Variance; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000838:Anions; D002118:Calcium / Q000097:blood / Q000378:metabolism; D002122:Calcium Chloride / Q000378:metabolism / Q000494:pharmacology; D002712:Chlorides / Q000097:blood / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000502:physiology; D004326:Drinking / Q000502:physiology; D001467:Hordeum / Q000592:standards; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology; D008903:Minerals / Q000097:blood / Q000378:metabolism; D009584:Nitrogen / Q000652:urine; D010758:Phosphorus / Q000378:metabolism / Q000494:pharmacology; D011897:Random Allocation; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology; D013025:Glycine max / Q000592:standards; D013455:Sulfur / Q000378:metabolism / Q000494:pharmacology; D013552:Swine / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D014508:Urea / Q000097:blood; D015430:Weight Gain / Q000502:physiology
chemical_list: D000838:Anions; D002712:Chlorides; D008903:Minerals; D010758:Phosphorus; D013455:Sulfur; D000641:Ammonia; D014508:Urea; D012964:Sodium; D008274:Magnesium; D002122:Calcium Chloride; D009584:Nitrogen; D002118:Calcium