title: Dietary electrolyte balance effects on performance and metabolic characteristics in growing steers.
abstract: The effects of dietary electrolyte balance (DEB; mEq of Na + K - Cl/100 g of DM) on performance and acid-base status of growing cattle consuming a corn silage-based diet were established using 120 Angus (n = 60) and Angus crossbred (n = 60) steers (247 +/- 2.4 kg). Treatments consisting of 0, 15, 30, or 45 mEq of DEB/100 g of DM were obtained by varying NH4Cl and NaHCO3. Average daily gain showed a linear increase (P < .05) with increased DEB for the first 28 d and a quadratic response (P < .05) for the remainder of the 84-d study. Average daily feed intake was not affected by DEB the first 28 d. However, feed intake over the entire feeding period showed a linear increase with increasing DEB (P < .01). On d 28, plasma Na, K, and Mg were not affected by DEB, whereas Ca followed a quadratic pattern (P < .10). On d 84, plasma Na and Mg decreased linearly with increasing DEB. Plasma Cl concentrations decreased linearly (P < .01) with increased DEB on d 28 and 84. On d 28 arterial blood pH and HCO3 increased linearly (P < .05) with increased DEB, whereas ionized Ca, pCO2, and pO2 were unchanged. On d 84, arterial blood pH (P < .10), HCO3 (P < .05), and ionized Ca (P < .10) increased quadratically, whereas pO2 and pCO2 were not affected by treatment. Ruminal pH increased linearly (P < .05) with increased DEB on d 28 but showed no differences on d 84. These data indicate that DEB affects performance and systemic values in growing feedlot cattle. A DEB in the range of 15 to 30 mEq seemed to provide normal homeostasis of growing steers fed a corn silage-based diet.
authors.affiliation: Department of Animal Science, North Carolina State University, Raleigh 27695-7621.
authors.forename: J G
authors.initials: JG
authors.lastname: Ross
authors.forename: J W
authors.initials: JW
authors.lastname: Spears
authors.forename: J D
authors.initials: JD
authors.lastname: Garlich
mesh_terms: D000136:Acid-Base Equilibrium; D000818:Animals; D001639:Bicarbonates / Q000097:blood; D002118:Calcium / Q000097:blood; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism; D002712:Chlorides / Q000097:blood; D004032:Diet; D004435:Eating; D004573:Electrolytes / Q000008:administration & dosage* / Q000097:blood; D006863:Hydrogen-Ion Concentration; D008297:Male; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry; D012820:Silage; D015430:Weight Gain; D003313:Zea mays
chemical_list: D001639:Bicarbonates; D002712:Chlorides; D004573:Electrolytes; D002118:Calcium