Effects of Dietary Potassium upon Growth, Serum Electrolytes and Intrarumen Environment of Finishing Beef Steers

Abstract

Two feeding trials were conducted to study the dietary K requirement of finishing beef steers. Twenty-four yearling steers were used in each trial which consisted of four diet treatments of six steers each. In both trials K₂CO₃ was added to a low K basal diet to make dietary K levels (oven-dry) ranging from 0.27 to 0.85% in the first trial and 0.36 to 0.77% in the second trial. Potassium deficiency, as indicated by poor appetite, loss in bodyweight, pica and low serum K, was observed in steers receiving diets containing 0.27 and 0.36% K. In trial 1 rumen fluid pH, in vitro microbial activity and rumen fluid levels of sodium and K, in general, increased as dietary K increased from 0.22 to 0.85%. The weight gain and feed efficiency data suggest that the K requirement for finishing steers was higher than 0.51% but not higher than 0.72% of the oven-dry diet in trial 1; while in trial 2 the K requirement was higher than 0.62% but not higher than 0.77% of the oven-dry diet. Copyright © 1969. American Society of Animal Science . Copyright 1969 by American Society of Animal Science