Date of this Version
Ninety-six crossbred yearling steers (656 lb) were assigned to either control (CON) or balanced (BAL) treatments. Steers were fed for 135 days in 12 waste-management pens with runoff collection basins. Control diet consisted of a DRC, 7.5 % roughage finisher formulated for 13.5 % protein and 0.35 % phosphorus. Balanced diet was formulated using the 1996 NRC model to meet the animal’s protein (11.5%) and phosphorus (0.22%) requirements. Gains were unaffected and feed efficiency tended to improve by feeding the BAL diet. Nitrogen and P excretion were lower with BAL steers compared with CON steers. Consequently, the manure’s N:P ratio was improved relative to crop needs from 1.9:1 to 3:1 for CON and BAL treatments respectively. Feeding at the animal’s requirement for protein and P decreases N and P excretion and improves waste characteristics without compromising animal performance.