AMMONIA OR UREA TREATMENT OF WHOLE HIGH MOISTURE SHELLED CORN

Abstract
Treatments of high moisture shelled corn were compared in diets containing approximately 60% (dry matter (DM) basis) corn silage. In an initial digestibility trial, treatments were: (1) ensiled, ground; (2) 1.5% (wt/wt) mixture of acetic: propionic acid, whole; (3) 2% (wt/wt DM basis) anhydrous ammonia, whole. Treatments were evaluated with six yearling steers in a double 3 × 3 latin square design. Urea was included in the ensiled and acid-treated corn diets to supply sufficient nitrogen. Ammoniating whole corn resulted in similar starch and energy digestibilities compared to ensiled ground corn. However, a large decrease in starch digestibility occurred with acid-treated whole corn. Digestibility of acid detergent fiber was greater (P < 0.05) with both ammoniated and acid-treated whole than ensiled ground corn. In a feedlot trial, two high moisture corn treatments compared were: (1) ensiled, ground; (2) 3.7% (wt/wt DM basis) urea, whole. Eighty Hereford yearling steers compared the two corn diets each with or without monensin. Temperatures rose steadily within bins plateauing approximately 21/2 wk after storage. The amount of urea that hydrolyzed to ammonia varied depending upon location within bins. A total of 1.4% DM loss occurred during storage. Urea-treatment tended to slightly reduce liveweight gain and feed efficiency. Monensin decreased intake (P < 0.05) and slightly improved feed efficiency (P > 0.05) with both types of corn. Effects of monensin on rumen VFA were similar with both corn diets. Type of corn had no effect on rumen VFA proportions.