Performance and Carcass Data of Steers Finished on Either Ammoniated or Nonammoniated Corn, Grain Sorghum, or Wheat Silage

Abstract

Two-hundred eighty-eight steers were used in a 3 × 2 factorial arrangement of treatments to compare the effect of ammoniation of three forages at time of ensiling to similar silages not ammoniated but supplemented with cottonseed meal at feeding. Three trials were conducted over a 3-yr period with 96 steers used per year. In each year, there were eight steers per pen with two pens per simple treatment. Silage sources were corn, grain sorghum, and wheat. The factorial design resulted in six simple treatments: ammoniated corn silage; nonammoniated corn silage plus cottonseed meal; ammoniated grain sorghum silage; nonammoniated grain sorghum silage plus cottonseed meal; ammoniated wheat silage; and nonammoniated wheat silage plus cottonseed meal. Liquid NH3 was applied at the rate of 3.5 g/kg of fresh silage to the ammoniated silage at the time it was placed in the silo. No silage source by nitrogen source interaction was present (P>0.05). Steers fed corn silage gained (P<0.001) 0.18kg more weight daily during the feeding period than steers fed grain sorghum silage, whereas steers fed grain sorghum silage gained (P<0.001) 0.12kg more weight daily than steers fed wheat silage. Dry matter intake of steers fed grain sorghum silage was 8% higher (P<0.001) than with steers fed corn silage and 10% higher (P<0.001) than with steers fed wheat silage. There was no difference in DMI between steers fed corn silage and steers fed wheat silage. Crude protein intake of steers fed ammoniated silage was 0.96 kg/d whereas steers supplemented with cottonseed meal consumed 1.02kg CP/d. There was no difference (P>0.442) in ADG of steers fed either silage that had been treated with ammonia at ensiling or silage that received cottonseed meal supplementation. Dry matter intake was higher (P=0.019) for steers that received the silage plus cottonseed meal than steers that received ammoniated silage. Because there was no effect of treatment of N source on gain, but steers fed ammoniated silage consumed less DM, the feed efficiency for steers fed ammoniated silage was increased (P<0.001).