Gaseous Ammonia Treatment of Corn Silage for Dairy Cows

Open Access
Publisher Website
Google Scholar
Abstract
In 2 experiments corn silages were treated at harvest with urea, gaseous ammonia or an ammonia-mineral solution and fed ad lib as the primary forage to 72 lactating Holstein cows in midlactation for 9-11 wk. Recoveries of added N were high (85-99%) for all treatments except gaseous ammonia (48%) added in a field harvester. An improved method for addition of gaseous ammonia at the blower through an auger box was developed and tested. Water insoluble N, lactic acid and pH in silages were highest for ammonia treatments, next for urea and lowest for controls; they were related directly to ammonia. Additions of ammonia and urea retarded increases in temperature and appearance of visible mold when silages were exposed to air, with ammonia more effective than urea. Persistencies for milk were as high for cows receiving treated silages as for controls and were not depressed when added ammonia furnished over 30% of the total N of the ration. No consistent differences from treatments were in silage intakes, conversion of feed to milk or changes in milk composition or body wt. Addition of gaseous ammonia to corn silage was as beneficial as other nonprotein N treatments, but retention by silage may be low.