The objectives of this project, which began last year, were to find out if the application of ammonia to rice straw during field baling was feasible with existing machinery and to measure the results by cattle feeding studies and by laboratory analyses. The studies were continued into the current year without additional funding.

As reported previously, bales made by the 4-foot by 5-foot Vermeer baler had the highest density, were the easiest to transport, and had the most uniform shape of the three balers used, in 1980 and 1981 tests. During the rainy season, an unmodified hammer mill such as a tub grinder was unsuitable to mill rice straw stored outside. Shear-bar cutter heads may be required.

Ammoniated bales were compared with those not ammoniated for a number of characteristics. Ammoniated bales had higher invitro digestibility, total solubles after enzyme, and total nitrogen. Also, the baler-ammoniated straw was relatively stable at 29 percent moisture, had more dry matter stored in the bale, and ash level did not increase. Net energy for maintenance and for gain was greater in the ammoniated rice straw.

Ammonia levels did not equalize throughout the mass of rice straw in the high density round bale, including even those bales enveloped in a polyethylene sleeve at baling time. It may be possible that a better designed applicator could achieve a more uniform ammonia level and increased in-vitro digestibility.

While the Vermeer 504F, 4-foot by 5-foot baler seemed to be the most adaptable baler for baler ammoniation, it would be commercially useful only under ideal weather and ground conditions. Modification necessary to adapt it or a similar baler to adverse weather conditions appear feasible. Some modifications to the 504E have been made.