Barrios-Urdaneta et al., 2002. Livest. Res. Rural Dev., 14 (4)

The “dry ammoniation” method was developed at “La Esperanza” farm, University of Zulia, Venezuela, located in a dry tropical area, as a means to improve the quality of tropical hays without the humidity problems observed with  the wet technique. 

The effects of storage time (14 and 21 days), water volume (200 and 400 ml/kg hay) and urea quantity (20 and 40 g/kg hay) on the crude protein content (CP) and in vitro digestibility of NDF were studied using a factorial arrangement design (2x2x2) plus one control (non-treated hay) with three replications per treatment. Small hay bales of 1 kg, made from several commercial hay bales of Brachiaria humidicola, were used as experimental units. The urea solutions were added into plastic containers (19 l) before placing the hay, leaving a space of 5-8 cm between the hay and the solution. Thereafter the containers were covered hermetically with a plastic sheet and stored under a roofed area.

The “dry ammoniation” improved the CP (3.2 to 8.3%) as well as the NDF in vitro digestibility (46.2 to 57.1%), when the control hay was compared against the average of the treated hays. The best result was obtained when the hay was stored for 21 days and treated with 200 ml of water + 40 g of urea/kg (10.6 % CP and 63.1% NDF in vitro digestibility).