Ammonium bicarbonate is a solid, non toxic compound wich could be easily handled and applied to roughages as an alternative source of ammonia. The preliminary experiments reported here were designed to study the possibility of using ammonium bicarbonate for treating wheat straw.

In the first experiment samples of 100 g of wheat straw were placed in 28 glass jars (11 volume). The jars were then assigned in a factorial design to four levels of ammonium bicarbonate (0, 25, 50 and 75 g/kg on ammonia basis) and to seven temperatures of treatment (0, 20, 40, 60, 80, 100 and 120°C for 3 hours). After the treatment the straw samples were ground with a laboratory hammer mill (5 mm sieve). Two g of each sample were incubated in two replicated nylon bags (Ørskov, Hovell and Mould, 1980) into the rumen of two cannulated cows and withdrawn after 48 hours. The cows (mean live weight 550 kg) were fed 1.8 kg/100 kg live weight of a diet based on 0.80 hay, 0.15 dried sugar beet pulp and 0.05 soyabean meal, supplemented with vitamins and minerals.