An ammonia treatment system for cereal straws has been recently developed i
n Japan. The new method is based on a contractor system and is referred to
as the "HOKUNOU-S" system. Ammoniation can be used for all types of silos,
including, stack, bag, tube and bunker silos as well as wrapped bales. In a
ddition, this technique is suitable for use where a safe, economical, labor
-saving treatment with ammonia can be applied. The injection system consist
s of a large-sized high-pressure vessel, a volume and pressure regulator, l
ead hose, an injection pipe and nozzle; the durability of this equipment an
d the safety of its handling comply with Japanese industrial standards. For
one treatment, normally 8 kg of ammonia is injected into a round bale 1.2
m in diameter within 1-2 min. About 10 t or 40 round bales of cereal straw
can be treated by a contractor within 1 h. By treating rice straw with ammo
nia, the TDN content of rice straw increased from 40 to 60%. As a result, t
reated rice straw was similar to good quality grass hay while treated barle
y and wheat straws were similar to grass hay harvested at a slightly later
stage. An adequate level of breeding efficiency in yearly calving was obtai
ned in the 3-year reproduction test using a total of 96 breeding cattle. Th
e cost varied with the supply and demand of straw, the length of the actual
working time of the wrapping machine, and field conditions (wet conditions
cause an increase in time and therefore an increase in harvesting expenses
).