Very dark green plant growth often contains higher levels of prussic acid. Most prussic acid is lost during the curing process. Therefore hay and silage are seldom toxic even if the original forage was. Do not leave green chop in a wagon over night and then feed. The heat that occurs will cause a release of prussic and make the feed more likely to be toxic.
Individual animals vary in susceptibility to prussic acid poisoning.
Cattle are more susceptible than sheep. Animals receiving grain with the pasture are less likely to be affected. Harvest Silage - Forage sorghums should be harvest at the mid dough stage for ensiling. At this point quality is still good and most types have dried down enough for ensiling. Non-heading types usually require a killing frost for the plant to get dry enough to ensile.