Systems of utilizing maize stover for feeding growing cattle

Systems analysis techniques were used to compare two selected maize stover systems with a conventional maize silage system for growing beef cattle. All systems were based on a 200 ha integrated farm currently utilizing 160 ha for a cash crop grain maize enterprise and 40 ha of maize silage for a cattle growing operation. The conventional maize silage system fed 423 cattle for an average gain of 160 kg liveweight per animal. Alternative systems fed an equal number of cattle and produced an equal gain per animal. One alternative (ammoniated system) involved harvesting wet maize stover with a forage harvester immediately after grain maize harvest and subsequent treatment with ammonia (4% dry matter basis) at storage. A second alternative (separated system) was designed to harvest and store mature whole-plant maize silage (50–55% H₂O) followed by separation into grain and stover fractions at feeding time. Cost per steer for the growing period was calculated using a cost simulation model for each system. The separated system had a lower mean cost per steer, while the ammoniated system had a slightly higher cost per steer than the conventional maize silage system, Can. $189, Can. $197 and Can. $195, respectively. Break-even shelled maize prices, representing the shelled maize price at which each alternative system had an equivalent cost per steer to the conventional system, were calculated. Break-even shelled maize prices were Can. $122 and Can. $140 t^?1 for the separated stover and ammoniated stover systems, respectively. The estimated reduction in cost per steer would appear to make the separated stover system feasible even at moderate shelled maize prices.