Breeding Approaches with the bm3 Mutation in Maize.

Historically plant breeders ignored breeding for silage yield and quality.  Tall silage hybrids were selected from hybrids bred for grain yield.  Certain grain hybrids filled a dual purpose role as both grain hybrids and silage hybrids.  With selection being made for grain yield, corn hybrids being used for silage were not selected for improved fiber digestibility or tonnage.  The net result was poor fiber digestibility hybrids with lots of grain.  The philosophy of the best grain hybrid being the best silage hybrid was prevalent in the past and continues to persist to this day.  Evidence of this is seen with reports of milk per acre instead of milk per ton.   Reporting on the amount of milk generated on an acre bases ignores dry matter intake of the dairy animal and focuses on yield instead of quality.  This paper lays out the importance of corn silage hybrids with improved fiber digestibility over conventional grain corn hybrids; the history of the bm3 mutation and some of the breeding efforts used to improve fitness and tonnage of bmr hybrids over the last 15 years.