W615S (50197-1-1-2-2-2-B) was developed from cycle 0 of the GEM Quality Synthetic (GQS C0) population. This inbred was initiated in winter nursery 2004-2005 by the UW Corn Silage Breeding program, and was generated after at least six generations of inbreeding, hybrid evaluation, and testing. The selection criteria utilized to generate this line included high forage yield and good nutritional characteristics, which provide an opportunity to increase the potential milk yield productivity of ruminant animals that are fed with hybrids produced using this line.