2. Materials and methods
2.1. Feedstock
The feedstock was provided by Wykey Farm, Shrewsbury, UK.
The 16-week-old CM was stored outside while the maize, which
had been harvested 12 months previously, was ensiled. After visual
inspection and removal of any non-biodegradable contaminants
the feedstock was homogenized by a macerating grinder
(S52/010 Waste Disposer, IMC Limited, UK), packed into plastic
storage bags and frozen at 18 C. The frozen feedstock was
thawed before use and stored at 4 C for a maximum period of
one week.