Effect of formic acid with formalin or barley incorporation into grass silage on silage fermentation and the performance of dairy cows

Perennial ryegrass was ensiled in three different ways: (1) with a formic acid with formalin silage additive at 4.0 1/t; (2) with an addition of 50 kg/t ground barley; and (3) no-additive. Formic acid with formalin produced well-fermented silage, which, when subsequently given to lactating dairy cows significantly enhanced daily dry matter (DM) intake and butterfat, protein and butterfat plus protein output and reduced the liveweight decrease experienced with the other treatments. The addition of ground barley at ensilage provided less benefit in terms of fermentation, but had a more pronounced effect upon daily silage DM intake and milk yield than formic acid with formalin treatment. The daily liveweight losses of cows given the non-additive-treated and ground-barley-treated silages were significantly higher than those given formic acid with formalin treated silage. Silage treatment had no significant effect upon cow fertility. (C) 1998 Silsoe Research Institute.