In studies conducted at Ohio State University, feeding dairy cows corn silage made from high oil corn hybrids increased fat corrected milk yields by 1.25 kg per day compared to conventional corn silage. Processing the whole plant at harvest to crush both the plant parts and kernels also boosted milk yield and fat content. In 1997, a high oil hybrid and conventional hybrid were grown at the Ohio Agricultural Research and Development Center near Wooster. Half of each field was harvested with a silage chopper equipped with two roller mill rolls, effectively crushing and shearing the chopped silage material. Longer forage is difficult to ensile because it's tough to pack uniformly.
Processing creates more uniform-sized particles and makes effective packing possible.
Four diets comprising 63 per cent corn silage and 37 per cent concentrate were fed to 32 Holstein cows, eight cows per ration. Concentrations of crude protein and fatty acids were higher in the high oil corn silage than in conventional silage. Cows fed high oil silage produced one kg more milk per day and 1.3 kg more fat corrected milk per day than cows fed conventional corn silage. Milk yields were similar between processing treatments with high oil corn silage. Cows receiving processed conventional corn silage produced 0.5 kg more milk than those receiving unprocessed silage made from conventional corn.