Effects of cattle dung application time on ryegrass silage quality

Effects of time interval between cattle dung application and harvest on ryegrass(Lolium multiflorum) silage quality were studied by making silage in small-scale silos(500 mL polyethylene barrel). Cattle dung was applied with the rate of 45 m3·ha-1 at the time of 10 weeks, 6 weeks and 2 weeks before harvest, in a 300 m2 ryegrass experimental field. Take the field with no cattle dung application as control treatment. Forage yields with different harvest time were recorded, and the chemical components of different silages were analyzed after a 90-day ensiling. The results showed that, dry matter contents of silages are 146~165 g·kg-1. Silages are low quality with high pH value and NH4+-N content, and low lactic acid content. More particularly, in silages of treatments applying cattle dung 2 weeks before the first cutting, the growth of clostridium butyricum was detected, and the silage has a high pH value(4.7) and NH4+-N content(194 g·kg-1 total N), and a low lactic acid content(89 g·kg-1 DM). So the application of cattle dung to ryegrass in spring will decrease its silage quality.