The response of screened manure fibre to ozone and sodium hydroxide treatments

Abstract

Screened manure fibre (SMF) has been sampled from a high producing dairy herd during 10 months at 23- to 27-day intervals. SMF samples have been analyzed for cell wall (CW) components and subjected to ozone and sodium hydroxide treatments. The mean content, on a dry matter (DM) basis, of neutral detergent fibre (NDF) in SMF samples was 82.8% and the variation was small. Sodium hydroxide and ozone reduced the NDF content on average by 20 and 35%, respectively. SMF contained, on a DM basis, 23.7–37.5% hemicellulose and the variation around the average value of 32.6% was remarkable. Hemicellulose was solubilised by both treatments, however, ozone had a stronger solubilizing effect than sodium hydroxide. Lignin was found to be the most variable fraction in SMF. The effect of sodium hydroxide on the lignin content of SMF was inconsistent; ozone, however, reduced the lignin content by about 35%. The cellulose content was practically unaffected by treatments. In vitro dry matter digestibility (IVDMD) of SMF was low, ranging from 23.8 to 36.2%. Increasing NaOH application from 5 to 8% increased IVDMD from 50 to 60%. Ozone-treated SMF was more digestible (65.2%) than the 8% NaOH-treated SMF.