2.2. Microbiology
Three freshly-voided faecal samples (1 g) from each pen were diluted and plated using the method by miles et al. Onto TBX, MRS and PCA (Oxoid, Basingstoke, UK) for enumeration of coliforms/Escherichia coli, Lactic acid bacteria (LAB) and total anaerobes, respectively. All media were incubated at 37 °C in the following conditions ; PCA : anaerobically for 48 h, MRS: aerobically with 5% CO2 for 48 h and TBX: aerobically for 24 h. A general linear model was used (week number × treatment) on logarithmically-valued counts to determine the effect of treatment and time on microbial levels. A level of p