Excreta viscosity as an indicator of microbial enzyme activity in the hindgut and as a predictor of between-bird variation in AME in broilers

Abstract

The apparent metabolisable energy (AME) value of an ingredient is not determined solely by the characteristics of the feed; rather it is a parameter reflecting the interaction between the feed and the animal. Thus, highly variable AME values are found between replicates within the same treatment when a low-ME wheat is fed to young broilers are found (Rogel et al., 1987; Hughes and Choct, 1997). The consequences of this variation are: (a) inaccuracy in least-cost diet formulations, and (b) uneven body weight of broilers at slaughter. Differences in gut morphology of the bird do not seem to offer any explanation for this variation (Hughes et a/., 2000). The current study examined whether indicators of microbial enzyme activities could be found to explain the between-bird variability in AME when a low-ME wheat diet was fed to three to four week old broilers.