Mean Leaf Area of the Canopy for Light Interception by Forages and Mean Retention Time of Feed in the Rumen for Feed Ingestion by Ruminants as Investigated using Simple Models

This study was conducted to take up the following two subjects: (1) relationships between light interception by the forage canopy and its mean leaf area weighted by the light attenuation curve [MLA], and (2) relationships between feed ingestion by ruminants and mean retention time of feed in the rumen weighted by the feed disappearance curve [MRT], using simple models for forages and those for ruminants. The following results were suggested: (1) when the canopy leaf area index [L] was high the small coefficient of light extinction [K_f] enabled the canopy to have large MLA which could intercept more amount of light, whereas the saturation of light interception occurred in lower L when the canopy had large K_f, (2) daily feed intake [DFI] by ruminants increased with the increase in MRT ¹ [=feed disappearance rate]. The present study using simple models suggested that MLA of the canopy of forages was like MRT^-1 of feed in the rumen of ruminants as indices for the estimation of energy ingestion.