A study of the effect of exposure in the reticulo-rumen of the cow on the strength of cotton, grass, hay and straw

Abstract

1. Changes in strength of cotton, Italian ryegrass leaf, hay stem and barley-straw stem on immersion in the contents of the reticulo-rumen, at two sites in the rumen and at one site in the reticulum, for periods of up to 56 h were measured using a cow on a hay diet. Specimens of the fibrous materials were immersed in the rumen digesta in such a way that they were not damaged by agitation or by rumination.2. Load-to-fracture and elongation were measured on a machine using a constant-speed cross-head at a strain of about 10−3/s. The ratio strength:density (breaking load/mass per unit length) was determined.3. Leaf of Italian ryegrass and stem of hay and of barley straw had strengths of about 37, 150 and 210 MN/m2. They lost strength at different rates when immersed in the rumen digesta, the times to half strength being in the ratio grass: hay: straw = 1:1.9:3.8. The similarity of this ratio to that for total time for eating and ruminating as given by Balch (1969), namely 1:2.0:3.5, for similar materials was noted.