Degradation Characteristics of Infrared Processed Barley Grain and Its Feeding Effects on Ruminal pH of Sheep

Abstract

This study was conducted to investigate the effects of infrared processing of barley for 60, 90, 120 and 150 seconds (s) on protein hydrophobicity, <em>in vitro</em> protein digestibility, degradation characteristics of protein and starch and its feeding effect on ruminal pH of sheep. The surface hydrophobicity of protein increased (P<0.04) as processing time increased. The degradation rate and effective rumen degradability of protein and starch decreased up to 90 s and remains constant at higher processing times (P<0.05). <em>In vitro</em> protein digestibility of barley increased at processing time of 60 and 90 s, remain constant at 120 s, then decreased at 150 s (P<0.05). Electrophoretic analysis showed aggregation of barley proteins that remain undegradable for longer time in the rumen. Ruminal pH of sheep fed processed barley was higher (P<0.05) than those fed untreated sample. There were no significant differences in ruminal pH of sheep fed barley processed at times over 90 s. It was concluded that infrared processing for 90 s, as shortest time, could decrease rate and extent of protein and starch degradation of barley in the rumen.