Abstract
Three rumen cannulated Japanese Corriedale crossbred (Suffolk × Corriedale) sheep (mean BW 35.1 kg) offered corn silage (CS) and chopped timothy hay (TH) ad libitum were used to examine the effect of forage properties (physical and chemical) on saliva secretion and rumination behavior. Eating and rumination behavior was monitored for each animal fitted with a muzzle which is equipped with a strain-gage unit for five consecutive days. Saliva secretion was estimated using a kinetics model based on the rumen fluid and water flux estimates across the rumen wall. Voluntary food intake and saliva secretion were significantly higher (P<0.05) in animals offered TH than CS. Total rumination time, number of rumination chews and number of regurgitated boli were markedly higher (P<0.05) due to TH feeding than CS. Chewing rate, chewing number/bolus and chewing time/bolus tended to be higher due to TH feeding than CS (P>0.05). Rumination index (min/100 g DMI) was significantly higher (P<0.05) due to TH feeding than for CS. It was elucidated that coarse forage feeding increased voluntary food intake, saliva secretion through mechanical stimulation of rumen fill compared with succulent fermented forage such as silage.
