Fluoroscopic studies of the stimulatory effects of copper sulphate and cobalt sulphate on the oesophageal groove of sheep

Abstract

Solid radiopaque markers were compared with barium sulphate suspension for the video-taped fluoroscopic investigation of oesophageal groove closure and forestomach bypass in recently-fed Romney hoggets. Oesophageal groove closure was clearly identifiable using both methods, although the 1.5 mm diameter solid markers showed a tendency to become lodged in the oesophageal groove and omasum, limiting their value for the study of forestomach bypass. Forestomach contractions, closure of the oesophageal groove and omasal function could be assessed using the solid radiopaque markers, which are potentially useful for studies of ruminant digestion. Ten ml of a 2% copper sulphate solution, when administered to the back of the oral pharynx 10 s before oral dosing, induced oesophageal groove closure in 55% (11 of 20) of the hoggets. Ten ml of a 2% cobalt sulphate solution had a similar effect (9 of 20), although the numbers of sheep investigated were too small for statistical comparison.