Improved Techniques in Oesophageal Fistulation of Sheep

Abstract

IntroductimThe use of oesophageal fistulae in sheep as a technique for obtaining samples of the forage ingested by grazing sheep has been reported by Torell (1954), Bath et al. (1956), Cook et al (1958). Heady & Torell (1959 and Luick et al (1959) in the U.S.A., and by McManus (1960) and Hamilton et a Z ( 1960) in Australia. Lesperance et al. (1960) have described a method for oesophageal fistulation of steers.Mechanical closure of the fistula, when it is not in use, is a major problem. It may be attempted either by permanent cannulation or by the fitting of stoppering devices. Cook et a2 (1958) reported success in the use of permanent cannulae, but our experience has not supported their The purpose of this communication is to report upon 37 cases of oesophageal fistulation in sheep additional to those reported on earlier (Hamilton et al 1960), the use of "split" plug stoppers for improved closure of fistulae, and the field performance of some of these animals. There are few references in the Iiterature on the performance of fistulated sheep under field conditions. Materials and Methods findings. (a) sheepThe sheep comprised 27 Border Leicester ewes, one Southdown X Merino ewe and 9 Border Leicester X Merino Crossbred wethers. The ages were from 2 to 3 years, except one (E55) which was aged 9 months at the time of operation. All the Border Leicester ewes had been mated prior to fistulation. (b) FistulationFistulation was effected either by the "direct" insertion of a latex plug stopper into a fistula with the muscularis mucosae sutured to the skin margins, or by the "insert" technique wherein the muscularis rnucosue was left intact and the flanges

Oesophageal fistulation of topi and wildebeest*

“…The major problems were oesophageal obstruction by ingesta, fistula enlargement with leakage, erosion, ulceration and infections. Similar conditions have been experienced in domestic animals (Dyne & Torell, 1964;McManus et al, 1962), in deer (Veteto et af., 1972) and with reindeer (Dieterich, 1975). These problems can usually be overcome if discovered early, Tender and nutritious food is essential, as is a well-fitted plug.…”

“…Two types of plugs were used and sometimes interchanged: a 'stopper' plug (Dyne & Torell, 1964) (see Figs. 1 and 2) and a 'split' plug (McManus, Arnold & Hamilton, 1962) (see Figs. 3 and 4).…”

The Use of Sheep Fitted With Obsophageal Fistulae in Grazing Studies

“…Although the concentrations of N and ash in the extrusa were lower immediately after turn-out than they were later in the experiment, the differences may be explained in terms of normal diurnal variations in the composition of the diet (see Table 1). Langlands (12) f'ound no difference between the N contents of the diets selected by fasted and unfasted sheep, though Amold et al (13) showed that over-night fasting resulted in a significant reduction in the N content of the diet. Where the digestibility of the diet is the important parameter it does not appear to matter whether the animals are fasted before sampling or not.…”

“…All the sheep were fistulated at least two months before they were used in grazing studies. The fistulae were prepared by the direct technique described by McManus, Arnold and Hamilton (13), and were closed with rubber split plugs. Initially a polythene plate and an underlying foam rubber washer were used to keep the plugs in place, but these were later found to be unnecessary in most of the sheep.…”

Comparative studies of ingestive behaviour and diet composition in oesophageal‐fistulated and non‐fistulated cows and sheep

“…Since the development of a satisfactory technique for oesophageal fistula tion (Torrell, 1954;McManus et al, 1962;Van Dyne and Torrell, 1964), the use of animals fistulated at the oesophagus has become widespread. Oesophageally fistulated animals .…”