An Evaluation of the Oesophageal Fistula Valve Technique

Abstract

The oesophageal fistula valve technique (Raats & Clarke‚ 1992) was evaluated in terms of its ability to reflect the daily forage selection pattern of free ranging goats over a period ot four seasons and two Stocking rates. During the. evaluation, the oesophageal fistula valve technique was compared to the standard oesophageal fistula bag technique and observed feeding behaviour. Comparisons were in terms of: (i) proportion of grass or bush.(% DM) in both the fistula bag and valve samples compared against the time spent grazing or browsing i (% of active feeding period); (ii) the changes in chemical composition (CP, NDF, ADF and ADL) of the bag samples versus that of valve samples and; (iii) diurnal changes in feeding behaviour and plant species selection pattern of free-ranging goats based on observations.