DIGESTIBILITY AND GASTROINTESTINAL TRANSIT-TIME OF DIETS CONTAINING DIFFERENT PROPORTIONS OF ALFALFA AND OAT STRAW GIVEN TO THOROUGHBREDS, SHETLAND PONIES, HIGHLAND PONIES AND DONKEYS

A series of 4 X 4 Latin-squaue digestibility trials was carried out to determine whether there were any differences between different types of equid in their ability to digest diets containing different levels of fibre and protein. The equids (Thoroughbreds, Highland ponies, Shet land ponies and donkeys) were offered one of four molassed diets in tu rn and these contained different proportions of alfalfa and oat straw: 1.0: 0, 0.67:0.33, 0.33:0.67, 0:1, respectively. The apparent digesti bility of dry matter (DM), organic matter (OM), gross energy (GE) crud e protein (CP), acid-detergent fibre (ADF) and neutral-detergent fibre (NDF) were estimated. The rate of passage of the different diets tons measured using Cr-mordanted fibre (Cu-fibre) and Co-ethylene diamine terra acetic acid. All animals digested the components of the high-fib re diets less well than those of the low-fibre diets (P < 0.001 for DM , OM, GE, CP and ADF). Donkeys digested fibre move effectively than th e other equids (P < 0.01 for ADF and NDF). he gastro-intestinal transi t rime of the high fibre diets was significantly less than that for th e low fibre diets (P < 0.001) and donkeys retained food residues longe r than the other equids (P < 0.01).