INFLUENCE OF LIVE MASS, RATE OF PASSAGE AND SITE OF DIGESTION ON ENERGY-METABOLISM AND FIBER DIGESTION IN THE OSTRICH (STRUTHIO-CAMELUS VARDOMESTICUS)

Energy metabolism and digestion of dietary fibre in growing ostrich ch icks were studied at different live masses (5 - 50 kg) by means of a t otal excreta collection method and a radioactive indicator method. Pas sage rate of digesta particles through the digestive tract and site of digestion were also investigated. Passage Tate within live mass group s varied considerably (from 21 to 76 h). Overall mean passage rate was 40.1 h and it was independent of live mass. Digestibility coefficient s for cell walls (NDF), hemicellulose and cellulose were 47%, 66% and 38% respectively, and were not influenced by live mass. The hindgut pr ovided a suitable nutritional environment for fermentative microflora, especially in the enlarged haustrated colon of the ostrich. Of the to tal metabolizable energy in the diet, 12% disappeared in the hindgut.