Influence of live mass, rate of passage and site of digestion on energy metabolism and fibre digestion in the ostrich (<i>Struthio camelus</i> var. <i>domesticus</i>)

Abstract

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

Energiemetabolisme en veselvertering is met behulp van totale  ekskretakolleksie sowel as 'n radioaktiewe merker by groeiende volstruiskuikens vanaf 5 tot 50 kg lewende massa bestudeer. Deurvloeitempo van digestapartikels en plek van vertering in die spysverteringskanaal is ook ondersoek. Deurvloeitempo het aansienlik tussen massagroepe gevarieer (21 tot 76 h), met 'n algehele  gemiddeld van 40.1 h en was onafhanklik van lewende massa. Die koeffisiente van verteerbaarheid van selwande, hemisellulose en sellulose was onderskeidelik 47%, 66% en 38% en is nie deur lewende massa beinvloed nie. Die relatiewe groot agterderm, en meer spesifiek die kolon, het 'n geskikte mikrohabitat vir  mikrobefermentasie verskaf. Van die totale metaboliseerbare dieetenergie is 12% uit die agterderm geabsorbeer.