TRUE AND APPARENT METABOLIZABLE ENERGY VALUES OF LUCERNE AND YELLOW MAIZE IN ADULT ROOSTERS AND MATURE OSTRICHES (STRUTHIO-CAMELUS)

In an experiment involving 30 roosters and 15 mature male ostriches th e apparent metabolizable energy (ME) values, corrected for zero nitrog en retention (AME(n)), were determined by balance method for maize and lucerne meal. A group of 10 roosters received maize as the sole dieta ry component. For the second group of 10 roosters a blend of 750 g/kg maize and 250 g/kg lucerne was prepared. The diet of the third group c onsisted of 500 g/kg maize and 500 g/kg lucerne meal. The ostrich basa l diet consisted of 1000 g/kg lucerne, and was blended in the ratios 5 0 lucerne: 50 maize and 25 lucerne: 75 maize. Each dietary treatment w as given to five ostriches, individually housed in metabolism crates. Food intake and excreta collection was carried out over a period of 5 days after the ostriches had been accustomed to the diets for 7 days. For roosters food intake and excreta collection lasted for 72 h after an adaptation period of 24 h. The AME(n) value for maize was 14.49 (s. e. 0.046) MJ/kg in roosters while in ostriches AME(n) values of 14.3 ( s.e. 1.81) and 14.5 (s.e. 0.845) MJ/kg for the 500 g/kg inclusion and 250 g/kg inclusion respectively were found. In roosters lucerne meal y ielded AME(n) values of 4.49 (s.e. 0.506) and 4.05 (s.e. 0.321) at 250 g/kg and 500 g/kg inclusion levels respectively. For the ostriches a value of 8.9 (s.e. 0.755) MJ/kg was found for lucerne. True ME, correc ted for zero nitrogen retention, (TME(n)) was computed by regressing g ross energy output on gross energy input over all feeding levels. Maiz e yielded values of 14.65 (s.e. 0.0455) and 14.9 (s.e. 0.351) for roos ters and ostriches respectively while corresponding values for lucerne were 4.03 (s.e. 0.118) and 8.6 (s.e. 0.296) MJ/kg. It was concluded t hat the ostriches were capable of digesting a high starch diet such as maize to the same extent as adult roosters but ostriches were capable of digesting a high fibre ingredient such as lucerne meal much more e fficiently.