Research note: A comparison of metabolisable energy values of lucerne and barley between young and mature ostriches

Apparent and true metabolisable energy (ME) values, corrected for zero nitr ogen retention, of lucerne and barley were compared in balance studies betw een young (six months old, 50 to 60 kg BW) and mature (30 months old, 110 t o 120 kg BW) ostriches. Birds were housed in individual metabolism crates a nd excreta collection were performed over a five day period after an adapta tion period of seven days. Apparent metabolisable energy, corrected for zer o nitrogen retention, (AME(N)) of 9.17+/-0.251 MJ/kg (lucerne) and 14.24+/- 0.136 MJ/kg (barley) for young ostriches do not differ (P>0.05) from values of 8.97+/-0.226 MJ/kg (lucerne) and 14.21+/-0.134 MJ/kg (barley) obtained for mature ostriches. Also no significant differences occurred between true metabolisable energy, corrected for zero nitrogen retention, (TMEN) values of 9.16+/-0.450 MJ/kg (lucerne) and 13.94+/-0.390 MJ/kg (barley) for young ostriches and 9.26+/-0.412 MJ/kg (lucerne) and 13.92+/-0.316 MJ/kg (barley ) for mature ostriches. It is concluded that similar AME(N) and TMEN values of feedstuffs would be suitable in ostrich diet formulation for age groups older than six months.