Growth rate, total body water volume, dry-matter intake and water consumption of domesticated ostriches (Struthio camelus)

Growth rate, total body water volume (TBW), dry-matter intake (DMI) and water consumption were determined in ostriches from hatching to 350 days at which time they weighed approximately 100 kg. A Gompertz equation was used to describe the sigmoidal growth curve; mature body mass (Mmb) wascalculated as 104·1 kg from this equation. Highest average daily gain (ADG) was 455 g/day which occurred between 70 days and 98 days. Time to reach 0·5 Mmb and to grow from 0·25 to 0·75 Mmb per Mmb025 were 46·8 days and 39·7 days, respectively. Maintenance energy requirements were 1·07 MJ/kg063per day and energy requirements for kg mb increase were 0·260 MJ/kg109: thes e values were derived from a non-linear regression model. TBW as a fraction of mb declined from 0·84 in 35-day-old chicks to 0·57 in 322-day-old birds, indicating a concomitant increase in the fraction of body lipid content. Mass specific DMI decreased from 0·061 g/g mb in chicks to 0·020 g/g mb in 322 to 350 day old birds, while mass specific water influx decreased from 0·21 ml/g mb to 0·046 ml/g mb during this time. The ratio of DMI to ADG increased steadily from 1·07 to 17·1; the ratio of water consumption to DMI remained relatively constant at approximately 2·3.