The performance of farmed ostrich hens in eastern Australia

A prospective observational epidemiological study was undertaken in the south-eastern region of Queensland in eastern Australia to collect accurate information on the performance of farmed ostriches, and to identify the most important constraints facing on-farm production. This paper (the first in a series of three) focuses upon aspects of the general study design and the productivity of ostrich hens on 12 farms in this region. These farms were a convenience sample and were visited regularly for at least 12 months from July 1993. Some general farm information was collected using a questionnaire; however, the focus of the study was mainly upon the performance of defined cohorts of hens (a cumulative total of 61 hens), eggs (910 eggs) and chicks (394 chicks). A number of methods was used to improve data quality. The study farms were managed by producers with a median of 2.5 years of active ostrich industry involvement, reflecting the recent establishment and rapid growth of the industry in this region. During the study period, 61 hens were observed for a period of 41.1 hen-years. Most hens were young (median age 2.7 years at the end of the observation period) and held in pairs. Egg production was poor, with the more-productive hens significantly older than those less-productive. Egg laying among the more-productive hens was clustered in time, with half of all eggs being laid within 2 days of a previous egg. Clutches of eggs were generally small (weighted mean 3.5 eggs) but were laid frequently (weighted mean 9.4 days between clutches). The farm and hen prevalences of Libyostrongylus douglassi infection were 33% and 40%, respectively.