Investigation on egg productivity of Ostriches (Struthio Camelus) 2. Morphologycal characteristics of eggs
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DOI: 10.22620/agrisci.2010.03.011
Author: Nikolova, M.
An investigation with five females and two males (sexual ratio of 1:2.5) of the Black African ostrich (Struthio camelus) during their first and second reproductive seasons was carried out. The birds were reared extensively during the whole experimental period. The average egg weight depending on the age of the ostrich hens was 1338.27±18.70g in the first and 1442.95±19.51g in the second reproductive year, respectively. The significant increase of weight of the different egg components within the reproductive phase and between the first and the second reproductive ages indicated the continuing growth and development of the hens. The average annual values were 730.92±6.73 and 789.89±5.66g for the egg white, 342.12±2.90 and 370.78±1.79g for the egg yolk, and 265.22±1.48 and 281.27±1.72g for the shell, respectively. Depending on the reproductive age, the ostrich eggs contained 54.60±0.23 and 54.78±0.13% of egg-white, 25.70±0.18 and 25.67±0.12% of yolk, and 19.80±0.13 and 19.68±0.14% of shell on the average. The participation of yolk in the egg structure significantly increased with age, the content of egg-white – significantly decreased and that of the shell showed a tendency of slight decrease. Shell thickness indicated a slight tendency of reduction during the reproductive season for all the studied ages, the average values being 1.89±0.05 in the first and 1.75±0.03mm in the second reproductive year. Ostrich eggs were significantly elongated at the start and the end of the egg laying period. The egg-shape became significantly elongated when the hens grew in age, the average values being 81.79±0.27 and 80.79±0.28% for the first and the second reproductive cycle respectively.