External and internal characteristics of ostrich eggs from Dibete Ostrich farm.

A total of 39 ostrich eggs from three different flocks (A, B and C) were obtained from Dibete Ostrich Multiplication Unit (DOMU) and used to assess the internal and external egg quality characteristics. The experiment was conducted at Botswana University of Agriculture and Natural Resources (BUAN). Eggs were individually weighed prior to opening in the Meat Science Laboratory at BUAN using a saw in order to remove the internal contents. Parameters studied include egg weight, shell thickness, shell weight, shell percentage, egg contents weight, egg shape index, egg surface area, SWUSA, albumen ratio, shell ratio, yolk ratio, yolk index, shell volume, shell density, egg volume, egg specific gravity. Results showed that only the Haugh unit was significantly (p<.0001) different among the flocks while other parameters were not significantly (p>0.05) different from each other. Egg weight was highly and positively correlated with egg contents weight, egg surface area, albumen ratio and egg volume (r=0.97884, 0.99958, 0.60295 and 0.98344, respectively; p<.0001, <.0001, <.0001 and<.0001, respectively) but highly and negatively correlated with yolk ratio (r=-0.60498; p=0.0001) and weakly and positively correlated with shell weight, Haugh unit and shell volume (r= 0.4648; p=0.0029, 0.36348; p=0.0229, and 0.45506; p=0.0036, respectively). Shell thickness was positively and significantly correlated with shell weight, shell percentage, SWUSA, shell ratio and shell density (r=0.48506, 0.51737, 0.53380, 0.51737, 0.50416, respectively; P=0.0017, 0.0007, 0.0005, 0.0007, 0.0011, respectively). Egg specific gravity was positively and significantly (r=0.43329; p=0.0059) correlated with shell volume. Ostriches of different ages should be reared separately though there is very little variation in quality traits.