Guidelines to Evaluate Ostrich Bird Size & Development
Over the years many photos of ostrich were taken with some sent to us. Recently there was reason to discuss the issue of how to visually judge bird development. These illutrations were put together with several photos side by side as a single illustration. For this illustration all photos include men alongside the birds as a guide to their size.
Photos A, B and C in figure 1 are birds from the Blue Mountain benchmark weight gain trial carried out in 1996 and discussed here and here. Using the fence and the man with these birds as a guide, it is possible to see how large these chicks were at the time of weighing. They were from good genetic origin, but good genetics still require the correct nutrients to achieve their optimum growth, health and performance. Observing these chicks one can tell they are young by their feathers and the faces. They were around 195 days (27 weeks) and weighed around 85kgs liveweight.
Photo D is an illustration of a scientist in the Netherlands scanning a breeder as part of a study to understand why the breeders were not breeding well. The scientist is kneeling and as you can see the bird looks very small alongside him. Note the very tiny body size. This study was carried out in 2002.
Photo E is a photo of some proud owners showing off their new breeders that they published on their website in 2003. These owners were part of an investment group starting an ostrich production business in Brazil. As new entrants to ostrich production, they had no idea that this bird was severely undersized. The head height of the bird is hardly as high as the men – her feather colouring confirms she is a mature bird and not a chick as in photos A, B and C.
The birds in photos D and E are severely stunted in their growth – this is not simply poor genetics, it is also poor diet during the growth period. Clearly, if a bird has failed to thrive during the development stage, their reproductive organs will not be able to develop adequately and this will impact on future production potential.
Our president Daryl Holle took a few photos of his own birds to provide bench mark guidelines to enable producers to gauge their own bird’s development. Always remember that benchmarking is about setting a base-line to judge one’s own bird performance and aiming to improve on. Figure 2 illustrates the measurement points and provides the figures for a fit and productive 4 year old breeding hen.
Height measurements need to be read with care…there are many tall birds with poor frames. The height must be accompanied with good depth, width and length of frame. This hen measures 1.5m (59 inches, which is 1 inch short of 5 feet) from the ground to the highest point on her back.
A quality bird should have good depth. Take the measurements from the top most part of back to the bottom of her fat pan area just behind the legs. The measurements on this hen: 68.7cm (27 inches)
Take the measurement from the base of the neck to the very base of the tail. This hen measures 1.14m (45 inches) from the very base of neck to the very base of her tail. Take the measurements from where the neck goes into the back and exactly where the tail begins to rise from the back.
Take an imaginary line (shown in green) from outside the drum muscles and measure straight across the back. The measurement on this hen is 66.04cm (26 inches).
Figure 3 provides a few more photographs of birds taken during the 1990s when there were some good genetics around supported by adequate nutrition. The men in Photographs A, B and C were all around 1.9m tall (6ft 3”) and taken in the United States. Photo D was taken in Australia. I don’t have any information on the size of these men, but it is evident from their comparative size to the fencing that these were strong men of reasonable build and height. The bird they are handling is an 18 month old bird.
The bird in Photo A is a 16 month old Bird that Daryl Holle purchased as a 3 month old bird in the early 1990s. Photo B is a Red Male – observe the amazing size of those feathers. At that time Reds were believed to produce poor feathers. This photo proves that when they have the adequate nutrition they not only are very large birds, they also can produce magnificent feathers.
The immature feathers of the birds in Photo C illustrates how well slaughter birds can grow when fed and managed correctly. It was this photo that first caught my attention when seeking information on work carried out outside South Africa. At the time I was based in South Africa and aware that local farmers were seeking information. The internet as a source for information was in its infancy. Photo D, taken in Australia, illustrates the size of this bird.
These photos were taken at the start of the industry as it attempted to develop outside South Africa. They provide evidence of the underlying genetics. Achieving commercial success depends on producing birds to this standard as the starting point.