It was found that the two machines were of similar precision but gave different absolute values for the same egg. This was thought to result from a systematic error in the Schoorl and Boersma machine.
The Voisey and Foster machine was found to be easier to use but the time required to take each measurement was 2 1/2 times that for the Schoorl and Boersma apparatus. 相似文献
The genetic correlations between hatchability and both early and late embryonic mortality were high and negative as was to be expected from part × whole correlations. However the genetic correlation between early and late embryonic mortality was also consistently positive indicating common genetic determination of these two independent traits. 相似文献
Limited evidence existed suggesting negative genetic correlations between egg size and hatchability. It is suggested that this relationship may be of the curvilinear type and this is substantiated by some data from a population selected for increased egg size.
The results are discussed from the viewpoint of their possible significance in practical breeding programmes. 相似文献
A comparison of these methods indicated that under the conditions of this experiment, backscatter count yielded low coefficients of variation and did not demonstrate differences between inbred lines. The other methods showed differences between lines with non‐destructive deformation possessing an acceptable combination of precision, ease of operation and cost. Deformation and force at failure and egg shell stiffness required expensive non‐portable apparatus but stiffness was nevertheless thought to be a useful parameter. Direct measurement of shell thickness was acceptable but necessitated breaking the eggs. 相似文献