Correlates of eggshell thickness
This study discussed the effects of age and genotype of birds and location of farm on eggshell thickness. The ultimate objective of the study is to determine the correlates of eggshell thickness which may be relevant to improve eggshell thickness. Secondary data on eggshell thickness collected from the Agricultural Development Programme(ADP), Umuahia were analyzed using the three-factor(fixed effect) analysis of variance. The results of the analysis showed that effects of location and genotype appeared not to be statistically significant. Age of birds was statistically significant. The two factor interactions: L X G and A X G also appeared to have significant effects on eggshell thickness. This may be attributable to the violation of the assumptions of the analysis of variance. A preliminary evaluation of the data showed that although the sample size is large, the data do not seem to have come from a normal population. The variance does not appear to be constant. Also, the data do not appear to be completely random. Therefore, a more appropriate data which meet the assumptions of the analysis of variance model should be collected in order to arrive at a more reliable conclusion.
KEY WORDS: factor, fixed effect, analysis of variance, significant, sample, population, model and random.