Study questions

1. Imagine a particular shape of a poultry house (maybe the one depicted in this case study) to be used to repeat this experiment. Assuming that 16 smaller surrounds have been made, each to contain 12 chicks. Describe how the experiment is to be laid out within the poultry house and how surrounds are to be allocated to diets. Sketch the analysis of variance.
2. Suppose that you find that the poultry house has room for only eight of the surrounds described in question 1. It is decided that the experiment should be run twice with different batches of chicks on each occasion. Describe how you will design the experiment and sketch the analysis of variance. Why do you think it is considered necessary to replicate this experiment when only eight surrounds are available?
3. The chickens in this study were of mixed sex. Describe how you would take sex into account within the experimental design and sketch the analysis of variance.
4. In poultry experiments it might sometimes be appropriate to take into account initial weight. Give an example from the literature where this has been done and describe how the researcher made use of initial weight, either in the design or in the analysis.
5. Assume that 5% of chickens fed the control diet died and that spent yeast reduced mortality, on average, by half. Assuming equal numbers of chickens per diet determine how many chickens will be needed in the experiment to demonstrate that the average effect of spent yeast on mortality is statistically significant (P<0.05).