Stress in cows prior to slaughter. What is the level of stress (if any) that cows undergo prior to being slaughtered? To answer this question, researchers designed an experiment involving cows bred in Normandy, France (Applied Animal Behaviour Science, June 2010). The heart rate (beats per minute) of a cow was measured at four different preslaughter phasesâ€”(1) first phase of visual contact with pen mates, (2) initial isolation from pen mates for prepping, (3) restoration of visual contact with pen mates, and (4) first contact with human prior to slaughter. Data for eight cows (simulated from information provided in the article) are shown in the accompanying table. The researchers analyzed the data using an analysis of variance for a randomized block design. Their objective was to determine whether the mean heart rate of cows differed in the four pre-slaughter phases.
a. Identify the treatments and blocks for this experimental design.
b. Conduct the appropriate analysis using a statistical software package. Summarize the results in an ANOVA table.
c. Is there evidence of differences among the mean heart rates of cows in the four pre-slaughter phases? Test using a = .05.