A Veterinarian Interested in Studying the Causes of Enteroliths in Horses

question 32

Multiple Choice

A veterinarian interested in studying the causes of enteroliths in horses suspects that a diet high in alfalfa may be a cause. The veterinarian decides to use the following design: identify 30 horses at high risk for enteroliths, and divide them into 10 groups of 3 horses. Some groups consist of horses in barn stalls, some groups consist of horses in outdoor paddocks, and some groups consist of horses in pastures. Within each group, one horse is randomly assigned to an alfalfa diet, one is assigned to a grass hay diet, and one horse is fed oat hay. When a horse is in a pasture, all the other horses in that pasture will also receive the diet of the study horse. Therefore, only one horse could be selected from a given pasture. The blocking is done:

• A)to reduce the potentially confounding effect of comparing more than two treatments.
• B)to reduce the potentially confounding effect that the type of housing may have.
• C)to increase the treatment effects.
• D)All of the answer options are correct.