Effects of chlordiazepoxide on competition for a preferred food in the rat

In rats with previous experience of chocolate this is a food that is rapidly taken and eaten for which rats will compete. Female rats preferred white and milk chocolate to dark chocolate, but male rats displayed no preferences among the different types, regardless of whether it was offered in a novel environment or in the home-cage. Chronic (5 days) administration of chlordiazepoxide (5 mg/kg) to dominant animals, as judged in a previous competition for chocolate, led to a fall in success, whether the animals had been previously housed together for 1, 2 or 6 months. There were no significant effects of chlordiazepoxide treatment on the behaviour of subordinate rats. The potential usefulness of serial chocolate competition as a test of dominance is discussed.