The expression of one behaviour by an animal limits the amount of time available to express other behaviours. In this experiment the amount of time animals had to forage was manipulated by decreasing the rate of food reinforcement available from a foraging device (the 'Edinburgh Foodball'). The aims of this experiment were to examine how decreased reinforcement rate affected the expression of foraging behaviour and the time budget of pigs. Six pregnant primiparous sows (Sus scrofa) were individually and sequentially exposed to two treatments-high or low reinforcement rate from the foraging device-in a balanced manner. Pigs responded to a decrease in reinforcement rate by increasing the proportion of time foraging and the rate of foraging responses, and by decreasing the time between foraging responses. On both treatments time spent feeding remained constant and daily food intake was significantly lower on the low reinforcement rate. Pigs during the hours of observations used (daylight) time spent sleeping first and then time from resting to accommodate the increase in time spent performing foraging behaviour. Furthermore, the results suggest that the amount of time spent searching for food is dependent upon the amount of time spent feeding and not, as expected, dependent on the amount of food consumed. The results suggest that foraging pigs are using a 'rule of thumb' controlling qualitative and quantitative aspects of foraging behaviour, which is based on maintaining a constant amount of time spent feeding.
- Time budget