Influence of physicochemical properties of fibrous diets on behavioural reactions of individually housed pigs

The objective of the study was to predict time spent on different behavioural activities of individually housed growing pigs from physicochemical properties of feeds. Maize cob, maize stover, sunflower hulls, veld grass, sawdust and lucerne were used to provide a wide range of physicochemical properties. The fibre sources were included at 0, 80, 160, 240, 320, 400 g/kg inclusion levels in pig diets. Time spent eating, drinking, lying down, sitting/standing and other activities was observed using video cameras. Pigs spent most of their time lying down (71.4%) followed by time spent eating (23%), drinking (3.2%) and sitting/standing (2.4%). Digestible energy (DE), bulk density (BD), acid detergent fibre (ADF) and water holding capacity (WHC) were the most important variables for predicting time spent on different behavioural activities (P < 0.001). Bulk density and ADF produced linear responses with time spent eating and drinking (P < 0.001). There was a quadratic response between time spent lying down and ADF content of feed (P < 0.001). Water holding capacity was the most important physicochemical property of feeds for predicting number of visits made by the pig to the feeder. Total time spent on each visit by a pig per day was best predicted by ADF. In conclusion, physicochemical properties of diets alter behaviour of penned growing pigs. (C) 2013 Elsevier B.V. All rights reserved.