Effects of feeding incremental levels of maize cob meal on physicochemical properties of bulkiness in digesta in growing pigs

• Changes in the physicochemical properties of digesta were assessed.
• There was a quadratic increase in stomach contents as maize cob inclusion level increased and the weight of the stomach also increased.
• Maize cob inclusion level only affected the pH of the distal colon but not the stomach, ileum, caecum and proximal colon.
• Changes in swelling capacity and water holding capacity differed with gut segments.

The objective of the study was to assess the influence of inclusion levels of maize cob meal on the physicochemical measurements of feed bulk of digesta in different gastrointestinal tract segments of growing pigs. Eighteen pigs were allocated to each of six diets containing maize cob levels at 0, 80, 160, 240, 320 and 400 g/kg DM inclusion levels. The initial mean body weight (BW) was 14±1.2 kg and the pigs were fed ad libitum. After four weeks, weights of the gastrointestinal tract (GIT) segments were recorded and the contents of digesta from the stomach and intestines were sampled for analyses of water holding capacity (WHC) and swelling capacity (SWC). In general, the WHC of digesta increased (P<0.05) from the stomach to ileum then decreased as the digesta moved through the hindgut. The WHC of digesta in the stomach, ileum and caecum decreased (P<0.05) with maize cob inclusion level. The SWC in the stomach decreased with the inclusion level of maize cob meal. The SWC of caecal digesta increased with maize cob inclusion level (P<0.05). Maize cob inclusion level had no effect on pH of all segments, except in the distal colon. Changes in the bulkiness of digesta along the GIT are, therefore, influenced by maize cob inclusion level in pig diets.