Factors affecting digestibility of barley-based diets for growing pigs

This study examined the effect of variety, location of production, enzyme addition and heat treatment on the apparent overall and ileal digestibilities of barley-based diets produced in Northern Ireland and fed to growing pigs. The study was carried out in two parts, each using 12 post valve T caecum cannulated (PVTC) pigs. The two most commonly produced barley varieties in Northern Ireland (NI), grown at three locations, were studied. The variety “Dandy” was found to be slightly inferior to “Riviera” in terms of overall and ileal digestibility and also in digestible energy (DE) content (15.2 vs. 15.6 MJ/kg DM, P < 0.05). Location effects were observed for both overall and ileal digestibility coefficients. Enzyme addition was investigated from three perspectives: (1) the effect of β-glucanase and xylanase supplementation, (2) the effect of β-glucanase supplementation alone and (3) the effects of three levels of β-glucanase supplementation. There was a lack of response to supplementation at either the overall or ileal level. Heat treatment was applied at 70 °C, 80 °C and 90 °C and increased overall digestibility of neutral detergent fibre (NDF) by 5%. Ileal digestibility of dry matter (DM), crude protein (CP) and energy were reduced by 3% when heat treatment was applied at 80 °C.