Processing of barley and enzyme supplementation in diets for young pigs

Two trials were conducted to study the influence of heat processing (HP) of barley and enzyme supplementation (ES) to diets for young pigs. In trial one, six treatments arranged factorially with two types of barley processing (raw or cooked-flaked) and three levels of ES (0, 600 and 1200 mg/kg) were used. Each treatment was replicated four times and five piglets caged together formed the experimental unit. The enzyme complex contained 3100 U α-amylase/g, 400 U xylanase/g and 225 U β-glucanase/g. Growth rate, feed intake and feed conversion were measured at 14 and 28 days. Coefficient of total tract apparent digestibility (CTTAD) of organic matter (OM), energy, crude protein (CP), ether extract (EE), crude fibre and starch were assessed at 14 days. In trial two, 16 piglets were used to measure ileal viscosity (VISC), apparent ileal digestibility of starch, pH at the stomach, caecum and colon and volatile fatty acid (VFA) concentration in the caecum. Only diets containing 0 or 600 mg ES/kg were used. From 0 to 14 days after weaning, piglets fed HP barley grew faster than piglets fed raw barley (0.213 kg per day versus 0.184 kg per day, P=0.050) but the effect disappeared thereafter. Barley processing increased coefficient of apparent ileal digestibility (CIAD) of starch (0.993 versus 0.984 for HP and raw barley diets; P=0.017) but VISC, digestive pH or VFA concentration of the caecum were not affected. None of the total tract digestibility coefficients studied was affected by dietary treatment. It is concluded that HP of barley improved piglet growth during the first 14 day post-weaning and increased apparent ileal digestibility of starch, but that ES had no effect on performance of piglets.