Fermented co-products and fermented compound diets for pigs: a review

This review deals with the properties of fermented diets and their effects on growth performance and gastrointestinal environment of pigs. In addition , some possible modes of action are hypothesized. Starch and sugar rich Liq uid co-products have a high potential for fermenting during storage. Soakin g compound feed with water is another means of achieving a fermented diet. These diets are characterized by a pH between 3.5 and 4.5, high levels of l actic acid, and, to a lesser extent, acetic acid and alcohol. Fermented die ts seem to improve growth performance of pigs, compared with non-fermented diets. The exact reasons for this are not pet clear; however, some hypothes es are given. Based on a Limited number of studies, fermented diets reduce the gastric pH and the number of Coliform bacteria in the gastrointestinal tract compared with non-fermented diets. Furthermore, there are some indica tions that fermented diets may positively affect pancreatic secretion, vill us architecture, digestibility and absorption of dietary nutrients. Ferment ed diets may reduce the physical activity of pigs. More specific studies on the effect and modes of action of fermented diets are needed to allow firm er conclusions to be drawn. (C) 1999 Elsevier Science B.V. All rights reser ved.