Mucilage in linseed: effects on the intestinal viscosity and nutrient digestion in broiler chicks

A study was conducted to obtain more information on the role of mucilage in the adverse effects produced by the use of linseed in chick diets. Mucilaginous material was extracted from linseed with hot distilled water (80 °C) for 2 h; after filtration the water-soluble extract was freeze-dried and ground. A maize/soyabean meal basal diet with supplemental linseed mucilage extract (0, 4, 8, 12 and 16 g kg−1) was given to chicks from 8 to 28 days of age. During the last 3 days the excreta were collected quantitatively, then the chicks were slaughtered and the jejunal and ileal contents were collected. Feeding the mucilage extract-containing diets to birds increased markedly, from 4.35 to 18.89 mPa s, the digesta viscosity at jejunal level. The apparent faecal digestibility of crude fat and major fatty acids and the dietary AMEn value (metabolisable energy corrected to zero nitrogen retention by the body) were linear and negatively influenced by the inclusion level of mucilage extract. However, the presence of mucilage in the diet did not affect the apparent ileal digestibility of crude protein and individual amino acids. These results seem to suggest that mucilage in linseed has lower antinutritional properties than those reported for whole linseed or linseed meal when included in chick diets. © 2002 Society of Chemical Industry