Large intestine morphology and microflora activity in piglets fed diets with two levels of raw or micronized blue sweet lupin seeds

Abstract Legumes are important protein source in human and animal nutrition. The experiment was performed on 32 weaned piglets divided into four groups. Animals were fed cereal-based diets with 109 g/kg of soybean meal and 150 g/kg of raw (LLR) or micronized (LLM) blue sweet lupin seeds or diets without soybean meal and with 300 g/kg of raw (HLR) or micronized (HLM) lupin seeds for 21 days. At the end of experiment tissue samples and digesta were taken from the caecum, proximal, middle and distal colon for histological measurements and analyses of dry matter, pH, short chain fatty acids, ammonia, phenolic compounds and bacterial enzyme activity. The animals fed diets with high lupin level had significantly smaller body weight gain (P = 0.001) than those fed diets with low lupin level aside from the micronizing process. Both, level and form of lupin had small effect on morphology of the large intestine. Dry matter content increased in caecum (P = 0.021) and in proximal colon (P = 0.048) in pigs fed diets with high level of lupin and in middle colon (P = 0.040) in pigs fed diets with micronized seeds. Only valeric acid concentration in caecum (P = 0.021) and proximal colon (P = 0.005) was affected by micronizing process. In distal colon valeric (P