Exemplary calculations of native thiamine (vitamin B₁) and riboflavin (vitamin B₂) contents in common cereal-based diets for monogastric animals

B vitamins, such as thiamine and riboflavin, are often supplemented in diets for farm animals to prevent deficiencies. However, information on the content of these two B vitamins in organic feedstuffs is scarce. Recently, up-to-date information was published by our group. The objective of this work was to use present data to determine the native contents of thiamine and riboflavin in diets used for monogastric animal feeding in organic farming. We used the results of our recent study on the native thiamine and riboflavin contents of organic wheat (Triticum aestivum L.), rye (Secale cereale L.), triticale (Triticosecale L.), barley (Hordeum vulgare L.), oats (Avena sativa L.), field peas (Pisum sativum L.), field beans (Vicia faba L.), and blue lupins (Lupinus angustifolius L.) from various variety field trials, which were conducted throughout Germany over 3 years, to calculate the minimum and maximum native amounts of thiamine and riboflavin in exemplary practical diets for swine and poultry. We found that exemplary common cereal-based diets in organic farming exceeded the thiamine recommendations for swine and poultry. However, riboflavin was deficient in most exemplary diets. To increase native riboflavin contents in the diet (i.e. for 100% organic diets), feedstuffs other than cereals and home-grown grain legumes are needed in monogastric animal feeding. In organic farming, roughage plays an important role. The inclusion of grass-clover silage has the potential to increase the native riboflavin contents in the diet. Evaluation of the use of grassland-derived or other products as suppliers of B vitamins, especially for monogastric animal feeding in organic farming, seems promising to improve riboflavin supply.