Carbohydrate and lignin contents of plant materials used in animal feeding

A total of 115 samples representing 38 different feedstuffs was analysed for carbohydrates and lignin. The samples were analysed for low-molecular weight (LMW) sugars by high-performance liquid chromatography, starch, fructan and mixed linked β(1 → 3;1 → 4)-D-glucan by colorimetry, total, soluble and insoluble non-starch polysaccharides (NSP) by gas-liquid chromatography and lignin by gravimetry. For all but alfalfa meal, almost quantitative recovery of carbohydrates and lignin was obtained with a deviation between calculated and analysed values of less than 2 g kg⁻¹ dry matter. The correlation between calculated and analysed values was 0.985 (P < 0.0001).The concentration (g kg⁻¹ dry matter) of LMW-sugars varied from 5 g kg⁻¹ and up to 137 g kg⁻¹ with the lowest values found in cereal substitutes, whole grain cereals and by-products while the protein concentrates in general had the highest content of LMW-sugars (57–137 g kg⁻¹). Starch was the main polysaccharide in whole grain cereals where it varied from 468 g kg⁻¹ in oats to 690 g kg⁻¹ in maize, in cereal by-products (93–902 g kg⁻¹) and in tapioca (768 g kg⁻¹). In contrast, the concentration of starch was low in all protein concentrates but peas and faba beans. The lowest levels of NSP and lignin were found in maize flour (NSP, 21 g kg⁻¹; lignin, 4 g kg⁻¹) and the highest levels in oat hull meal (NSP, 503 g kg⁻¹; lignin, 148 g kg⁻¹). There was also a significant variation in NSP and lignin in protein concentrates with the NSP value varying from 189 g kg⁻¹ in faba beans to 451 g kg⁻¹ in white lupins and with lignin varying from 12 g kg⁻¹ in white lupins to 133 g kg⁻¹ in sunflower cake. Grass meal, alfalfa meal and sugar beet fibre had in general high concentrations of NSP and lignin with values in grass and alfalfa meals of NSP: 329–426 g kg⁻¹ and lignin: 128–169 g kg⁻¹ and in sugar beet fibre 779 g kg⁻¹ and 35 g kg⁻¹, respectively.