Nine Polish varieties of pea (P. sativum L.) differing in flower colour, from white to purple, were evaluated for chemical and amino acid composition and in vitro for predicted ileal digestibility of protein (pdN) and predicted digestibility of energy (pdE) for pigs. In selected varieties differing in tannin content the apparent metabolizable energy value corrected for zero N balance (AME_N), apparent digestibility of protein and fat and effect of enzymes reducing viscosity of digesta on this parameters were estimated in chickens; apparent metabolizable energy value (AME), true digestibility and biological value of protein was determined in rats. Tannin content had most pronounced negative effect on protein digestibility in chicken (r= -0.93; P<0.05) and rats (r= -0.89; P<0.05), pdN for pigs (r= -0.98; P<0.001) as well as AME_N for chicken (r= -0.99; P<0.001) and AME for rats (r= -0.95; P<0.01), while nutrient content in peas had no significant effect on measured parameters. AME_N values of pea did not depend on supplementation of pea-containing diet with xylanase. Seeds of coloured-flowered cultivars, which are rich in tannins are less effectively utilized by monogastric animals than white-flowered ones. The degree of decline in nutrient utilization depends on tannin content in the seeds, which is correlated with the colour of the flowers.