Growing goslings were divided Into 4 experimental groups and fed concentrates /the control/ or supplemented diet of oat alfalfa meal, dry beet pulp In the amounts providing additional 5-10 g of crude fibre, from 4-8 week, and 15 g from 9-11 week, per day and head as compared with the control group. The effect of crude fibre source on crude protein concentration in dry matter of duodenum, small intestine, caecum and large intestine contents of goslings in 5, 8, 11 week of life, was studied. Concentration of crude protein in the content of allintestine sections studied, given the supplement of crude fibre was higher than in the control group. However, it increased with the age of goslings, regardless of the diet applied. The level of total protein in blood serum of the goslings fed diets including crude fibre of different content and quality, did not very significantly among the groups; it increased significantly with the age. Balance trials performed in 8 week of life, showed that nitrogen retention and apparent digestibility of crude protein dropped with the increase in cellulose and lignin content in the ration.