SUPPLEMENTATION OF VARIOUS PROTEIN-SOURCES WITH CRYSTALLINE AMINO-ACIDS IN DIETS FOR FATTENING PIGS

In a feeding experiment with PiDL fattening pigs the four treatments were cereal based diets with soybeanmeal, field beans (vicia faba), fi eld peas (pisum sativum ssp. arvense) or rapeseed meal as protein sour ces. Pigs were fed ad libitum in three phases (30-50,50-75,75-100 kg l ive weight). The ME-content of feed-components was calculated from det ermined coefficients of digestibility, the content of amino acids was analyzed. The provision of the pigs with energy and nutrients was in a ccordance with the recommendations of the Gesellschaft fur Emahrungsph ysiologie (1987). The experimental diets were calculated in a way that isoleucine was provided by the cereals and the respective protein sou rces whereas the amino acids lysine, methionine, threonine and tryptop han were supplemented in crystalline form according to the recommendat ions of provision. The contents of crude protein of the diets were 145 ,133 and 118 g per kg for phase 1-3 respectively. Biological performan ces were not different in pigs fed soybean meal, field beans or field peas. Daily gain was 619 g and feed per gain 3,17. Feeding rapeseedmea l caused a significant reduction of daily gain to 574 g. There were no differences in the portion of lean muscle being 57% for all treatment s. Calculated N-excretion was compared with conventional feeding witho ut supplementation of amino acids and was reduced to 60-70 % by the us e of crystalline amino acids in diets with soybean meal as well as wit h home grown protein sources.