| Abstract: | 9 pigs of a live weight at the beginning of the experiment of 33 kg received in 3 consecutive series of experiments (3 animals/group) a basic barley ration of 1.0-1.2 kg per animal and day. In groups 1 to 9 the following supplements were given: 1 = without N-supplement, 2 = 10.5 g urea, 3 = 79 g dried skim milk, 4 = 11 g urea, 5 = without N-supplement, 6 = 110 g horse bean coarse meal, 7 = without N-supplement, 8 = 95 g dried skim milk, 9 = 120 g horse bean coarse meal. In groups 1-6 the ration was supplemented with 150-165 g DM partly hydrolysed straw meal per animal and day. After 20 days the animals received a single dosis of 0.5 g/kg0.75 15N-urea (72.1 atom-% 15N-excess) with the morning meal of the first day of the experiment. During the four days of the experiment groups 1-6, due to the straw meal supplement, excreted significantly higher N-amounts than the corresponding groups 7-9. In comparison with the first day of the experiment (1 h after the morning meal) urea concentration in the blood decreased to the following percentage in the sequence 1-9: 64; 65; 77; 54; 64; 73; 82; 88; 84 on the second day of the experiment (1 h before the evening meal. Between the excretion of 15N-excess in faeces (y = mg) during the four days of the experiment and the concentration of urea in the blood (x = mmol/l) there was the following significant negative correlation: y = -40.1 X +340.(ABSTRACT TRUNCATED AT 250 WORDS) |
