ILEAL AND FECAL DIGESTIBILITY IN PIGLETS OF FIELD BEANS (VICIA-FABA L) VARYING IN TANNIN CONTENT

The ileal and faecal digestibility of nutrients of four varieties of f ield beans was determined in piglets (15-30 kg) fitted with a post-val vular T caecum cannula. The varieties differed in their content of con densed tannins. Beans of a white flowering variety (cultivar 'Blandine ') had a low content of condensed tannins (< 0.1%). The other beans or iginated from coloured flowering varieties and had a medium (0.4%) (cu ltivar 'Herz Freya') or high tannin content ( 1.0%) (cultivars 'Mythos ' and 'Alfred'). The low-tannin beans were evaluated as such and after autoclave treatment (30 min, 105-degrees-C). Beans were included in t he diets at a level of 300 g kg-1. Diets were tested in 18 piglets in two experimental periods (n = 6). The ileal N digestibility (%) was hi gher (P < 0.05) for the low-tannin beans (85.7) than for the medium- a nd high-tannin varieties (73.7, 72.4, 71.5 for 'Herz Freya', 'Mythos' and 'Alfred', respectively). Faecal N digestibility values were 89.3, 85.7, 82.4 and 79.4 for 'Blandine', 'Herz Freya', 'Mythos' and 'Alfred ' beans, respectively. The values for 'Blandine' and 'Alfred' beans di ffered significantly (P < 0.05). For individual amino acids difference s in digestibility between 'Blandine' beans and the average value for beans of the three tannin-containing varieties ranged from 8 units for aspartic acid to 18 units for cystine. Autoclaving the low-tannin fie ld beans 'Blandine' did not improve their N digestibility at the ileal (85.7 (raw) versus 82.3 (autoclaved)) and the faecal level (89.3 vers us 88.9). Apparent ileal digestibility of starch was similar for all r aw and the autoclaved beans. The absence of condensed tannins in field beans seems to have a positive effect on ileal and faecal digestibili ty of particularly crude protein and amino acids of faba beans in pigs . Autoclaving low-tannin faba beans did not improve the nutritional va lue for pigs.