COMPARISON OF FABA BEANS (VICIA FABA) WITH SOYBEAN MEAL OR FIELD PEAS (PISUM SATIVUM) AS PROTEIN SUPPLEMENTS IN BARLEY DIETS FOR GROWING–FINISHING PIGS

Forty-eight Yorkshire pigs were fed, ad libitum, 18% protein diets which contained 0, 7.5, 15 and 30% faba beans (Vicia faba L. cv. Ackerperle), over the growth period from 25 to 90 kg liveweight. An additional 16 pigs were similarly fed diets containing 15% faba beans or 15% field peas (Pisum sativum L. cv. Trapper). In experiment I, replacement of soybean meal (44% protein) by faba beans as the protein supplement resulted in a significant (P < 0.05) linear reduction in growth rate, from 784 g to 727 g/day, and a linear improvement in Carcass Value Index, from 103.5 to 106.5. The latter effect appeared to be a result of a reduction in backfat thickness rather than an increase in areas of lean tissue. Feed to gain ratio of pigs fed the 7.5% faba bean diet (3.30 kg feed/kg gain) was significantly (P < 0.05) better than all other levels examined. In experiment II, significant differences in live performance and in carcass characteristics of pigs fed faba beans or field peas were not detected. Calculation of the replacement value of faba beans, in relation to barley and soybean meal prices, confirmed the conclusions from other studies which suggested that the greatest benefit is obtained when faba beans constitute part but not all of the supplementary protein in diets for growing–finishing pigs.