Legume Seeds and Rapeseed Press Cake as Replacers of Soybean Meal in Feed for Fattening Pigs

The possibility of replacing soybean meal with a mixture of legume seeds and rapeseed press cake (RPC) was evaluated on 60 pigs weighing about 30 kg at the beginning of the experiment. Pigs were allocated to 5 experimental groups. Group I (control) received standard feed mixture containing soybean meal as a main protein source. Next groups received rapeseed press cake (RPC) mixed with fodder pea (Pisum sativum var. Ramrod) - group II, field bean (Vicia faba var. Kasztelan) - group III, blue lupin (Lupinus angustifolius var. Regent) - group IV or yellow lupin (Lupinus luteus var. Mister) - group V. Soybean protein was replaced by experimental protein sources at about 30% in grower (17% legumes, 13% rapeseed press cake) and at 100% in finisher diets (experimental proteins in equal ratio accounted for about 55% of mixture protein). Limited feeding was used, water was available ad libitum. Half the animals in each group received mixtures supplemented with fibrolytic enzymes Ronozyme VP and Ronozyme WX. Apparent digestibility of feed nutrients was estimated using the balance method on 30 fatteners not used in the fattening experiment, weighing about 40 kg for grower and 70 kg for finisher diets. Gross composition of legume seeds and RPC, amino acid composition of their protein, glucosinolate content in RPC and tannin content in faba bean and alkaloids in lupins were analysed. Carcass traits and meat quality were also estimated. Legume protein content ranged from 19.6% (pea) to 39.8% (yellow lupin). RPC protein contained more sulphur amino acids than legume protein. There was no significant difference in protein and fat digestibility. Body weight gains of fatteners fed with blue lupin were comparable to controls but significantly lower than those of the remaining groups. Supplemental enzymes improved body weight gains of fatteners receiving field bean. There was no significant difference in carcass traits and meat quality except for sensory analysis. It is concluded that the mixture of RPC and legume seeds can replace soybean meal in fattener feed.