Nutritive value for growing pigs of pekilo protein and torula yeast grown in spent sulphite liquour

The digestibility and nutritive value of pekilo protein (Paecilomyces varioti), and torula yeast (Candida utilis) were determined for four pigs weighing 35—50kg. The proportion of pekilo or torula was 30% of the barley-based diet. The crude fat was determined by the standard ether extraction method and by the HCl-ether method. The first method indicated a low fat content and a highly negative digestibility of fat, but the second showed that the pig is able to digest and absorb a large part of the ether-insoluble fat. The energy value thereby increased 14 % for pekilo and 12 % for torula over those obtained by the conventional ether method. The same energy value was obtained for barley by both methods. The energy values (HCI-ether method) obtained for pekilo and torula were 0.96 and 0.95 F.U./kg DM(F. U. = 0.7 kg starch), or 13.41 and 12.98 MJ ME/kg DM, respectively. The protein values, corrected for nucleic acid nitrogen, were 434 and 358g DCP/kg DM. The only significant difference between pekilo and torula was the DCP value (P< 0.001). The nitrogen balances in the pekilo and torula trials were very high and identical (24.4 and 24.0 g N/d), confirming the value of these feeds as protein supplements to cereal feeds for pigs.