Effects of partial replacement of wheat by oats and tallow, or tallow residue in the diets of growing pigs

Abstract

Fifty-six female pigs were used to evaluate a tallow derived by-product of soap manufacture as an energy source for pigs and to study the effect of replacing increasing proportions (0, 33, 66 and 100 per cent) of the energy supplied by wheat in pig diets with a combination of oats and tallow or oats and the tallow by-product. All diets were fed in restrictive amounts and pig performance and carcase quality were compared between 20 and 45 kg and 20 and 70 kg liveweight. The tallow by-product and the feed grade 'gut' tallow used in the experiment were found to contain 31 and 38 MJ of digestible energy for pigs respectively. Substitution of 33 or 66 per cent wheat in the diet with an equal amount of energy from oats and tallow or oats and the tallow by-product had no significant effect on pig performance or carcase quality but reduced the cost of the diet by up to $6 tonne-1. The complete replacement of wheat in the diet with either oats and tallow or the tallow by-product significantly depressed growth rate, food conversion and the apparent digestibility of dietary protein by the pig. Linear fat measurements and the proportion of lean in the ham at 70 kg liveweight did not differ . . significantly between treatments.