Performance and carcass characteristics of growing-finishing pigs fed barley-based diets supplemented with Linpro (extruded whole flaxseed and peas) or soybean meal

Abstract

The objective of this experiment was to determine the effects of feeding graded levels of Linpro (a 50:50 combination of extruded full-fat flax seed and peas) on pig performance and carcass traits, particularly the fatty acid composition of backfat. Eighty crossbred pigs (Camborough 15 Line female × Canabred sire, Pig Improvement Canada Ltd., Airdrie, AB) weighing an average of 22.7 ± 2.2 kg were assigned on the basis of sex, weight and litter to one of five dietary treatments in a 5 × 2 factorial arrangement (treatment × sex). The experimental diets were based on barley and soybean meal and contained 0, 7.5, 15, 22.5 or 30% Linpro during the growing period (22.7–69.7 kg) and 0, 6, 12, 18 or 24% Linpro during the finishing period (69.7–111.1 kg). Digestibility coefficients for dry matter were not significantly affected by incorporation of Linpro in the diet. Digestibility coefficients for crude protein (P = 0.01) and gross energy (P = 0.04) exhibited a cubic effect due to Linpro incorporation with the highest digestibility coefficients observed for pigs fed 7.5% Linpro. Over the entire experimental period (22.7–111.1 kg), daily gain was affected both linearly (P = 0.02) and quadratically (P = 0.04) by Linpro inclusion. The most rapid gains were obtained by pigs fed 7.5% Linpro (6% in finisher), while pigs fed 30% Linpro (24% in finisher) gained weight the slowest. Feed intake was not significantly affected by Linpro inclusion, while feed conversion exhibited a quadratic effect (P = 0.02) with pigs fed the highest and lowest levels o f Linpro showing the poorest feed conversion. Linpro inclusion, had no significant effects on carcass traits including slaughter weight, carcass weight, dressing percent, carcass value index, lean yield, loin fat or loin lean. Inclusion of 30% Linpro (24% in finisher) significantly (P < 0.05) increased the levels of linolenic acid in backfat and this increase could provide significant health benefits for consumers of pork. Linpro would appear to be an acceptable alternative to soybean meal as a protein supplement for use in growing-finishing swine diets and can be incorporated at levels as high as 22.5% in the grower period and 18% in the finisher period without detrimental affects on pig performance. Key words: Swine, extrusion, flax, peas, digestibility, growth, backfat