Evaluation of pea screenings and canola meal as a supplementary protein source in barley-based diets fed to growing-finishing pigs

Abstract

The effects of substituting canola meal (CM) and ground pea screenings (PM) for soybean meal (SBM) in barley (B)-based diets were determined with a factorial design using 60 male castrates (3 pen−1) over the period 25–97-kg average liveweight. The five mash diets (B/SBM, with 15% SBM; B/CM, with 18.7% CM; B/CMp, with 12.4% CM + 14.1% PM; B/PMc, with 6.1% CM + 28.3% PM; and B/PM, with 42.5% PM) contained 2.4% supplement (minerals and vitamins) and were fed ad libitum. Growth rate (821, 845, 850, 880 and 812 g d−1, respectively, P < 0.06) was increased with the CM–PM blends, but gain:feed was unaffected (283, 289, 294, 298 and 293 g kg−1, P > 0.10). Compared with the SBM-fed pigs, using CM reduced the dressing percent, carcass grade, apparent digestibility of energy and nitrogen but increased liver weight (P < 0.01). The B/PM diet may have been deficient in isoleucine for pigs in the initial weeks, but subsequent performance was not impaired. Compared with B/CM-fed pigs, B/PM pigs had higher carcass grades (P < 0.05) and their lean tissue had relatively more marbling (P < 0.01) and a higher degree of saturated fat (P < 0.01). Differences among the five diets, however, did not affect the sensory evaluation of the cooked lean (P > 0.05). Apart from an apparently lower digestibility of energy and nitrogen, results with the mixed-source diets confirmed that CM and PM were complementary sources of supplementary amino acids for growing-finishing pigs. Key words: Pigs, canola meal, peas, growth rate, carcass