Effect of dietary canola on fatty acid composition of bovine adipose tissue, muscle, kidney, and liver.

The purpose of this study was to determine effects of feeding canola and soybean products as protein supplements on fatty acid composition of adipose tissue and muscle of slaughter bulls and steers and on fatty acid composition of kidney and liver total lipids of bulls. Products included canola meal (CM), extruded canola (EC, full-fat), ground canola (GC, full-fat), soybean meal (SBM), and extruded soybeans (ES, full-fat). Tissues were obtained at slaughter from 75 crossbred beef bulls and 50 crossbred beef steers fed corn silage (17.2 to 29.7% of DM), ground corn (56.5 to 75.0% of DM), and protein supplements (6.8 to 21.6% of DM). The DMI was not influenced by dietary fat in either trial. Gain: feed was greater (P < .05) for bulls fed CM than for bulls fed ES, EC, or GC. Carcasses were not influenced appreciably by dietary fat. Adipose tissue of EC-fed cattle had the lowest percentage of 16:0 (P < .05, vs SBM, CM, and GC), whereas both EC- and GC-fed cattle had the highest 18:0 (P < .05). In muscle (pectoral), EC-fed bulls had a higher percentage of 18:1 than SBM-fed bulls (P < .05), and EC-fed steers had the lowest 16:0 and 16:1 and highest 18:0, 18:3, and 20:1 (P < .05). Kidney total lipids of EC- and GC-fed bulls had the lowest percentage of 16:0 and highest 18:1 and 18:3 (P < .05); bulls fed ES had the highest percentage of 18:2. Liver-lipid 16:0 was highest in ES-fed bulls and lowest in EC-fed bulls, which also had the highest 18:0 (P < .05). Bulls fed EC and GC had the highest 18:3 and 20:5 (P < .05). In conclusion, dietary full-fat canola and in some cases full-fat soybeans altered the fatty acid composition of lipids of adipose tissue, muscle, kidney, and liver of beef cattle.