Two hundred gilts and 200 barrows, housed within sex in pens of 25, were randomly allotted to two replications of four dietary treatments to determine the effects of incorporating 30, 20, 10 or 0% extruded soybeans (ESB), displacing a commercial protein supplement, in barley-based grower and finisher diets for pigs. Growth, feed intake and carcass quality of the pigs, and meat quality and fatty acid composition of the pork from a random subset of the pigs on test were determined. No sex × diet interactions were observed. ESB inclusion rate had no effect on growth rate; however, per-pen feed consumption decreased numerically with increasing ESB resulting in an improvement in feed efficiency. The 30% ESB inclusion rate increased carcass fat content (P < 0.05) compared with the control, whereas lean content was unaffected. Meat colour and marbling score were similar across all treatments whereas fat and lean firmness was reduced by the 30% ESB inclusion rate (P < 0.05) compared with all other treatments. Increasing ESB in the diet altered the fatty acid content of the pork by decreasing the amount of short-chain saturated and monounsaturated fatty acids and increasing the amount of long-chain polyunsaturated fatty acids (PUFA). The results of this study indicate that ESB can be used as the sole source of supplemental protein in barley-based diets for pigs with no detrimental effects on performance and minimal negative effects on carcass and meat quality. Alteration of fatty acid content of pork from feeding ESB has both positive and negative implications for consumer acceptance by increasing PUFA content while concomitantly increasing the risk of premature oxidation. Key words: Extruded soybeans, pigs, pork, growth, fatty acids, meat quality
Tannins as feed additives to modulate ruminal biohydrogenation: Effects on animal performance, milk fatty acid composition and ruminal fermentation in dairy ewes fed a diet containing sunflower oil