NAKED OATS (Avena nuda) WITH AND WITHOUT LYSINE SUPPLEMENTATION, FOR BOARS AND BARROWS: GROWTH, CARCASS AND MEAT QUALITY, ENERGY AND NITROGEN METABOLISM

Abstract

Thirty-six boars and 36 barrows were fed four diets. The control was a fortified corn-soybean meal diet. Diets 50 L and 100 L were lysine-supplemented, and 48% and 95%, respectively, of the corn and soybean meal were replaced by Tibor naked oats. Diet 100 (unsupplemented) contained 95% naked oats. The diets were pelleted and given ad libitum to pigs housed three per pen. At a slaughter liveweight of approximately 90 kg, the left side of the carcass was used for carcass and meat quality examinations and samples were taken for fatty acid (FA) analysis. Additionally, 24 boars and 24 barrows were fed the four diets in a metabolism trial to determine metabolizable energy and nitrogen values. Daily gain by pigs fed Diet 100 was less (P < 0.01), and their times to market weight were 10 and 8 d longer, respectively, than pigs fed Diets 50 L and 100 L. Boars ate significantly less feed daily than barrows, and the rate of gain for boars was less and feed efficiency higher than for barrows. Total yield of lean meat was less (P < 0.05) from Diet 100 pigs than from those fed the other diets. The carcass index was higher (P < 0.05) for boars (106) than for barrows (102). The FA profile for the Tibor naked oats was very similar to that reported in a previous study even though the two crops were grown on different farms and 1 yr apart. Naked oats increased significantly the concentration of 18:1n–9 and 20:1 in the carcass backfat, but did not influence the quality of the loin muscle fat. An increased (P < 0.05) intensity of flavor in the pork loin roasts was associated with the naked oats diets. Boar roasts scored higher (P < 0.05) for juiciness than those from barrows; there was no difference in boar taint between the two sexes. The metabolizable energy value of the control diet was higher than those of the oats diets; significantly higher when corrected for N retained. Pigs fed Diet 100 L retained (P < 0.05) the most N (18.7 g d−1) and Diet 100 the least (15.8 g d−1). Nitrogen retention as a proportion of N intake was more (P < 0.05) for boars than for barrows. This study supported the inclusion of at least 48% naked oats in a diet for growing-finishing pigs. Key words: Boars, oats (naked), metabolism, carcass, fatty acids, meat quality