EFFECTS OF VITAMIN B12 ON PERFORMANCE AND CARCASS TRAITS OF PIGS FED DIETS SUPPLEMENTED WITH PROPIONIC ACID OR CALCIUM PROPIONATE
Effects of vitamin B12 supplementation of diets containing propionic acid (PA) or calcium propionate (CP) on average daily gain (ADG), feed conversion efficiency (FCE), backfat measurements and fatty acid (FA) composition, were studied utilizing 80 crossbred pigs averaging 22.5 kg. Diets based on barley-soybean meal, containing 0, 3.5 or 7% PA or CP were fed with and without the addition of 4.95 mg of vitamin B12 per kg of diet. The addition of PA depressed average daily feed(ADF) intake, while CP had no effect. ADG was reduced when either 7% PA or CP was fed, but ADG was slightly improved when 3.5% PA or CP was fed. FCE was improved when 3.5 or 7% PA or 3.5% CP was fed, but 7% CP depressed FCE. Vitamin B12 supplementation slightly improved the ADG and FCE of pigs fed CP, but had no effect on pigs fed PA. None of these differences was significant at the 5% level. Addition of CP significantly reduced the thickness of carcass backfat in treated pigs. Supplementation with vitamin B12 eliminated this reduction. A similar, though non-significant, trend was observed with PA. Pigs fed 7% PA or CP had significantly higher levels of odd-chain FA 17:0 and 17:1 in carcass back fat. Addition of vitamin B12 mollified this effect. In addition, vitamin B12 supplementation of PA-treated pigs significantly increased the levels of the unsaturated FA 18:2 and 18:3.