Corn distillers dried grains with solubles (cDDGS) can replace portions of corn and soybean meal (SBM) in swine diets. However, high dietary inclusions of cDDGS can reduce growth performance, which is most likely related to high dietary concentrations of one of the branched-chain amino acids (BCAA), leucine (Leu). The objective of this study was to identify the effects of feeding diets with cDDGS inclusions of 30% (grower) and 20% (finisher) with different ratios of BCAA to lysine (Lys) on the growth performance, blood amino acid profile, carcass traits, and economics of growing-finishing pigs. A total of 1,140 pigs with an average starting body weight of 63 lbs were housed in a tunnel ventilated barn containing 45 pens with 25 or 26 pigs per pen. Pigs were fed one of five dietary treatments over four dietary phases until marketed. Diets consisted of a corn-SBM diet, a corn-SBM-cDDGS diet without BCAA to Lys adjustments, or one of three corn-SBM-cDDGS with BCAA to Lys adjustments from SBM for growing (Grow), finishing (Finish), or growing and then finishing (Grow-Finish) recommendations. After 11-weeks, pigs were marketed through a commercial abattoir to collect carcass traits. Pigs fed diets with the BCAA to Lys ratio adjusted for finishing pigs by SBM had a greater overall average daily gain (P < 0.05) than pigs fed the other cDDGS diets. The dietary treatments did not affect the hot carcass weight or carcass yield. However, the same diet that improved growth performance resulted in greater (P < 0.05) iodine value of the pork belly. One pig from each pen was bled at the end of the growing and finishing phases. The blood concentration of nitrogen from amino acid breakdown at the end of growing phase and the blood amino acid concentration of Leu and Val were greater (P < 0.05) in pigs fed the Finish diet. Feeding the Finish diet had a greater net income over feed and facility costs than the corn-SBM diet and numerically greater than the other cDDGS diets. In conclusion, feeding 30% (grower) and 20% (finisher) cDDGS diets with the BCAA to Lys ratio for the finishing phase recommendation adjusted by SBM inclusion will benefit swine producers by improving growth performance and providing economic benefit.
Ryan Samuel,