Empiric narrowing of the net energy value of reduced-oil corn distillers’ dried grain with solubles for growing-finishing pigs

Abstract

and Beltranena, E. 2015. Empiric narrowing of the net energy value of reduced-oil corn distillers' dried grain with solubles for growing-finishing pigs. Can. J. Anim. Sci. 95: 225Á241. This study attempted to empirically narrow down the net energy (NE) value of reduced-oil corn distillers' dried grains and solubles (RO-cDDGS) by evaluating the response in pig growth performance, live backfat and loin depth, carcass traits, and primal pork cuts tissue composition to feeding diets formulated increasing the assumed NE value of RO-cDDGS, expecting a brisk change in slope of the response at the point at which the NE value of RO-cDDGS would be identified. In total, 1056 cross-bred pigs (31.7 kg) housed in 48 pens by gender were fed dietary regimens including 30% RO-cDDGS (6.7% ether extract) with assumed NE values of 1.7, 1.85, 2.0, 2.15, 2.3, or 2.45 Mcal kg(1 over five growth periods (Grower 1: days 0Á21, Grower 2: days 22Á42, Grower 3: days 43Á63, Finisher 1: days 64Á76, Finisher 2: day 77 to market weight). Pig body weights were measured and feed disappearance (ADFI) was calculated by pen on days 0, 21, 42, 63, 76 and weekly thereafter until target slaughter weight (120 kg). For the entire trial (days 0Á76), increasing the assumed NE value of RO-cDDGS linearly increased (PB0.01) ADFI and total lysine intake, did not affect NE intake and daily weight gain (ADG), quadratically decreased (P B0.05) feed efficiency, linearly decreased (P B0.05) live backfat depth and backfat:loin depth ratio, and did not affect carcass characteristics or pork primal cut tissue composition. Segmented regression only identified a change in slope for carcass ADG and lean ADG at 1.85 Mcal kg (1 . These results indicate that the experimental approach taken was not reliable in narrowing down the NE value of RO-cDDGS because the decrease in dietary NE was too small (0.03 Mcal kg(1 d), which limited the change in dietary Lys:NE ratio with increasing assumed NE value of RO-cDDGS. The approach resulted in progressive, but small changes in slope rather than a clearly identifiable point where one could conclude that the incremental dietary energy contribution from RO-cDDGS changed the response in a given variable.Key words: Carcass traits, distillers' dried grains with solubles, growth performance, net energy, pig Smit, M. N., Zamora, V., Young, M. G., Campbell, N., Uttaro, B. et Beltranena, E. 2015. Resserrement empirique de la valeur d'e´nergie nette de la dreˆche de distillerie de maı¨s avec solubles (a`teneur re´duite en huile) pour les porcs en croissancefinition. Can. J. Anim. Sci. 95: 225Á241. Cette e´tude avait pour but le resserrement de la valeur d'e´nergie nette (NE Á « net energy ») de la dreˆche de distillerie de maı¨s avec solubles (a`teneur re´duite en huile) (RO-cDDGS Á « reduced-oil corn distillers' dried grains and solubles ») en e´valuant la re´ponse des porcs a`l'alimentation par die`tes formule´es pour accroıˆtre la valeur NE pre´sume´e de RO-cDDGS selon la performance de croissance, l'e´paisseur du gras dorsal (vif) et profon...