Abstract:
The aim of this study was to determine growth responses and apparent total tract nutrient digestibility in growing pigs fed diets containing graded levels of distillers dried grains with solubles (DDGS) and to determine the effect of a multicarbohydrase enzyme (MC) supplementation on visceral organ mass and fasting whole-body oxygen consumption (FWBOC). In Experiment 1, 48 pigs (25.5 ± 0.14 kg BW) were assigned on the basis of sex and BW (2 pigs per pen) to 4 diets (6 pens per diet) based on corn-barley-soybean meal with 0, 10, 20 and 30% DDGS in a 42-d trial. Apparent total tract digestibilities (ATTD) of energy and other nutrients were determined using acid insoluble ash (AIA) as the indigestible marker. Inclusion of DDGS in the diets decreased (linear, P < 0.05) average daily gain (ADG) and tended to decrease gain to feed ratio (G:F) (linear, P = 0.067) but not average daily feed intake (ADFI) (P > 0.10); however, pigs fed the 20% DDGS diet had similar ADG as pigs fed the 0% DDGS diet. Increasing DDGS content in the diet linearly decreased (P < 0.01) the ATTD of DM, energy and CP (cubic, P < 0.05) but not (P > 0.10) P and Ca; however, ATTD of neutral detergent fiber (NDF) increased (linear, P < 0.01) when DDGS was included in the diet. In Experiment 2, 24 pigs (19.9 ± 0.46 kg BW) were randomly assigned to 3 corn-soybean meal-basal diets (8 pigs per diet): Control (C, 0% DDGS); basal diet with 30% DDGS (C+30% DDGS) or C+30% DDGS supplemented with MC (C+30% DDGS+MC). On d 15, WBOC during the 24- to 30-h postprandial period was determined using an open-circuit indirect calorimeter on 4 pigs per diet. On d 28, pigs were killed to determine visceral organ mass and intestinal morphology. There was no diet effect (P > 0.10) on final BW, FWBOC, and liver, spleen, pancreas, heart, stomach and caecum weights relative to empty BW. However, pigs fed the C and C+30% DDGS+MC had heavier (P = 0.05) empty BW compared with those fed unsupplemented 30% DDGS-containing diet. Small intestine, colon plus rectum and the portal-drained viscera (PDV) were heavier (P < 0.05) in DDGS-fed pigs compared with C; supplementing with MC substantially decreased the effect of DDGS on the weight of these visceral organs. Feeding pigs DDGS tended to decrease (P < 0.10) villous height (VH) and VH:CD in the ileum. Results show that including DDGS in grower pig diets up to 20% has no effect on performance although ATTD of energy, DM, and N may be reduced. Inclusion of DDGS at 30% increased PDV mass and reduced dressing percentage but these effects were overcome by a multicarbohydrase enzyme supplementation.
