A.M. Hilbrands

Effects of abrupt introduction and removal of high and low digestibility corn distillers dried grains with solubles from the diet on growth performance and carcass characteristics of growing-finishing pigs

Two experiments were conducted to evaluate the effects of feeding continuously a diet containing 40% dried distillers grains with solubles (DDGS) or intermittently diets containing 20 or 40% DDGS on growth performance and carcass quality of pigs. Responses of the pigs to abrupt introduction and removal of dietary DDGS with differing concentrations of standardized ileal digestible (SID) AA were also evaluated. In Exp. 1, crossbred pigs (n=216; initial BW=51.3±3.1 kg) were assigned randomly to 1 of 4 treatments, which included a corn-soybean meal control (CON), a 20% DDGS diet (D20), a switch between D20 and CON (D20-CON), and a switch between a 40% DDGS diet and CON (D40-CON) with 6 pens per treatment. Pigs abruptly introduced and removed from a 20% DDGS diet (D20-CON) exhibited no differences in growth performance or carcass quality compared with CON pigs. However, intermittently feeding a 40% DDGS diet (D40-CON) resulted in lighter HCW (P<0.05) compared with all other treatments. In Exp. 2, crossbred pigs (n=324; initial BW=33.2±3.0 kg) were assigned randomly to 1 of 6 treatments, including a corn-soybean meal control (CON), a 40% low SID AA DDGS diet (LD), a 40% high SID AA DDGS diet (HD), LD and CON diets alternated (LD-CON), HD and CON diets alternated (HD-CON), or HD and LD diets alternated (HD-LD) with 6 pens per treatment. Final BW and ADG were less (P<0.05) for LD and HD-LD pigs compared with CON pigs, but HD pigs tended to have reduced (P<0.10) final BW and ADG. Loin muscle area was smaller for LD and HD-LD pigs compared with CON pigs (P<0.05). Percentage carcass lean was not affected by dietary treatment. Backfat of DDGS-fed pigs was more unsaturated than CON pigs, but AA digestibility of DDGS did not affect this response. Digestibility of AA in DDGS can influence pig performance and carcass quality when fed at high concentrations (40% or more). The use of a high SID AA DDGS source may diminish some of the negative responses observed for growth performance and carcass characteristics when feeding high concentrations of DDGS if accurate values of SID AA are used in diet formulation. Periodic inclusion and removal of 40% DDGS from diets did not adversely affect growth performance or carcass quality regardless of the SID AA digestibility of the DDGS used. These results indicate that it is possible to abruptly incorporate and remove DDGS from grower-finisher swine diets without meaningful detrimental effects on growth performance or carcass quality.

Growth performance of nursery pigs fed diets containing increasing levels of a novel high-protein corn distillers dried grains with solubles1

Abstract The objective of this study was to use the recently determined ME and standardized ileal digestibility (SID) values of AA for a novel high-protein distillers dried grains with solubles (HP-DDGS; PureStream 40, Lincolnway Energy LLC, Nevada, IA) to determine the optimal dietary inclusion rates in diets for nursery pigs. Three hundred and sixty pigs (BW = 6.79 ± 0.02 kg) were blocked by BW, and pens within blocks were assigned randomly to one of four dietary treatments (10 pens/treatment, 9 pigs/pen). Dietary treatments consisted of adding 0%, 10%, 20%, or 30% HP-DDGS to nursery diets during phase 2 (days 7–21) and phase 3 (days 21–42) of a three-phase nursery feeding program. Diets within each phase were formulated to contain equivalent amounts of ME, SID Lys, Met, Thr, and Trp, Ca, standardized total tract digestible P, vitamins, and trace minerals. Calculated SID Leu to Lys ratios for 0%, 10%, 20%, and 30% HP-DDGS diets were 119%, 137%, 156%, and 173% in phase 2 diets and 120%, 131%, 143%, and 160% in phase 3 diets. The SID Ile to Lys ratios ranged from 60% to 69% in phase 2 diets and from 54% to 59% in phase 3 diets. The SID Val to Lys ratios ranged from 63% to 79% in phase 2 diets and 64% to 68% in phase 3 diets. Body weight and feed disappearance were measured weekly. During phase 2, ADG, ADFI, and G:F were reduced linearly (P < 0.01) as the diet inclusion rate of HP-DDGS increased. Similarly in phase 3, increasing dietary levels of HP-DDGS depressed ADG, ADFI, and G:F linearly (P < 0.01). Overall growth performance of phases 2 and 3 of nursery pigs was negatively affected by increasing levels of HP-DDGS in these diets. Pigs acquired a Streptococcus suis and Escherichia coli disease challenge during the experiment. Although no differences in morbidity were observed throughout the experiment, including HP-DDGS in diets tended to decrease (P = 0.08) mortality. In conclusion, a linear decrease in nursery pig growth performance was observed as increasing levels of HP-DDGS were added in diets, which was probably due to overestimation of SID AA content of the HP-DDGS, antagonistic effects of excess Leu, and the effects of relatively high fiber content.