P. E. Urriola

Digestibility of dietary fiber in distillers coproducts fed to growing pigs

The objective of this work was to measure the apparent ileal digestibility (AID) and the apparent total tract digestibility (ATTD) of dietary fiber in different sources of distillers dried grains with solubles (DDGS) and to calculate hindgut fermentation of dietary fiber in DDGS fed to growing pigs. Diets, ileal digesta, and fecal samples from pigs fed corn or diets containing 1 of 28 sources of distillers coproducts were analyzed for fiber. Of the 28 sources of coproducts, 24 sources were corn DDGS (C-DDGS), 1 source was sorghum DDGS (S-DDGS), 1 source was DDGS from a blend of sorghum and corn (SC-DDGS), 1 source was C-DDGS from beverage production (DDGS(beverage)), and a source of corn distillers dried grain (DDG) was also included in the experiment. Total dietary fiber (TDF) and DM were analyzed in all DDGS sources, ileal digesta, and fecal samples. Hindgut fermentation was calculated by subtracting values for AID from values for ATTD. In 10 sources of DDGS and in ileal and fecal samples from pigs fed those sources, crude fiber, ADF, NDF, insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) were also determined. Concentrations of CP, ether extract, and ash were also analyzed in these samples, and concentrations of organic residue (OR) were calculated by subtracting the concentration of CP, ether extract, and water from OM. The AID and the ATTD of TDF differed (P < 0.01) among sources of C-DDGS. The average AID of TDF in 10 sources of C-DDGS (21.5%) was not different (P > 0.05) from the AID of TDF in corn (16.5%), but the ATTD and the hindgut fermentation of TDF in the 10 sources of C-DDGS (44.5 and 23.0%, respectively) were greater (P < 0.05) than in corn (23.1 and 6.6%, respectively). The AID of crude fiber, NDF, IDF, SDF, and TDF were not different between C-DDGS and S-DDGS, but the AID of ADF was greater (P < 0.01) in S-DDGS (57.4%) than in C-DDGS (36.8%). The ATTD of OR in S-DDGS (72.5%) and SC-DDGS (68.4%) were less (P < 0.05) than in C-DDGS (77.1%), but the ATTD of ADF, NDF, IDF, SDF, and TDF were not different among the 3 sources of DDGS. The AID, ATTD, and hindgut fermentation of TDF were not different between DDGS from an ethanol plant and DDGS from a beverage plant. The average AID, ATTD, and hindgut fermentation of TDF in the 24 sources of C-DDGS were 23.0, 47.3, and 24.4%, respectively. It is concluded that the AID and ATTD of fiber differ among sources of DDGS and those differences may contribute to differences in the digestibility of energy in DDGS.

Amino acid digestibility of distillers dried grains with solubles, produced from sorghum, a sorghum-corn blend, and corn fed to growing pigs.

The objective of this experiment was to measure the concentration and digestibility of CP and AA in distillers dried grains with solubles (DDGS) produced from sorghum (S-DDGS) or a blend of sorghum and corn grains (SC-DDGS), and to compare these values with the digestibility of CP and AA in corn-based DDGS (C-DDGS). Eleven growing barrows (initial BW = 44.6 +/- 6.5 kg) were surgically fitted with a T-cannula in the distal ileum and allotted to a Youden square design with 11 diets and 8 periods. One diet contained 66.7% S-DDGS, 1 diet contained 66.7% SC-DDGS, 8 diets contained 66.7% C-DDGS, and 1 diet was N-free. Chromic oxide (0.3%) was used in all diets as an indigestible marker. The direct procedure was used to measure apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA in the 10 sources of DDGS. Results of the experiment showed that the AID of Lys was not different among S-DDGS, SC-DDGS, and C-DDGS. The mean SID of CP, Arg, and Lys in C-DDGS were not different from values obtained in S-DDGS and SC-DDGS. The SID of Trp in S-DDGS (72.0%) was greater (P < 0.01) than in C-DDGS (64.9%), but there was no difference between C-DDGS and SC-DDGS (62.4%). The SID of CP and all AA were different among the 8 sources of C-DDGS (P < 0.01). Among the indispensable AA, Lys had the greatest variation and the SID ranged from 55.7 to 68.7%. The concentration of total and digestible AA was highly correlated (r(2)) for Arg (0.88), Ile (0.85), Leu (0.82), Phe (0.84), and Trp (0.84), but reduced r(2) values were observed for Lys (0.66) and Thr (0.39). A low correlation between the concentration and digestibility of AA indicates that it is desirable to develop in vitro procedures to predict digestible AA concentration in DDGS. In conclusion, SID values for CP and Lys in S-DDGS and SC-DDGS are within the range of values obtained in C-DDGS, but for many other AA, SID values in S-DDGS and in SC-DDGS are less than in C-DDGS.

Effects of distillers dried grains with solubles on amino acid, energy, and fiber digestibility and on hindgut fermentation of dietary fiber in a corn-soybean meal diet fed to growing pigs

The objective of this experiment was to measure the effect of distillers dried grains with solubles (DDGS) on the digestibility of AA, energy, and fiber, on the fermentation of fiber, and on the first appearance of digesta at the end of the ileum, in the cecum, and in the feces of growing pigs fed a corn-soybean meal-based diet. Sixteen pigs (initial BW = 38.0 +/- 1.6 kg) were prepared with a T-cannula in the distal ileum and a T-cannula in the cecum and allotted to 2 treatments. In period 1, all pigs were fed a corn-soybean meal diet. In periods 2, 3, and 4, pigs were fed the control diet or a diet containing corn, soybean meal, and 30% DDGS. First appearance of digesta at the end of the ileum, in the cecum, and over the entire intestinal tract was measured at the end of period 4. The apparent ileal digestibility (AID) and the apparent total tract digestibility (ATTD) of nutrients were measured, and the concentration of VFA was analyzed in ileal, cecal, and fecal samples. The AID of Lys (74.1%) in the DDGS diet was less (P < 0.05) than in the control diet (78.6%), but the AID of most other AA and GE, NDF, and total dietary fiber (TDF) were not different between the 2 diets. The ATTD of GE (81.0%), NDF (57.2%), TDF (55.5%), and DM (81.7%) were less (P < 0.05) in the DDGS diet than in the control diet (86.0, 69.3, 66.0, and 87.2%, respectively). The concentration of VFA in ileal, cecal, and fecal samples was not different between pigs fed the 2 diets. The pH of ileal and cecal digesta from pigs fed the DDGS diet (6.3 and 5.5) was greater (P < 0.01) than from pigs fed the control diet (5.8 and 5.3). The ATTD of DM, GE, ADF, NDF, and TDF did not change with collection period, but the AID of ADF, NDF, and TDF increased (P < 0.05) from period 2 to period 4. The concentration of all VFA, except isobutyrate, was greater (P < 0.05) in cecal samples from period 4 compared with period 2, and the concentration of all VFA except propionate and isovalerate were greater (P < 0.05) in fecal samples collected in period 4 compared with those collected in period 2. The first appearance of digesta at the end of the ileum, in the cecum, and in the feces was not affected by DDGS. In conclusion, pigs fed the diet containing DDGS had less digestibility of Lys, GE, ADF, NDF, and TDF than pigs fed the control diet. The digestibility of DM and GE was not influenced by collection period, but the concentration of VFA in cecal digesta and feces increased with the length of time pigs received the diets.

Comparative digestibility of energy and nutrients in fibrous feed ingredients fed to Meishan and Yorkshire pigs

The objective of this experiment was to test the hypothesis that differences in the digestibility of total dietary fiber among breeds of pigs is influenced by the type of fiber fed and also by the age of the pig. Five Meishan pigs (BW: 77.2 ± 15.2 kg; 5 mo old), 5 light Yorkshire pigs (BW: 80.1 ± 11.2 kg; 4 mo old), and 5 heavy Yorkshire pigs (BW: 102.1 ± 3.5 kg, 5 mo old) were surgically prepared with a T-cannula in the distal ileum. A corn-soybean meal diet (control) was formulated with 5 g•kg(-1) of titanium dioxide as an indigestible marker. Three additional diets were formulated by replacing 30% of the control diet with 30% of distillers dried grains with solubles (DDGS), soybean hulls, or sugar beet pulp, and 1 diet was formulated by replacing 15% of the control diet with 15% pectin. Each group of pigs was allotted to a 5 × 5 Latin square design, and pigs were fed the 5 experimental diets during five 14-d periods. Fecal samples were collected on d 12, and ileal digesta were collected on d 13 and 14 of each period. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of GE and nutrients in each ingredient were calculated using the substitution method. Hindgut disappearance was calculated as the difference between ATTD and AID. When fed the control diet, Meishan pigs tended (P < 0.10) to have a greater AID of GE and CP (78.6 and 80.3%, respectively) than light (77.0 and 78.9%, respectively) and heavy (75.7 and 76.9%, respectively) Yorkshire pigs, and they had a greater (P < 0.05) ATTD of DM, GE, and carbohydrates (89.2, 89.5, and 95.5%, respectively) than light (86.6, 86.4, and 92.4%, respectively) and heavy (87.0, 86.6, and 93.0%, respectively) Yorkshire pigs. The ATTD of DM, GE, CP, carbohydrates, and total dietary fiber in DDGS (75.4, 76.3, 81.3, 78.0, and 75.3%, respectively) was greater (P < 0.01) in Meishan pigs than in light (55.7, 58.5, 66.7, 49.2, and 39.0%, respectively) and heavy (59.8, 62.9, 70.0, 51.1, and 55.7%, respectively) Yorkshire pigs. There were no differences among the 3 groups of pigs in the ATTD of GE or nutrients in soybean hulls, sugar beet pulp, or pectin. The hindgut disappearance of DM and carbohydrates in DDGS by Meishan pigs (26.8 and 52.9%, respectively) was greater (P < 0.05) than in the light (10.0 and 22.8%, respectively) and Heavy Yorkshire pigs (12.2 and 20.0%, respectively), but for the other ingredients, no differences in hindgut disappearance among Meishan, light Yorkshire, and heavy Yorkshire pigs were observed. In conclusion, Meishan pigs have a greater ATTD of DM, GE, and some nutrients in corn-soybean meal diets and in DDGS than Yorkshire pigs.

Growing Chlorella sp. on meat processing wastewater for nutrient removal and biomass production

In this work, Chlorella sp. (UM6151) was selected to treat meat processing wastewater for nutrient removal and biomass production. To balance the nutrient profile and improve biomass yield at low cost, an innovative algae cultivation model based on wastewater mixing was developed. The result showed that biomass yield (0.675-1.538 g/L) of algae grown on mixed wastewater was much higher than that on individual wastewater and artificial medium. Wastewater mixing eased the bottleneck for algae growth and contributed to the improved biomass yield. Furthermore, in mixed wastewater with sufficient nitrogen, ammonia nitrogen removal efficiencies (68.75-90.38%) and total nitrogen removal efficiencies (30.06-50.94%) were improved. Wastewater mixing also promoted the synthesis of protein in algal cells. Protein content of algae growing on mixed wastewater reached 60.87-68.65%, which is much higher than that of traditional protein source. Algae cultivation model based on wastewater mixing is an efficient and economical way to improve biomass yield.

Mitigating ammonia nitrogen deficiency in dairy wastewaters for algae cultivation

This study demonstrated that the limiting factor to algae growth on dairy wastewater was the ammonia nitrogen deficiency. Dairy wastewaters were mixed with a slaughterhouse wastewater that has much higher ammonia nitrogen content. The results showed the mixing wastewaters improved the nutrient profiles and biomass yield at low cost. Algae grown on mixed wastewaters contained high protein (55.98-66.91%) and oil content (19.10-20.81%) and can be exploited to produce animal feed and biofuel. Furthermore, algae grown on mixed wastewater significantly reduced nutrient contents remained in the wastewater after treatment. By mitigating limiting factor to algae growth on dairy wastewaters, the key issue of low biomass yield of algae grown on dairy wastewaters was resolved and the wastewater nutrient removal efficiency was significantly improved by this study.

Pork fat quality of pigs fed distillers dried grains with solubles with variable oil content and evaluation of iodine value prediction equations

Back, belly, and jowl fat samples of pigs fed control corn-soybean meal-based diets and diets containing 4 sources of distillers dried grains with solubles (DDGS) were used to determine the impact of feeding DDGS with variable oil content on pork fat quality and to evaluate the precision and accuracy of published iodine value (IV) prediction equations. Dietary treatments consisted of 4 corn-soybean meal diets containing 40% DDGS from different sources with 10.7, 5.6, 14.2, or 16.0% ether extract (EE; as-fed) content. Diets did not contain any other supplemental lipid sources. Regardless of fat depot, SFA content (g/100 g fat) of pigs fed 5.6% EE DDGS (35.4) was greater ( < 0.05) than that of pigs fed 14.2 or 16.0% EE DDGS sources (34.4 and 30.2, respectively) and tended to be greater ( < 0.10) than that of pigs fed 10.7% EE DDGS (34.6). Pigs fed 10.7 and 14.2% EE DDGS had greater ( < 0.01) SFA concentration than pigs fed 16.0% EE DDGS. Regardless of fat depot, MUFA content (g/100 g fat) of pigs fed 10.7, 5.6, and 14.2% DDGS sources were similar (43.7, 43.1, and 43.0, respectively) but were greater ( < 0.01) than that of pigs fed 16.0% EE DDGS (40.0). A dietary treatment × fat depot interaction was observed for PUFA ( < 0.05) and IV ( = 0.079). Pigs fed 10.7, 5.6, and 14.2% DDGS sources had reduced ( < 0.01) PUFA concentration and IV compared with pigs fed 16.0% EE DDGS, but the magnitude of responses in PUFA and IV to the variable oil content of DDGS was greater in backfat than in belly and jowl fat. Carcass fat IV data were used to evaluate prediction error (PE) and bias of published carcass fat IV prediction equations. Equations using dietary C18:2 content or IV product as a single predictor resulted in highly variable PE (g/100 g) ranging from 3.43 to 8.36 and bias (g/100 g) ranging from -5.05 to 5.66. Using equations that included additional diet composition information and pig growth performance factors decreased PE (3.27 to 4.73) and bias (-3.37 to 1.73) of prediction for backfat compared with equations only based on the characteristics of dietary lipid, but this improvement was limited in the prediction for belly and jowl fat. Predictions based on percentage of DDGS in diets had the greatest PE (6.66 to 9.19) and bias (5.53 to 8.00).

Comparison of Thermal and Non-Thermal Processing of Swine Feed and the Use of Selected Feed Additives on Inactivation of Porcine Epidemic Diarrhea Virus (PEDV)

Infection with porcine epidemic diarrhea virus (PEDV) causes diarrhea, vomiting, and high mortality in suckling pigs. Contaminated feed has been suggested as a vehicle of transmission for PEDV. The objective of this study was to compare thermal and electron beam processing, and the inclusion of feed additives on the inactivation of PEDV in feed. Feed samples were spiked with PEDV and then heated to 120–145°C for up to 30 min or irradiated at 0–50 kGy. Another set of feed samples spiked with PEDV and mixed with Ultracid P (Nutriad), Activate DA (Novus International), KEM-GEST (Kemin Agrifood), Acid Booster (Agri-Nutrition), sugar or salt was incubated at room temperature (~25°C) for up to 21 days. At the end of incubation, the virus titers were determined by inoculation of Vero-81 cells and the virus inactivation kinetics were modeled using the Weibull distribution model. The Weibull kinetic parameter delta represented the time or eBeam dose required to reduce virus concentration by 1 log. For thermal processing, delta values ranged from 16.52 min at 120°C to 1.30 min at 145°C. For eBeam processing, a target dose of 50 kGy reduced PEDV concentration by 3 log. All additives tested were effective in reducing the survival of PEDV when compared with the control sample (delta = 17.23 days). Activate DA (0.81) and KEM-GEST (3.28) produced the fastest inactivation. In conclusion, heating swine feed at temperatures over 130°C or eBeam processing of feed with a dose over 50 kGy are effective processing steps to reduce PEDV survival. Additionally, the inclusion of selected additives can decrease PEDV survivability.

Effects of adding supplemental tallow to diets containing 30% distillers dried grains with solubles on growth performance, carcass characteristics, and pork fat quality in growing–finishing pigs

Crossbred pigs (n = 315) were blocked by initial BW (6.8 ± 1.1 kg) and randomly assigned to 1 of 4 dietary treatments to evaluate the effects of dietary inclusion of tallow and corn distillers dried grains with solubles (DDGS) on pig growth, carcass traits, and pork fat quality. Diets consisted of a corn-soybean meal control diet (CON) and another 3 corn-soybean meal diets containing 5% tallow (T), 30% DDGS (D), or 5% tallow plus 30% DDGS (TD) in a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain similar levels of available P and standardized ileal digestible Lys:ME among treatments. Pigs were housed in 40 pens, with 7 to 8 pigs per pen, to provide 10 replicates per treatment. Overall ADG did not differ among treatments. Compared with CON (2.76 kg/d) and T (2.59 kg/d), feeding 30% DDGS reduced the ADFI (interaction, P > 0.05) of pigs when fed with 5% tallow (2.45 kg/d for TD) but not when fed alone (2.76 kg/d for D). There was no effect of DDGS on overall G:F, but pigs fed diets with tallow had greater (P < 0.01) G:F (0.4) than pigs fed no tallow (0.37). Feeding tallow increased (P < 0.01) HCW, carcass yield, and backfat depth of pigs independent of DDGS. Feeding DDGS reduced (P < 0.01) belly firmness, as measured by belly flop angle, independent of tallow (D = 71.8° and TD = 57.7° vs. CON = 134.0° and T = 113.4°) and tallow also tended to reduce belly firmness (P < 0.10). Feeding DDGS and tallow reduced the concentration of SFA in belly fat, while the concentration of MUFA were increased (P < 0.01) by feeding tallow but not DDGS. Conversely, feeding DDGS increased (P < 0.01) the concentration of PUFA in belly fat but there was no effect of tallow. An interaction (P = 0.03) between DDGS and tallow for iodine value (IV) of belly fat was observed, in which addition of tallow or DDGS increased the IV of belly fat (64.22 for T and 71.22 for D vs. 59.01 for CON) but addition of both reduced IV (67.88 for TD). The IV of belly fat and backfat were correlated (P < 0.01) with the IV product of the diet fed in phase 3 (r = 0.49 and r = 0.81, respectively). In conclusion, adding 5% tallow to 30% DDGS diets improved G:F and carcass yield while reducing the IV of belly fat. However, pork fat firmness as measured by belly flop angle was not improved.

Prediction of the concentration of standardized ileal digestible amino acids in distillers dried grains with solubles.

Values for the concentration of standardized ileal digestible (SID) CP, Lys, Met, Thr, and Trp from 34 sources of distillers dried grains with solubles (DDGS) were obtained from a series of 5 experiments with the objective of predicting the concentration of SID AA from physical and chemical assays. The concentration of NDF, ADF, hemicellulose, acid detergent insoluble CP (ADICP), and KOH soluble protein (SolCP) were measured and calculated in all DDGS sources. Likewise, particle size was measured and color of each source of DDGS was determined with a Minolta colorimeter and HunterLab spectrometer and was expressed as lightness (L*), redness (a*), and yellowness (b*). The HunterLab spectrometer also provided optical density that was recorded between 400 and 700 nm. Front face fluorescence was measured at 360 nm excitation and recorded from 380 to 600 nm. Multiple linear regression and principal components analyses were performed to predict the concentration of SID AA among DDGS sources, and predicted means as well as predicted residual sums of squares (PRESS) were calculated to estimate accuracy and precision of the model. Some correlations (P < 0.05) were observed between ADF, hemicellulose, ADICP, and SolCP with SID CP and AA but were generally low (r < 0.51). There was a greater association (R(2) = 0.40; P < 0.05) between L* and SID Lys among DDGS sources when L* was less than 50 than when samples had L* values greater than 50. In addition, a* was negatively correlated (P < 0.05) with SID CP (r = -0.41), Lys (r = -0.59), and Met (r = -0.50) whereas b* tended to be positively correlated (P < 0.10) with SID Lys (r = 0.31) and Trp (r = 0.30) and was correlated (P = 0.05) with SID Met (r = 0.43) and Thr (r = 0.36). There were no correlations between NDF or particle size with SID CP and AA. Optical density, along with CP, was highly predictive of SID Lys (R(2) = 0.97; PRESS = 0.05), Thr (R(2) = 0.94; PRESS = 0.06), and Trp (R(2) = 0.93; PRESS = 0.004) but not SID Met (R(2) = 0.39; PRESS = 0.12). Front face fluorescence was also highly predictive of SID Lys (R(2) = 0.99; PRESS = 0.07), Met (R(2) = 0.95; PRESS = 0.05), Thr (R(2) = 0.99; PRESS = 0.008), and Trp (R(2) = 0.99; PRESS = 0.006). In conclusion, correlations between ADICP, SolCP, NDF, particle size, and color measurements with SID AA concentrations were poor, but optical density and front face fluorescence methods appear to provide good predictions of SID AA concentrations in DDGS. However, these prediction equations need to be validated using samples of DDGS from a separate data set.