A growth performance and carcass evaluation study was conducted to determine the maximal inclusion rate of corn distillers dried grain with solubles (DDGS) in grower-finisher pig diets when formulated on a total AA basis. A total of 240 (28.4 ± 0.8 kg of BW) crossbred pigs [(Yorkshire × Landrace) × Duroc] were allotted randomly within sex and weight outcome groups to 1 of 24 pens. Pens were assigned randomly within the initial BW groups to 1 of 4 dietary treatment sequences in a 5-phase grower-finisher feeding program in a 4 × 3 factorial arrangement of treatments. The inclusion level of DDGS (0, 10, 20, or 30%) in the diet and the initial BW class [low (23.2 kg), medium (28.1 kg), or high (33.8 kg)] served as the main factors for the grower-finisher performance study. All diets were formulated to contain similar concentrations of total Lys, ME, calcium, and phosphorus within each phase. Pigs were slaughtered and carcass data were collected when the average BW of pigs in a pen reached 114 ± 2.25 kg. Dietary treatment and initial weight groups did not interact for any response variables, and only the main effects of dietary treatment are presented. Pigs fed the 20 or 30% DDGS diets had reduced ADG (P < 0.05) compared with that of the 0 or 10% DDGS groups, but ADFI was unaffected by dietary treatment. Gain:feed decreased when pigs were fed 30% DDGS (P < 0.05) compared with the 0, 10, and 20% DDGS dietary inclusion levels. Loin depth was lower in pigs fed the 30% DDGS diets (P < 0.05), but backfat depth and percentage of carcass lean did not differ among treatments. Iodine number of carcass fat increased linearly (P < 0.01) with increasing dietary DDGS concentration, and belly firmness adjusted for belly thickness was reduced (P < 0.05) for pigs fed the 30% DDGS diets compared with pigs fed the 0 or 20% DDGS diets. Color measurements, ultimate pH, and visual evaluations (color, firmness, and marbling scores) of the LM did not differ among treatments. Cooking loss, 24-h drip loss, and total moisture loss were not affected by DDGS in the diets. However, differences were detected between 0 and 20% DDGS treatments for 11-d purge loss (P < 0.05). Dietary treatment did not affect Warner-Bratzler shear force of cooked loin chops. Results from this study indicate that when diets for grower-finisher pigs are formulated on a total AA basis, less than 20% DDGS should be included in the diet for optimal performance and carcass composition. Feeding DDGS in swine finishing diets did not have any detrimental effects on pork muscle quality. Copyright © 2006. . Copyright 2006 Journal of Animal Science

Application of feed processing methods and use of exogenous feed additives in an effort to improve nutrient digestibility of plant-based feed ingredients for swine has been studied for decades. The following review will discuss several of these topics, including: fiber characterization, impact of dietary fiber on gastrointestinal physiology, energy, and nutrient digestibility, mechanical processing of feed on fiber and energy digestibility, and the use of exogenous enzymes in diets fed to growing pigs. Taken together, the diversity and concentration of chemical characteristics that exists among plant-based feed ingredients, as well as interactions among constituents within feed ingredients and diets, suggests that improvements in nutrient digestibility and pig performance from mechanical processing or adding exogenous enzymes to diets fed to swine depends on a better understanding of these characteristics, but also relating enzyme activity to targeted substrates. It may be that an enzyme must not only match a target substrate(s), but there may also need to be a ′cocktail′ of enzymes to effectively breakdown the complex matrixes of fibrous carbohydrates, such that the negative impact of these compounds on nutrient digestibility or voluntary feed intake are alleviated. With the inverse relationship between fiber content and energy digestibility being well described for several feed ingredients, it is only logical that development of processing techniques or enzymes that degrade fiber, and thereby improve energy digestibility or voluntary feed intake, will be both metabolically and economically beneficial to pork production.

Food waste has been a major barrier to achieving global food security and environmental sustainability for many decades. Unfortunately, food waste has become an even bigger problem in many countries because of supply chain disruptions during the COVID-19 pandemic and African Swine Fever epidemic. Although Japan and South Korea have been leaders in recycling food waste into animal feed, countries that produce much greater amounts of food waste, such as the United States and the European Union, have lagged far behind. Concerns about the risk of transmission of bacteria, prions, parasites, and viruses have been the main obstacles limiting the recycling of food waste streams containing animal-derived tissues into animal feed and have led to government regulations restricting this practice in the U.S. and EU. However, adequate thermal processing is effective for inactivating all biological agents of concern, perhaps except for prions from infected ruminant tissues. The tremendous opportunity for nitrogen and phosphorus resource recovery along with several other environmental benefits from recycling food waste streams and rendered animal by-products into animal feed have not been fully appreciated for their substantial contribution toward solving our climate crisis. It is time to revisit our global approach to improving economic and environmental sustainability by more efficiently utilizing the abundant supply of food waste and animal tissues to a greater extent in animal feed while protecting human and animal health in food animal production systems.

Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition, quality, feeding value, and price among sources. Common measures of lipid quality include moisture, insolubles, and unsaponifiables (MIU), titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances (TBARS), and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same source. Furthermore, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a metabolic oxidative challenge.

Crossbred pigs (n = 512) with an average initial BW of 22.1 ± 0.54 kg were used to evaluate growth performance, carcass characteristics, and pork fat quality of grower-finisher pigs fed corn-soybean meal diets containing increasing content of distillers dried grains with solubles (DDGS). One of 4 dietary treatments was randomly assigned to each pen within sex. Dietary treatment and sex were the main factors in a 3-phase feeding program (BW = 22 to 53 kg, 53 to 85 kg, and 85 to 115 kg). Dietary treatments consisted of a corn-soybean meal control, or a corn-soybean meal diet containing 10, 20, or 30% DDGS. Overall, increasing the dietary DDGS content had no effect on ADG (P = 0.74), but ADFI was linearly reduced and G:F was linearly increased (P < 0.01). Dressing percentage, LM marbling and firmness, and belly firmness were linearly reduced (P < 0.01), but percentage of fat-free lean was linearly increased (P < 0.05) with increasing dietary DDGS. Subjective LM color score (P = 0.65), drip loss (P = 0.37), and ultimate pH of LM (P = 0.21) were not influenced by dietary DDGS. Japanese color scores for backfat (P = 0.41) and belly fat (P = 0.85) were similar among dietary treatments (P = 0.41). Feeding an increasing content of DDGS linearly increased (P < 0.05) PUFA concentration, particularly linoleic acid (C18:2), in belly fat, backfat, and LM intramuscular fat, but the increase in LM intramuscular fat was smaller in magnitude (P < 0.05) than in backfat and belly fat. Pigs fed an increasing content of DDGS had a linear increase (P < 0.05) in the iodine value of backfat, belly fat, and LM intramuscular fat of 58.4 to 72.4, 61.5 to 72.3, and 54.8 to 57.7, respectively. Oxidation of LM intramuscular fat measured on d 0, 14, 21, and 28 of storage was not affected by dietary treatment. Taste tests for LM showed no effects of diet on flavor, off-flavor (P = 0.36), tenderness (P = 0.66), juiciness (P = 0.58), and overall acceptability (P = 0.52) scores. Similarly, bacon flavor (P = 0.88), off-flavor, crispiness, and overall liking scores were not affected by increasing dietary DDGS, but bacon fattiness (P < 0.01) and tenderness (P < 0.05) scores were linearly reduced. These results showed no negative effects on growth performance or dressing percentage when growing-finishing pigs were fed diets containing up to 30% DDGS, but fat quality may not meet the standards of all pork processors when feeding diets containing more than 20% DDGS. Copyright © 2010. American Society of Animal Science .

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 (r²) for Arg (0.88), Ile (0.85), Leu (0.82), Phe (0.84), and Trp (0.84), but reduced r² 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. Copyright © 2009. .