Fed Distillers Grains Research Articles

Effect of feeding distiller's grains and supplementing with dietary antioxidants on ground beef color during retail display

Effect of feeding distiller's grains and supplementing with dietary antioxidants on ground beef color during retail display

Effect of Distillers Feedstuffs and Lasalocid on Campylobacter Carriage in Feedlot Cattle

Campylobacter bacteria are foodborne pathogens that can colonize the gut of food animals. Limited in their ability to ferment sugars, Campylobacter can derive energy for growth via amino acid catabolism. The objectives of the present studies were to test whether supplemental distillers grains containing high amounts of rumen-undegradable intake protein or supplemental lasalocid may, by promoting amino acid flow to the lower bovine gut, increase intestinal carriage of Campylobacter. In study one, 10 steers (5 per treatment) were adapted to diets formulated to achieve 0 or 30% dried distillers grains. After an initial 14-day adaptation to the basal diet, control and treated steers were fed their respective diets for 23 days, after which time they were fed supplemental lasalocid for an additional 8 days, followed by a 5-day withdrawal. In study two, 24 steers preacclimated to a basal diet were adapted via 3-day periodic increases to dietary treatments formulated to achieve 0, 30, or 60% wet corn distillers grains with solubles. Analysis of Campylobacter bacteria cultured from duodenal and fecal samples in study one and from fecal samples in study two revealed no effect of dried distillers grains or wet corn distillers grains with solubles on the prevalence or concentrations of duodenal or fecal Campylobacter. The results from study one indicated that colonized steers, regardless of treatment, harbored higher Campylobacter concentrations when transitioned to the basal diet than when coming off pasture. Campylobacter carriage was unaffected by lasalocid. These results provide no evidence that feeding distillers grains high in rumen-undegradable intake protein or supplemental lasalocid contributes to increased intestinal carriage of Campylobacter in fed cattle.

Impacts of dietary fat level and saturation when feeding distillers grains to high producing dairy cows.

This experiment was conducted to determine whether increasing the net energy (NEL ) of a total mixed ration (TMR) with mainly unsaturated fat from corn distillers dried grains with solubles (DDGS) vs. rumen inert (RI)-saturated fat has similar impacts on animal performance. The experiment was an incomplete Youden square with three treatments and four 28-days periods, completed on a large commercial dairy using three early lactation pens each with approximately 380 multiparity cows. The TMR for all treatments was the same, except for 150 g/kg dry matter (DM) of each TMR which contained 90 g/kg high-protein DDGS (HPDDGS) and 60 g/kg beet pulp (i.e. low-fat control diet; LFC); 150 g/kg DDGS (i.e. high-fat diet with unsaturated fat; HFU); or 111 g/kg HPDDGS, 20 g/kg beet pulp and 19 g/kg RI fat (i.e. high-fat diet with saturated fat; HFS). The DM intake was highest (p < 0.05) for HFU-fed cows. Milk, fat and true protein yields, as well as milk energy output, were higher (p < 0.01) when cows were fed HFS vs. HFU and LFC diets. Milk true protein concentration was lowest (p < 0.01) for HFS-fed cows, but milk fat % was lowest (p < 0.01) for HFU and highest (p < 0.01) for HFS-fed cows. There were numerous differences (p < 0.01) in milk fatty acid levels amongst diets. The increase in body condition score was lowest (p < 0.01) for LFC. Whole tract digestibility of acid detergent fibre was lower (p < 0.01) for LFC vs. HFS cows, and fat digestion was lowest (p < 0.01) for LFC-fed cows. This DDGS, high in unsaturated fatty acids, was fed at high levels (i.e. 152 g/kg DM) with little impact on animal performance vs. a lower fat control diet, although addition of an RI-saturated fat to create a diet with a similarly higher fat level resulted in higher animal productivity.

Evaluation of feeding distiller's grains, containing virginiamycin, on antimicrobial susceptibilities in fecal isolates of Enterococcus and Escherichia coli and prevalence of resistance genes in cattle1

Dried distiller's grains (DG) produced from ethanol fermentations dosed with 0 (control), 2, or 20 mg/kg virginiamycin-based product or spiked with virginiamycin (VM) postfermentation were fed to cattle and effects on antimicrobial susceptibility, and prevalence of antimicrobial resistance genes in commensal bacteria was examined. Biological activity assays of DG (from each fermentation) indicated a concentration of 0, 0.7, and 8.9 mg/kg VM, respectively. Twenty-four crossbred beef steers were fed 1 of 4 diets (containing 8% of each of the different batches of DG) and a fourth using 8% of the control DG (0 mg/kg VM) + 0.025 g/kg V-Max50 (positive control) for 7 wk. Fecal samples were collected weekly throughout the experimental period and cultured for Escherichia coli and Enterococcus, and isolates were examined for antimicrobial susceptibility, antimicrobial resistance genes (vatE, ermB, and msrC in Enterococcus), and integrons (E. coli). No treatment differences (P > 0.05) were observed in antimicrobial susceptibility of the E. coli isolates. Enterococcus isolates were resistant to more antimicrobials; however, this was influenced by the species of Enterococcus and not treatment (P > 0.10). The prevalence of ermB was greater (P < 0.05) in the control isolates after 4 and 6 wk while at wk 7, prevalence was greater (P < 0.01) in the 0.7 and 8.9 mg/kg VM treatments. Taken together, the minor treatment differences observed for the presence of ermB coupled with the lack of effect on antimicrobial susceptibility patterns suggest that feeding DG containing VM residues should have minimal if any impact on prevalence of antimicrobial resistance.

Effect of natural antioxidant concentration on lipid oxidation of ready to eat ground beef links from cattle fed distillers grains in different phases of production

Lipid oxidation occurs most commonly in phospholipids and polyunsaturated fatty acids that will readily undergo free-radical chain reactions resulting in deterioration of the lipid. Lipid oxidation reduces shelf life and decreases overall desirability of the product by increasing the evidence of “warmed over” or “rancid” flavors. The use of plant extracts, such as rosemary or green tea, is becoming increasingly popular in meat processing as a natural antioxidant to increase shelf life of cooked meat products. This becomes particularly beneficial for companies seeking to clean up labels or use “natural” labeling claims for their product. Therefore , the objective of this study was to evaluate the effectiveness of natural rosemary and green tea extract in cooked beef from cattle fed distillers grains. Procedure

Impact of Management Practices and Distillers' Grains Feeding on the Prevalence ofEscherichia coliO157 in Feedlot Cattle in Minnesota

Escherichia coli O157 is a foodborne pathogen that can be transmitted by contaminated ground beef and is shed naturally in cattle feces. Recent reports indicated that feeding distillers' grains (DG) to cattle increased fecal shedding and prevalence of E. coli O157. In Minnesota, feeding DG with solubles (DGS) to livestock became widespread within the last 10 years, but there is no report about the prevalence of E. coli O157 in beef cattle in this state. This study was undertaken to survey the fecal prevalence of E. coli O157 in cattle fed diets containing DG and its association with environmental conditions and management practices. Fecal samples were collected from three feedlots during a 1-year period. All animals in those feedlots were fed different DGS levels. E. coli O157 presence was determined using a combination of enrichment, immunomagnetic separation, plating onto sorbitol MacConkey agar, and confirmation of isolates by immunoassay and multiplex virulence genes polymerase chain reaction analysis. Overall, E. coli O157 was confirmed in 9.7% of samples. Prevalence during summer was 30% and declined to less than 10% the rest of the year. In animals grouped by dietary DGS concentration, no significant difference in prevalence (12.0 and 5.5%) was detected between the low and the high average groups (less and more than 20%). Previous feeding of DGS before arriving to the feedlot also had no influence on fecal prevalence. The presence of several interacting variables, uncontrolled in a real-life feedlot environment, was the likely reason for our observation and suggested that at the levels studied, DGS had no effect on the STEC O157 prevalence in cattle populations.

Effects of feeding dried distillers grains with supplemental starch on fecal shedding of Escherichia coli O157:H7 in experimentally inoculated steers1

Distillers grains (DG), a co-product of ethanol production used as protein and energy supplements in cattle diets, have been shown to increase fecal shedding of Escherichia coli O157:H7, a major foodborne pathogen. The reason for the positive association is not known. Because DG often replaces grain in the diet, decreased starch content and flow to the hindgut may create a favorable environment for E. coli O157:H7. Our objective was to determine whether the addition of starch to a corn DG-supplemented diet negates the effects of DG on fecal shedding of E. coli O157:H7. We conducted a study with 21 steers fed 1 of 3 diets: a corn grain-based basal diet (CON), basal diet supplemented with 25% corn dried DG (DDG), and basal diet supplemented with 25% DDG with corn starch (DDG+S) added at a level intended to increase starch concentration to that of the CON diet. Steers, housed individually in a biosafety level 2 animal facility, were randomly allocated to treatment diets and orally inoculated with a 5-strain mixture (10(9) cfu per steer) of nalidixic acid-resistant (Nal(R)) E. coli O157:H7. Fecal samples were collected for 5 wk, and on d 35, steers were euthanized and necropsied to collect gut content samples. Fecal or gut samples were cultured to determine prevalence and concentrations of Nal(R) E. coli O157:H7. Dietary starch concentrations, based on feed analysis, were 46.3% in the CON compared with 43.3 and 41.3% in the DDG and DDG+S diets, respectively. Steers fed DDG or DDG+S diets shed Nal(R) E. coli O157:H7 more often (P = 0.0027 and 0.0003, respectively) and at greater concentrations (1.9 or 2.0 cfu/g; P = 0.0025 and 0.0006) than those fed CON diet (1.4 cfu/g), but no difference was observed between DDG and DDG+S diets. Cumulative prevalence and concentrations of Nal(R) E. coli O157:H7 were greater in gut samples collected at necropsy in steers fed DDG and DDG+S diets compared with those fed CON diet, but no difference was observed between DDG and DDG+S diets. The lack of effect of starch addition to the DDG diet on fecal shedding of E. coli O157:H7 may be because either the decreased starch content in the DG-supplemented diet is not a factor in the increased shedding of E. coli O157:H7 or inclusion of pure starch in the diet may not have achieved our intended goal to have starch flow into the hindgut similar to that of corn grain. The study confirms our previous finding of the positive association between feeding DG and fecal shedding of E. coli O157:H7.

Feeding crude glycerin decreases fecal shedding of E. coli O157:H7 in growing cattle (2012)

Introduction Crude glycerin is a byproduct of ethanol production and is used as a carbohydrate source for cattle feed. Glycerin levels in previous studies have ranged from 0 to 20% of diet dry matter, and concentrations of 8% or less generally improve feedlot performance. At even low levels of glycerin, however, the activity of cellulolytic bacteria is depressed, ultimately leading to poorer fiber digestion. This observation suggests that glycerin may affect a specific population of bacteria in the gut. Crude glycerin can account for 8 to 10% of the weight of dried distillers grains with solubles, because it is one of the primary end-products when yeast ferments sugars to produce ethanol. Addition of 25% dried distillers grains with solubles to a feedlot diet increased the prevalence of Escherichia coli O157:H7 in feces of cattle. These observations led us to question whether glycerin might be the component of distillers grains responsible for the increases in prevalence of E. coli O157:H7 that often are observed in cattle fed distillers grains. To address this question, we added glycerin to diets of growing cattle and subsequently evaluated fecal shedding of E. coli O157:H7.

Effects of vitamin E on color stability and palatability of strip loin steaks from cattle fed distillers grains

The objective of this study was to determine the effect of preslaughter antioxidant supplementation to cattle fed wet distillers grains on carcass yield and quality grade, and on the color stability and consumer acceptability of steaks. Two hundred five crossbred steers were fed 35% wet distillers grains with the supplementation of 4 different levels of α-tocopheryl acetate: 0, 125, 250, and 500 IU•animal(-1)•d(-1) for 97 d. Chuck rolls (n = 69) and strip loins (n = 185) were collected and processed at 4 and 7 d postslaughter, respectively. Chucks were ground and separated into 0.23-kg samples. Strip loins were faced and cut into 2.54-cm steaks and packaged in a polyvinyl chloride overwrapped (PVC) package, a vacuum package, or modified atmosphere packages (MAP) for further color, α-tocopherol, objective tenderness, palatability, and proximate analysis. Color was measured objectively using a HunterLab Miniscan XE spectrophotometer (HunterLab Associates Inc., Reston, VA) and subjectively by a trained color panel, and a consumer panel was used to indicate which treatments affected retail acceptability and purchase decisions. Warner-Bratzler shear force measurements were used for objective tenderness, and a trained panel assessed subjective palatability characteristics. Instrumental color measurements revealed little difference for ground beef in both PVC and MAP packages, but diets with 500 and 250 IU•animal(-1)•d(-1) of vitamin E had a longer (P < 0.05) retention of redness and yellowness in steaks as compared with steaks from animals receiving less vitamin E. Subjective color evaluation for strip steaks indicated that greater vitamin E was more likely (P < 0.05) to maintain color stability, overall acceptability, and consumer purchase preference while decreasing percentage of discoloration. No significant differences (P > 0.10) were observed for objective tenderness and sensory attributes of strip steaks, and no differences (P > 0.10) were observed in protein, fat, and moisture percentages of ground beef. Lipid oxidation analysis indicated that steaks packaged in PVC for 7 d and MAP for 1, 3, and 7 d, and ground beef packaged in MAP and PVC for 0 and 7 d of retail display required greater inclusion of vitamin E (500 and 250 IU•animal(-1)•d(-1)) to remain below the 2.28 mg of malonaldehyde/kg threshold. Ultimately, 500 IU•animal(-1)•d(-1) of vitamin E should be supplemented to cattle fed wet distillers grain-based diets when products are packaged in MAP to maximize retail shelf life.

Preliminary Investigation of the Association between Feeding Starch-based Ethanol Co-Products and Salmonella Species Shedding in Commercial Feedlots

Fecal shedding of Salmonella spp in feedlot cattle is an important component of pre-harvest food safety. Prevalence of salmonella in feedlot cattle varies and may be influenced by factors affecting hindgut and environmental ecology. Feedlots in the Texas Panhandle have begun to incorporate wet corn distiller's grains (WDGS) in their rations due to the increase in starch-based ethanol production in the region. Previous research has identified an association between feeding distiller's grains and shedding of E.coli O157:H7. These findings indicate that changes in starch, fiber, and fat composition of rations containing WDGS may impact hindgut ecology favoring the colonization and shedding of specific microorganisms. The objective of this study was to estimate the association between feeding WDGS and fecal shedding of Salmonella spp in feedlot cattle.

Evaluation of Feeding Dried Distiller's Grains with Solubles and Dry-Rolled Corn on the Fecal Prevalence ofEscherichia coliO157:H7 andSalmonellaspp. in Cattle

Escherichia coli O157:H7 and Salmonella are foodborne pathogens that reside in the gut of cattle and are shed in the feces. Previous work indicated a positive association between feeding cattle distiller's grains (DG) and an increase in E. coli O157:H7 prevalence. Feeding processed grains also has been shown to affect fecal prevalence of E. coli O157:H7. The objective of this study was to evaluate the effect of feeding DG and dry-rolled corn (DRC), alone or in combination, on fecal prevalence of E. coli O157:H7 and Salmonella in finishing cattle. Cattle were allotted to pens (n = 28), and fed dietary treatments (n = 150 days) structured in a 2 x 2 factorial arrangement; the factors were 0% or 25% dried corn DG with solubles (DDGS) and 0% or 25% DRC in steam-flaked corn-based high-grain diets. Fecal samples were collected from each pen floor before initiating dietary treatments and at least once every 2 weeks after final diets began. Overall prevalence of E. coli O157:H7 in fecal samples was 5.1%. There were no significant effects of DDGS, DRC, or sampling time on E. coli O157:H7 prevalence (p > 0.20). Overall prevalence of Salmonella in pen floor fecal samples was 23.7%, and sampling week affected prevalence (p < 0.01), ranging from < 1% (week 1) to 77.5% (week 17). Salmonella prevalence was not affected by cattle diet, and no work had previously reported an association between either DG or DRC and Salmonella prevalence. Lack of an association between E. coli O157:H7 prevalence and feeding DG or DRC is contrary to previous observations. Further research is needed to understand inconsistencies between studies of E. coli O157:H7 prevalence and potential associations with DG and grain-processing methods.

Distillers grains do not change carcass composition but change some fatty acids when added to finishing diet (2009)

Introduction Distillers grains are a by-product of ethanol production and have become increasingly available in recent years. Some research has revealed negative effects of distillers grains on quality and yield grades. Distillers grains contain substantial amounts of unsaturated fats and therefore could alter the ratios of saturated and unsaturated fats to achieve a more desirable composition in beef. Heterocyclic amines are the carcinogenic compounds released during high-temperature grilling of meat and would be increased if fat composition is changed. Our objectives were to evaluate effects of feeding distillers grains on carcass fatness, fatty acid profiles, and formation of heterocyclic amines.

Combinations of steam-flaked corn, dry-rolled corn, and dried distillers grains yield beef with similar yet subtle changes in sensory traits (2009)

Introduction Rapid expansion of fuel ethanol production has made available abundant supplies of distillers grains with solubles, which are well-suited as a substitute for cereal grains in finishing cattle diets. Several recently reported experiments have revealed that feeding distillers grains may have adverse effects on carcass value as a result of the tendency to produce carcasses with lower quality grades and/or higher yield grades. The effects on quality grade have been most evident in flaked-grain diets, but effects on yield grade are more or less independent of the type of grain fed. In Kansas, two common methods for processing grains are steam flaking and dry rolling. Thus, feeding cattle distillers grains with different grain processing types is an important consideration for feedlots. Our experiment was designed to evaluate meat quality and composition in heifers fed flakedcorn diets containing dry-rolled corn and/or dried corn distillers grains.

Diet,Escherichia coliO157:H7, and Cattle: A Review After 10 Years

Escherichia coli are commensal bacteria that can account for up to 1% of the bacterial population of the gut. Ruminant animals are reservoirs of the pathogenic bacteria E. colil strain O157:H7, and approximately 30% of feedlot cattle shed E. coli O157:H7. Feedlot and high-producing dairy cattle are fed high grain rations in order to increase feed efficiency. When cattle are fed high grain rations, some starch escapes ruminal microbial degradation and passes to the hindgut where it undergoes fermentation. Ten years ago researchers demonstrated that populations of total E. coli were higher in grain-fed than in forage-fed cattle, and when cattle were abruptly switched from a high grain diet to an all hay diet, total E. coli populations declined 1000-fold within 5 days and reduced the ability of the surviving E. coli to survive an acid shock mimicking passage through the human gastric stomach. This research provoked many questions about the effects of diet or E. coli O157:H7 populations that have not been conclusively answered to date. Subsequent research has shown that diet does affect E. coli O157:H7 populations, but the effects have varied in magnitude and impact. Further studies have demonstrated that the effects of forage feeding on E. coli O157:H7 populations may be due to concentrations of tannins and phenolic acids in forages. Other ration components such as rapidly ruminally fermented grains (e.g., barley) increase the shedding of E. coli O157:H7, and in some situations, feeding distillers grains can increase fecal shedding of E. coli O157:H7 due to VFA concentrations. Data from researchers across North America indicate that diet does impact STEC/EHEC populations in cattle prior to slaughter; however the economic, logistic and practical impacts of dietary changes must be examined and accounted for.

Feeding Supplemental Dried Distiller’s Grains Increases Faecal Shedding of Escherichia coli O157 in Experimentally Inoculated Calves

Escherichia coli O157 is an important foodborne pathogen and asymptomatic cattle serve as major reservoirs for human infection. We have shown a positive association between feeding distiller's grains and E. coli O157 prevalence in feedlot cattle. The objective of this study was to determine the effect of feeding dried distiller's grain (DDG) on faecal shedding of E. coli O157 in calves experimentally inoculated with E. coli O157. Holstein calves (five per treatment group), fed steam-flaked corn-based high-grain diets supplemented with 0% (control) or 25% DDG, were orally inoculated with a five-strain mixture (6 x 10(9) CFU/calf) of nalidixic acid-resistant (NalR) E. coli O157. Faecal samples were taken three times per week for 6 weeks to determine the prevalence and concentration of Nal E. coli O157. At the end of the study (day 43), calves were euthanized and necropsied. Ruminal, caecum, colon, and rectal contents, and rectoanal mucosal swab (RAMS) samples were collected at necropsy to determine NalR E. coli O157 concentration. There was a trend for an interaction between treatment and faecal sampling day. The concentration of NalR E. coli O157 in the faeces was significantly higher in faecal samples from calves fed DDG compared with control calves on days 35, 37, 39 and 42. At necropsy, the concentration of NalR E. coli O157 was higher in the caecum (P = 0.01), colon (P = 0.03) and rectum (P = 0.01) from calves fed DDG compared with control animals. The number of sites at necropsy positive for NalR E. coli O157 was higher in calves fed DDG compared with calves in the control treatment (P < 0.001). Our results indicate that E. coli O157 gut persistence and faecal prevalence increased in calves fed DDG, which potentially have important implications for food safety.

Impact of beef cattle diets containing corn or sorghum distillers grains on beef color, fatty acid profiles, and sensory attributes1,2

Strip loins from 236 carcasses from crossbred yearling steers were collected on each of 2 slaughter dates (slaughter 1 or 2) to determine the effects of feeding corn or sorghum distillers grains (DG) on beef color, fatty acid profiles, lipid oxidation, tenderness, and sensory attributes. Dietary treatments consisted of a steam-flaked corn (SFC) diet without (control) or with 15% (DM basis) corn dry or wet DG (CDDG and CWDG) or sorghum dry or wet DG (SDDG and SWDG) and alfalfa hay (R). Additional treatments included SDDG or SWDG with no alfalfa hay (NR). In slaughter 2, steaks from steers fed SFC had lesser L*, but greater a* (P < 0.05) values than those from steers fed DG. When comparing sorghum and corn DG steaks, the same color differences were detected. Steaks from steers fed sorghum DG had lower L*, but greater a* (P < 0.05) values than those from steers fed corn DG. Also, L* values in steaks from steers fed SWDG with R were greater (P < 0.05) than those from steers fed SWDG with NR. In slaughter 1, feeding DG increased (P < 0.05) steak n-6 fatty acid concentrations compared with SFC. In both slaughter groups, feeding dry DG increased (P < 0.05) steak linoleic acid concentrations compared with wet DG. In slaughter 2, feeding corn DG diets increased (P < 0.05) linoleic acid concentrations of steaks compared with sorghum DG diets. In addition, increased (P < 0.05) concentrations of alpha-linolenic acid in steaks resulted from feeding SDDG or SWDG with R compared with those sorghum treatments with NR. In each slaughter group, feeding DG increased (P < 0.05) the n-6:n-3 ratio of steaks compared with SFC, and feeding corn DG increased (P < 0.05) this ratio compared with sorghum DG. Furthermore, steaks from steers fed corn DG had greater (P < 0.05) concentrations of trans-vaccenic acid than those from steers fed sorghum DG. In slaughter 1, the CLA isomer 18:2, trans-10, cis-12 was greater (P < 0.05) in steaks from DG diets. On d 1 of retail display, steaks from steers fed SDDG with R in slaughter 2 had greater (P < 0.05) thiobarbituric acid reactive substances values than those from steers fed SDDG with NR. Feeding DG at 15% of the dietary DM did not affect sensory attributes or Warner-Bratzler shear force values of steaks. Feeding DG from either corn or sorghum as either a wet or dry by-product had no effect on beef sensory attributes.

Feeding distillers grains supplements to improve amino acid nutriture of lambs consuming moderate-quality forages1,2

We hypothesized that providing dried distillers grains with solubles (DDGS) would improve the N retention and use of nutrients by wethers fed a moderate-quality bromegrass hay. Additionally, we hypothesized that treatment effects on nutrient fluxes would be similar after 3, 6, or 9 wk on treatment. Chronic indwelling catheters were surgically implanted in a mesenteric artery, mesenteric vein, hepatic vein, and portal vein of 9 Suffolk x Dorset wethers (initial BW +/- SD = 57.4 +/- 6.1 kg). Wethers had ad libitum access to moderate-quality bromegrass hay (8.44% CP, DM basis) and received 100 g/d of either a corn-based (Corn, n = 4) or a DDGS-based (n = 5) supplement. There was no difference in DMI (P = 0.85) or DM digestibility (P = 0.46) between the 2 groups. There was a numerically greater N intake (21.5 vs. 18.4 g/d; P = 0.14) and N retention (4.4 vs. 2.5 g/d; P = 0.15) when wethers were supplemented with DDGS instead of Corn. Wethers fed DDGS had a greater (P = 0.008) release of alpha-amino N from the portal-drained viscera (PDV, 37.9 mmol/h) than those fed Corn (14.1 mmol/h). Similarly, there was a shift (P = 0.004) from a net splanchnic uptake to a net release of alpha-amino N in wethers fed DDGS (9.1 mmol/h) compared with those fed Corn (-9.6 mmol/h). However, there was no difference in ammonia release from the PDV (P = 0.49) or hepatic release of urea-N (P = 0.19) between the 2 treatments. There were very limited interactions between nutrient fluxes and the length of time after the initiation of treatments. However, there was a tendency (interaction, P = 0.07) for the PDV release of alpha-amino N to be greater at 6 and 9 wk after the initiation of the treatments than after 3 wk on treatment for wethers fed DDGS, although there was no difference over time for wethers fed the Corn supplement. Additionally, there were changes in numerous nutrient fluxes between 3 and 6 wk after the initiation of treatments regardless of treatment. These data indicate that DDGS is a viable supplement to enhance the nutriture of ruminants consuming moderate-quality forages. Additionally, these data indicate that the effects are discernible after 3 wk on treatment, with modest alterations in nutrient flux after additional time on treatment.

Evaluation of Dried and Wet Distillers Grains Included at Two Concentrations in the Diets of Lactating Dairy Cows

The purpose of this study was to determine the lactation performance of dairy cows fed dried or wet distillers grains (DG) with solubles (DDGS or WDGS) at 2 dietary concentrations. A trial using 15 cows was designed as a replicated 5×5 Latin square with periods of 4wk each and data collected during wk 3 and 4 of each period. Diets, on a dry matter basis, were: control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS. All diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mixes. Dry matter intake (DMI) tended to be greater for cows fed control than DG (23.4, 22.8, 22.5, 23.0, and 21.9kg/d for control, 10% DDGS, 20% DDGS, 10% WDGS, and 20% WDGS). Milk yield (39.8, 40.9, 42.5, 42.5, and 43.5kg/d) was greater for cows fed DG than control. Milk fat percentage (3.23, 3.16, 3.28, 3.55, and 3.40%) was similar for cows fed control and DG, but greater for cows fed WDGS than DDGS. Milk fat yield was greater for cows fed DG than control and tended to be greater for cows fed WDGS than DDGS. Milk fat from cows fed DG, especially 20% DG, was more unsaturated and contained more cis-9, trans-11 conjugated linoleic acid than when fed the control diet. Milk protein percentage (3.05, 3.01, 3.02, 3.11, and 3.06%) was similar for cows fed control and DG but greater for cows fed WDGS than DDGS. Milk protein yield was greater for cows fed DG than control, tended to be greater for cows fed WDGS than DDGS, and tended to be greater for cows fed 20% DG than 10% DG. Milk urea nitrogen was similar for cows fed control and DG but greater for cows fed WDGS than DDGS and tended to be higher for cows fed 20% DG than 10% DG. Ruminal ammonia concentrations were greater for cows fed WDGS than DDGS. Overall, feeding DG improved feed efficiency (1.70, 1.79, 1.87, 1.84, and 1.92kg of energy-corrected milk/kg of DMI) by increasing yields of milk, protein, and fat while tending to decrease DMI.

Meat quality responses to feeding distiller's grains to finishing Holstein steers1,2

Strip loins from two experiments were used to evaluate effects of feeding dry (DDG) or wet (WDG) distiller's grains on beef color, tenderness, and sensory traits of Holstein steers. In Exp. 1, conducted at the University of Illinois at Champaign-Urbana, dietary treatments consisted of a control whole corn-corn silage diet with soybean meal (SBM) or diets formulated with 12.5% DDG plus urea, 25% DDG, 25% WDG, 50% DDG, or 50% WDG (DM basis). In Exp. 2, conducted at Iowa State University, dietary treatments consisted of cracked corn-corn silage-hay diets with either SBM or urea (Urea) as the control diets, or diets formulated with 10, 20, or 40% DDG or WDG (DM basis). Within each study, strip loins from each of four steers (representing 45.7 and 66.6% of steers in Exp. 1 and 2, respectively) in four replicate pens per treatment were aged for 13 d at 4 degrees C for subsequent color, tenderness, and palatability evaluation. Color of steaks was measured objectively using a HunterLab Miniscan XE spectrophotometer and was subjectively evaluated by a trained panel. Tenderness was measured using the Warner-Bratzler shear force (WBSF) instrument on steaks cooked to 70 degrees C. For sensory evaluation, 95 consumers were recruited to evaluate tenderness, juiciness, and flavor of cooked steaks. In Exp. 1, steaks from steers fed 25% WDG had higher (P < 0.05) a* values after 138 h of simulated retail display than all other treatments, except for those from steers fed 12.5% DDG. In Exp. 2, a greater (P < 0.05) percentage of steaks from steers fed 40% DDG or 40% WDG were considered moderately undesirable during retail display (steaks that received a consumer acceptability score of 3 or less). There were no (P = 0.20 in Exp. 1, and P = 0.33 in Exp. 2) differences among treatments in Exp. 1 and Exp. 2 for WBSF (1.47 +/- 0.66 kg and 1.58 +/- 0.72 kg, respectively) or taste panel tenderness (5.7 +/- 0.30 and 6.2 +/- 0.22, respectively), beef flavor (6.0 +/- 0.23 and 6.2 +/- 0.22, respectively), and juiciness (5.6 +/- 0.31 and 5.8 +/- 0.23). Feeding distiller's grains at up to 50% of the dietary DM did not affect tenderness or sensory traits, and seems to be a viable feed alternative without negatively impacting sensory attributes.

Effect of Increasing Oil from Distillers Grains or Corn Oil on Lactation Performance

The objective of this study was to evaluate production response and more specifically percentage and yield of fat in milk from dairy cows fed distillers grains with added solubles (DGS). It was hypothesized that the oil present in DGS would decrease milk fat yield. Four dietary treatments consisted of dried DGS replacing soybean meal and soybean hulls. The DGS inclusion rates as a percentage of dry matter (DM) were 0, 5, 10, and 15% DGS. To determine the role of oil in DGS, a fifth diet similar to 0% DGS with added corn oil (OIL) was included. Twenty multiparous Holsteins were assigned to a replicated, 5×5 Latin Square design with periods of 21 d. Diets were formulated to have similar crude protein and neutral detergent fiber (NDF) concentration. Feeding OIL or 15% DGS resulted in similar production of milk, milk protein, and milk fat. Increasing dietary DGS linearly increased milk production and milk true protein yield. Adding corn oil increased milk yield and, although milk true protein yield also tended to increase with oil, milk true protein concentration decreased. The addition of DGS or OIL did not significantly change fat yield from 0% DGS; however, fat concentration in milk was significantly decreased by DGS due to increased fluid milk production. In diets containing approximately 28% NDF, cottonseed, blood and fish meal, feeding DGS to bring total dietary fatty acids to 5% of diet DM increased milk and milk protein yield without decreasing milk fat yield. Reduced proportions of shorter chain fatty acids and increased proportions of longer chain fatty acids in milk as dietary fatty acid content increased suggests that de novo fatty acid synthesis in the mammary gland was inhibited but this was offset by increased secretion of long-chain fatty acids, presumably absorbed from the diet. Therefore, our hypothesis that feeding corn oil either as DGS or as pure corn oil would decrease milk fat yield was not correct.