Evaluation of dried distillers grains and roughage source in steam-flaked corn finishing diets

Effect of inclusion of distillers grains with solubles and crude glycerin in beef cattle finishing diets on ruminal fermentation and fatty acid biohydrogenation

An experiment was conducted to evaluate the impact of feeding bio-fuel co-products on ruminal fermentation characteristics and composition of omasal digesta flow. Four ruminally cannulated Holstein steers (371 ± 5 kg) were used in a 4 × 4 Latin Square design. Omasal sample collection and triple marker technique was used to quantify fatty acid omasal flow. Treatments were applied as a 2 × 2 factorial where a steam flaked corn (SFC) basal diet (DGS-N CG-N) was replaced with 40% of diet DM as corn distillers grains (DGS; DGS-Y CG-N) or 10% of diet DM as crude glycerin (DGS-N CG-Y) or 40% of diet DM distillers grains and 10% of diet DM as crude glycerin (DGS-Y CG-Y). No effects were observed for the interaction of DGS and glycerin on measured rumen characteristics. Dietary inclusion of glycerin decreased (P = 0.05) ruminal content 4-h post feeding on a DM basis but did not influence DMI (P = 0.64). Feeding DGS had no effect (P = 0.34) on particulate passage to the omasum (kg/d) in spite of greater (P = 0.04) DMI. Feeding DGS reduced flow rate (% of rumen volume/h) (P = 0.05) but did not affect total VFA concentration (P = 0.46) or average ruminal pH (P = 0.72). No differences (P > 0.05) were observed in ruminal parameters when feeding glycerin, besides ruminal particulate content (kg) on DM basis (P = 0.05). An interaction of DGS and glycerin affected intake of stearic (P < 0.01), linoleic (P < 0.01), and linolenic acid (P < 0.01). An interaction of DGS and glycerin did not affect individual fatty acid flow with respect to intake for stearic (P = 0.17), linoleic (P = 0.18), or linolenic acid (P = 0.66). Dietary inclusion of glycerin had no impact on g of linolenic (P = 0.16) or linoleic (P = 0.32) acid transformed. A trend was identified for cattle fed diets with glycerin to have increased (P = 0.07) grams of conjugated linoleic acid (CLA; C18:2 cis-9, trans-11) per gram of linoleic acid intake, with no impact on the percent of saturated fat (P = 0.44) or unsaturated fat (P = 0.43) in omasal flow. For cattle fed diets with DGS, fewer grams of linoleic (P < 0.01) and linolenic (P < 0.01) were present in digesta flow per gram of intake. Inclusion of DGS in the treatment diets also increased (P < 0.01) stearic acid flow (g) and CLA flow (g) per gram of stearic and linoleic acid intake, respectively. Observed differences in CLA proportion post fermentation may indicate interrupted biohydrogenation when glycerin is fed.

Assessment of corn wet distillers grains fed to crossbred bulls on feeding behavior, rumen morphology, liver abscesses and blood parameters

Corn ethanol production has been growing in Brazil in the last ten years, generating by-products to feedlot diets. This study evaluates the effects of the inclusion of low-fat corn wet distillers grains (LF-WDG) on feeding behavior, ruminal health, liver abscesses and blood parameters of F1 Angus-Nellore bulls feedlot finished. Our hypothesis is that evaluation of data from feeding behavior, rumen and liver health would help to explain animal performance. In this trail, one-hundred animals were fed for 129 days with diets containing amounts of 0 (control), 15, 30 and 45% of LF-WDG replacing corn grain and soybean meal. Evaluations of fluctuation of dry matter intake (DMI) were carried out. Additionally, feeding behavior data were assessed by monitoring (24-h period) the feeding, rumination, time spent eating (TSE), and time expended on other activities (resting and number of meals per day). Blood variables such as pH, bicarbonate, total CO2 content, and base excess in extracellular fluid (Beecf) were determined. After slaughter, rumen epithelium was classified according to the incidence of lesions (rumenitis) and abnormalities (papillae clumped), and samples were collected for morphology and histology evaluations. Moreover, livers were scored for severity of abscesses as follow: as unabscessed (0), one or two small abscesses (A−), two to four small active abscesses (A) or one or more large, active abscesses (A+). The DMI (kg/day) differed (P = 0.03) among treatments and there is a tendency of 15 and 30 LF-WDG (% DM) had lower %DMI fluctuation compared to 0 or 45%. The TSE increased linearly (P < 0.01) as the amounts of inclusion of LF-WDG increased. Moreover, neutral detergent fiber (NDF) intake, NDF consumption rate and NDF rumination efficiency increased linearly (P < 0.01) in response to LF-WDG feeding. The incidence of rumenitis tended (P = 0.08) to be greater at 45% LF-WDG, while keratin thickness decreased linearly in bulls fed LF-WDG (P < 0.01). The severity of liver abscesses (score A+) increased linearly (P = 0.02). Regarding blood parameters, only Beecf decreased linearly (P < 0.01) in response to LF-WDG feeding. Therefore, the hypothesis of the current study was confirmed. We previous reported that F1 Angus-Nellore bulls fed LF-WDG show greater weight gain (1.94 ± 0.09 kg/day) and final body weight (620 ± 18.8 kg) when compare to control (1.8 ± 0.09 kg/day and 602 ± 18.8 kg, respectively). Here, we conclude that inclusion of 15 to 30% LF-WDG in feedlot diets improved feeding behavior without impairing ruminal health and blood parameters, driving performance and weigh gain of crossbred bulls. However, bulls fed 45% LF-WDG had greater severity of liver abscesses.

Does distillers' grains supplementation affect beef cattle performance, carcass characteristics, and meat quality? A meta-analysis study

This study evaluated, through meta-analysis, the effect of distillers' grains (DG) supplementation to beef cattle on their performance, carcass parameters, and meat fatty acid profile. Eighty-one peer-reviewed publications with 439 treatments means were included in the data set. The effects of DG supplementation to beef cattle were evaluated using weighted mean differences (WMD) between the control group (diets with no DG) and DG group (diets with DG). Heterogeneity was explored by meta-regression and subgroup analysis using genetic type, treatment period, DG type, amount of DG in diet (g DG/kg DM), sulfur in diet (g S/kg DM), ether extract in diet (g EE/kg DM), feed systems (pasture or total mixed ration), and concentrate level in the diet (g/kg DM). Meat fatty acid profile was more affected when DG was fed to crossbreed animals. In Angus animals, DG inclusion to the diets had little effect on meat fatty acid profile whereas, a pronounced reduction was reported in meat omega-6/omega-3 ratio. In response to DG inclusion to the diets, an increase in diet sulfur content up to 6.0 g/kg and ether extract content up to 110 g/kg had no adverse effects on performance, carcass parameters, and meat physicochemical characteristics. Distillers' grains inclusions in amounts between 500 and 600 g DG/kg provided the greatest responses when evaluating carcass parameters and meat fatty acid profile. Increased CLA c9 t11, linolenic acid, and total PUFA and reduced myristic acid concentration in meat were reported when animals were fed diets containing DG.

Influences of starter NDF level on growth performance and rumen development in lambs fed isocaloric and isonitrogenous diets

Neutral detergent fiber (NDF), as the main component of structural carbohydrate in forage, is a vital factor impacting the performance of young ruminants. The objective of this study was to evaluate the effect of starter NDF level on the rumen fermentation and morphometrics of lambs fed isocaloric and isonitrogenous diets. One hundred Hu sheep lambs (18 days of age and 6.1 ± 0.1 kg body weight [BW]) were randomly assigned to one of the four starter diets differing in their NDF levels on a dry matter (DM) basis: 1) diet with 14% NDF (NDF14), 2) diet with 18% NDF (NDF18), 3) diet with 22% NDF (NDF22), and 4) diet with 26% NDF (NDF26). Lambs were fed milk replacer with designed starters from 21 to 60 d of age and then transitioned to the same starter feed until 90 d of age. Six lambs from each treatment (close to the average BW of the corresponding treatment) were selected and slaughtered at 90 d of age for measuring rumen fermentation, anatomical development, and morphometric characteristics. Lambs receiving NDF22 and NDF26 starter diets had greater (P < 0.05) intake of starter and total DM, and average daily gain during the overall period, thereby heavier (P < 0.05) final weights at 90 d of age compared with those fed NDF14 starter diet. At 90 d of age, lambs fed NDF22 and NDF26 starters had higher rumen pH, followed by lower propionate, higher acetate concentrations (P < 0.05), and a higher acetate-to-propionate ratio compared with those fed NDF14 and NDF18 starters (P < 0.05). No significant differences of the full and empty weight of reticulorumen were observed among treatments; however, the reticulorumen weight expressed as a percentage of the complex stomach weight was lower (P < 0.05) in lambs fed NDF22 and NDF26 starters compared with those fed NDF14 starter. Furthermore, NDF14 lambs had the thickest keratin layer and epithelium compared with those in the other treatments but showed the thinnest muscle layer (P < 0.05). These results suggest that increasing starter NDF levels can ameliorate the rumen fermentation environment and alleviate hyperkeratosis and plaque formation in the rumen epithelium. In summary, including 22% and 26% NDF in the pelleted starter can improve the performance of lambs.

Meat quality traits and feeding distillers grains to cattle: a review

Livestock management and meat production involve a series of steps that affect meat quality. Animal genetics, nutrition and diets, slaughter procedures and meat-preservation conditions are some of the parameters that should be controlled to maintain meat quality. In regard to animal nutrition and diets, novel ingredients are increasingly used, distillers grains (DG) being an example. DG are obtained as a co-product from bioethanol production and comprise the fat, protein, fibre and micronutrient portion of the grains. Many papers have studied the inclusion of DG in finishing diets and their effect on growth performance and meat characteristics, but a review on the effects on meat quality is needed. Feeding with DG influences beef colour; nevertheless, a relationship between the level of inclusion and colour development has not been established yet. In addition, feeding DG-inclusion diets sometimes increases meat discoloration during retail display. Also, the composition of fatty acids is modified since total polyunsaturated fatty acid content in meat increases with the inclusion of DG in finishing diets. This increment in polyunsaturated fatty acid content is likely to contribute to lipid oxidation processes and might be related to meat discoloration due to myoglobin oxidation. However, meat tenderness has not been modified in most of the cases. This review focused on recent studies on DG inclusion, animal performance and meat quality. Key points that need further research are also identified and discussed.

Effects of wet corn distiller's grains with solubles and nonprotein nitrogen on feeding efficiency, growth performance, carcass characteristics, and nutrient losses of yearling steers12

Wet distiller's grains with solubles (WDGS) are a common by-product feedstuff generated by the grain-ethanol industry, and it is used extensively by the cattle feeding industry. Distillers grains are typically high in protein; however, the protein in WDGS has a low ruminal degradability, and thus may result in a deficiency of RDP in the diet even when dietary CP concentrations are high. Assessment of the RDP needs in diets containing WDGS is needed to aid the cattle feeding industry in managing feed costs and potential environmental issues. To that end, we conducted 2 feeding studies to evaluate the supplemental RDP requirements of beef cattle fed steam-flaked corn-based finishing diets. In Exp. 1, 525 yearling steers (initial body weight = 373 ± 13 kg) received treatments in a 2 × 3 + 1 factorial. Dietary factors included WDGS (15 or 30% of DM) and nonprotein N (NPN; 0, 1.5, or 3.0% of DM) from urea (0, 0.52, and 1.06%). The control diet without WDGS contained 3.0% NPN (1.06% urea) and cottonseed meal. Diets were formulated to have equal crude fat concentrations. Overall gain efficiency among steers fed 15% WDGS was greatest for 1.5% NPN and least for 0% NPN (P = 0.07, quadratic), whereas gain efficiency decreased linearly (P < 0.09) as NPN increased in the 30% WDGS diets. Dressing percent was greater (P < 0.01) for the Control diet than for 15 or 30% WDGS. In Exp. 2, 296 steer calves (initial BW = 344 ± 12 kg) were fed 1 of 4 experimental diets that included a Control diet without WDGS (contained 3% NPN from urea, and cottonseed meal) and 15% WDGS diets with either 1.50, 2.25, or 3.00% NPN (0.52, 0.78, and 1.04% urea, respectively, on a DM basis). Overall gain efficiency on either a live or carcass-adjusted basis was not different among treatments (P > 0.15). Dietary NPN concentration did not influence growth performance (P > 0.21). Increasing dietary WDGS concentration resulted in decreasing (P < 0.05) diet digestibility (determined with an internal marker) and increasing (P < 0.05) N volatilization losses (determined by diet and manure N:P ratio); however, the effects of NPN level on digestibility and N losses were somewhat inconsistent across experiments. Results suggest that optimum performance for cattle fed 15% WDGS occurred when the diet contained between 1.5 and 2.25% NPN. However, no supplemental NPN was needed to support optimum performance in diets containing 30% WDGS.

Effects of roughage source and inclusion in beef finishing diets containing corn wet distillers' grains plus solubles

Two experiments were conducted to determine the effects of roughage source and inclusion in diets containing wet distillers' grains plus solubles (WDGS) on finishing cattle performance and ruminal metabolism. In Exp. 1, 385 crossbred steer calves (initial BW = 346 kg [SD 29]) were used in a finishing trial. A control diet with no roughage inclusion was compared with 6 diets containing either alfalfa hay (ALF), corn silage (CSIL), or corn stalks (CSTK) at 2 inclusions as a 3 × 2 factorial. Alfalfa hay was included at 4 (low) or 8% (standard) of diet DM. Diets containing CSIL or CSTK were formulated to provide total dietary NDF equal to the low and standard ALF inclusion diets. The final diets contained 6.13 and 12.26% CSIL or 3.04 and 6.08% CSTK (DM basis). All diets contained 30% WDGS and a 1:1 mixture of dry-rolled and high-moisture corn (DM basis). Cattle fed no roughage had reduced ( < 0.01) DMI and tended ( ≤ 0.10) to have the lowest final BW and ADG compared with cattle fed roughage. There were no differences ( ≥ 0.11) in DMI, ADG, or G:F due to roughage source. Cattle fed a standard inclusion of roughage had greater ( ≤ 0.04) DMI and ADG compared with cattle fed diets with low inclusion, regardless of roughage source. Feed efficiency tended to be different among treatments ( = 0.09), with cattle fed no roughage having greater G:F than all treatments ( ≤ 0.06) except cattle fed the low level of CSTK, which had a similar G:F ( = 0.48). Feed efficiency was not affected by source of roughage ( = 0.23) or inclusion of roughage ( = 0.49). In Exp. 2, 6 ruminally fistulated steers (347 kg BW [SD 25]) were used in a 6 × 6 Latin square design. Treatments were arranged as a 2 × 3 factorial with ALF or CSTK included at zero, low, or standard levels similar to Exp. 1. Apparent total tract digestibility (%) of DM, OM, and NDF decreased linearly ( ≤ 0.07) due to increasing roughage inclusion. Average, maximum, and minimum ruminal pH increased linearly ( ≤ 0.09) as roughage inclusion was increased. Based on the results of this study, low levels of CSTK improved cattle performance relative to low inclusions of ALF or CSIL. Diets with standard inclusions of ALF, CSIL, or CSTK had similar performance. Roughage sources can be exchanged to provide equal NDF in finishing diets containing 30% WDGS without negatively impacting finishing cattle. Based on ADG, eliminating roughages when 30% WDGS was included in finishing diets was not beneficial.

Biofuel feedstock and blended coproducts compared with deoiled corn distillers grains in feedlot diets: Effects on cattle growth performance, apparent total tract nutrient digestibility, and carcass characteristics

Crossbred steers (British × Continental; = 192; initial BW 391 ± 28 kg) were used to evaluate the effects of feeding ethanol coproducts on feedlot cattle growth performance, apparent nutrient digestibility, and carcass characteristics. Steers were blocked by initial BW and assigned randomly to 1 of 6 dietary treatments within block. Treatments (replicated in 8 pens with 4 steers/pen) included 1) control, steam-flaked corn-based diet (CTL), 2) corn dried distillers grains with solubles (DGS; DRY-C), 3) deoiled corn dried DGS (DRY-CLF), 4) blended 50/50 corn/sorghum dried DGS (DRY-C/S), 5) sorghum dried DGS (DRY-S), and 6) sorghum wet DGS (WET-S). Inclusion of DGS was 25% (DM basis). The DGS diets were isonitrogenous, CTL was formulated for 13.5% CP, and all diets were balanced for ether extract. Final shrunk BW, ADG, and DMI did not differ among CTL and DGS treatments ( ≥ 0.19). Overall G:F did not differ from CTL for DRY-C, DRY-CLF, or WET-S ( ≥ 0.12); however, G:F was 9.6% less for DRY-S compared with CTL ( < 0.01) and tended ( = 0.09) to be less for DRY-C/S than CTL. For grain source, ADG and G:F were less for DRY-S vs. DRY-C ( < 0.05), but blending DRY-C/S tended ( = 0.07) to increase ADG and increased ( = 0.05) carcass-adjusted G:F vs. DRY-S. For WET-S, final BW and ADG were greater ( < 0.05), and G:F tended ( = 0.06) to be greater than for DRY-S. There was no difference in ADG, DMI, or G:F of steers fed DRY-C vs. DRY-CLF ( ≥ 0.35). Apparent DM and OM digestibility did not differ for CTL, DRY-C, DRY-CLF, and WET-S ( ≥ 0.30) but were lower for DRY-C/S and DRY-S ( < 0.05). Nutrient digestibility was lower for DRY-S vs. DRY-C ( < 0.01), but apparent digestibility of OM, DM, NDF, ADF, CP, ether extract, and starch were increased ( < 0.01) for DRY-C/S vs. DRY-S. Although starch digestibility did not differ between DRY-S and WET-S ( 0.18), digestibility of other measured nutrients was greater for WET-S vs. DRY-S ( < 0.01). Ether extract digestibility was greater for DRY-CLF vs. DRY-C ( < 0.05). Carcass weight, dressing percent, and marbling score did not differ between CTL and DGS diets ( ≥ 0.23). For DRY-S, HCW was lower than for DRY-C ( = 0.02); however, compared with DRY-S, HCW tended to be greater for DRY-C/S ( = 0.10) and WET-S ( = 0.07). At a moderately high (25% DM) inclusion, blending C/S or feeding WET-S resulted in cattle growth performance and carcass characteristics similar to those of CTL and corn-based coproducts.

Characteristics of Wet and Dried Distillers Grains on In vitro Ruminal Fermentation and Effects of Dietary Wet Distillers Grains on Performance of Hanwoo Steers

Two experiments were conducted to evaluate the nutrient composition, in vitro dry matter disappearance (IVDMD) and organic matter disappearance (IVOMD) of three kinds of distillers grains (DG); i) wet distillers grains (WDG, KRW 25/kg), ii) dried distillers grains (DDG, KRW 280/kg), iii) dried distillers grains with solubles (DDGS, KRW 270/kg) produced from tapioca 70% and rice 30%, and to evaluate dietary effects of WDG on the performance of Hanwoo steers. In Exp. 1, twelve-WDG, four-DDG and one-DDGS were collected from seven ethanol plants. Average crude protein, crude fiber, neutral detergent fiber, and acid detergent fiber of WDG, DDG, and DDGS were: 32.6%, 17.8%, 57.5%, and 30.2% for WDG, 36.7%, 13.9%, 51.4%, and 30.5% for DDG, and 31.0%, 11.9%, 40.3%, and 21.2% for DDGS (DM basis), respectively. The DDGS had a higher quantity of water-soluble fraction than WDG and DDG and showed the highest IVDMD (p<0.05) in comparison to others during the whole experimental time. The IVDMD at 0 to 12 h incubation were higher (p<0.05) in DDG than WDG, but did not show significant differences from 24 to 72 h. The same tendency was observed in IVOMD, showing that DG made from tapioca and rice (7:3) can be used as a feed ingredient for ruminants. Considering the price, WDG is a more useful feed ingredient than DDG and DDGS. In Exp. 2, 36 Hanwoo steers of 21 months (495.1±91 kg) were randomly assigned to one of three dietary treatments for 85 days; i) Control (total mixed ration, TMR), ii) WDG 10% (TMR containing 10% of WDG, as fed basis), and iii) WDG 20% (TMR containing 20% of WDG, as fed basis). With respect to body weight and average daily gain, there were no differences between control and WDG treatments during the whole experimental period. Dry matter intake of control (9.34 kg), WDG 10% (9.21 kg) and 20% (8.86 kg) and feed conversion ratio of control (13.0), WDG 10% (13.2) and 20% (12.1) did not show differences between control and WDG treatments. Thus, the use of WDG up to 20% in TMR did not show any negative effect on the performance of Hanwoo steers.

Digestive development in neonatal dairy calves with either whole or ground oats in the calf starter

A series of 3 trials was conducted to determine effects of whole or ground oats in starter grain on reticulorumen fermentation and digestive system development of preweaned calves. Male Holstein calves (43.1±2.3kg at birth; n=8, 9, and 7 for trials 1, 2, and 3, respectively) were housed in individual pens in a heated facility; bedding was covered with landscape fabric to prevent consumption of bedding by the calves. In trials 1 and 2 only, calves were fitted with rumen cannulas by wk 2 of life. In all trials, a fixed amount of starter (containing 25% oats either ground and in the pellet or whole) was offered daily; orts were fed through the cannula in trials 1 and 2. Calves were randomly assigned to an all-pelleted starter or pellets plus whole oats. Rumen contents (trials 1 and 2) were sampled weekly at -8, -4, 0, 2, 4, 8, and 12 h after grain feeding for determination of pH and volatile fatty acids. Calves were killed 3 wk (trial 1) or 4 wk (trials 2 and 3) after grain was offered; organs were harvested, emptied, rinsed, and weighed to gauge digestive organ development. Starter intake was not different between treatments. Weekly measurements of rumen digesta pH did not change and only subtle changes were observed in molar proportions of individual volatile fatty acids. Molar proportion of butyrate and pH linearly decreased with age, whereas acetate proportion increased. Reticulorumen weight and papillae length tended to be greater for calves fed pelleted starter, whereas abomasum weight was greater for calves fed pellets plus whole oats. Fecal particle size and starch content were greater for calves fed pellets plus whole oats. Under the conditions of this study, physical form of oats in starter grain did not affect rumen fermentation measurements; greater rumen weight and papillae length in calves fed pelleted starter may be the result of greater nutrient availability of ground oats. Under the conditions of this study with young calves on treatments for <4 wk, increasing particle size of the starter by feeding whole oats did not affect rumen fermentation nor did it improve digestive system development.

Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets

Four male lambs (Katahdin; average live weight 25.9±2.9 kg) with “T” type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p<0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p<0.01). Replacing corn with DDGS increased (linear, p≤0.02) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs.

Effects of Combining Feed Grade Urea and a Slow-release Urea Product on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy in Steers Fed Diets with Different Starch:ADF Ratios

As a result of the cost of grains, the replacement of grains by co-products (i.e. DDGS) in feedlot diets is a common practice. This change produces diets that contain a lower amount of starch and greater amount of fibre. Hypothetically, combining feed grade urea (U) with slow release urea (Optigen) in this type of diet should elicit a better synchrony between starch (high-rate of digestion) and fibre (low-rate of digestion) promoting a better microbial protein synthesis and ruminal digestion with increasing the digestible energy of the diet. Four cannulated Holstein steers (213±4 kg) were used in a 4×4 Latin square design to examine the combination of Optigen and U in a finishing diet containing different starch:acid detergent fibre ratios (S:F) on the characteristics of digestive function. Three S:F ratios (3.0, 4.5, and 6.0) were tested using a combination of U (0.80%) and Optigen (1.0%). Additionally, a treatment of 4.5 S:F ratio with urea (0.80% in ration) as the sole source of non-protein nitrogen was used to compare the effect of urea combination at same S:F ratio. The S:F ratio of the diet was manipulated by replacing the corn grain by dried distillers grain with solubles and roughage. Urea combination did not affect ruminal pH. The S:F ratio did not affect ruminal pH at 0 and 2 h post-feeding but, at 4 and 6 h, the ruminal pH decreased as the S:F ratio increased (linear, p<0.05). Ruminal digestion of OM, starch and feed N were not affected by urea combination or S:F ratio. The urea combination did not affect ADF ruminal digestion. ADF ruminal digestion decreased linearly (p = 0.02) as the S:F ratio increased. Compared to the urea treatment (p<0.05) and within the urea combination treatment (quadratic, p<0.01), the flow of microbial nitrogen (MN) to the small intestine and ruminal microbial efficiency were greater for the urea combination at a S:F ratio of 4.5. Irrespective of the S:F ratio, the urea combination improved (2.8%, p = 0.02) postruminal N digestion. As S:F ratio increased, OM digestion increased, but ADF total tract digestion decreased. The combination of urea at 4.5 S:F improved (2%, p = 0.04) the digestible energy (DE) more than expected. Combining urea and Optigen resulted in positive effects on the MN flow and DE of the diet, but apparently these advantages are observed only when there is a certain proportion of starch:ADF in the diet.

Effects of roughage concentration in dry-rolled corn-based diets containing wet distillers grains with solubles on performance and carcass characteristics of finishing beef steers

Distillers grains and distillers solubles are by-products of grain fermentation used to produce ethanol and contain greater concentrations of NDF and ADF, compared with other grains and concentrates they replace in feedlot diets. Typical finishing diets in the United States contain 8.3% and 9.0% roughage. Therefore, it is plausible that the dietary concentration of roughage can be altered when distillers grains are included in feedlot diets. The effects of roughage concentration in dry-rolled, corn-based diets containing wet distillers grains with solubles (WDGS) were evaluated in steers (n = 128; initial BW = 339 kg), using Calan gates. Each diet was based on dry-rolled corn and contained 25% WDGS with coarsely ground alfalfa hay (AH), replacing corn at 2% (AH-2), 6% (AH-6), 10% (AH-10), and 14% (AH-14) of DM. Feed offered was recorded daily, orts were measured weekly, and BW was measured on d 0, 1, 35, 70, 105, 140, 174, and 175. After commercial harvest and chilling, carcasses were evaluated on-line with a beef carcass grading camera to assess marbling and yield grade traits. The data were analyzed using the Mixed Procedure of SAS, in which contrast statements were used to separate linear and quadratic effects of AH inclusion. Decreasing concentrations of AH in the finishing diet resulted in a tendency for a quadratic response (P = 0.07) in final BW, where BW increased from 2 to 6% AH inclusion but then decreased from 6 to 14% inclusion. Similarly, ADG from d 0 to end responded quadratically (P < 0.01), in which ADG increased from 2 to 6% yet subsequently decreased from 6 to 14% AH inclusion. Dry matter intake from d 0 to end increased linearly (P = 0.02) as AH inclusion increased in the diet, whereas G:F increased from 2 to 6% AH inclusion and then decreased linearly (P < 0.01) from 6 to 14% AH inclusion. Concentration of AH in the finishing diet did not affect HCW, marbling score, or the proportion of cattle grading USDA choice (P ≥ 0.18). However, dressing percent and LM area did respond in a quadratic manner (P < 0.02), in which they decreased from 2 to 10% AH inclusion and increased from 10 to 14% AH in the diet. Yield grade and adjusted 12th rib fat responded quadratically (P < 0.01), in which both increased from 2 to 6% AH inclusion and decreased from 6 to 14% inclusion. Analysis of responses of G:F and ADG on AH predict the apex at 3% and 7% for G:F and ADG, respectively, when fed in diets containing 25% WDGS.

Effects of 35% corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on animal performance, carcass characteristics, beef fatty acid composition, and sensory attributes

Fifty-four individually-fed Hereford-Angus cross steers (initial BW = 308 ± 9 kg) were used in an unbalanced randomized block design with a 2 × 2 factorial treatment arrangement to determine effects of corn processing method and corn wet distillers grains plus solubles (WDGS) inclusion in finishing diets on animal performance, carcass and beef characteristics, and sensory attributes. Dietary treatments included steam-flaked corn- (SFC) and dry-rolled corn (DRC)-based finishing diets containing 0 or 35% WDGS (DM basis; 0SFC and 35SFC, 0DRC and 35DRC, respectively). Yellow grease was used to equilibrate fat content of diets. Steers were fed 174 d, and were harvested on a single date when the mean ultrasound fat thickness was estimated to be 1.30 cm. No interactions between corn processing and WDGS were observed for performance or carcass characteristics (P ≥ 0.11). Final BW (556 ± 14 kg) and ADG (1.43 ± 0.06 kg) were not affected (P ≥ 0.25) by dietary treatment. Steers fed SFC-based diets consumed less feed, and were 10.6% more efficient (P < 0.01) than those fed DRC-based diets. Including WDGS in finishing diets improved feed efficiency of steers consuming both SFC- and DRC-based diets (P ≤ 0.04). Dietary treatment did not affect HCW, dressing percentage, fat thickness, or yield grade (P ≥ 0.27). Including WDGS in finishing diets decreased the concentration of 16:1cis-9, 18:1cis-9, and 18:1cis-11 fatty acids, and tended (P ≤ 0.10) to increase total fat concentration of steaks compared with diets without WDGS. A corn processing method by WDGS interaction was detected for 18:1trans-11 where steaks from 0DRC diets had decreased concentrations compared with other diets. There were no dietary effects on palatability attributes (P > 0.20). Livery-organy aromatics (P = 0.03) and sweet basic tastes (P = 0.01) in steaks from the 35SFC treatment were more intense than in other treatments, but were barely detectable. Thiobarbituric acid reactive substances tended to be greater in steaks from steers fed WDGS after 5 d of storage (P = 0.10), and were greater after 7 d. (P < 0.01). Inclusion of WDGS used in this experiment improved G:F with minimal impacts on carcass characteristics. Both WDGS inclusion and corn processing method impacted fatty acid composition. However, diet had minimal impacts on palatability attributes. When compared with diets fat-equilibrated with yellow grease, the primary concern with incorporating WDGS appears to be decreased shelf-life after 5 d of storage.

Effects of twenty percent corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on heifer performance, carcass characteristics, and manure characteristics

Two hundred sixty-four crossbred heifers (initial BW = 354 kg ± 0.5) were used to determine effects of corn processing method and wet distillers grains plus solubles (WDGS) inclusion in finishing diets on animal performance, carcass characteristics, and manure characteristics. The study was conducted as a randomized complete block with a 2 × 2 factorial arrangement of treatments. Dietary treatments included steam-flaked corn (SFC)- and dry-rolled corn (DRC)-based finishing diets containing 0 or 20% WDGS (0SFC, 20SFC, 0DRC, and 20DRC, respectively). Heifers averaged 154 d on feed and were marketed in 3 groups. There were no interactions between corn processing method and WDGS detected (P ≥ 0.29) for any performance or carcass response variables. Heifers fed diets containing WDGS tended to have greater final BW (P = 0.10) and increased G:F (P = 0.08) compared with heifers fed diets without WDGS. Heifers fed SFC-based diets consumed 7% less feed (P < 0.01) and were 9% more efficient (P < 0.01) than heifers fed DRC-based diets. Carcass characteristics were not affected by corn processing method or WDGS inclusion (P ≥ 0.16). Intakes of OM, N, P, and K were greater (P ≤ 0.05) for heifers fed DRC-based diets than those fed SFC-based diets, which resulted in greater net accumulation of the nutrients in the manure (P ≤ 0.04). Heifers fed diets containing WDGS had greater (P < 0.01) intakes of N, P, and K than heifers fed diets without WDGS. As a result, a greater net accumulation of P and K (P ≤ 0.03) and N (P = 0.10) were present in the manure from cattle fed diets containing WDGS compared with those fed diets without WDGS. There was no interaction (P ≥ 0.16) between corn processing and WDGS on N volatilization losses. Nitrogen volatilization losses from manure (expressed as a percentage of intake and g·heifer(-1)·d(-1)) were greater (P < 0.01) for heifers fed SFC-based diets than heifers fed DRC-based diets. Feeding DRC-based finishing diets to heifers resulted in increased manure production and nutrient excretion and decreased N volatilization. Both corn processing method and WDGS inclusion affected animal performance and manure characteristics.

Wet distillers grains plus solubles concentration in steam-flaked-corn-based diets: Effects on feedlot cattle performance, carcass characteristics, nutrient digestibility, and ruminal fermentation characteristics

Two experiments were conducted to determine the effects of wet distillers grain plus solubles (WDG; <15% sorghum grain) concentration in steam-flaked corn (SFC) diets on feedlot performance, carcass characteristics, ruminal fermentation, and diet digestibility. In Exp. 1, six hundred crossbred steers (364 ± 35 kg of BW) were used in a randomized complete block design with 8 replications/treatment. Dietary treatments consisted of a dry-rolled corn (DRC) control diet without WDG, a SFC control without WDG, and SFC with 4 WDG concentrations (15, 30, 45, 60% DM basis) replacing SFC, cottonseed meal, urea, and yellow grease. Final BW, ADG, G:F, HCW, and 12th-rib fat depth were greater (P ≤ 0.05) for SFC compared with DRC. Dry matter intake tended (P = 0.06) to be greater for DRC compared with SFC. Final BW, ADG, G:F, HCW, 12th-rib fat depth, and marbling score decreased linearly (P < 0.01) with increasing WDG concentration. In Exp. 2, six ruminally and duodenally cannulated crossbred steers (481 ± 18 kg of BW) were used in a 6 × 6 Latin square design using the same diets as Exp. 1. Ruminal, postruminal, and total tract OM and NDF digestibility were not different (P > 0.14) for DRC compared with SFC. Ruminal and total tract starch digestibility were greater (P < 0.01) for SFC compared with DRC. Dry matter and OM intake were not different (P ≥ 0.43) among WDG treatments. Ruminal and total tract OM digestibility decreased linearly (P < 0.01) with increasing WDG concentration. Intake, ruminal digestibility, and total tract digestibility of NDF increased linearly (P < 0.01) with increasing WDG concentration. Starch intake decreased linearly (P < 0.01) with increasing WDG concentration. Ruminal starch digestibility increased (P = 0.01) with increasing concentration of WDG. Total tract starch digestibility decreased quadratically (P < 0.01) with increasing concentration of WDG. Feeding SFC improved steer performance compared with DRC. The concentration of WDG and corn processing method influences nutrient digestibility and ruminal fermentation. The addition of WDG in SFC-based diets appears to negatively affect animal performance by diluting the energy density of the diet.

Wheat distillers grains in feedlot cattle diets: feeding behavior, growth performance, carcass characteristics, and blood metabolites

A study was conducted to evaluate feed intake, ADG, carcass quality, eating behavior, and blood metabolites in feedlot beef steers fed diets that varied in proportion of wheat dried distillers grains with solubles (DDGS) replacing barley grain or barley silage. Two hundred crossbred steers (BW = 489 ± 30 kg) were blocked by BW and randomly allotted to 20 pens (5 pens per treatment). Steers were fed 1 of 4 diets: control without DDGS (CON), 25% (25DDGS), 30% (30DDGS), or 35% (35DDGS) wheat DDGS (DM basis). The CON diet consisted of 15% barley silage and 85% barley-based concentrate; the 3 wheat DDGS diets were formulated by substituting 20% barley grain and 5, 10, or 15% silage, respectively, with 25, 30, or 35% wheat DDGS so that the 35DDGS diet contained no silage. The diets were formulated such that wheat DDGS was substituted for both barley grain and barley silage to evaluate whether wheat DDGS can be fed as a source of both energy and fiber in feedlot finishing diets. Dry matter intake of steers fed 25DDGS was greater (P < 0.01), but final BW, ADG, and G:F were not different compared with steers fed CON diet. Carcass characteristics and liver abscess score were not different between CON and 25DDGS. Steers fed 25DDGS had longer eating time (min/d; P < 0.01), greater meal frequency (P < 0.04), but a slower eating rate (P < 0.04). Replacing barley silage with increasing amounts of wheat DDGS (from 25DDGS to 35DDGS) linearly reduced (P < 0.01) DMI. Final BW, ADG, and G:F were not affected by increasing amounts of wheat DDGS. Carcass traits were not different, whereas liver abscess scores linearly (P < 0.01) increased as more barley silage was replaced by wheat DDGS. Eating time (min/d) and duration of each meal linearly (P < 0.02) decreased, whereas eating rate (min/g of DM) linearly (P < 0.01) increased with increasing replacement of barley silage. Blood urea N was doubled (P < 0.01) compared with CON by inclusion of wheat DDGS. Results indicate that wheat DDGS can be used effectively in feedlot diets, decreasing the need for barley grain or silage without negatively affecting growth performance and carcass characteristics. A reduction in the amount of roughage required to maintain growth performance is a potential advantage in feedlot operations because forage is costly and often of limited availability. Thus, DDGS can be a possible alternative as long as they are available and cost effective; however, increased incidence of liver abscess and increased N content of manure need to be considered when greater amounts of wheat DDGS are included in finishing diets.

Effects of roughage concentration in steam-flaked corn-based diets containing wet distillers grains with solubles on feedlot cattle performance, carcass characteristics, and in vitro fermentation

Two studies were conducted to evaluate effects of wet distillers grains with solubles (WDG) and dietary concentration of alfalfa hay (AH) on performance of finishing beef cattle and in vitro fermentation. In both studies, 7 treatments were arranged in a 2 × 3 + 1 factorial; factors were dietary concentrations (DM basis) of WDG (15 or 30%) and AH (7.5, 10, or 12.5%) plus a non-WDG control diet that contained 10% AH. In Exp. 1, 224 beef steers were used in a randomized complete block (initial BW 342 kg ± 9.03) finishing trial. No WDG × AH interactions were observed (P > 0.12). There were no differences among treatments in final shrunk BW or ADG (P > 0.15), and DMI did not differ with WDG concentration for the overall feeding period (P = 0.38). Increasing dietary AH concentration tended (P < 0.079) to linearly increase DMI, and linearly decreased (P < 0.05) G:F and calculated dietary NE(m) and NE(g) concentrations. Carcasses from cattle fed 15% WDG had greater yield grades (P = 0.014), with tendencies for greater 12th-rib fat (P = 0.054) and marbling score (P = 0.053) than those from cattle fed 30% WDG. There were no differences among treatments (P > 0.15) in HCW, dressing percent, LM area, KPH, proportions of cattle grading USDA Choice, and incidence of liver abscesses. In Exp. 2, ruminal fluid was collected from 2 ruminally cannulated Jersey steers adapted to a 60% concentrate diet to evaluate in vitro gas production kinetics, H(2)S production, IVDMD, and VFA. Relative to the control substrate, including WDG in substrates increased (P < 0.01) H(2)S production and decreased total gas production (P = 0.01) and rate of gas production (P = 0.03). Increasing substrate WDG from 15 to 30% increased (P < 0.05) H(2)S production and decreased (P < 0.001) total gas production, with a tendency (P = 0.073) to decrease IVDMD and fractional rate of gas production (P = 0.063). Treatments did not significantly affect (P > 0.09) molar proportions or total concentration of VFA. Results indicate that including 15 or 30% WDG in steam-flaked corn-based diets did not result in major changes in feedlot performance or carcass characteristics, but increasing AH concentration from 7.5 to 12.5% in diets containing WDG decreased G:F. Including WDG in substrates decreased rate and extent of gas production and increased H(2)S production. Changes in various measures of in vitro fermentation associated with AH concentrations were not large.