Crystal D. Buckner

Effect of corn processing method and corn wet distillers grains plus solubles inclusion level in finishing steers

Two experiments were conducted to determine the effect of corn processing method and corn wet distillers grains plus solubles (WDGS) level on steer performance and metabolism. In Exp. 1, 480 crossbred steer calves (314 +/- 18 kg of BW) were used in a finishing experiment with a randomized complete block design and a 3 x 4 treatment structure. Diets were based on dry-rolled (DRC), high-moisture (HMC), or steam-flaked corn (SFC) with increasing levels of WDGS (0, 15, 27.5, or 40%; DM basis). A corn processing x WDGS level interaction (P < 0.01) was observed for ADG and G:F. Average daily gain and G:F increased linearly (P < 0.01) in steers fed DRC; ADG increased quadratically (P = 0.04) and G:F increased linearly (P = 0.02) in steers fed HMC; and ADG decreased quadratically (P = 0.02) with no change in G:F (P = 0.52) in steers fed SFC as WDGS increased. In Exp. 2, 7 ruminally fistulated steers (440 +/- 41 kg of BW) were used in a 6-period crossover design with 3 x 2 factorial treatment structure. Diets were the same as those fed in Exp. 1, except they contained only 2 levels of WDGS (0 or 40% of diet DM). Total tract starch digestibility was greater (P < 0.01) for steers fed SFC than for steers fed DRC or HMC. Minimum ruminal pH was less (P < 0.01) for steers fed SFC than for steers fed HMC or DRC. Variance of ruminal pH was different among all 3 processing methods with DRC < HMC < SFC (P < 0.10). In situ 22-h DM digestibility of DRC and HMC and starch digestibility of DRC were greater (P < 0.10) in steers fed DRC compared with steers fed HMC or SFC. Steers fed 0% WDGS had less (P < or = 0.02) intake of DM, OM, NDF, and ether extract compared with steers fed 40% WDGS. Total tract digestibility of DM and OM was greater (P < or = 0.08) and digestibility of ether extract tended (P = 0.11) to be less for steers fed 0% WDGS compared with steers fed 40% WDGS. Maximum ruminal pH and pH variance were greater (P < or = 0.08) in steers fed 0% WDGS. A corn processing x WDGS level interaction (P = 0.09) was observed for ruminal acetate to propionate ratio (A:P). Within diets containing 0% WDGS, A:P in steers fed SFC was less (P < or = 0.08). In diets containing 40% WDGS, A:P was similar between processing methods and not different from the SFC with 0% WDGS. The corn processing x WDGS level interaction observed in the finishing experiment may be due to the decreased ruminal A:P in DRC and HMC diets with 40% WDGS.

Evaluation of Dry Distillers Grains Plus Solubles Inclusion on Performance and Economics of Finishing Beef Steers1

A 167-d feedlot study was conducted to evaluate feeding increasing levels of dry distillers grains plus solubles (DDGS) to finishing cattle and the impact on performance and profitability. Crossbred steer calves (n = 240, BW = 306 ± 24.5 kg) were used in 30 pens with dietary treatments of 0, 10, 20, 30, and 40% DDGS dietary inclusion (DM basis). Quadratic relationships (P 0.15) by DDGS level, but G:F tended to be quadratic (P = 0.10) as 20% DM inclusion had the greatest value, although steers fed all levels of DDGS had numerically greater G:F compared with steers fed no DDGS. Carcass characteristics, other than hot carcass weight, were not affected by DDGS treatment. Energy value of DDGS at 10 to 40% dietary inclusion resulted in a quadratic trend (P = 0.10) and remained above corn, with the highest values at 10 and 20% inclusion averaging 127% of corn. When DDGS was priced equally to corn, all levels of DDGS from 10 to 40% inclusion resulted in higher profits compared with a dry-rolled corn based diet regardless of corn price. The greatest returns were observed when cattle were fed 20% DDGS. These data indicate that DDGS can be fed up to 40% DM to improve cattle performance and result in economic profits, with optimum levels at 20 to 30% diet DM.

Nutrient variability for distillers grains plus solubles and dry matter determination of ethanol by-products1

ABSTRACT Three experiments were conducted to evaluate nutrient content and DM determination methods of dry milling byproducts. In Exp. 1, nutrient composition was determined for wet distillers grains plus solubles (WDGS) and modified distillers grains plus solubles (MDGS) from 6 ethanol plants with 10 samples collected per day, across 5 d, and sampling was repeated over 4 separate months. Mean composition was 31.0% CP, 11.9% fat, 0.84% P, and 0.77% S (DM basis). Coefficients of variation for DM content were greater for some plants than others, and variation occurred within and across days. Variability was small for CP and P, whereas fat differed among ethanol plants. Large variation in means and CV were observed for S in period 1, but variation subsequently decreased. Coefficients of variation for S were similar for samples collected within the same day and across days. In Exp. 2, samples of WDGS, MDGS, Dakota Bran Cake, and distillers solubles were used to determine DM content by drying samples at 105°C for 3, 8, and 24 h and 60°C for 24 and 48 h, vacuum oven drying, toluene distillation, and Karl Fischer titration. Compared with toluene distillation, drying at 105°C resulted in less DM (P ≤ 0.10) and vacuum drying and Karl Fischer titration resulted in greater DM (P

Effect of feeding combinations of wet distillers grains and wet corn gluten feed to feedlot cattle.

Three experiments were conducted to evaluate the use of combinations of wet corn gluten feed (WCGF) and wet distillers grain plus solubles (WDGS) in dry-rolled and high-moisture corn-based finishing diets for beef cattle. In Exp. 1, 250 steers (BW = 343 +/- 13.5 kg) were fed 5 treatments consisting of a corn-based, control diet with 0% coproducts, and diets including 30% WCGF, 30% WDGS, 15% WCGF plus 15% WDGS, or 30% WCGF plus 30% WDGS. No associative effects resulted from feeding 15% WCGF plus 15% WDGS; DMI, ADG, and G:F were intermediate between steers fed WCGF or WDGS at 30% of diet DM. Feeding coproducts in combinations at 30 and 60% of diet DM increased ADG, G:F, and final BW (P < 0.05) compared with the corn-based diet. In Exp. 2, 280 yearling steers (BW = 370 +/- 0.45 kg) were used to evaluate feeding 0, 25, 50, or 75% coproducts as a combination of 50% WCGF:50% WDGS (DM basis). Additional diets were fed containing decreased alfalfa hay at 5, 2.5, and 0% (DM basis) as coproduct blend inclusions increased at 25, 50, and 75% (DM basis), respectively. No interactions were observed between alfalfa hay and coproduct blend levels, and no effects on ADG or G:F (P > 0.21) were observed due to alfalfa hay. Intake, ADG, and G:F responded quadratically (P < 0.05) across coproduct levels, with the greatest ADG and G:F at 25 and 50% blend, and similar ADG and G:F for the 0 and 75% blend levels. In Exp. 3, 504 steers (BW = 376 +/- 16 kg) were fed to evaluate 0, 10, 15, 20, 25, and 30% (DM basis) WDGS in diets containing 30% WCGF (DM basis) as well as a control diet with no coproducts. The inclusion of 30% WCGF in the diets increased DMI, ADG, and G:F (P < 0.05) when compared with control. Response to inclusion level of WDGS tended to be quadratic for DMI (P = 0.12), quadratic for ADG (P = 0.05), and no effect for G:F (P = 0.96). Greatest ADG was achieved with 15 to 20% WDGS inclusion in diets containing 30% WCGF. The use of combinations of WCGF and WDGS in finishing diets resulted in similar or improved steer performance compared with corn, suggesting replacement of corn with coproduct combinations up to 75% diet DM is possible if a roughage source is fed.

Impact of source of sulfur on ruminal hydrogen sulfide and logic for the ruminal available sulfur for reduction concept

Effects of organic and inorganic sources of S on intake, intake pattern, ruminal pH, VFA profile, and ruminal H2S gas concentration ([H2S]) were evaluated, which lead to development of a procedure to measure ruminal S availability for reduction [ruminal available S (RAS)] as well as compare with an estimated number [adjusted ruminal protein S (ARPS)]. Ruminally cannulated crossbred beef steers (n = 5; BW = 548 ± 46 kg) were assigned to 1 of 5 diets in a 5×5 Latin square design and fed ad libitum in five 21-d periods. Steers were fed a dry-rolled corn diet (CON), inorganic S source (ammonium sulfate; INORG), organic S source (corn gluten meal) fed at 9.8 (ORG-L) or 23% of diet DM (ORG-H), or wet distillers grains with solubles (WDGS) fed at 50% of diet DM. For the laboratory procedure, individual ingredients were incubated with ruminal fluid from heifers fed 60% corn-based diets (n = 2) and McDougalls buffer. Bottles were cooled in ice, centrifuged, and decanted, and the precipitate was analyzed for S. Steers fed INORG tended (P = 0.12) to consume 12% less DM. Total S intake was greater (P < 0.01) for steers fed WDGS (60 g/d) followed by ORG-H, and the lowest S intake was observed for CON (22 g/d). Intakes of ARPS and RAS were greater (P < 0.01) for steers fed WDGS followed by INORG, ORG-H, ORG-L, and CON diets. Steers fed WDGS and INORG diets spent 13% more time eating (P < 0.01) compared with other treatments. There was an interaction (P = 0.05) between treatment and time for ruminal [H2S]. Similar [H2S] were observed for steers fed INORG and WDGS diets (P = 0.28), which were greater (P ≤ 0.05) than other treatments. Greater ruminal [H2S] at 8 h compared with 13 h postfeeding was observed for steers fed ORG-H, ORG-L, and CON diets (P ≤ 0.04). Nearly 65% of ruminal [H2S] variation was explained (linear; P < 0.01) by RAS intake, ARPS explained 58% (linear; P < 0.01), S intake explained 29% (quadratic; P < 0.01), average ruminal pH explained 12% (linear; P < 0.01), and area below ruminal pH 5.6 explained 16% (linear, P < 0.01) of the variation. A 6% decrease in acetate (P = 0.01), 20% increase in propionate molar proportions (P = 0.02), and a lower acetate:proprionate ratio (P = 0.02) were observed for steers fed INORG compared with CON diet. The RAS concept is important for predicting ruminal [H2S] rather than just total S in the diet. Coefficients of RAS for individual ingredients can be predicted using in vitro procedures. Ruminal [H2S] may also modulate intake pattern.

Effect of corn bran and steep inclusion in finishing diets on diet digestibility, cattle performance, and nutrient mass balance

One metabolism trial and 2 finishing trials were conducted to evaluate the effects of adding corn bran and steep liquor (steep) in replacement of dry-rolled corn (DRC) on diet digestibility, cattle performance, and nutrient mass balance in open feedlot pens. The metabolism trial (Exp. 1) used 8 ruminally cannulated heifers in a 4 × 4 Latin square design and the 2 finishing trials used 128 steer calves fed for 167 d (Exp. 2) and 256 yearling steers fed for 126 d (Exp. 3). Dietary treatments for all trials included a DRC-based control (CON), 30% corn bran (30/0), 30% corn bran plus 15% steep (30/15), and 45% corn bran plus 15% steep (45/15), in which by-products replaced DRC and molasses in the diet (DM basis). Diets were not isonitrogenous or isoenergetic. In the metabolism trial, feeding the by-product diets produced greater rumen pH (5.95) than CON (5.76; P < 0.01). Total tract DM and OM digestibility were greater for heifers fed CON than the by-product diets (P < 0.01). Dry matter and NDF ruminal disappearance (%/h) of corn bran were numerically less for cattle fed the CON diet than the by-product diets (2.36 vs. 2.84 and 0.72 vs. 1.66, respectively). In the performance trials, steers fed the by-product diets consumed more DM (P = 0.06) and G:F was either similar for all diets in Exp. 2 (P = 0.56) or less for cattle fed 30/0 than the other diets in Exp. 3 (P = 0.05). Percent N loss was reduced in Exp. 2 by including corn bran in diets compared with CON (P < 0.01). However, in Exp. 3, no differences in percent N loss were detected among treatments (P = 0.16), but more N was removed in the manure from pens where steers were fed by-products (P = 0.01). Although steep did not improve diet digestibility, it was beneficial in maintaining cattle performance in the feedlot studies. Feeding corn bran in combination with steep increased manure N removed and N in compost, but decreased percent N lost during the winter months only.

Ruminally undegradable protein content and digestibility for forages using the mobile bag in situ technique

Four experiments were conducted to evaluate RUP content and digestibility for smooth bromegrass, subirrigated meadow, upland native range, and warm-season grasses. Samples were collected from esophageally cannulated cows or ruminally cannulated steers. Forages were ruminally incubated in in situ bags for durations of time based on 75% of total mean retention time, which was based on IVDMD and rate of passage calculations. One-half of the bags were duodenally incubated and excreted in the feces, and NDIN was analyzed on all bags for RUP calculations. Crude protein was numerically greater early in the growing cycle for grasses compared with later as grasses matured (P ≤ 0.32). The RUP was 13.3%, 13.3%, and 19.7% of CP for smooth bromegrass, subirrigated meadow, and upland native range, respectively. These values tended to be lower early in the growth cycle and increased (linear P ≤ 0.13) as forages matured for warm-season grasses and subirrigated meadows. Because both CP and RUP content change throughout the growing season, expressing RUP as a percentage of DM gives more consistent averages compared with RUP as a percentage of CP. Coefficient of variation values for RUP as a percentage of DM averaged 0.21 over all 4 experiments compared with 0.26 for RUP as a percentage of CP. Average RUP as a percentage of DM was 2.03%, 1.53%, and 1.94% for smooth bromegrass, subirrigated meadow, and upland native range, respectively. Total tract indigestible protein (TTIDP) linearly increased with maturity for subirrigated meadow samples (P < 0.01). A quadratic response (P ≤ 0.06) for TTIDP was observed in smooth bromegrass and warm-season grass samples. Digestibility of RUP varied considerably, ranging from 25% to 60%. Subirrigated meadow, native range, and smooth bromegrass samples tended to have linear decreases (P ≤ 0.11) in RUP digestibility throughout the growing season. The amount of digested RUP was fairly consistent across experiments and averages for smooth bromegrass, subirrigated meadow, and upland native range were 0.92%, 0.64%, and 0.49% of DM, respectively. Warm-season grasses in Exp. 2 had greater RUP (4.31% of DM) and amount of RUP digested (2.26% of DM), possibly because of cattle selecting for leadplant that contains more CP than the grasses. Forages can vary in CP, RUP, TTIDP, and RUP digestibility depending on the forage type, year, and time within year, but RUP digestibility is likely less than what previous sources have reported.

E valuation of modifications to the neutral-detergent-fiber analysis procedure for corn and distillers grains plus solubles 1

Six experiments were conducted to evaluate methods for measuring NDF in corn and distillers grains plus solubles. Methods included using sodium sulfite, α-amylase (AMY), amyloglucosidase, heat and steam with an autoclave, grinding methods, and a pre–fat extraction to decrease factors that interfere with measuring NDF accurately. Using sodium sulfite and AMY resulted in decreased (P < 0.01) corn NDF values, but these decreases were different dependent on dry-rolled corn or high-moisture corn (interaction P < 0.01). Two doses of AMY (0.5 mL each) was optimum at decreasing dry-rolled corn, high-moisture corn, and steam-flaked corn NDF, but using amyloglucosidase, heat and steam with an autoclave, or both did not aid in decreasing corn NDF. Grinding corns through a 1-mm Tecator Cyclomill, compared with a Wiley mill, resulted in decreased corn NDF (P < 0.01). Using a pre–fat extraction method before the traditional NDF method resulted in decreased NDF values for distillers grains plus solubles (P < 0.01) compared with using 100 or 200 mL of NDF solution. The recommended methods for obtaining accurate NDF concentrations include using cyclo grinding and adding two 0.5 mL of AMY doses and 0.5 g of sodium sulfite for corn and pre–fat extraction for distillers grains plus solubles.

Evaluation of a prefermentation-fractionated by-product corn grain dry milling ethanol process in growing and finishing cattle diets1

ABSTRACT Two experiments were conducted to evaluate feeding a new by-product feed containing bran and solubles from a prefermentation-fractionated dry milling process, Dakota Bran (DBRAN), and compare this to feeding dry distillers grains plus solubles (DDGS). In the growing experiment, 256 crossbred steer-calves (BW = 281 ± 23.2 kg) were fed 4 diets designed as a 2 × 2 factorial with factors of level (15 or 30%) and type (dried and pelleted DBRAN or DDGS fed as a meal) in which by-products replaced a 70:30 blend (DM basis) of bromegrass hay and alfalfa haylage. No significant interactions (P ≥ 0.33) were observed for cattle performance between by-product level and type. Ending BW, ADG, DMI, and G:F increased (P