M. K. Luebbe

Nutrient mass balance and performance of feedlot cattle fed corn wet distillers grains plus solubles.

Two experiments using 96 steers each were conducted to evaluate the effect of corn wet distillers grains plus solubles (WDGS) concentration on steer performance, N loss, and P mass balance. Feeding WDGS as an energy source instead of protein may increase N release into the environment but also the amount of N removed in the manure. Calves (BW = 294 ± 33 kg) were fed 167 d from November to May (WIN), and yearlings (BW = 373 ± 24 kg) were fed 133 d from June to October (SUM). Treatments consisted of 0, 15, and 30% dietary inclusion of WDGS (DM basis) replacing corn (CON, 15WDGS, 30WDGS, respectively). Basal diets consisted of high-moisture and dry-rolled corn fed at a 1:1 ratio, 7.5% alfalfa hay, 5% molasses, and 5% supplement (DM basis). The CON and 15WDGS diets were formulated to meet MP requirements, and 30WDGS exceeded MP requirements. Dry matter intake, ADG, and HCW increased linearly (P < 0.05) with WDGS concentration in the WIN, whereas DMI and ADG increased linearly (P < 0.10) in the SUM. Efficiency of BW gain was not different (P > 0.10) among treatments in either experiment. Nitrogen and P intake increased linearly (P < 0.01) with WDGS concentration in both experiments. Calculated retention of N and P increased linearly (P ≤ 0.05) with WDGS concentration in the WIN but not in the SUM (P > 0.10). Calculated excretion of N and P increased linearly (P < 0.01) with WDGS concentration in both experiments. Amount of N removed in the manure was not different (P = 0.26) among treatments in the WIN but increased linearly (P = 0.05) with WDGS concentration in the SUM. Amount of P and OM removed increased linearly (P ≤ 0.05) with WDGS concentration in both experiments. Amount of N lost (kg/steer) increased linearly (P < 0.05) with WDGS concentration in both experiments. Expressed as a percentage of N excretion, N volatilization rate (amount of N lost divided by N excretion) was not different (P > 0.30) among treatments and averaged 68.3 and 77.0 in the WIN and SUM, respectively. More N volatilized when WDGS were fed, but not all of the additional N excreted was volatilized. Regressing the amount of OM on the pen surface against manure N, 98% of the variability for manure N in the WIN and 92% in the SUM was accounted for. Feeding WDGS increased the total amount of N lost to volatilization; however, not all of the additional N excreted was lost because of an increase in the proportion of manure OM.

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.

Effects of monensin and tylosin in finishing diets containing corn wet distillers grains with solubles with differing corn processing methods.

A total of 3,632 crossbred steers were used in 3 separate randomized complete-block designed finishing experiments. Data from Exp. 1 were analyzed separately whereas data were combined for Exp. 2 and 3, based on corn processing method used [Exp.1 = equal combination of dry-rolled and high-moisture (DRC:HMC); Exp. 2 and 3 = steam-flaked (SFC)]. Steers were fed 1 of 5 treatments to evaluate the effects of monensin and tylosin in feedlot diets containing 25% corn wet distillers grains with solubles (WDGS; DM basis). Treatments included: 1) corn-based diet (no WDGS) with 360 mg/d monensin and 90 mg/d tylosin (CORN+MT), 2) 25% wet distillers grains with solubles (WDGS-CON), 3) 25% WDGS with 360 mg/d monensin (WDGS+M), 4) WDGS with monensin and tylosin at same levels as treatment 1, and 5) WDGS with 480 mg/d monensin and 90 mg/d tylosin (WDGS+HIMT). In Exp. 1, WDGS+MT increased (P < 0.01) ADG (6.5%), G:F (6.9%), and HCW (3.0%) compared with CORN+MT. Alternatively, in Exp. 2 and 3, WDGS+MT had no effect on ADG (P = 0.18), decreased (P < 0.01) G:F by 3.2%, and did not affect HCW (P = 0.57) compared with CORN+MT. In Exp. 1, addition of monensin to a WDGS diet increased G:F by 3.1% (P = 0.03) and tended to increase G:F in Exp. 2 and 3 (P = 0.09) compared with WDGS-CON. For all experiments, addition of monensin and tylosin in a diet containing WDGS increased G:F (P < 0.01) and reduced total and severe liver abscesses (P < 0.01) compared with WDGS-CON. Additionally, HCW was increased in Exp. 2 and 3 (P < 0.01) and tended to increase in Exp. 1 (P = 0.09) when monensin and tylosin were fed in a WDGS diet compared with WDGS-CON. Feeding WDGS+MT reduced total liver abscesses by 79.3% (Exp. 1) and 57.6% (Exp. 2 and 3) compared with WDGS-CON. Compared with WDGS+MT, minimal differences were observed when monensin was fed at 480 mg/steer daily with tylosin in diets containing WDGS. Inclusion of WDGS in finishing steer diets did not alter effectiveness of monensin with tylosin in improving G:F and reducing prevalence of liver abscesses, regardless of corn processing method. Corn processing method appears to be an important factor in performance response to WDGS with feeding value of WDGS, measured as an increase in feed efficiency, being greater in a DRC:HMC-based diet compared with a SFC-based diet.

Effects of nitrogen fertilization and dried distillers grains supplementation: nitrogen use efficiency.

In a 3-yr study, 135 crossbred steers (330 ± 10 kg) were used in a randomized complete block design to evaluate corn dried distillers grains plus solubles (DDGS) fed to yearling steers as a substitute for forage and N fertilizer and its effect on N use efficiency in yearling steers grazing smooth bromegrass pastures. Steers were initially stocked at 6.8 animal unit months (AUM)/ha on nonfertilized smooth bromegrass pastures (CONT), at 9.9 AUM/ha on smooth bromegrass pastures fertilized with 90 kg of N/ha (FERT), or at 9.9 AUM/ha on nonfertilized smooth bromegrass pastures with 2.3 kg (DM) of DDGS supplemented daily per steer (SUPP). Paddock was the experimental unit, with 3 replications per treatment per year for 3 yr. Paddocks were strip-grazed, and put-and-take cattle were used to maintain similar grazing pressure among treatment paddocks during the 160-d grazing season. Steers consumed less forage (P < 0.01), but total N intake for SUPP was greater (P < 0.01) per steer and per hectare than for FERT, and both were greater (P < 0.01) than for CONT. Nitrogen retention for steers in the SUPP treatment was increased (P < 0.01) by 31% compared with N retention in the CONT and FERT treatments. Nitrogen retention per hectare for SUPP was 30 and 98% greater (P < 0.01) than N retention per hectare for FERT and CONT, respectively. Nitrogen excretion per steer and per hectare were also greater (P < 0.01) for SUPP than FERT, and both were increased (P < 0.01) compared with CONT. Animal N use efficiency was similar (P = 0.29) for steers in the CONT, FERT, and SUPP treatments. However, system-based N use improved (P < 0.01) by 144% for SUPP compared with FERT. The DDGS increased N intake and N excretion in yearling steers. However, because of improvements in BW gain and increases in stocking rate of pastures, DDGS can be a useful tool to increase the efficiency of N use in smooth bromegrass grazing systems.

Limit feeding nonlactating, nonpregnant beef cows with bunkered wet distillers grains plus solubles or distillers solubles1

ABSTRACT Nonlactating, nonpregnant beef cows (593 ± 10.0 kg) were used in a completely randomized design to evaluate the performance of limit-fed diets containing bunkered wet distillers grains plus solubles (WDGS; n = 24) or bunkered condensed corn distillers solubles (DS; n = 22) compared with a control diet offered ad libitum (CON; n = 24). Cows were stratified by age and BW and randomly assigned to pens (3 pens/treatment, 7 or 8 cows per pen). The WDGS and DS were mixed and stored with 30% and 59% ground cornstalks (DM basis), respectively, for 30 d before feeding. Diets were fed for 76 d and formulated to maintain BW. Both WDGS and DS diets contained 41% by-product and 59% cornstalks at time of feeding, with DMI limited to 7.7 kg/d. The CON diet consisted of 43% bromegrass hay, 34% cornstalks, and 23% alfalfa haylage and was fed ad libitum (DMI = 10.4 kg/d). The WDGS diet was 4.1% fat and 0.24% sulfur. The DS diet was 5.5% fat and 0.37% sulfur on a DM basis. Initial BW and BCS among treatments were similar. Final BW was greater (P

The Economic Effects of Sorting Cattle by Weight and Time of Year into Different Production Systems1

A 2-yr study using 288 steers each year was conducted to determine the economic effects of sorting and feeding genetically similar cattle in different production systems. Steers were purchased at weaning in November and assigned randomly into sorted or unsorted groups. Unsorted steers were assigned randomly to 1 of 3 production systems: calf-fed steers (enter feedlot after weaning), summer yearling, or fall yearling; n = 48 steers per system yearly. For sorted steers, the heaviest third were calf fed and the remaining steers grazed cornstalks during winter. After winter grazing, the heaviest half of those steers were fed as summer yearlings, and the lightest half were fed as fall yearlings. Initial steer price was calculated using breakeven analysis for sorted calf-fed steers, and all other profits and losses are relative to sorted calf-fed steers, with a defined profit of

Influence of corn hybrid and processing method on nutrient digestibility, finishing performance, and carcass characteristics

0/steer. Steer values were determined using 2007 average prices. Initial steer costs were greatest for sorted calf-fed steers and lowest for sorted fall yearlings. There were 2-way and a 3-way interaction for profit/loss. In yr 1, fall yearling gains on grass were normal, and the sorted fall yearlings were more profitable than were the sorted calf-fed steers. The reverse was true in the second year, when pasture gains of the fall yearlings were below normal. Marketing cattle on a grid decreased profit of summer yearlings because of low QG and decreased profitability of unsorted fall yearlings because of overweight carcasses. For the overall system, sorting did not increase profit on either a live or a grid-based marketing system.

Effect of Feeding DAS-59122-7 Corn Grain and Nontransgenic Corn Grain to Individually Fed Finishing Steers1

A finishing trial and a digestion trial were conducted to evaluate the effects of corn hybrid and processing method on nutrient digestibility, finishing performance, and carcass characteristics. A 2 x 5 factorial arrangement of treatments was used for both trials. Factors included 2 processing methods, dry-rolled (DRC) or high-moisture (HMC), and 5 commercially available corn hybrids. The finishing trial (Exp. 1) utilized 475 yearling steers (379 +/- 15 kg initial BW), stratified by BW into 2 blocks then assigned randomly to 1 of 60 pens (8 steers/pen). Treatments were assigned randomly to pens with 6 pens/treatment. Diets consisted of 67.5% corn (each hybrid processed as DRC or HMC), 20% wet corn gluten feed, 7.5% alfalfa hay, and 5% supplement. The digestion trial (Exp. 2) used 2 ruminally and duodenally fistulated Holstein steers (560 kg of BW) and the mobile bag technique. Bags were ruminally incubated for 22 h. For total tract digestibility, bags were subjected to a simulated abomasal pepsin digestion, inserted into the duodenum, and collected in the feces. No significant interactions between corn hybrid and processing method were observed in Exp. 1; therefore, only main effects are presented. Feeding HMC decreased (P < 0.01) DMI and increased (P < 0.01) G:F compared with cattle fed DRC. Hybrid tended to affect (P = 0.12) G:F, but did not affect (P > 0.36) any other variable. For Exp. 2, feeding HMC increased (P < 0.01) DM and starch digestibility compared with DRC, but to varying degrees depending on the hybrid. Correlating the results of the 2 trials across processing methods, strong relationships were observed between G:F and postruminal starch digestibility (r = 0.84) and total-tract starch digestibility (r = 0.73). When evaluated within processing method, these relationships weakened and were not significant. The results of these trials indicate that processing method had a larger effect on performance and digestibility than hybrid, and no interaction was observed between processing method and hybrid, suggesting hybrid effects were consistent across processing methods.

Effects of feeding field peas in combination with distillers grains plus solubles in finishing and growing diets on cattle performance and carcass characteristics1

An experiment was conducted to evaluate feeding transgenic corn containing the cry34Ab1 and cry35Ab1 genes from a Bacillus thuringiensis strain and the phosphinothricin acetyltransferase (pat) gene from Streptomyces viridochromogenes to finishing cattle compared with nontransgenic corn. Expression of the cry34Ab1 and cry35Ab1 genes confers resistance to corn rootworms, and the pat gene confers tolerance to herbicides containing glufosinate-ammonium. Sixty crossbred steers (396 kg) were individually fed either transgenic corn (DAS-59122-7; 59122), a near-isogenic, nontransgenic control (Control), and a conventional, nontransgenic corn for 109 d to evaluate nutritional equivalency (20 steers/treatment). The corn was coarsely rolled (geometric mean diameter = 4,200 µm) and treatments were offered in the finishing diet at 82% of diet DM. Gain (P = 0.38) and G:F (P = 0.80) were similar between 59122 and Control with a tendency for a difference in DMI (P = 0.08). When adjusted using the statistical analysis of false discovery rate, DMI, ADG, and G:F were not different between Control and 59122 (P > 0.33). No differences were observed between Control and 59122 for HCW, marbling score, LM area, fat depth, or calculated USDA YG (P > 0.12). The genetically modified corn DAS-59122-7 was nutritionally equivalent to a near-isogenic control when fed to finishing steers. Feeding corn grain containing these transgenic traits did not influence steer performance or carcass quality.

Using Sweet Bran instead of forage during grain adaptation in finishing feedlot cattle.

ABSTRACT Two studies were conducted to evaluate field peas and wet or dry corn distillers grains with solubles (WDGS and DDGS, respectively) in finishing and growing diets. In Exp. 1, British crossbred steers (n = 352, initial BW 356 ± 27 kg) were used in a randomized block design with factors being 0 or 20% field peas and 0 or 30% WDGS in dry-rolled corn (DRC) based finishing diets (DM basis). There was an interaction (P