Search

The use of distiller's grains (DG) in beef cattle finishing diets is a common practice. However, the effects of supplemental fat on performance and nutrient losses of cattle fed diets containing DG are not known. Therefore, we fed 398 crossbred yearling heifers (initial BW = 373.5 kg) for 106 d to determine the effects of dietary fat concentration and sorghum-based wet distiller's grains with solubles (SWDGS) on performance, carcass characteristics, and nutrient losses of finishing cattle. Treatments included two 92% concentrate, steam-flaked corn (SFC)-based diets with 0% or 3% added fat from yellow grease and 3 SFC-based diets with 15% SWDGS (DM basis) that contained either 0%, 1.5%, or 3% added fat (8 pens per treatment) in a randomized block design. Overall DMI and ADG were 5% to 6% greater (P < 0.01) for heifers fed 15% SWDGS than for those fed 0% SWDGS. Among heifers fed 15% SWDGS, DMI was greatest (P = 0.04; quadratic effect) and ADG tended (P = 0.12; quadratic effect) to be greatest for heifers fed 1.5% fat. The ADG:DMI did not differ between 0% SWDGS with 0% or 3% fat, and was not altered by replacing a portion of SFC with SWDGS (P > 0.36). However, ADG:DMI tended to increase as more fat was added to diets with 15% SWDGS (P = 0.06). Average hot carcass weight (HCW) was 5 kg greater (P = 0.05) when SWDGS was fed, but HCW tended to be greatest for heifers fed 15% SWDGS with 1.5% fat (P = 0.09, quadratic effect). Heifers fed 0% SWDGS with 0% fat tended to have a lower marbling score, less rib fat, lower average yield grade (P < 0.08), and more (P < 0.01) yield grade 1 carcasses than heifers fed 0% SWDGS with 3% fat. Averaged across fat levels, heifers fed 15% SWDGS had more rib fat and a higher yield grade (P < 0.03) than heifers fed 0% SWDGS. Feeding 15% SWDGS did not alter carcass quality grade distribution compared to feeding 0% SWDGS, but 15% SWDGS produced fewer yield grade 3 carcasses (P = 0.03) than 0% SWDGS. The calculated NEg of SWDGS (1.36 Mcal/kg) was 91% of the tabular value for dry rolled corn (1.50 Mcal/kg) and 84% of the tabular value for SFC (1.62 Mcal/kg). Nitrogen intake, and N excretion were greater (P < 0.05) in heifers fed 15% SWDGS than in heifers fed the 0% SWDGS diets, but N loss as a % of N intake was less (P < 0.05). Our results suggest adding 1.5% fat to diets containing 15% SWDGS may improve beef cattle performance; however, feeding logistics need to be considered when pricing wet DG., (Published by Oxford University Press on behalf of the American Society of Animal Science 2019.)

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., (Published by Oxford University Press on behalf of the American Society of Animal Science 2019.)

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.

Two experiments were conducted to explore the effects of a sodium saccharin-based dietary sweetener (Sucram) on growth performance, health, and physiological responses of feedlot steers. In Exp. 1, 173 newly-received male calves purchased from auction barns were fed 0, 100, 200, or 300 g of Sucram/t of DM over 56 d. Overall, ADG and G:F (P > 0.10) were not different among treatments, but steers receiving 200 g Sucram/t displayed numerically greater ADG (23%). In addition, DMI was 17% greater for steers receiving 200 g of Sucram/t compared to steers fed the control diet (cubic effect, P = 0.09). The morbidity rate for respiratory disease did not differ (P > 0.50) among treatments. In Exp. 2, 15 steers (initial BW = 261 ± 28 kg) were used to evaluate the effects of Sucram on apparent total tract digestibility, plasma metabolite concentrations, and urine monoamine metabolite concentrations. Treatments consisted of ad libitum access to a 60% concentrate diet (Control), ad libitum access to Control + 200 g of Sucram/t of DM (Adlib), and Control + 200 g of Sucram/t of DM with feed intake paired to the Control (Paired). By design, steer DMI during the metabolism period did not differ (P = 0.34) between Paired and Control, but DMI tended (P = 0.14) to be 8.2% greater for Adlib than for Control. Treatments did not alter (P > 0.17) apparent total tract nutrient digestibility. Postprandial plasma citrulline concentration was lower (P = 0.03) for Adlib than for Control and tended to be lower (P = 0.13) for Paired than for Control. Plasma homocysteine concentration was reduced (P < 0.03) by feeding Sucram. Urinary concentrations of ethylmalonic acid, vanillymandelic acid, and 5-hydroxyindolacetic acid were greater (P < 0.06) for Adlib than for Control; Paired steers had a greater (P = 0.02) urine vanillymandelic acid concentration than Control steers and tended (P < 0.12) to have a greater urinary concentration of ethylmalonic and 5-hydroxyindolacetic acid than Control steers. Serum insulin was greater for Adlib than for Control steers (P = 0.04) and tended to be greater for Paired than for Control steers (P = 0.14), but serum prolactin area did not differ (P > 0.22) among treatments. Supplementation with Sucram may increase feed intake by newly-received, stressed feedlot calves. Saccharin supplementation reduced plasma homocysteine and increased urinary excretion of vanillymandelic acid, suggesting an improved activity of the dopamine reward system.

Three studies were designed to evaluate effects of wet distillers grains with solubles (WDGS) on health and performance of newly received beef cattle, in vitro gas production, molar proportions and total concentrations of VFA, and IVDMD. In Exp. 1 and 2, 219 (BW = 209 kg, SE = 2.2 kg; Exp. 1) and 200 beef steers (BW = 186 kg, SE = 3.2 kg; Exp. 2) were used in randomized complete block design receiving studies. The 4 dietary treatments (DM basis) were a 65% concentrate, steam-flaked corn (SFC)-based receiving diet without WDGS (CON) or diets that contained 12.5, 25.0, or 37.5% WDGS. There were no differences among the 4 receiving diets in BW (P ≥ 0.61), ADG (P ≥ 0.75), DMI (P ≥ 0.27), and G:F (P ≥ 0.35), or in the proportion of cattle treated for morbidity from bovine respiratory disease in either of the 2 experiments. In Exp. 3, in vitro methods were used to determine the effects of WDGS on IVDMD, total gas production, and molar proportions and total concentrations of VFA. Substrates used for the incubations contained the same major components as the diets used in Exp. 1, with ruminal fluid obtained from steers fed a 60% concentrate diet. Total gas production was less (P = 0.03) for the average of the 3 WDGS substrates than for CON, with a linear decrease (P = 0.01) in total gas production as WDGS concentration increased in the substrates. In contrast to gas production, IVDMD was greater for the average of the 3 WDGS concentrations vs. CON (P ≤ 0.05) at 6 and 12 h and increased (P ≤ 0.02) with increasing WDGS concentration at 6 (linear and quadratic) and 12 h (linear) of incubation. At 48 h, there was a quadratic effect (P = 0.05) on IVDMD, with the greatest value for 25% WDGS. Molar proportion of butyrate increased linearly (P < 0.01) as the concentration of WDGS increased in the substrate, and the average of the 3 substrates containing WDGS had a greater proportion of butyrate (P = 0.03) than CON. Performance data from Exp. 1 and 2 indicate that including WDGS in the SFC-based diets for newly received cattle can be an effective at concentrations up to 37.5% of the DM. In vivo measurements are needed to corroborate the in vitro fermentation changes noted with addition of WDGS.

Two experiments were conducted to evaluate the effects of wet distillers grains plus solubles (DG) and roughage source on finishing cattle performance, carcass characteristics, and in vitro fermentation. In Exp. 1, crossbred beef steers (n=224, initial BW=349 kg) were used in a randomized complete block design with a 2 × 3 + 1 factorial arrangement of treatments. Experimental diets were a standard steam-flaked corn (SFC)-based control (no DG and 10% alfalfa hay), and either 15 or 30% DG (DM basis) with roughage sources of alfalfa hay (15-AH and 30-AH), Coastal bermudagrass hay (15-BG and 30-BG), or sorghum silage (15-SS and 30-SS). Within each DG concentration, roughages provided an equivalent percentage of NDF to 7.5% AH. Steers consuming 15% DG had greater (P < 0.04) final BW, ADG, and G:F than those fed 30% DG. Feeding AH as the roughage source with DG resulted in decreased final shrunk BW and ADG (P < 0.02) compared with BG and SS. Feeding SS as the roughage source decreased (P=0.01) G:F relative to BG. Hot carcass weight was greater (P < 0.01) for steers consuming 15 vs. 30% DG, tended to be least for diets with AH as the roughage source (P=0.06), and did not differ for the control vs. the other diets (P=0.86). Control cattle had an increased (P=0.05) proportion of USDA Choice or greater carcasses compared with the average of the other treatments. In Exp. 2, the same 2 × 3 +1 factorial arrangement as in Exp. 1 was used to examine the effects of roughage source and DG on IVDMD, culture fluid osmolality, and gas production kinetics. In vitro DMD tended (P < 0.09) to be greater for BG compared with SS at 6 and 36 h of incubation and was greater for AH vs. the mean of BG and SS at 18 h (P=0.01). Culture fluid osmolality, asymptotic maximal gas production, fractional rate of gas production, and lag time of gas production did not differ among treatments (P > 0.14). Overall, feeding 15% DG in SFC-based diets increased ADG, BW, and HCW relative to 30% DG. In addition, feeding AH tended to decrease ADG, final BW, and HCW relative to the other 2 roughage sources, whereas BG improved G:F over SS. These data suggest that including the smaller amount of DG and BG as the roughage source resulted in improved performance relative to other combinations, and that substituting roughages on the basis of equivalent NDF concentration might not be ideal for optimizing performance when feeding SFC-based finishing diets that contain DG., (© 2011 American Society of Animal Science. All rights reserved.)

The diet adaptation period is widely considered a critical period of time in which nutritional management practices can promote or impair subsequent performance and health. Performance studies indicate that adapting feedlot cattle with incremental increases in dietary concentrate, from approximately 55 to 90% of diet DM, in 14 d or less, while allowing ad libitum access to the diet, generally results in reduced performance during adaptation or over the entire feeding period. However, the number of cattle involved in these studies does not allow insight into the frequencies of metabolic disorders associated with the management practices tested. Adapting cattle by restricting the quantity of higher-concentrate diets offered shows promise for improving production efficiency, but further development is needed for application in commercial feedlots. Evidence suggests considerable diversity in the ability of animals to cope with ingested cereal grain, and indicates that diet adaptation procedures should affect the frequency of health-impaired or low-performing cattle in a pen. Individuals that seem to effectively regulate voluntary feed intake during adaptation generally display a steady increase in DMI as dietary concentrate is increased. These data also highlight a seemingly counterproductive, repeating cycle of overconsumption, followed by a pronounced reduction in ruminal pH, by cattle that appear to cope less favorably with grain adaptation. At least a portion of this diversity may relate to the maintenance of protozoal populations. Increases in amylolytic bacteria seemed to follow the increment of additional concentrate. Protozoa were most numerous when the diet contained approximately 60% concentrate, and lactate-utilizing bacteria increased more markedly when the diet contained more than approximately 70% concentrate. Available in vivo data suggest that the number of lactate-utilizing bacteria may reach a plateau for a given diet composition after 2 to 7 d, but thorough assessments of the time course of events using modern techniques are lacking. Further research is needed to characterize how the quantity and frequency of increases in cereal grain consumption, reflective of industry practices, impact microbial dynamics, and to identify the biological features that allow certain animals to adapt more readily to high-concentrate diets.