C.H. Ponce

Effects of roughage source and distillers grain concentration on beef cattle finishing performance, carcass characteristics, and in vitro fermentation

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.

Effects of bulk density of steam-flaked corn in diets containing wet corn gluten feed on feedlot cattle performance, carcass characteristics, apparent total tract digestibility, and ruminal fermentation

The effects of varying bulk density of steam-flaked corn (SFC) in diets containing wet corn gluten feed (WCGF; Sweet Bran; Cargill Corn Milling, Blair, NE) have not been defined. In Exp. 1, yearling steers (n = 108; initial BW = 367 ± 1.18 kg) were housed in 27 pens (4 steers/pen) and received 1 of 3 different SFC bulk density treatments in a randomized complete block design. Bulk density treatments were 283, 335, or 386 g/L SFC in diets containing 25% WCGF (% of DM). Steers were fed once daily to provide ad libitum access to feed for an average of 163 d. For a 5-d period before d 70 of the experiment, DMI was measured, and fecal samples were collected from each pen for measurement of nutrient digestibility using dietary acid insoluble ash as a marker. Varying bulk densities of SFC did not affect (P ≥ 0.233) overall DMI, ADG, or G:F on a live- or carcass-adjusted basis. Dressing percent and LM area increased linearly (P ≤ 0.05) as bulk density increased, but other carcass traits were not affected by treatments. Intake of DM, OM, and CP during the 5-d digestion phase did not differ among bulk densities; however, starch intake increased linearly (P = 0.004) as bulk density of SFC increased. Digestibility of DM, OM, and CP tended (P ≤ 0.065) to decrease and starch digestibility decreased (P = 0.002) linearly as bulk density of SFC increased. In Exp. 2, a 3 × 3 Latin square design was used for collection of ruminal fluid from 3 ruminally cannulated Jersey steers adapted to the same diets used in Exp. 1. Bulk density did not affect NH3 concentrations, VFA molar proportions, ruminal fluid osmolality, and IVDMD of the diets. Total gas production increased linearly (P = 0.003) as bulk density of SFC increased from 283 to 335 g/L, but it decreased (P = 0.002) at 386 g/L. Present data suggest that bulk density can be increased up to 386 g/L in finishing diets containing 25% (DM basis) WCGF without affecting cattle performance and with limited effects on ruminal fermentation; however, digestibility of starch seemed to be affected negatively by increased bulk density in these diets.

Effects of dietary concentration of wet distillers grains on performance by newly received beef cattle, in vitro gas production and volatile fatty acid concentrations, and in vitro dry matter disappearance

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.

Effects of receiving diets based on wet corn gluten feed on performance and morbidity of newly received beef heifers and in vitro fermentation

VFA proportions. Total gas produced was greater (P = 0.013) for the control than for the average of RAMP and Test Starter substrates. In contrast to gasproduction results, IVDMD was greater (P ≤ 0.013) for the 2 Sweet Bran–based substrates than for the control at most incubation times. Total VFA and the acetate:propionate ratio did not differ (P > 0.052) between control and average of the RAMP and Test Starter substrates, but proportion of butyrate was increased (P = 0.002) with the 2 complete starter substrates compared with the control. Results indicate that heifers fed the 2 complete starter diets used in this experiment did not perform as well as control heifers, but dietary treatments did not affect bovine respiratory disease morbidity during the receiving period. Contrasting results for IVDMD and gas production presumably reflect differences in major ingredients of the substrates and perhaps the proportion of soluble components in Sweet Bran.

Effects of dietary supplementation of a yeast product on performance and morbidity of newly received beef heifers

ABSTRACT Two truckloads of beef heifers (n = 237; average initial BW = 191 kg) were used to evaluate the effects of a yeast culture/ enzymatically hydrolyzed yeast extract product (Celmanax; Varied Industries Corporation, Mason City, IA) included in a 65% concentrate receiving diet on growth performance and bovine respiratory disease morbidity during a 35-d receiving period. Treatments (replicated in 12 pens of 9 to 11 heifers per pen over the 2 truckloads) included 1) the 65% concentrate receiving diet with the addition of Celmanax (1.8 g/d per heifer of enzymatically hydrolyzed yeast cell wall and yeast cell metabolites, diluted with a carrier to a total of 14 g/d per heifer) or 2) the receiving diet without Celmanax (control; 14 g/d per heifer of carrier only). No load × treatment interactions (P > 0.15) were detected for any measures of performance or bovine respiratory disease morbidity. Initial BW did not differ (P > 0.53) between treatments nor did BW on d 35 (P = 0.33). Average daily gain for d 0 to 14 (P = 0.05) and for the overall 35-d (P = 0.08) period tended to be greater for Celmanax heifers than for control heifers. Receiving-diet DMI was greater (P ≤ 0.03) by the Celmanax heifers than by the control heifers at all the measurement periods during the experiment, but G:F did not differ (P ≥ 0.17) between treatments. The proportion of heifers treated one time for bovine respiratory disease tended (P = 0.09) to be less with the Celmanax treatment (4.1 ± 2.09% for Celmanax vs. 10.5 ± 3.92% for control). Results suggest that feeding Celmanax at 14 g/d per heifer can have positive effects on short-term performance and health of newly received beef cattle fed a 65% concentrate (steam-flaked corn–based diet) during the summer.

CASE STUDY: Effects of Morinda citrifolia extract on performance and morbidity of newly received beef heifers1

ABSTRACT Effects of Morinda citrifolia extract (MorindaMax, Morinda Agriculture, Provo, UT) on performance, health, and immune competence of newly received beef cattle were evaluated with 126 beef heifers (average BW = 191 kg). Treatments were fed as a daily top-dressed supplement for the first 10 d of the receiving period and included 1) control treatment [888 IU of α-tocopherol per 100 kg of BW daily, supplied in 83.6 g (DM basis) of a ground corn mixture per heifer] or 2) Morinda citrifolia extract (MorindaMax fed at 66.6 g of Morinda citrifolia extract per 100 kg of BW plus ground corn to equal that supplied by the control treatment). Final BW did not differ (P = 0.773) between treatments. No difference was observed in overall DMI (P = 0.796), but ADG for the 35-d period tended (P = 0.079) to be less in heifers treated with MorindaMax. Gain efficiency did not differ between treatments for the first 21 d of the experiment, but for the overall 35-d period, G:F was greater for control heifers than for those treated with MorindaMax (P = 0.018). The proportion of cattle treated for respiratory disease was not affected by treatments (P = 0.599). Supplementation of MorindaMax increased (P = 0.042) the oxidative burst intensity by the primary neutrophil population compared with the control treatment, and MorindaMax heifers had a greater (P = 0.045) total leukocyte count than did control heifers. Results from this experiment do not support an advantage of feeding MorindaMax on receiving period performance or health in these heifer calves that had low morbidity during the receiving period, but MorindaMax fed for the first 10 d of a 35-d receiving period seemed to have immunomodulatory effects that need further exploration.

Effects of the proportion of solubles in wet distillers grains plus solubles on in vitro fermentation and hydrogen sulfide production

Effects of substrates containing different proportions of distillers solubles (DS) to distillers grain (DG) on IVDMD, H2S production, gas production kinetics, VFA proportions, and culture fluid osmolality were evaluated in a randomized block design with a 2 × 3 + 1 factorial arrangement of treatments. Treatment substrates consisted of 15 or 30% DG with DS added within each DG concentration to yield proportions of DG:DS of 100:0, 75:25, and 50:50; the steam-flaked corn–based control treatment contained no DG. Two ruminally cannulated Jersey crossbred steers (BW = 590 kg) fed a 60% concentrate, steam-flaked corn–based diet were used as ruminal fluid donors. Duplicate cultures were incubated for 24 h to measure IVDMD and 48 h for gas production kinetics, with incubations replicated on separate days. No differences were observed among treatments for IVDMD (P > 0.15), but H2S production was increased (P < 0.01) by 39 and 73% for 15 and 30% DG, respectively, relative to the control. Moreover, H2S production increased linearly as the proportion of DS increased (P < 0.01). Osmolality was greater for the control (P < 0.001) than for other treatments, decreased (P < 0.001) with increasing DG concentration, increased linearly (P < 0.001) with increased DS in substrates, and increased over time (P < 0.001). Fractional rate of gas production (h- 1) was less (P = 0.01) for 30 versus 15% DG, and lag time of gas production decreased as DS increased in substrates (linear, P = 0.02). Molar proportion of acetate was least (P = 0.02), propionate was greatest (P < 0.01), and acetate:propionate ratio was least (P = 0.02) for the control versus other treatments. In general, including DG in substrates and increasing proportions of DS increased H2S production, reflecting increased S concentrations. For both 15 and 30% DG, substrates with greater proportions of DS had increased total gas production and culture fluid osmolality.

CASE STUDY: Effects of a direct-fed microbial on finishing beef cattle performance, carcass characteristics, and in vitro fermentation

ABSTRACT Two experiments were conducted to evaluate the effects of BeefPro (CE however, steers fed BeefPro tended (P = 0.10) to have a greater carcass-adjusted final BW. Steers fed BeefPro tended (P 0.55) did not differ between treatments on a live-weight or carcass-adjusted basis. In the in vitro study, the same treatments as in the performance study were used in high-concentrate substrates to determine IVDMD and gas production kinetics. Neither gas production kinetics nor IVDMD was altered by BeefPro at 21.2 mg/kg of DM compared with control (P ≥ 0.10). Although in vitro data did not provide evidence of alterations in ruminal fermentation by including BeefPro in substrates, feedlot performance data suggest that BeefPro, when fed daily at a dose of 200 mg per steer, can have positive effects on DMI and ADG of finishing beef cattle.