Two studies were conducted to evaluate the effects of corn (CDG) and sorghum (SDG) wet distillers grains with solubles on feedlot cattle performance, carcass characteristics, and apparent total tract digestion of nutrients. In Exp. 1, 224 steers were used in a randomized complete block design (initial BW 391.1 +/- 9.51 kg) and fed steam-flaked corn (SFC)-based diets consisting of (DM basis) 0% distillers grains (CON), 15% SDG, 30% SDG, 15% CDG, 30% CDG, 15% of a 50:50 blend of SDG and CDG, and 30% of a 50:50 blend of CDG and SDG. Decreased carcass-adjusted final BW and HCW (P < or = 0.05) were noted as the inclusion amount of distillers grains increased in the diet. Body weight gain efficiency did not differ among the CDG, 50:50 SDG and CDG blend, and CON treatments, but G:F was numerically less with either amount of SDG than for CON, and decreased (P < or = 0.05) as distillers grains were increased from 15 to 30%. Cattle fed CON had greater carcass yield grades than those fed the distillers grain diets (P < or = 0.05). In Exp. 2, crossbred beef steers (n = 36; initial BW 567.3 +/- 53.1 kg) were used in a generalized randomized block design and fed SFC-based diets with 0% distillers grains (CON) and 15% (DM basis) CDG or SDG. Digestibility was determined with a pulse dose of Cr(2)O(3). Feeding steers 15% CDG or SDG increased intakes of CP and NDF (P < or = 0.05), but intakes of DM, OM, and starch did not differ among treatments (P >o r = 0.07). Apparent total tract digestibilities of DM, OM, CP, NDF, and starch (P > or = 0.25) did not differ among the 3 treatments. Fecal pH averaged over all sampling times was not affected by treatment, nor were average fecal pH values for prefeeding samples (0, 24, 48, and 72 h after the pulse dose) or for samples taken after feeding (12, 36, and 60 h after the pulse dose; P > or = 0.11). Results suggest that with 15% distillers grains in the DM, G:F was similar for cattle fed the CDG, 50:50 SDG and CDG blend, and CON diets. Feeding 30 vs. 15% distillers grains decreased G:F, but including 15% CDG or SDG in SFC-based diets did not affect apparent total tract digestibilities in feedlot steers.

The effects of wet distillers grains with solubles (WDG) on in vitro rate of gas production, IVDMD, H(2)S production, and VFA were evaluated. Five substrate treatments that were balanced for ether extract content were arranged in a 2 x 2 + 1 factorial. Factors were concentration (15 or 30%; DM basis) and source of WDG (corn or sorghum WDG; CDG and SDG, respectively) plus a 0% WDG control in substrates with steam-flaked corn as the basal grain. Control substrates had greater (P < 0.01) IVDMD and total gas production per gram of substrate DM than WDG-based substrates, and IVDMD was greater (P = 0.03) for CDG than for SDG substrates. Increasing WDG inclusion from 15 to 30% decreased IVDMD and total gas production (P < 0.05), but H(2)S production (micromol/g of fermentable DM) increased (P = 0.01) as inclusion of WDG increased. There were no differences (P > or = 0.10) among treatments in proportions of major VFA, acetate:propionate ratio, and total VFA concentration. These results suggest that including WDG in the substrate decreased IVDMD and gas production, which was particularly evident as WDG increased from 15 to 30% of substrate DM. In addition, CDG seemed to be more digestible than SDG. Hydrogen sulfide production increased with increasing WDG in the substrate, reflecting greater S concentrations in WDG, but in vitro VFA profiles were not affected by WDG concentration or source.

One hundred forty-four cull cows (body condition score = 2.10 ± 0.61; BW = 456 ± 47 kg) were organized into a 2 × 2 factorial design (48 pens, 12 pens/treatment, and 3 cows/pen) to evaluate the effect of dietary roughage level and oral drenching of Megasphaera elsdenii NCIMB 41125 (M. elsdenii culture; Lactipro Advance; MS Biotec Inc., Wamego, KS) on performance and carcass characteristics. Cattle were finished over a 42-day realimentation period, and aggressively stepped up over a 10-day period to either a high roughage finisher (HRF; 25% roughage) or a low roughage finisher (LRF; 10% roughage). Within diet, cattle were administered no probiotic or 100 mL of M. elsdenii culture (M. elsdenii NCIMB 41125, 2 108 cfu/mL) on day 0. No diet × probiotic interactions were detected (P ≥ 0.15), suggesting that the magnitude of the response was not influenced by the concentrate level of the diet. The main effect of diet triggered several significant responses. Decreasing roughage level tended to improve average daily gain (ADG) by 9.7% (0.26 kg, P = 0.08), while decreasing dry matter intake (DMI) by 0.9 kg (P = 0.09), provoking a 19.7% enhancement of feed efficiency (0.036 units, P &lt; 0.01). However, interim data revealed declines of performance parameters among both diets with a significant difference between treatments only documented during the final phase of the realimentation period. During the final 14 days, LRF posted a 0.68 kg increase in ADG (P = 0.05) and a 2.0 kg decrease in DMI (P = 0.01), translating to improved feed efficiency (0.054 units, P = 0.03). This suggests that increasing the caloric density of finishing diets may help offset the regression of performance typically observed following a compensatory gain. No carcass traits were impacted by either diet or M. elsdenii culture (P ≥ 0.08). Overall, oral drenching of M. elsdenii culture tended to augment ADG (0.26 kg, P = 0.08) and carcass ADG (0.20 kg, P = 0.10). Implying that M. elsdenii culture was effective at alleviating the acidosis risk prompted by the rapid step-up period employed in the trial and may help capitalize on the narrow timeline of compensatory gain in cull cow realimentation.

Forty-five beef cull cows [body weight (BW) = 503 ± 58 kg; body condition score (BCS) = 2.1 ± 0.6] were randomized into two treatments to compare the effects of oral drenching of no probiotic vs. 100 mL of Megasphaera elsdenii NCIMB 41125 (M. elsdenii culture; Lactipro Advance; 2 × 108 cfu/mL; MS Biotec, Inc., Wamego, KS) on the realimentation of cull cows. The study featured a rapid 0-d step-up of concentrate-naïve cull cows to a 90% concentrate diet (1.43 Mcal/kg of NEg). The cows were finished for 35 d and were fitted with a wireless rumination tag (Allflex Flex Tag; SCR Engineers, Ltd, Netanya, Israel), which tracked head movement to record eating and chewing activity. Rumen morphometrics was recorded on the harvest floor, with each carcass assigned a rumenitis score, and a fragment of the cranial sac removed for further papillae analysis. An additional 23, thin, non-fed cull cows were harvested at the same abattoir to compare the effects of concentrate realimentation on ruminal morphometrics. Megasphaera elsdenii culture-drenched cattle registered a 13.3% increase in rumination time (39.27 min/d, P = 0.03) during the first week of the trial compared to controls. A numerical rumination advantage for M. elsdenii culture-administered cattle was observed during week 2 of trial (P = 0.17), with no differences between treatments from weeks 3 to 5 (P ≥ 0.40). Subjective rumenitis evaluations approached a tendency (P = 0.12), with non-M. elsdenii culture-drenched concentrate-fed cattle logging twice the score of their day 0 cohorts (2.52 vs. 1.17) suggesting considerable lactic insults occurred to the ruminal epithelium in the short 35-d trial. Despite the short feeding duration, concentrate realimentation prompted a significant improvement in mean papillae area (P &lt; 0.01). Among concentrate-fed treatments, M. elsdenii culture-drenched cattle posted superior absorptive surface area (P = 0.01) and a greater ratio of papillae area of absorptive surface area (P = 0.05), suggesting that M. elsdenii culture is favorably altering the ecology of the rumen and promoting papillae growth perhaps by mitigating lactate-driven pH drops. In conclusion, M. elsdenii culture application in a 0-d step-up protocol to finishing diets can help mitigate the effects of ruminal acidosis.

Simmental–Angus calves [n = 135; 72 steers and 63 heifers; body weight (BW) = 212.4 kg ± 36.1] were early weaned (~5 mo) to evaluate multiple feeding regimens (conventional vs. aggressive energy diets ± Megasphaera elsdenii NCIMB 41125 (M. elsdenii culture (MEC); Lactipro Advance; MS Biotec Inc., Wamego, KS) in order to elucidate the optimal development strategy. Objectives were measured by tracking the effects of caloric density and oral drenching of growing phase performance and subsequent carcass traits. The 72-d experiment featured three groups: 1) control (CON), fed exclusively a 35% roughage diet; 2) aggressive (AGR), fed a blend of a 10% and 35% roughage diets; 3) MEC, fed the same diet as AGR and drenched with 50 mL of M. elsdenii NCIMB 41125 on day 1. A subset of calves (n = 45) was equipped with wireless rumination tags (Allflex Flex Tag; SCR Engineers, Ltd; Netanya, Israel), which logged daily rumination and general activity. Skeletal growth variables were assessed by measuring wither and hip height pretrial and posttrial. Ultrasonography provided additional resolution concerning growing phase compositional gain, which was later verified by carcass data collection. Data were analyzed as a nested analysis of variance with BW and gender serving as blocking factors. The increased caloric density of the diets administered to MEC and AGR calves resulted in greater average daily gain and gain:feed values compared with CON even during the first 21 d of diet acclimation (P ≤ 0.05). Additional fiber concentration of CON diets led to increased rumination times in 9 of the 10 wk of trial (P ≤ 0.10). No differences amongst treatments were detected for skeletal variables or ultrasound 12th rib fat. Cattle fed CON diets posted 3.4% inferior BW at the end of the growing period trial and a 3.8% reduction in hot carcass weight (HCW), reinforcing the theory that intensifying caloric intake during the growing phase does not compromise future feedlot performance. Ultrasound marbling scores for MEC-treated cattle were 19° greater than AGR treated cattle (P ≤ 0.05) at the end of the growing phase trial. Nearly the exact same advantage (22°) was observed in the cooler 5 mo later (P = 0.42). Implying MEC metabolically imprinted cattle to favor marbling development. It appears that maximizing dietary caloric density in light-weight calves does not adversely affect the growth curve, while oral dosing of MEC during the growing period may be a precursor for enhanced quality grade.