Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers.

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ±â€…29.4 kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2 mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2 mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2 wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2 mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2 wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05 kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980 kg) and shrunk final BW (P < 0.01, 350 vs. 366 kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05 kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2 mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

Produced by the fungus Claviceps purpurea, ergot alkaloids (EA) are toxic to beef cattle when consumed and can lead to reduction in feed intake and growth performance, vasoconstriction of the blood vessels, hyperthermia, damage to extremities (ears, tails, and hooves) and in severe cases, death. Grain is often cleaned to meet quality standards, and the resulting screenings are often utilized for feeding livestock and can have high concentrations of EA. The application of heat during pelleting of EA contaminated grain has been suggested to reduce its toxicity. Backgrounding and finishing beef cattle feeding experiments were conducted to assess the effect of continuously or intermittently feeding EA contaminated grain (2 mg/kg of diet DM) either as a pellet or as mash on growth performance, health, and animal welfare. Feeding EA grain continuously or intermittently either as a mash or pellet drastically reduced growth performance of steers, with no difference between treatments.

Effect of water sulfate and dietary bismuth subsalicylate on feed and water intake, ruminal hydrogen sulfide concentration, and trace-mineral status of growing beef heifers.

In the Northern Great Plains, cattle may be exposed to water with an elevated sulfate concentration resulting in ruminal hydrogen sulfide (H2S) production and risk of copper deficiency. There are currently few strategies available to help mitigate effects arising from high-sulfate water (HS). The objective of this study was to evaluate the effects of feeding a moderate-forage diet with or without bismuth subsalicylate (BSS; 0.0% vs. 0.4% DM basis) when provided water with a low- (LS; 346 ±â€…13) or HS (4,778 ±â€…263 mg/L) concentration on feed and water intake, ruminal H2S concentration, and liver and serum trace-mineral concentrations. Twenty-four Limousin × Simmental cross beef heifers (221 ±â€…41 kg) were stratified based on initial liver Cu into a completely randomized block design with a 2 × 2 factorial treatment arrangement. Feed and water intake (measured weekly), ruminal H2S concentration (measured on days 42 and 91), liver (measured on days -13 and 91), and serum trace-mineral concentrations (measured on days 1, 28, 56, and 91) were evaluated. Initial liver trace-mineral concentrations were used as a covariate in the statistical model. Water intake tended to be reduced with the inclusion of BSS (P = 0.095) but was not affected by water sulfate (P = 0.40). Water sulfate and BSS did not affect dry matter intake (DMI; P ≥ 0.89). Heifers consuming HS had a ruminal H2S concentration that was 1.58 mg/L more (P < 0.001) than LS. The inclusion of BSS reduced (P = 0.035) ruminal H2S concentration by more than 44% (1.35 vs. 0.75 mg/L). Regardless of the water sulfate concentration, heifers fed BSS had lesser liver Cu concentration (average of 4.08 mg/kg) than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS (42.2 vs. 58.3; sulfate × BSS, P = 0.019). The serum concentration of Cu did not differ over time for heifers not provided BSS; whereas, heifers provided BSS had lesser serum Cu concentration on day 91 than on days 28 and 55 (BSS × time, P < 0.001). The liver concentration of selenium was reduced (P < 0.001) with BSS inclusion but the selenium concentration in serum was not affected by sulfate, BSS, or time (P ≥ 0.16). BSS reduced ruminal H2S concentration, but depleted liver Cu and Se. Moreover, sulfate concentration in water did not appear to affect DMI, water intake, or growth, but increased ruminal H2S and reduced liver Cu concentration.

Water containing a high concentration of sulfate increases the risk of hydrogen sulfide production in the rumen and consequently of polioencephalomalacia. In addition, water with a high-sulfate concentration may induce copper deficiency indicated by depleted liver copper concentration. Bismuth subsalicylate (BSS) can bind to sulfides and may reduce the risk of hydrogen sulfide production and therefore may mitigate risks associated with high-sulfate water. In this study, the effects of water sulfate concentrations (346 ±â€…13 vs. 4,778 ±â€…263 mg/L) were tested along with 0.0% vs. 0.4% of dietary BSS. Water intake tended to be reduced with the inclusion of BSS but was not affected by water sulfate. Water sulfate concentration and BSS did not affect dry matter intake (DMI). Heifers consuming high-sulfate water (HS) had a ruminal H2S concentration that was 1.58 mg/L more than low-sulfate water (LS). The inclusion of BSS reduced ruminal H2S concentration by 44% (1.35 vs. 0.75 mg/L). Regardless of the water sulfate concentration, heifers fed BSS had lesser liver Cu concentration than heifers not provided BSS, and when not provided BSS, HS had lesser Cu than LS. BSS reduced ruminal hydrogen sulfide concentration but depleted liver Cu. Sulfate concentration in water did not affect DMI, water intake, or growth, but increased ruminal hydrogen sulfide concentration and reduced liver Cu concentration.

A Pine Enhanced Biochar Does Not Decrease Enteric CH4 Emissions, but Alters the Rumen Microbiota.

The objective of this study was to examine the effect of a pine enhanced biochar (EB) on rumen fermentation, apparent total tract digestibility, methane (CH4) emissions, and the rumen and fecal microbiome of Angus × Hereford heifers fed a barley silage-based diet. The experiment was a replicated 4 × 4 Latin square using 8 ruminally cannulated heifers (565 ± 35 kg initial BW). The basal diet contained 60% barley silage, 35% barley grain and 5% mineral supplement with EB added at 0% (control), 0.5, 1.0, or 2.0% (DM basis). Each period lasted 28 days, consisting of 14 days adaptation and 14 days of measurements. Samples for profiling of the microbiome in rumen liquid, solids and feces were collected on d 15 before feeding. Rumen samples for fermentation characterization were taken at 0, 3, 6, and 12 h post feeding. Total collection of urine and feces was conducted from days 18 to 22. Heifers were housed in open-circuit respiratory chambers on days 26-28 to estimate CH4 emissions. Ruminal pH was recorded at 1-min intervals during CH4 measurements using indwelling pH loggers. Data were analyzed with the fixed effects of dietary treatment and random effects of square, heifer within square and period. Dry matter intake was similar across treatments (P = 0.21). Ammonia N concentration and protozoa counts responded quadratically (P = 0.01) to EB in which both were decreased by EB included at 0.5 and 1.0%, compared to the control and 2.0% EB. Minimum pH was increased (P = 0.04), and variation of pH was decreased (P = 0.03) by 2.0% EB. Total tract digestibility, N balance and CH4 production were not affected (P ≥ 0.17) by EB. Enhanced biochar decreased the relative abundance of Fibrobacter (P = 0.05) and Tenericutes (P = 0.01), and increased the relative abundance of Spirochaetaes (P = 0.01), Verrucomicrobia (P = 0.02), and Elusimicrobia (P = 0.02). Results suggest that at the examined concentrations, EB was ineffective at decreasing enteric CH4 emissions, but did alter specific rumen microbiota.

Effects of a recombinant fibrolytic enzyme on fiber digestion, ruminal fermentation, nitrogen balance, and total tract digestibility of heifers fed a high forage diet1.

A metabolism study was conducted using 8 ruminal cannulated beef heifers to investigate the effects of a recombinant fibrolytic enzyme (RFE; xylanase XYL10C) selected specifically for forage-fed ruminants on ruminal pH, fermentation, nitrogen balance, and total tract digestibility of heifers. The experiment was a cross-over design with 2 treatments and 2 periods. The 2 treatments were a basal diet containing 60% barley silage, 30% barley straw, and 10% supplement (DM basis) without (control) or with RFE. The enzyme was sprayed onto the barley straw at a rate of 6.6 × 104 IU·kg-1 DM 24 h before feeding. Each period comprised 2 wk of diet adaptation and 1 wk of sampling and data collection. Feed intake and total tract digestibility of DM, OM, NDF, and ADF were unaffected by RFE. Ruminal pH including mean, minimum, maximum, and duration pH <5.8, did not differ between treatments. Total VFA concentration, molar proportion of individual VFA, and acetate-to-propionate ratio were also not affected by RFE. However, ruminal NH3-N concentration (P < 0.06) and endoglucanase activity (P < 0.08) in ruminal fluid tended to be higher with RFE. Nitrogen utilization and microbial protein synthesis were not affected by treatment. These results indicate that XYL10C did not improve fiber digestion in heifers fed a high forage diet, despite the fact that it was specifically selected for this trait in laboratory assays. However, the increased ruminal NH3-N concentration suggests it potentially increased ruminal proteolytic activity.