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Within Australia, approximately 6.4% of total greenhouse gas emissions are from animal methane (CH4) derived from enteric fermentation. Mitigation of ruminant CH4 is a key concept in support of sustainable agriculture production; dietary manipulations a viable strategy to lower CH4 release during enteric fermentation. In order to determine the effects of dose response of biochar and wood vinegar supplementation on fermentation parameters and CH4 production, this study utilized in vitro batch culture incubations. It is hypothesized that the addition of either biochar or wood vinegar will successfully reduce enteric CH4 emissions without negative modification of other fermentation parameters. Three feed substrates (vegetable mixed ration, maize silage, and winter pasture) were separated into treatments containing either biochar at 0%, 0.5%, 1%, 2%, and 4% DM replacing substrate (w/w basis), or wood vinegar at 0%, 0.25%, 0.5%, 1%, and 2% into incubation media volume (v/v). At 6, 12, and 24 hours after inoculation, total gas volume, and methane (CH4 %) were measured. Volatile fatty acid (VFA) concentrations, media pH, and in vitro dry matter digestibility were measured at 24 hours. Biochar at various dosages had no effect (P > 0.05) on fermentation characteristics other than decreased in vitro dry matter digestibility (IVDMD; P = 0.01) at 2% and 4% (DM basis) inclusion. Similar to biochar, dose response of wood vinegar had no effect on in vitro fermentation characteristics. However, feed substrate had major effects on all fermentation parameters (P = 0.01) where winter pasture > vegetable mixed ration > maize silage for all recorded fermentation characteristics. Biochar and wood vinegar supplementation were ineffectual in mitigating CH4 production or modifying fermentation characteristics, thus rejecting the initial hypothesis. These results suggest the use of biochar is not an effective tool for methane mitigation in ruminant livestock and infers that studies previously reporting success must better define the systemic mechanisms responsible for the reduction in CH4. [ABSTRACT FROM AUTHOR]

As contamination with cereal ergot has been increasing in western Canada, this study evaluated impacts of feeding a mycotoxin binder (Biomin® II; BB) on nutrient digestibility, alkaloid recovery in feces, and lamb growth performance. Forty-eight ram lambs (25.9 ± 1.4 kg) were randomly assigned to one of four barley-based diets: Control (C), no added alkaloids, Control + BB fed at 30 g/head per day (CBB); Ergot, 2564 ppb total R + S epimers (E); Ergot + BB, 2534 ppb R + S epimers (EBB). Lambs were fed ab libitum for up to 11 weeks until slaughter at >46 kg live weight. Both average daily gain (ADG) and gain/feed ratio were greater (p < 0.01) for lambs fed C and CBB diets as compared with those containing added ergot, although dry matter intake was not affected by dietary ergot or BB. Serum prolactin concentrations were two times higher in EBB- compared with E-fed lambs (p < 0.05), although both were lower than in C or CBB (p < 0.001) lambs. Rectal temperatures were greater in lambs receiving dietary ergot (p ≤ 0.001) than in C- and CBB-fed lambs. In a digestibility study using eight ram lambs, treatment with BB increased neutral detergent fiber (NDF) digestibility (p = 0.01). Nitrogen retention (g) was greater (p < 0.05) for lambs receiving C or CBB compared with ergot-contaminated diets. Feces of EBB lambs had 38.5% greater (p < 0.001) recovery of alkaloids compared with those fed E. Based on sparing of prolactin, BB may reduce impacts of ergot alkaloids by increasing their excretion in feces. Accordingly, concentrations of dietary alkaloids, which would not harm sheep, would be increased by feeding BB. [ABSTRACT FROM AUTHOR]

The objective of the present study was to compare the short term measurement (30 min/day for 3 days) face mask system (FM), with SF 6 tracer and respiration chamber (RC) techniques for measuring CH 4 emissions from crossbred (Holstein × Gyr) yearling bulls fed at three intake levels. Data were derived from 17 individuals in a completely randomized design experiment in a repeated measures scheme. Bulls were fed a diet consisting of 59.6% corn silage and 40.4% concentrate on a DM basis at three levels of DM intake (DMI) of 1.2% of BW, 1.8% of BW and ad libitum . After an adaptation period, CH 4 emissions were measured first using the SF 6 tracer technique, followed by the FM and RC techniques, respectively. Daily CH 4 emission (g/day) from bulls differed (P < 0.007) with CH 4 measurements techniques, with highest emissions measured using RC (107.9 ± 15.36), followed by FM (103.2 ± 11.86) then SF 6 tracer technique (87.9 ± 10.16). The CH 4 emissions adjusted for differences in DMI and BW did not differ among techniques, averaging 21.5 g/kg DMI and 0.4 g/kg BW, respectively. Total CH 4 emissions (g/day) were positively correlated with DMI as measured by all three techniques (SF 6 r = 0.93; FM r = 0.93; RC r = 0.96). The concordance correlation coefficient (CCC) for CH 4 emission (g/d) were 0.82, 0.82 and 0.74 for comparisons of SF 6 vs RC, FM vs RC and FM vs SF 6 , respectively. The day-to-day (21.3%) and animal-to-animal (13.4%) variation in CH 4 yield (g/kg DMI) was greater from bulls using the FM technique, compared to SF 6 (18.8% and 6.8%, respectively) and RC (12.9% and 7.5%, respectively) techniques. We conclude that the short-term FM technique generated CH 4 measurements that were comparable to those estimated using SF 6 and chamber techniques across a range of DMI levels. However, the FM method may have limitations in terms of assessing enteric CH 4 mitigation strategies that are applied over a short duration to low numbers of animals due to higher animal-to-animal and day-to-day coefficients of variation than either the SF 6 or RC techniques. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effect of a pine enhanced biochar (EB) on rumen fermentation, apparent total tract digestibility, methane (CH 4 ) 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 CH 4 emissions. Ruminal pH was recorded at 1-min intervals during CH 4 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 CH 4 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 CH 4 emissions, but did alter specific rumen microbiota., (Copyright © 2019 Terry, Ribeiro, Gruninger, Chaves, Beauchemin, Okine and McAllister.)