No abstract

Ergot alkaloid mycotoxins produced by the fungus Claviceps purpurea, are contaminants of cereal crops and grasses. The objectives of this study were to determine the correlation between number of ergot sclerotia and weight compared to the total ergot alkaloid concentration, to evaluate the effect of grinding process (i.e. particle size (PS)) on ergot alkaloid analysis using high performance liquid chromatography – tandem mass spectrometry, and to determine the impact of sample volume on analytical variability. This study demonstrated that correlations exist between both ergot sclerotia count (R2=0.7242, P<0.001) and ergot sclerotia weight (R2=0.9618, P<0.001) compared to the total alkaloid concentration of 6 ergot alkaloids. However, at alkaloid ergot concentrations below 350 µg/kg grain, ergot sclerotia count (R2=0.0002, P=0.956) and ergot sclerotia weight (R2=0.0064, P=0.769) were not correlated to the total alkaloid concentration. A lower variability (P=0.041), defined by coefficient of variation (CV), was observed using a commercial UDY cyclone sample mill (PS=192 µm, CV=9 µg/kg) as compared to a household coffee grinder (PS=516 µm, CV=66 µg/kg). Total amount and concentration of individual ergot alkaloids varied (P<0.05) among sclerotia of similar weight. For the analytical method, CV was numerically reduced as sample volume increased (97% CV for 75 ml to 64% CV for 1000 ml; mean of all concentrations) but increased as sample concentration declined (17% CV for 81,678 µg/kg to 284% for 35 µg/kg; mean of all sample volumes). This implies that analysis of small sample volumes at low ergot alkaloid concentrations may result in highly variable and potentially misleading results. In conclusion, number of ergot sclerotia and weight are unreliable indicators of alkaloid content at ergot concentrations below 350 µg/kg and particle size influences the variability. An analytical approach with fine grinding (mean PS<200 µm, 85% particles <400 µm) of a large sample should be used to assess low-level ergot contamination.

Ergot alkaloids, produced by the fungus Claviceps purpurea, are contaminants of cereal crops. Depending on various factors, the relative composition of individual ergot alkaloids can differ among samples. The objective was to determine if the percentage of individual ergot alkaloids were similar across different cereal grains (barley n=39, rye n=7, triticale n=9, wheat n=94) collected in Western Canada over different years. Ergocristine was the predominant alkaloid accounting for half of the total alkaloids in all grain types. This study documented that barley, rye, triticale and wheat collected across Western Canada had similar percentages of ergocornine (6±1%, P=0.201), ergocristine (48±2%, P=0.939), ergocryptine (17±2%, P=0.302) and ergosine (5±0.5%, P=0.239). There were differences between grain types for ergometrine (P=0.027) and ergotamine (P=0.011), which ranged between 6 to 13% and 11 to 24%, respectively, of the total alkaloid content in different cereals. Both barley and wheat alkaloid percentages were similar between 2015 and 2016; ergocornine (7±1%, P=0.969), ergocristine (47±2%, P=0.680), ergocryptine (18±2%, P=0.572), ergometrine (8±1%, P=0.080), ergosine (15±1%, P=0.119) and ergotamine (P=0.189). The ergocornine percentage was higher in wheat (P=0.017) as compared to barley for 2015/2016 samples. Ergometrine was higher in barley (P=0.002) as compared to wheat for 2015/2016 samples. While two of the alkaloid proportions varied statistically, overall proportions of the six ergot alkaloids were comparable among the four grain types collected across Western Canada. If proportions of ergot alkaloids are similar across a region, then it may be deemed acceptable to recommend a maximum total ergot alkaloid concentration for that region. However, areas that exhibit variation among the ergot alkaloid proportions, individual ergot alkaloid guidelines based on a toxic equivalence factor, may be more appropriate. In contrast, since major differences were not seen between years or grain type, from a producer perspective there may be limited biological/toxicological significance for individual alkaloid guidelines.

Ergot alkaloids are toxic secondary metabolites produced by the fungus Claviceps purpurea that contaminate cereal grains. Current Canadian standards allow 2 to 3 parts per million of ergot alkaloids in animal feed. The purpose of this study was to determine whether hemodynamic parameters were altered when beef cows were fed permissible levels of ergot alkaloids (i.e., <3 ppm) on a short-term basis. A dose-response relationship between ergot alkaloid concentration and hemodynamic changes in caudal (coccygeal), median sacral, and internal iliac arteries was hypothesized. Beef cows were randomly allocated to: Control (<15 μg total ergot alkaloids/kg dry matter), Low (132 μg/kg), Medium (529 μg/kg), and High (2115 μg/kg) groups (n = 4 per group). Animals were fed 8.8 kg of dry matter daily for 4 days (pre-treatment), 7 days (treatment), and 4 days (post-treatment). The caudal, median sacral, and internal iliac arteries were examined daily using ultrasonography in B-mode and Doppler (color and spectral) mode and hemodynamics endpoints were analyzed by repeated measures mixed model analyses. Caudal artery diameter decreased in the Medium (p = 0.004) and High (p < 0.001) groups compared to pre-treatment values and the pulsatility index increased (p ≤ 0.033) in all ergot treatments during the post-exposure period compared to the Control group. Blood volume per pulse (mL) and blood flow (mL/min) through the caudal artery during the treatment period were reduced in the Medium (−1.0 mL reduction; p ≤ 0.004) and High (−1.1 mL p ≤ 0.006) groups compared to pre-treatment values. The median sacral artery diameter decreased in the Medium (p = 0.006) and High (p = 0.017) treatments compared to the Control group. No differences were detected in any hemodynamic endpoints for the internal iliac artery except changes in pulse rate (p = 0.011). There was no treatment (p > 0.554) or Treatment*Time interaction (p > 0.471) for plasma prolactin concentration or body temperature. In conclusion, alterations in caudal artery hemodynamics were detected when cows were fed 529 and 2115 μg ergot alkaloids per kg dry matter per day for 1 week. The caudal artery was more sensitive to ergot alkaloids than the median sacral and internal iliac arteries. Our results partially support the hypothesis of a dose-response effect of ergot alkaloids in feed on hemodynamics.

Cows were fed ration for 9 wk containing 5, 48, 201, and 822 μg kg−1 ergot alkaloids. The objective was to evaluate the impact of ergot consumption in beef cow–calf operations. Ergot alkaloids up to 822 μg kg−1 did not alter the weight of peripartum and postpartum beef cows (P = 0.93) or nursing calves (P = 0.08), rectal temperature (P = 0.16), or plasma prolactin concentrations (P = 0.30) at moderate ambient temperatures. Ergot did not influence the time (>1 ng mL−1; P = 0.79) or the progesterone concentration (P = 0.38) at the time of first postpartum rise or the size of the first (14 ± 0.6 mm; P = 0.40) and second (13 ± 0.5 mm; P = 0.41) follicles to ovulate. The maximum size of the first postpartum corpus luteum (CL) was 4 mm larger in the 822 μg kg−1 ergot group compared with the control (P = 0.03) for the first ovulation post partum, but not for the second (P = 0.11). There was no effect of ergot exposure on the number of days until the appearance of the first (43 ± 4 d; P = 0.95) or second (52 ± 4 d; P = 0.98) CL post partum. Ergot alkaloid concentrations up to 822 μg kg−1 did not affect pregnancy rates (X2 = 0.36). In conclusion, ergot alkaloid exposure for 9 wk to concentrations as high as 822 μg kg−1 did not alter performance in pregnant and postpartum beef cattle at moderate ambient temperatures.