Forage Animal Production Research Unit

United States, United States

Forage Animal Production Research Unit

United States, United States
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Harlow B.E.,University of Kentucky | Lawrence L.M.,University of Kentucky | Harris P.A.,Center for Pet Nutrition | Aiken G.E.,Forage Animal Production Research Unit | And 2 more authors.
PLoS ONE | Year: 2017

Cereal grains are often included in equine diets. When starch intake exceeds foregut digestion starch will reach the hindgut, impacting microbial ecology. Probiotics (e.g., lactobacilli) are reported to mitigate GI dysbioses in other species. This study was conducted to determine the effect of exogenous lactobacilli on pH and the growth of amylolytic and lactate-utilizing bacteria. Feces were collected from 3 mature geldings fed grass hay with access to pasture. Fecal microbes were harvested by differential centrifugation, washed, and re-suspended in anaerobic media containing ground corn, wheat, or oats at 1.6% (w/v) starch and one of five treatments: Control (substrate only), L. acidophilus, L. buchneri, L. reuteri, or an equal mixture of all three (107 cells/mL, final concentration). After 24 h of incubation (37ÊC, 160 rpm), samples were collected for pH and enumerations of total amylolytics, Group D Gram-positive cocci (GPC; Enterococci, Streptococci), lactobacilli, and lactate-utilizing bacteria. Enumeration data were log transformed prior to ANOVA (SAS, v. 9.3). Lactobacilli inhibited pH decline in corn and wheat fermentations (P < 0.0001). Specifically, addition of either L. reuteri or L. acidophilus was most effective at mitigating pH decline with both corn and wheat fermentation, in which the greatest acidification occurred (P < 0.05). Exogenous lactobacilli decreased amylolytics, while increasing lactate-utilizers in corn and wheat fermentations (P < 0.0001). In oat fermentations, L. acidophilus and L. reuteri inhibited pH decline and increased lactate-utilizers while decreasing amylolytics (P < 0.0001). For all substrates, L. reuteri additions (regardless of viability) had the lowest number of GPC and the highest number of lactobacilli and lactate-utilizers (P < 0.05). There were no additive effects when lactobacilli were mixed. Exogenous lactobacilli decreased the initial (first 8 h) rate of starch catalysis when wheat was the substrate, but did not decrease total (24 h) starch utilization in any case. These results indicate that exogenous lactobacilli can impact the microbial community and pH of cereal grain fermentations by equine fecal microflora ex vivo. Additionally, dead (autoclaved) exogenous lactobacilli had similar effects as lives lactobacilli on fermentation. This latter result indicates that the mechanism by which lactobacilli impact other amylolytic bacteria is not simple resource competition.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


PubMed | University of Kentucky and Forage Animal Production Research Unit
Type: | Journal: Frontiers in nutrition | Year: 2015

It was hypothesized that isoflavones may attenuate ergot alkaloid-induced vasoconstriction and possibly alleviate diminished contractility of vasculature after exposure to ergot alkaloids. The objective of this study was to determine if prior incubation of bovine mesenteric vasculature with the isoflavones formononetin (F), biochanin A (B), or an ergovaline-containing tall fescue seed extract (EXT) and their combinations affect ergotamine (ERT)-induced contractility. Multiple segments of mesenteric artery and vein supporting the ileal flange of the small intestine were collected from Angus heifers at slaughter (n=5, bodyweight=63939kg). Duplicates of each vessel type were incubated in tissue culture flasks at 37C with a 50-mL volume of Krebs-Henseleit buffer containing: only buffer (control); or 110(-6)M EXT; F; or B; and combinations of 110(-6)M EXT+F; 110(-6)M EXT+B; 110(-6)M F+B; or 110(-6)M EXT+F+B. After incubation for 2h, sections were mounted in a multimyograph chamber. The ERT dose responses were normalized to 0.12M KCl. Pretreatment with F, B, and F+B without EXT resulted in similar contractile responses to ERT in mesenteric artery and all incubations containing EXT resulted in a complete loss of vasoactivity to ERT. In mesenteric artery pretreated with EXT, treatments that contained B had higher contractile responses (P<0.05) at ERT concentrations of 110(-7) and 510(-7)M. Also, treatments containing B tended (P<0.1) to have greater responses than treatments without B at ERT concentrations of 110(-6), 510(-6), and 510(-5)M. In mesenteric vein pretreated with EXT, treatments containing F had greater contractile responses to ERT at 110(-5), 510(-5), and 110(-4)M (P<0.05). These data indicated that F and B at 110(-6)M and their combination did not impact the overall contractile response to ERT in mesenteric vasculature. However, F and B may offset some of the vasoconstriction caused by prior exposure to ergot alkaloids.


Taghavi-Nezhad M.,Bu - Ali Sina University | Alipour D.,Bu - Ali Sina University | Flythe M.D.,Forage Animal Production Research Unit | Zamani P.,Bu - Ali Sina University | Khodakaramian G.,Bu - Ali Sina University
Animal Production Science | Year: 2014

Gas (CO2 and CH4) and ammonia production in the rumen represent major sources of lost carbon and nitrogen, respectively. The essential oils of some plants have been shown to decrease gas and ammonia production by selectively inhibiting rumen microbes. Particularly, those of Zataria multiflora (ZEO; thymol 21%, carvacrol 32%) and Mentha spicata (SEO; carvone 55%) were evaluated in vitro as ruminant-feed additives. The experiments employed mixed rumen microbes and a hyper-ammonia-producing bacterium (HAP) isolated from the rumen of a Mehraban sheep. Both ZEO and SEO decreased in vitro fibre digestibility and also gas production by mixed rumen microbes that were fermenting a typical growing-lamb diet. ZEO decreased ammonia concentration in mixed culture of rumen microbes, but SEO exerted the opposite effect. A bacterial isolate (MT8) was obtained from the rumen of a Mehraban sheep, and the 16S rRNA gene sequence indicated that it was most closely related to Clostridium bifermentans. Isolate MT8 exhibited rapid ammonia production when peptides were the growth substrate, which indicated that MT8 was a HAP. Both oils inhibited the growth and ammonia production of isolate MT8. However, ZEO decreased ammonia production at lower doses, and to a greater degree, than did SEO. These results indicated that both essential oils could potentially be used to modulate rumen fermentation. The detrimental effects on fibre digestion could be problematic in high-forage diets, and this requires further investigation. Isolate MT8 is the first described HAP from the Mehraban sheep rumen. Results on ammonia production by isolate MT8 and mixed rumen microbes indicate differential mode of action of each oil on this parameter. © 2014 CSIRO.


Craig A.M.,Oregon State University | Klotz J.L.,Forage Animal Production Research Unit | Duringer J.M.,Oregon State University
Frontiers in Chemistry | Year: 2015

Ergot-induced disease in humans was known long before Biblical times and has been the root cause for countless human epidemics spanning from the early fourteenth century to the late sixteenth century. In contrast, many of these same ergot alkaloids have been utilized for their medicinal properties to mitigate migraine headaches and have had indications as anti-carcinogens. Although ergot alkaloids have been used for centuries by humans, basic pharmacokinetic data has not been documented for clinical disease in livestock. Consequently, a threshold dose and accurate dose-response data have yet to be established. Throughout the past several years, new detection techniques have emerged to detect these alkaloids at the parts per billion (ppb) level which has allowed for new efforts to be made with respect to determining threshold levels and making accurate clinical diagnoses in affected animals. This perspectives article provides a critical initial step for establishing a uniform interpretation of ergot toxicosis from limited existing data. © 2015 Craig, Klotz and Duringer.


PubMed | Forage Animal Production Research Unit and Oregon State University
Type: | Journal: Frontiers in chemistry | Year: 2015

Ergot-induced disease in humans was known long before Biblical times and has been the root cause for countless human epidemics spanning from the early fourteenth century to the late sixteenth century. In contrast, many of these same ergot alkaloids have been utilized for their medicinal properties to mitigate migraine headaches and have had indications as anti-carcinogens. Although ergot alkaloids have been used for centuries by humans, basic pharmacokinetic data has not been documented for clinical disease in livestock. Consequently, a threshold dose and accurate dose-response data have yet to be established. Throughout the past several years, new detection techniques have emerged to detect these alkaloids at the parts per billion (ppb) level which has allowed for new efforts to be made with respect to determining threshold levels and making accurate clinical diagnoses in affected animals. This perspectives article provides a critical initial step for establishing a uniform interpretation of ergot toxicosis from limited existing data.


Kagan I.A.,Forage Animal Production Research Unit | Flythe M.D.,Forage Animal Production Research Unit
Journal of Visualized Experiments | Year: 2014

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species. © JoVE 2006-2014. All Rights Reserved.


Aiken G.E.,Forage Animal Production Research Unit | Flythe M.D.,Forage Animal Production Research Unit
Frontiers in Chemistry | Year: 2014

A fungal endophyte (Neotyphodium coenophialum) infects most plants of "Kentucky 31" tall fescue (Lolium arundinaceum) and produces ergot alkaloids that cause persistent constriction of the vascular system in grazing livestock. Consequently, animals undergoing this toxicosis cannot regulate core body temperature and are vulnerable to heat and cold stresses. An experiment was conducted to determine if the caudal and auricular arteries in goats (Capra aegagrus hircus) vasoconstrict in response to ergot alkaloids. Seven, rumen fistulated goats were fed ad libitum orchardgrass (Dactylis glomeratia) hay and ruminally infused with endophtye-free seed (E-) for a 7-day adjustment period. Two periods followed with E- and endophyte-infected (E+) seed being randomly assigned to the 2 goat groups in period 1 and then switching treatments between groups in period 2. Infused E+ and E- seed were in equal proportions to the hay such that concentrations of ergovaline and ergovalanine were 0.80 μg per g dry matter for the E+ treatment. Cross-sections of both arteries were imaged using Doppler ultrasonography on days 0, 2, 4, 6, 8, and 12 in period 1 and on days 0, 1, 2, 3, 6, 7, and 9 in period 2. Differences from average baseline areas were used to determine presence or absence of alkaloid-induced vasoconstriction. Carotid arteries initiated constriction on imaging day 2 in both periods, and auricular arteries initiated constriction on imaging day 2 in period 1 and on day 6 in period 2. Luminal areas of the carotid arteries in E+ goats were 46% less than baseline areas in both periods after vasoconstriction occurred, whereas auricular arteries in E+ goats were 52% less than baseline areas in period 1 and 38% in period 2. Both arteries in E+ goats in period 1 relaxed relative to baseline areas by imaging day 2 after they were switched to the E- treatment. Results indicated that goats can vasoconstrict when exposed to ergot alkaloids that could disrupt their thermoregulation. © 2014 Aiken and Flythe.


Klotz J.L.,Forage Animal Production Research Unit
Toxins | Year: 2015

Consumption of feedstuffs contaminated with ergot alkaloids has a broad impact on many different physiological mechanisms that alters the homeostasis of livestock. This change in homeostasis causes an increased sensitivity in livestock to perturbations in the ambient environment, resulting in an increased sensitivity to such stressors. This ultimately results in large financial losses in the form of production losses to livestock producers around the world. This review will focus on the underlying physiological mechanisms that are affected by ergot alkaloids that lead to decreases in livestock production. © 2015 by the authors; licensee MDPI, Basel, Switzerland.


Kagan I.A.,Forage Animal Production Research Unit | Flythe M.D.,Forage Animal Production Research Unit
Journal of visualized experiments : JoVE | Year: 2014

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species.


PubMed | Forage Animal Production Research Unit
Type: Journal Article | Journal: Toxins | Year: 2015

Consumption of feedstuffs contaminated with ergot alkaloids has a broad impact on many different physiological mechanisms that alters the homeostasis of livestock. This change in homeostasis causes an increased sensitivity in livestock to perturbations in the ambient environment, resulting in an increased sensitivity to such stressors. This ultimately results in large financial losses in the form of production losses to livestock producers around the world. This review will focus on the underlying physiological mechanisms that are affected by ergot alkaloids that lead to decreases in livestock production.

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