Progress 10/15/12 to 08/29/17
Outputs
Progress Report Objectives (from AD-416): Objective 1: Determine the disposition of ergot alkaloids in forage- animal tissues/fluids, and implications for human health and food safety and the fundamental biological processes underlying ergot alkaloid- [forage-animal]-plant-environment interactions. Subobjective 1.A: Determine tissue distribution of ergovaline and lysergic acid in cattle consuming diets containing ergot alkaloids. Subobjective 1.B: Determine the metabolites of ergovaline and lysergic acid in urine and bile of exposed steers. Subobjective 1.C: Determine the metabolites formed and disappearance rate of ergovaline and lysergic acid when incubated in mixed rumen microbial cultures. Subobjective 1.D: Identify the transport route, mechanism, and possible metabolism of ergotamine, ergovaline, and lysergic in the bovine small intestine. Subobjective 1.E: Determine the effect of EI TF fescue on gene expression and histology of equine endometrium. Subobjective 1.F: Determine the serotonin and a-adrenergic receptors present in ruminal and mesenteric vasculature. Subobjective 1.G: Determine the effect of dose- and time-defined exposure of EA on physiological, biochemical, and molecular parameters of maturing cattle. Subobjective 1.H: Determine the effect of dose and short term EA exposure on rumen motility. Subobjective 1.I: To determine the effects the EA exposure and body fat store on adipose tissue EA accumulation and the subsequent effects on tissue metabolism, homeostasis and development of necrotic fat in cattle. Subobjective 1.J: Determine the impact of increasing dietary concentrations and �pulse� feeding of EI TF seed (source of EA) on epigenetic modifications (DNA methylation) of promoter elements responsible for pro-inflammatory (IL-1beta, IL-6 IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10 & IL-13) cytokine production in the young adult (5-10 y) and aged (20+ y) horse. Objective 2: Optimize legume/grass mixtures, including nontoxic (novel) and toxic (wild-type) endophyte-infected tall fescue, in integrated forage-animal pasture systems to improve animal performance, health and well-being and forage yield, quality, persistence and resiliency. Subobjective 2.A: Determine the effects of EI TF seed head expression on EA concentrations, animal performance and recovery from FTOX. Subobjective 2.B: Use supplementation to mitigate FTOX by improving our knowledge concerning how supplemental nutrients interact with forage quality and EI TF to affect animal performance. Objective 3: Determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well being and forage utilization efficiencies of forage-animals. Subobjective 3.A: Determine the effect of clover phenolic compounds on cellulolytic and amylolytic bacteria. Subobjective 3.B: Determine whether amine production in the equine large intestine during carbohydrate overload is a consequence of carbohydrate availability or of decreased large intestinal pH and the interaction between plant carbohydrate concentrations and plant phenolic concentrations on the activity of gastrointestinal microbes. Approach (from AD-416): Forage systems provide low cost feed while mitigating man�s impact on the environment. Currently, the available fundamental biological information for predicting animal performance in response to plant nutrients under varying environmental, genetic, physiological status, and management conditions is limited. Even more problematic is the poor understanding of the effects of plant nutraceuticals and anti-quality factors on nutrient intake, metabolism and assimilation for product, health maintenance, or work by the animal. To increase the sustainability of forage-based enterprises, it is essential that a better understanding be developed of the fundamental biological processes underlying the interactions between the animal, plant, and environment. This is particularly essential for endophyte-infected forages that produce toxicants. This Project Plan, through the development and utilization of cutting-edge technologies and real world testing, proposes to decipher the complex interactions within the animal-plant interface in order to accomplish the following objectives: improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems; determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well-being and forage utilization efficiencies of forage-animals; determine the fundamental biological processes underlying the interactions between forage animals, plants, and the environment including the epigenetic effects of forage nutrients and secondary metabolites in the forage- animal; and define the toxicokinetics and toxicodynamics of the ergot alkaloids in forage-animals. Transport studies were completed that determined the role of peptide transporter 1 (a transporter located on the brush border of the small intestinal epithelium) in the active transport of ergotamine, ergovaline, lysergic acid, and cephalexin (positive control) across a cell monolayer. Experiments were completed using selective agonists for serotonin receptors 1B, 1D, 2A, 2B, 4, and 7, the mesenteric and ruminal arteries and veins have been assessed for populations of the aforementioned receptors. A number of Streptococcus bovis varieties of equine and bovine origins were collected in order to evaluate their ability to produce amines, the active ingredients believed to cause laminitis. The final year of a grazing experiment with steers grazing mixed-grass pastures was concluded that evaluated the effects of isoflavones on weight gain performance and rumen characteristics. Color Doppler ultrasound data was collected in a collaborative project with Clemson University to verify vasoconstriction of pregnant ewes exposed to toxic ergot alkaloids. Saphenous veins were biopsied from the ewes to assess saturation of vasculature systems with ergot alkaloids. Uterine Endometrial biopsies were collected from mares that were ovulating and fed either a control diet or toxic endophyte-infected seed. Tissues were fixed for paragon embedding for histology or processed and stored for RNA extraction and analysis. The feeding trial portion of an experiment was completed that is evaluating the effect of ergot alkaloids on epigenetic regulation of inflammation in horses. Accomplishments 01 Ergot alkaloids exert their negative impact on blood vessels supporting the rumen and small intestines through the serotonin 2A receptors. This finding has permitted subsequent research to focus in on this specific receptor subtype and the manner of interactions it has with ergot alkaloids. 02 Feeding a 1:1 mixture of inorganic and organic forms of selenium ameliorate some of the negative effects of ergot alkaloids on cattle that graze toxic endophyte-infected tall fescue. In particular, supplementation of the mixture improved liver function and elevated concentrations of prolactin in the blood that are typically depressed in cattle that graze toxic endophyte-infected tall fescue. It was also demonstrated that supplementation with organic and inorganic selenium is a cost-effective treatment to mitigate immune system depression during weaning-shipping of beef calves that have grazed toxic endophyte- infected tall fescue. 03 Rumen motility in cattle is reduced by consumption of toxic endophyte- infected tall fescue. Reductions in dry matter intake associated with the altered rumen motility are a major factor in decreased productivity of ruminants that consume toxic endophyte-infected tall fescue. This information will be valuable in developing management techniques to mitigate or alleviate fescue toxicosis. 04 The vascular systems of steers that graze chemical seed head suppressed toxic endophyte-infected tall fescue were determined to be less saturated with toxic ergot alkaloids and have improved post-graze weight gain performance than those that grazed unsuppressed tall fescue. Growing calves that are background on toxic endophyte-infected tall fescue that is chemically treated to suppress seed heads can have improved performance in the feed yard. Fifty thousand acres of tall fescue was treated to control seed heads in the spring of 2017.
Impacts
(N/A)
Publications
- Zhou, S., Li, H., Garlapalli, R., Nokes, S.E., Flythe, M.D., Rankin, S.E., Knutson, B.L. 2017. Hydrolysis of model cellulose films by cellulosomes: Extension of quartz crystal microbalance techniques to multienzymatic complexes. Journal of Biotechnology. 241:42-49.
- Harbison, A.B., Price, L., Flythe, M.D., Br�uer, S.L. 2017. Micropepsia pineolensis gen. nov., sp. nov., a mildly acidophilic alphaproteobacterium isolated from a poor fen, and proposal of Micropepsiaceae fam. nov. within Micropepsiales ord. nov. International Journal of Systematic and Evolutionary Microbiology. 67:839-844.
- Harlow, B.E., Flythe, M.D., Aiken, G.E. 2017. Effect of biochanin A on corn grain (Zea Mays) fermentation by bovine rumen amylolytic bacteria. Journal of Applied Microbiology. 122(4): 870-880.
- Harlow, B.E., Lawrence, L.M., Harris, P.A., Aiken, G.E., Flythe, M.D. 2017. Exogenous lactobacilli mitigate microbial changes associated with grain fermentation (corn, oats, and wheat) by equine fecal microflora ex vivo. PLoS One.
- Harlow, B.M., Goodman, J.P., Lynn, B., Flythe, M.D., Ji, H., Aiken, G.E. 2017. Ruminal tryptophan-utilizing bacteria degrade ergovaline from tall fescue seed extract. Journal of Animal Science. 95:980-988.
- Marfo-Ahenkora, E., Aiken, G.E., Flythe, M.D. 2014. Fermentation characteristics and nutritive value of low moisture silage made from mature bermudagrass (C. dactylon) and switchgrass (P. virgatum) in mixture with alfalfa (M. sativa) or treated with urea and plantain (Musa AAB). Ghana Journal of Agricultural Science. 47(1):15-29.
- Pszczolkowski, V.L., Bryant, R.W., Harlow, B.E., Aiken, G.E., Martin, L.J., Flythe, M.D. 2016. Effects of spent craft brewers� yeast on fermentation and methane production by rumen microorganisms. Advances in Microbiology. 6:716-723.
- Harlow, B., Bryant, R., Cohen, S., O'Connell, S., Flythe, M.D. 2016. Degradation of spent craft brewer�s yeast by caprine rumen hyper ammonia- producing bacteria. Letters in Applied Microbiology. 63(4):307-312. doi:10. 1111/lam.12623.
- Klotz, J.L., Aiken, G.E., Bussard, J.R., Foote, A.P., Harmon, D.L., Goff, B.M., Schrick, F., Strickland, J.R. 2016. Vasoactivity and vasoconstriction changes in cattle related to time off toxic endophyte- infected tall fescue. Toxins. 8:271. doi:10.3390/toxins8100271.
|
Progress 10/01/15 to 09/30/16
Outputs
Progress Report Objectives (from AD-416): Objective 1: Determine the disposition of ergot alkaloids in forage- animal tissues/fluids, and implications for human health and food safety and the fundamental biological processes underlying ergot alkaloid- [forage-animal]-plant-environment interactions. Subobjective 1.A: Determine tissue distribution of ergovaline and lysergic acid in cattle consuming diets containing ergot alkaloids. Subobjective 1.B: Determine the metabolites of ergovaline and lysergic acid in urine and bile of exposed steers. Subobjective 1.C: Determine the metabolites formed and disappearance rate of ergovaline and lysergic acid when incubated in mixed rumen microbial cultures. Subobjective 1.D: Identify the transport route, mechanism, and possible metabolism of ergotamine, ergovaline, and lysergic in the bovine small intestine. Subobjective 1.E: Determine the effect of EI TF fescue on gene expression and histology of equine endometrium. Subobjective 1.F: Determine the serotonin and a-adrenergic receptors present in ruminal and mesenteric vasculature. Subobjective 1.G: Determine the effect of dose- and time-defined exposure of EA on physiological, biochemical, and molecular parameters of maturing cattle. Subobjective 1.H: Determine the effect of dose and short term EA exposure on rumen motility. Subobjective 1.I: To determine the effects the EA exposure and body fat store on adipose tissue EA accumulation and the subsequent effects on tissue metabolism, homeostasis and development of necrotic fat in cattle. Subobjective 1.J: Determine the impact of increasing dietary concentrations and �pulse� feeding of EI TF seed (source of EA) on epigenetic modifications (DNA methylation) of promoter elements responsible for pro-inflammatory (IL-1beta, IL-6 IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10 & IL-13) cytokine production in the young adult (5-10 y) and aged (20+ y) horse. Objective 2: Optimize legume/grass mixtures, including nontoxic (novel) and toxic (wild-type) endophyte-infected tall fescue, in integrated forage-animal pasture systems to improve animal performance, health and well-being and forage yield, quality, persistence and resiliency. Subobjective 2.A: Determine the effects of EI TF seed head expression on EA concentrations, animal performance and recovery from FTOX. Subobjective 2.B: Use supplementation to mitigate FTOX by improving our knowledge concerning how supplemental nutrients interact with forage quality and EI TF to affect animal performance. Objective 3: Determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well being and forage utilization efficiencies of forage-animals. Subobjective 3.A: Determine the effect of clover phenolic compounds on cellulolytic and amylolytic bacteria. Subobjective 3.B: Determine whether amine production in the equine large intestine during carbohydrate overload is a consequence of carbohydrate availability or of decreased large intestinal pH and the interaction between plant carbohydrate concentrations and plant phenolic concentrations on the activity of gastrointestinal microbes. Approach (from AD-416): Forage systems provide low cost feed while mitigating man�s impact on the environment. Currently, the available fundamental biological information for predicting animal performance in response to plant nutrients under varying environmental, genetic, physiological status, and management conditions is limited. Even more problematic is the poor understanding of the effects of plant nutraceuticals and anti-quality factors on nutrient intake, metabolism and assimilation for product, health maintenance, or work by the animal. To increase the sustainability of forage-based enterprises, it is essential that a better understanding be developed of the fundamental biological processes underlying the interactions between the animal, plant, and environment. This is particularly essential for endophyte-infected forages that produce toxicants. This Project Plan, through the development and utilization of cutting-edge technologies and real world testing, proposes to decipher the complex interactions within the animal-plant interface in order to accomplish the following objectives: improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems; determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well-being and forage utilization efficiencies of forage-animals; determine the fundamental biological processes underlying the interactions between forage animals, plants, and the environment including the epigenetic effects of forage nutrients and secondary metabolites in the forage- animal; and define the toxicokinetics and toxicodynamics of the ergot alkaloids in forage-animals. The CACO-2 cell line (the selected model for intestinal enterocytes) and the associated technologies have been fully established in laboratory for the conduct of alamarblue toxicity studies to define a range of alkaloid concentrations that can be used to study transport without altering cell viability. Data have been collected to characterize the adrenergic receptor populations of the ruminal and mesenteric vascular beds and their vasoactivity in the presence or absence of ergovaline. The first year of a grazing experiment that is using rumen fistulated and non- fistulated steers indicated that the isoflavone biochanin A in red clover reduces ammonia production by rumen bacteria to increase bypass protein and enhance steer weight gain. Ex vivo experiments are demonstrating breakdown of the ergot alkaloid, ergovaline, by rumen bacteria. Ex vivo studies are indicating that biochanin A mitigates the adverse effect that starch has on the cellulolytic bacteria in the rumen. Data have been collected with equines showing that bacteria rapidly colonize the gastrointestinal tracts of foals and the bacterial biodiversity resembles the dam within a few weeks of life. Accomplishments 01 Toxic ergot alkaloids bind different types of specialized receptors in the blood vessels of cattle to induce constricted blood flow. However, densities of these different receptors differ across blood vessels that causes organs and tissues to vary in altered function from ergot alkaloid exposure. Current research by ARS in Lexington, Kentucky is defining the receptor densities present along the digestive tract and how they are affected by ergot alkaloid exposure. Results have shown that certain receptors in the arteries and veins of the gut are altered by exposure to ergovaline, whereas others are not, or minimally, present in the vessels. Understanding densities of the various receptor groups over the multitude of arteries and veins can provide which organs and tissues to target in developing technologies that mitigate the ergot alkaloid-induced vasoconstriction. 02 Tryptophan-degrading bacteria in the rumens of cattle can degrade toxic ergot alkaloids. Results of experiments by ARS researchers from Lexington, Kentucky has shown breakdown of ergovaline, the major and most toxic ergopeptine produced by the endophyte that causes fescue toxicosis, with the extent of degradation being enhanced with increases in protein as a substrate. This research will lead to development of management strategies to potentially have complete detoxification of ergot alkaloids by rumen microbes for improving cattle health and production, and save the high costs association with fescue toxicosis. 03 Biochanin A, a phytoestrogen produced by red clover, reduces ammonia production in the rumen. Biochanin A demonstrates to inhibit hyper- ammonia producing bacteria that degrade protein and adversely affect amino acid profiles entering the small intestines. A grazing experiment with pastures of mixed cool-season grasses demonstrated that feeding dried distillers grains as a protein source did not increase average daily gain of steers, but adding biochanin A to the protein supplement significantly increased average daily gain over the pasture- only control treatment. Biochanin A produced by red clover can benefit animal performance by improving the quality of digested protein and the environment by reducing the excretion of ammonia. 04 Bochanin A improves fiber digestion. Follow-up research by ARS in Lexington, Kentucky has shown that inhibition of hyper-ammonia producing bacteria increases the cellulolytic bacteria to potentially increase ruminal degradation of fiber. This research will lead to development of technologies that can increase the rate of digestion of consumed forage and improve nutrient efficiency of grazing ruminants and improve environmental quality.
Impacts
(N/A)
Publications
- Aiken, G.E. 2016. Grazing management options in meeting objectives of grazing experiments. Professional Animal Scientist. 32:1-9.
- Klotz, J.L. 2015. Physiologic effects of ergot alkaloids: What happens when excretion does not equal consumption? Journal of Animal Science. 93:5512-5521.
- Klotz, J.L. 2015. Activities and effects of ergot alkaloids on livestock physiology and production. Toxins. 7:2801-2821. doi:10.3390/toxins7082801.
- Aiken, G.E., Williams, D.W. 2015. Forage yield and nutritive value of turf bermudagrasses managed to simulate a horse pasture management scheme in the U.S. Upper Transition Zone. Crop, Forage & Turfgrass Management. doi: 10.2134/cftm2015.0139.
- Pratt, S.L., Stowe, H.M., Whitlock, B.K., Strickland, L., Miller, M., Calcatera, S.M., Dimmick, M.D., Aiken, G.E., Schrick, F.N., Long, N.M., Duckett, S.K., Andrae, J.G. 2015. Bulls grazing Kentucky 31 tall fescue exhibit impaired growth, semen quality, and decreased semen freezing potential. Theriogenology. 83:408-414.
- Harlow, B.E., Lawrence, L.M., Flythe, M.D. 2015. Sample handling factors affecting the enumeration of lactobacilli and cellulolytic bacteria in equine feces. Journal of Equine Veterinary Science. 35(9):744-748. doi:
- Jia, Y., Harmon, D.L., Flythe, M.D., Klotz, J.L. 2015. Interaction of isoflavones and endophyte-infected tall fescue seed extract on vasoactivity of bovine mesenteric vasculature. Frontiers in Nutrition: Animal Nutrition and Metabolism. doi: 10.3389/fnut.2015.00032.
- Harlow, B.E., Donley, T.M., Lawrence, L.M., Flythe, M.D. 2015. Effect of starch source (corn, oats or wheat) and concentration on fermentation by equine fecal microbiota in vitro. Journal of Applied Microbiology. doi: 10. 1111/jam.12927.
- Kagan, I., Dinkins, R.D., Taylor, N.L. 2016. Phenolic profiles and polyphenol oxidase (PPO) gene expression of red clover (Trifolium pratense) selected for decreased postharvest browning. American Journal of Plant Sciences. 7:1478-1489.
- Villalba, J.J., Spackman, C., Goff, B.M., Klotz, J.L., Griggs, T., MacAdam, J.W. 2015. Interaction between a tannin-containing legume and endophyte- infected tall fescue seed on lambs� feeding behavior and physiology. Journal of Animal Science. 94:845-857. doi: 10.2527/jas.2015-9790.
|
Progress 10/01/14 to 09/30/15
Outputs
Progress Report Objectives (from AD-416): Objective 1: Determine the disposition of ergot alkaloids in forage- animal tissues/fluids, and implications for human health and food safety and the fundamental biological processes underlying ergot alkaloid- [forage-animal]-plant-environment interactions. Subobjective 1.A: Determine tissue distribution of ergovaline and lysergic acid in cattle consuming diets containing ergot alkaloids. Subobjective 1.B: Determine the metabolites of ergovaline and lysergic acid in urine and bile of exposed steers. Subobjective 1.C: Determine the metabolites formed and disappearance rate of ergovaline and lysergic acid when incubated in mixed rumen microbial cultures. Subobjective 1.D: Identify the transport route, mechanism, and possible metabolism of ergotamine, ergovaline, and lysergic in the bovine small intestine. Subobjective 1.E: Determine the effect of EI TF fescue on gene expression and histology of equine endometrium. Subobjective 1.F: Determine the serotonin and a-adrenergic receptors present in ruminal and mesenteric vasculature. Subobjective 1.G: Determine the effect of dose- and time-defined exposure of EA on physiological, biochemical, and molecular parameters of maturing cattle. Subobjective 1.H: Determine the effect of dose and short term EA exposure on rumen motility. Subobjective 1.I: To determine the effects the EA exposure and body fat store on adipose tissue EA accumulation and the subsequent effects on tissue metabolism, homeostasis and development of necrotic fat in cattle. Subobjective 1.J: Determine the impact of increasing dietary concentrations and �pulse� feeding of EI TF seed (source of EA) on epigenetic modifications (DNA methylation) of promoter elements responsible for pro-inflammatory (IL-1beta, IL-6 IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10 & IL-13) cytokine production in the young adult (5-10 y) and aged (20+ y) horse. Objective 2: Optimize legume/grass mixtures, including nontoxic (novel) and toxic (wild-type) endophyte-infected tall fescue, in integrated forage-animal pasture systems to improve animal performance, health and well-being and forage yield, quality, persistence and resiliency. Subobjective 2.A: Determine the effects of EI TF seed head expression on EA concentrations, animal performance and recovery from FTOX. Subobjective 2.B: Use supplementation to mitigate FTOX by improving our knowledge concerning how supplemental nutrients interact with forage quality and EI TF to affect animal performance. Objective 3: Determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well being and forage utilization efficiencies of forage-animals. Subobjective 3.A: Determine the effect of clover phenolic compounds on cellulolytic and amylolytic bacteria. Subobjective 3.B: Determine whether amine production in the equine large intestine during carbohydrate overload is a consequence of carbohydrate availability or of decreased large intestinal pH and the interaction between plant carbohydrate concentrations and plant phenolic concentrations on the activity of gastrointestinal microbes. Approach (from AD-416): Forage systems provide low cost feed while mitigating man�s impact on the environment. Currently, the available fundamental biological information for predicting animal performance in response to plant nutrients under varying environmental, genetic, physiological status, and management conditions is limited. Even more problematic is the poor understanding of the effects of plant nutraceuticals and anti-quality factors on nutrient intake, metabolism and assimilation for product, health maintenance, or work by the animal. To increase the sustainability of forage-based enterprises, it is essential that a better understanding be developed of the fundamental biological processes underlying the interactions between the animal, plant, and environment. This is particularly essential for endophyte-infected forages that produce toxicants. This Project Plan, through the development and utilization of cutting-edge technologies and real world testing, proposes to decipher the complex interactions within the animal-plant interface in order to accomplish the following objectives: improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems; determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well-being and forage utilization efficiencies of forage-animals; determine the fundamental biological processes underlying the interactions between forage animals, plants, and the environment including the epigenetic effects of forage nutrients and secondary metabolites in the forage- animal; and define the toxicokinetics and toxicodynamics of the ergot alkaloids in forage-animals. Samples are being analyzed from a preliminary experiment that is determining the effects of ergot alkaloids on gene expression of drug transporters. Procedures have been refined in synthesizing intermediates in a chain of chemical reactions that ultimately synthesizes ergovaline. Studies were completed that identified Enterococcus faecalis as the etiological agent in starch-associated equine hindgut acidosis. Other microbial studies determined that a known etiological agent in fructan- associated equine hindgut acidosis grows more rapidly on short-chain fructans that on long-chain fructans. The first year of a grazing experiment indicated that supplementation with isoflavones extracted from red clover can increase weight gain efficiency of steers on temperate grass pastures. A preliminary experiment was conducted to evaluate calf temperament as a source of variation in grazing experiments. Accomplishments 01 Ergot alkaloids do not affect the architecture of the mare uterus. There is reduced fertility and early embryonic losses in mares grazing toxic endophyte-infected tall fescue, which could be partly due to effects of ergot alkaloids on uterine cells and tissues. Uterine tissues did not differ between mares consuming endophyte-infected tall fescue seed and those mares consuming endophyte-free seed. Although ergot alkaloid-induced constriction of blood vessels was detected in mares that consumed infected seed, there were no detectable effects on uterine cells and tissues. Effects of ergot alkaloids on equine reproduction can now focus on such factors as hormones or body condition rather than the alteration of uterine architecture from ergot alkaloid exposure. 02 Ruminants grazing endophyte-infected tall fescue have reduced nutrient efficiencies. It has not been determined if ergot alkaloid-induced constriction of blood vessels occurs in the gastrointestinal tract of ruminants. An experiment demonstrated that ergot alkaloids cause ruminal and mesenteric blood vessels of cattle to constrict and reduce blood flow to the gastrointestinal tract. This experiment provided strong indication that ergot alkaloid-induced constriction of arteries and veins of the gastrointestinal tract could have major implications on the digestive efficiency of cattle grazing toxic endophyte-infected tall fescues and could be a factor in poor growth performance and body condition of cattle that is often observed. 03 Reduced gut motility in ruminants grazing endphyte-infected tall fescue will ultimately reduce nutrient intake. Gut motility has a major influence on rate of passage and digestibility of feed. An experiment that infused extract of the toxic ergopeptine, ergovaline, into ruminally-fistulated steers found a reduction in gut motility. Negative response of gut motility to ergot alkaloid exposure could be a major factor in the lower dry matter intakes that are consistently observed in cattle grazed on toxic endophyte-infected tall fescue. Poor cattle performance and body condition will be reflected by low dry matter intake. 04 Cattle selectively graze seed heads of endophyte-infected tall fescue that have high concentrations of toxic ergot alkaloids. Steers grazed on endophyte-infected tall fescue that were treated to suppress seed head emergence were determined to have relieved alkaloid-induced vasoconstriction and improved post-graze weight gain as compared to those grazing untreated pastures. 05 Grasses that produce short-chain fructan carbohydrates could be the solution to the laminitis problem. Rapid fermentation of carbohydrate in the hindgut is one of the primary causes of laminitis in horses, which is a malady of major concern in the industry. It was determined from a laboratory experiment that Enterococcus faecalis is the causal agent in starch associated laminitis. Another experiment determined that the length of a fructan carbohydrate chain affects fermentation characteristics. Short-chain fructans are more readily fermented than long-chain fructans. Selection of grass species or cultivars that produce long-chain fructans could be an option for eliminating the laminitis that can occur on cool-season grass pastures.
Impacts
(N/A)
Publications
- Aiken, G.E., Flythe, M.D. 2014. Vasoconstrictive responses by the carotid and auricular arteries in goats to ergot alkaloid exposure. Frontiers in Chemistry. 2:101. DOI: 10.3389/fchem.2014.00101.
- Goff, B.M., Aiken, G.E., Witt, W.W., Burch, P.L., Schrick, F.N. 2015. Forage nutritive value and steer responses to grazing intensity and seed- head suppression of endophyte-free tall fescue in mixed pastures. Professional Animal Scientist. 31(2):120-129. DOI: 10.15232/pas.2014-01366.
- Flythe, M.D., Aiken, G.E., Gellin, G.L., Klotz, J.L., Goff, B.M., Andries, K. 2015. Hops (Humulus lupulus) �-acid as an inhibitor of caprine rumen hyper-ammonia-producing bacteria in vitro. Agriculture, Food and Analytical Bacteriology. 5:29-36.
- Flythe, M.D., Elia, N.M., Schmal, M.B., Nokes, S.E. 2015. Switchgrass (Panicum virgatum) fermentation by Clostridium thermocellum and Clostridium beijerinckii sequential culture: effect of feedstock particle size on gas production. Advances in Microbiology. 5:311-316.
- Kim, D., McLeod, K.R., Koontz, A.F., Foote, A.P., Klotz, J.L., Harmon, D.L. 2015. Effect of intake on fasting heat production, respiratory quotient and plasma metabolites measured using the washed rumen technique. Animal. 9:58-66.
- Klotz, J.L., Barnes, A.J. 2014. Isolating and using sections of bovine mesenteric artery and vein as a bioassay to test for vasoactivity in the small intestine. Journal of Visualized Experiments. 92:e52020.
- Aiken, G.E., Burns, M.G., Stowe, H.M., Andrae, J.G., Pratt, S.L. 2015. Vasoconstrictive responses of the testicular and caudal arteries in bulls exposed to ergot alkaloids from tall fescue. Professional Animal Scientist. 31:130-136. doi:10.15232\pas.2014-01373.
- Huihua, J., Fannin, N., Klotz, J.L., Bush, L.P. 2014. Tall fescue seed extraction and partial purification of ergot alkaloids. Frontiers in Chemistry: Chemical Biology. 2:110.
- Egert, A.M., Klotz, J.L., McLeod, K.R., Harmon, D.L. 2014. Development of a methodology to measure the effect of ergot alkaloids on forestomach motility using real-time wireless telemetry. Frontiers in Chemistry: Chemical Biology. 2:90.
- Craig, A., Klotz, J.L., Duringer, J.M. 2015. Cases of ergotism in livestock and associated ergot alkaloid concentrations in feed. Frontiers in Chemistry: Chemical Biology. 3:8. doi:10.3389/fchem.2015.00008.
- Klotz, J.L., Smith, D.L. 2015. Recent investigations of ergot alkaloids incorporated into plant and/or animal systems. Frontiers in Chemistry: Chemical Biology. 3:23. doi:10.3389/fchem.2015.00023.
- Stowe, H.M., Millar, M., Burns, M.G., Calcatera, S.M., Andrae, J.G., Aiken, G.E., Schrick, F.N., Cushing, T., Bridges, W.C., Pratt, S.L. 2014. Effects of toxicosis on bull growth, semen characteristics and breeding soundness evaluation. Journal of Animal Science. 91:3686-3692.
- Goff, B.M., Aiken, G.E., Witt, W.W., Williamson, J.A., Flynn, E.S., Burch, P.L. 2014. Timing and rate of Chaparral treatment affects tall fescue seedhead development and pasture plant densities. Forage and Grazinglands. DOI: 10.2134/FG-2013-0001-RS.
- Koontz, A.F., Kim, D., Mc Leod, K.R., Klotz, J.L., Harmon, D.L. 2014. Effect of fescue toxicosis on whole body energy and nitrogen balance, in situ degradation and ruminal passage rates in Holstein steers. Animal Production Science. 55:988-998. doi.org/10.1071/AN14037.
|
Progress 10/01/13 to 09/30/14
Outputs
Progress Report Objectives (from AD-416): Objective 1: Determine the disposition of ergot alkaloids in forage- animal tissues/fluids, and implications for human health and food safety and the fundamental biological processes underlying ergot alkaloid- [forage-animal]-plant-environment interactions. Subobjective 1.A: Determine tissue distribution of ergovaline and lysergic acid in cattle consuming diets containing ergot alkaloids. Subobjective 1.B: Determine the metabolites of ergovaline and lysergic acid in urine and bile of exposed steers. Subobjective 1.C: Determine the metabolites formed and disappearance rate of ergovaline and lysergic acid when incubated in mixed rumen microbial cultures. Subobjective 1.D: Identify the transport route, mechanism, and possible metabolism of ergotamine, ergovaline, and lysergic in the bovine small intestine. Subobjective 1.E: Determine the effect of EI TF fescue on gene expression and histology of equine endometrium. Subobjective 1.F: Determine the serotonin and a-adrenergic receptors present in ruminal and mesenteric vasculature. Subobjective 1.G: Determine the effect of dose- and time-defined exposure of EA on physiological, biochemical, and molecular parameters of maturing cattle. Subobjective 1.H: Determine the effect of dose and short term EA exposure on rumen motility. Subobjective 1.I: To determine the effects the EA exposure and body fat store on adipose tissue EA accumulation and the subsequent effects on tissue metabolism, homeostasis and development of necrotic fat in cattle. Subobjective 1.J: Determine the impact of increasing dietary concentrations and �pulse� feeding of EI TF seed (source of EA) on epigenetic modifications (DNA methylation) of promoter elements responsible for pro-inflammatory (IL-1beta, IL-6 IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10 & IL-13) cytokine production in the young adult (5-10 y) and aged (20+ y) horse. Objective 2: Optimize legume/grass mixtures, including nontoxic (novel) and toxic (wild-type) endophyte-infected tall fescue, in integrated forage-animal pasture systems to improve animal performance, health and well-being and forage yield, quality, persistence and resiliency. Subobjective 2.A: Determine the effects of EI TF seed head expression on EA concentrations, animal performance and recovery from FTOX. Subobjective 2.B: Use supplementation to mitigate FTOX by improving our knowledge concerning how supplemental nutrients interact with forage quality and EI TF to affect animal performance. Objective 3: Determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well being and forage utilization efficiencies of forage-animals. Subobjective 3.A: Determine the effect of clover phenolic compounds on cellulolytic and amylolytic bacteria. Subobjective 3.B: Determine whether amine production in the equine large intestine during carbohydrate overload is a consequence of carbohydrate availability or of decreased large intestinal pH and the interaction between plant carbohydrate concentrations and plant phenolic concentrations on the activity of gastrointestinal microbes. Approach (from AD-416): Forage systems provide low cost feed while mitigating man�s impact on the environment. Currently, the available fundamental biological information for predicting animal performance in response to plant nutrients under varying environmental, genetic, physiological status, and management conditions is limited. Even more problematic is the poor understanding of the effects of plant nutraceuticals and anti-quality factors on nutrient intake, metabolism and assimilation for product, health maintenance, or work by the animal. To increase the sustainability of forage-based enterprises, it is essential that a better understanding be developed of the fundamental biological processes underlying the interactions between the animal, plant, and environment. This is particularly essential for endophyte-infected forages that produce toxicants. This Project Plan, through the development and utilization of cutting-edge technologies and real world testing, proposes to decipher the complex interactions within the animal-plant interface in order to accomplish the following objectives: improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems; determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well-being and forage utilization efficiencies of forage-animals; determine the fundamental biological processes underlying the interactions between forage animals, plants, and the environment including the epigenetic effects of forage nutrients and secondary metabolites in the forage- animal; and define the toxicokinetics and toxicodynamics of the ergot alkaloids in forage-animals. In vitro studies with ruminally-fistulated goats have been initiated to determine ruminal degradation of ergot alkaloids. Studies are almost complete in identifying serotonergic receptors present in the ruminal and mysenteric blood vessels. Experiments evaluating gut motility responses in cattle to ergot alkaloids have either been initiated or concluded. Data is being collected in the second and final year of determining blood flow recovery from exposure to ergot alkaloids in steers after they are conditioned to grazing either seed head suppressed or unsuppressed endophyte-infected tall fescue and placed on non-toxic diets. Improvements have been made to the extraction method for clover phenolics for quantification purposes. A plant secondary metabolite in hops was identified to reduce the conversion of carbohydrates to fructans in the hingut of horses. Significant Activities that Support Special Target Populations: Interviewed for an episode of Down on the Farm on the RFD cable network to discuss FAPRU activities directed towards small farm production at the Eden Shale Demonstration Farm. Presentation on implementing a 300-Day grazing system at the Kentucky Grazing Conference. Attended by more than 50 small farmers extension agents. Lexington, KY. Presentation on managing around fescue toxicosis was given at a meeting of the Anderson County Cattlemen Association on managing around fescue toxicosis. Attended by over 60 small farmers. Lawrenceburg, KY. Accomplishments 01 Development of a method to collect continuous real-time rumen motility data in cattle. Preliminary research has shown that ergot alkaloids decrease gut motility, which could reduce dry matter intake and animal performance. A method was developed and validated for evaluating the impact of dosing cattle with ergot alkaloid containing tall fescue seed on rumen motility. The method will serve as a research tool in studying effects of alkaloids/toxins on gut motility, which has major implications on nutrient intake and digesion/absorsorption. 02 Gene expression of the serotonin receptors as influenced by ergot alkaloids. Gene expression of serotonin receptors functionally associated with gut motility, and five additional signal transduction genes associated with the function of these 2 receptors could be adversely affected by ergot alkaloids. An experiment has shown that both receptor types and all associated intracellular signal transduction genes were down regulated (i.e., fewer were present) in the steers on an endophyte-infected tall fescue treatment as compared to an endophyte-free tall fescue treatment. These results provide possible explanation for a decrease in gut motility that would explain the decreased intake and daily gain observed in cattle with fescue toxicosis. 03 Ergot alkaloids affect pituitary function. The pituitary gland is responsible for the production and secretion of several major hormones that control other endocrine glands and regulate major physiological processes such as growth, metabolism, maturation, reproduction, lactation, and vasoregulation, all functions known to be adversely affected in cattle exhibiting signs of fescue toxicosis. Genomic and targeted Nanostring analyses of Ribonucleic Acid expression profiles in pituitary glands found that cattle grazed on endophyte-infected tall fescue had altered expression of genes associated with lactation, growth, reproduction, and selenium metabolism. These findings provide potential targets for selective breeding of genotypes with a higher resistance to toxicosis, and will enable the development of innovative technologies to ameliorate the effects of ergot alkaloids on forage- based livestock production. 04 Ergot alkaloids affect ruminal absorption of volatile fatty acids. Expression of genes associated with volatile fatty acid transport across the ruminal wall could be adversely effected by ergot alkaloids and therefore reduce absorption of metabolizable energy. An experiment demonstrated that steers dosed with endophyte-infected seed exhibited a depression of ruminal absorption of ergot alkaloids that was linked to a decrease in the expression of genes associated with volatile fatty acid transport systems in the rumen. Results indicated that fescue toxicosis can impair volatile fatty acid transporter systems in the rumen and contribute to decreased body weight gain and metabolic function associated with fescue toxicosis in cattle. 05 Cow herds that graze endophyte-infected tall fescue can have reduced reproductive performance. Much of the research has focused on how ergot alkaloids produced by the endophyte adversely affects reproductive hormones and ovarian development, but limited research with bulls has shown subtle effects on bull fertility. Part of this effect could be due to adverse effects of ergot alkaloid-induced constriction of blood flow to the testes of bulls. Color Doppler ultrasonography was used to determine that testicular arteries exhibited persistent vasoconstriction in bulls consuming endophyte- infected tall fescue as compared to those consuming nontoxic tall fescue. These results indicate that reduced blood flow to the testis of bulls consuming endophyte-infected tall fescue could contribute to the reduced fertility of bulls grazing endophyte-infected tall fescue. 06 Mitigation of the adverse effects of fructans on the hindgut of horses. Horses on lush spring pastures can consume too much of a carbohydrate called fructan. Streptococcus bacteria in the horse hindgut convert fructan to acids and toxic amines. Among other problems, the amines can cause inflammation in the hooves and lameness, a condition called pasture-associated laminitis. A secondary metabolite from the hops plant was determined to inhibit Streptococcus in the horse hindgut and decrease the conversion of fructan to acids and amines. The safety of hops for horses has not been determined, but this well-known food ingredient could represent a natural product to control the underlying cause of pasture-associated laminitis.
Impacts
(N/A)
Publications
- Klotz, J.L., Aiken, G.E., Johnson, J.M., Brown, K.R., Bush, L.P., Strickland, J.R. 2013. Antagonism of lateral saphenous vein serotonin receptors from steers grazing endophyte-free, wild-type, or novel endophyte-infected tall fescue. Journal of Animal Science. 91:4492-4500.
- Kim, D., Mcleod, K.R., Klotz, J.L., Koontz, A.F., Foote, A.P., Harmon, D.L. 2013. Evaluation of a rapid determination of heat production and respiratory quotient in holstein steers using the washed rumen technique. Journal of Animal Science. 91:4267-4276.
- Foote, A.P., Kristensen, N.B., Klotz, J.L., Kim, D., Koontz, A.F., Mcleod, K.R., Bush, L.P., Schrick, F.N., Harmon, D.L. 2013. Ergot alkaloids from endophyte-infected tall fescue decrease reticuloruminal epithelial blood flow and volatile fatty acid absorption from a washed reticulorumen. Journal of Animal Science.
- Koontz, A.F., Kim, D., Foote, A.P., Bush, L.P., Klotz, J.L., Mcleod, K.R., Harmon, D.L. 2013. Alteration of fasting heat production during fescue toxicosis in Holstein steers. Journal of Animal Science. 91:3881-3888.
- Kato, D., Elia, N.M., Flythe, M.D., Lynn, B.C. 2014. Pretreatment of lignocellulosic biomass using Fenton chemistry. Bioresource Technology. 162:273-278.
- Pesqueira, A., Harmon, D.L., Branco, A.F., Klotz, J.L. 2014. Bovine lateral saphenous veins exposed to ergopeptine alkaloids do not relax. Journal of Animal Science. 92:1213-1218.
- Scharf, B., Was, L.E., Aiken, G.E., Spiers, D. 2008. Regional differences in sweat rate response of steers to short-term heat stress. Journal of Biometeorology. 52:725-732.
- Egert, A.M., Kim, D., Schrick, F., Harmon, D.L., Klotz, J.L. 2014. Dietary exposure to ergot alkaloids decreases contractility of bovine mesenteric vasculature. Journal of Animal Science. 92:1768-1779.
- Flythe, M.D., Harrison, B., Kagan, I., Klotz, J.L., Gellin, G.L., Goff, B. M., Aiken, G.E. 2013. Antimicrobial activity of red clover (Trifolium pratense L.) extract on caprine hyper ammonia-producing bacteria. Agriculture, Food and Analytical Bacteriology. 3:176-185.
- Foote, A.P., Penner, G.P., Walpole, M.E., Klotz, J.L., Brown, K.R., Bush, L.P., Harmon, D.L. 2014. Acute exposure to ergot alkaloids from endophyte- infected tall fescue does not alter absorptive or barrier function of the isolated ruminal epithelium. Animal. 8(7):1106-1112.
- Harlow, B.E., Lawrence, L.M., Kagan, I., Flythe, M.D. 2014. Inhibition of fructan-fermenting equine fecal bacteria and Streptococcus bovis by hops (Humulus lupulus L.) �-acid. Journal of Applied Microbiology. 117:329-339.
- Kagan, I., Flythe, M.D. 2014. Thin-layer chromatographic (TLC) separations and bioassays of plant extracts to identify antimicrobial compounds. Journal of Visualized Experiments. 85:e51411. doi:10.3791/51411.
- Aiken, G.E. 2014. Cool-season annual grasses interseeded into bermudagrass with improved cold-tolerance for grazing in the upper south. Forage and Grazinglands. doi:10.2134/FG-2012-0137-RS.
|
Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): Objective 1: Determine the disposition of ergot alkaloids in forage- animal tissues/fluids, and implications for human health and food safety and the fundamental biological processes underlying ergot alkaloid- [forage-animal]-plant-environment interactions. Subobjective 1.A: Determine tissue distribution of ergovaline and lysergic acid in cattle consuming diets containing ergot alkaloids. Subobjective 1.B: Determine the metabolites of ergovaline and lysergic acid in urine and bile of exposed steers. Subobjective 1.C: Determine the metabolites formed and disappearance rate of ergovaline and lysergic acid when incubated in mixed rumen microbial cultures. Subobjective 1.D: Identify the transport route, mechanism, and possible metabolism of ergotamine, ergovaline, and lysergic in the bovine small intestine. Subobjective 1.E: Determine the effect of EI TF fescue on gene expression and histology of equine endometrium. Subobjective 1.F: Determine the serotonin and a-adrenergic receptors present in ruminal and mesenteric vasculature. Subobjective 1.G: Determine the effect of dose- and time-defined exposure of EA on physiological, biochemical, and molecular parameters of maturing cattle. Subobjective 1.H: Determine the effect of dose and short term EA exposure on rumen motility. Subobjective 1.I: To determine the effects the EA exposure and body fat store on adipose tissue EA accumulation and the subsequent effects on tissue metabolism, homeostasis and development of necrotic fat in cattle. Subobjective 1.J: Determine the impact of increasing dietary concentrations and �pulse� feeding of EI TF seed (source of EA) on epigenetic modifications (DNA methylation) of promoter elements responsible for pro-inflammatory (IL-1beta, IL-6 IFN-gamma and TNF-alpha) and anti-inflammatory (IL-10 & IL-13) cytokine production in the young adult (5-10 y) and aged (20+ y) horse. Objective 2: Improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems. Subobjective 2.A: Determine the effects of EI TF seed head expression on EA concentrations, animal performance and recovery from FTOX. Subobjective 2.B: Use supplementation to mitigate FTOX by improving our knowledge concerning how supplemental nutrients interact with forage quality and EI TF to affect animal performance. Objective 3: Determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well being and forage utilization efficiencies of forage-animals. Subobjective 3.A: Determine the effect of clover phenolic compounds on cellulolytic and amylolytic bacteria. Subobjective 3.B: Determine whether amine production in the equine large intestine during carbohydrate overload is a consequence of carbohydrate availability or of decreased large intestinal pH and the interaction between plant carbohydrate concentrations and plant phenolic concentrations on the activity of gastrointestinal microbes. Approach (from AD-416): Forage systems provide low cost feed while mitigating man�s impact on the environment. Currently, the available fundamental biological information for predicting animal performance in response to plant nutrients under varying environmental, genetic, physiological status, and management conditions is limited. Even more problematic is the poor understanding of the effects of plant nutraceuticals and anti-quality factors on nutrient intake, metabolism and assimilation for product, health maintenance, or work by the animal. To increase the sustainability of forage-based enterprises, it is essential that a better understanding be developed of the fundamental biological processes underlying the interactions between the animal, plant, and environment. This is particularly essential for endophyte-infected forages that produce toxicants. This Project Plan, through the development and utilization of cutting-edge technologies and real world testing, proposes to decipher the complex interactions within the animal-plant interface in order to accomplish the following objectives: improve productivity of forage-based animal systems through optimization of legume/grass mixtures and management of nontoxic (novel) and or control of toxic (wild-type) endophyte-infected tall fescue in pasture systems; determine forage nutrient and forage plant secondary metabolite effects on the gut biome to improve the health, well-being and forage utilization efficiencies of forage-animals; determine the fundamental biological processes underlying the interactions between forage animals, plants, and the environment including the epigenetic effects of forage nutrients and secondary metabolites in the forage- animal; and define the toxicokinetics and toxicodynamics of the ergot alkaloids in forage-animals. This report documents the early progress made in meeting objectives of the 2012-2017 Project Plan. Non-toxic endophyte tall fescues were planted to serve as control pastures in evaluating effects of nutrient supplementation on mitigation of fescue toxicosis. A mesenteric and vein bioassay was developed and validated for studying serotonergic and adrenergic receptors. Ergot alkaloid-induced vasoconstriction in steers grazed on seed head suppressed toxic fescue pastures was alleviated in 2 to 3 weeks after they were placed on non-toxic diets, and it was alleviated in those grazed on unsuppressed toxic fescue pastures in 5 to 6 weeks after the steers were placed on non-toxic diets. Goats have been ruminally fistulated and once recovered from the surgeries will be used for in vitro studies that will determine the effect of biochanin A on cellulolytic rumen bacteria. Significant Activities that Support Special Target Populations: Presentation at the 2012 Summit on Bioenergy and Bioproducts on metabolic control of Clostridium thermocellum via selective inhibition and compensatory product information, San Antonio, Texas. Presentation at the Mississippi Grazing Conference on managing around fescue toxicosis. Attended by more than 70 livestock producers. Raymond, Kentucky. Organized a workshop with the Kentucky Cooperative Extension Service on implementing a 300-day grazing season. Attended by more than 60 producers and extension agents. Lawrenceburg, Kentucky. Presentation on implementing a 300-day grazing season at a University of Kentucky Grazing School. Attended by more than 40 livestock producers. Princeton, Kentucky. Accomplishments 01 Evaluation of a ruminally dosed tall fescue seed extract as a model for fescue toxicosis. Consumption of endophyte infected fescue results in reduced feed intake and subsequent animal performance. Little is understood in regards to how the toxins impact animal nutrient digestion and metabolism independent of these changes in feed intake because the toxins are typically a component of grazed forage. A steer model of fescue toxicosis was developed and validated whereby the toxins are dosed ruminally and feed intake is controlled. This model will provide a means to study the impact of fescue toxicosis on animal nutrient digestion and metabolism and hereby increase our understanding of this phenomenon. 02 Rapid determination of fasting heat production and respiratory quotient in Holstein steers using the washed rumen technique. Consumption of endophyte infected fescue results in reduced feed intake and subsequent animal performance. Little is understood in regards to how the toxins impact animal nutrient digestion and metabolism independent of these changes in feed intake because the toxins are typically a component of grazed forage. A steer model was developed and validated for rapidly determining fasting metabolism. This model will provide a means to determine fasting metabolism in steers experiencing fescue toxicosis because the toxins are added in a known quantity to the rumen using our seed extract. This model will be useful for other areas as it is an improved means of estimating energy requirements. 03 Alteration of fasting heat production during fescue toxicosis. Consumption of endophyte infected fescue results in reduced feed intake and subsequent animal performance. Little is understood in regards to how the toxins impact animal nutrient digestion and metabolism independent of these changes in feed intake because the toxins are typically a component of grazed forage. Determined the fasting metabolism of steers that were ruminally dosed with ergot alkaloids. This experiment determined that steers experiencing fescue toxicosis have a reduction in basal metabolic rate. 04 Ergot alkaloids from endophyte-infected tall fescue decrease reticuloruminal epithelial blood flow and volatile fatty acid absorption. Consumption of endophyte infected fescue results in reduced feed intake and subsequent animal performance. Little is understood in regards to how the toxins impact animal nutrient digestion and metabolism independent of these changes in feed intake because the toxins are typically a component of grazed forage. A previously developed model of fescue toxicosis was used to determine that the presence of fescue toxins reduces rumen epithelial blood flow and volatile fatty acid absorption. These effects can contribute to the reduced growth rates when animals consume toxic fescue. 05 Timing of chemical application to suppress seed head emergence of tall fescue. Treatment of toxic endophyte-infected tall fescue with Chaparral herbicide can suppress emergence of toxic seed heads to enhance cattle performance and mitigate fescue toxicosis, but the time of year to apply the chemical for optimum suppression is not known. It was determined from a small-plot experiment that maximum suppression occurs when tall fescue is treated in the late-spring when seed emergence is initiated rather than in early spring or late fall. Plant losses were observed with late fall and early spring, but not with the late-spring application. These results provide a recommendation for maximizing the suppression of tall fescue seed heads and the benefits to animal performance and well being.
Impacts
(N/A)
Publications
- Taghavi-Nezhad, M., Alipoura, D., Flythe, M.D., Zamani, P. 2013. The effect of essential oils of Zataria multiflora and Mentha spicata on the in vitro rumen fermentation, and growth and deaminative activity of amino acid-fermenting bacteria isolated from Mehraban sheep. Small Ruminant Research. 81(2):178-181.
- Harlow, B.E., Lawrence, L.M., Flythe, M.D. 2013. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge. Veterinary Microbiology. 166:225-232.
- Johnson, J.M., Aiken, G.E., Phillips, T.D., Barrett, M., Klotz, J.L., Schrick, F.N. 2012. Steer and pasture responses for a novel endophyte tall fescue developed for the upper transition zone. Journal of Animal Science. 90:2402-2409.
- Kirch, B.H., Moser, L.E., Waller, S.S., Klopfenstein, T.J., Klotz, J.L. 2011. Protein degradation of smooth bromegrass switchgrass and big bluestem in grazing cattle. The Professional Animal Scientist. 27:422-427.
- Klotz, J.L., Brown, K.R., Xue, Y., Matthews, J.C., Boling, J.A., Burris, W. R., Bush, L.P., Strickland, J.R. 2012. Alterations in serotonin receptor- induced contractility of bovine lateral saphenous vein in cattle grazing endophyte-infected tall fescue. Journal of Animal Science. 90:682-693.
- Aiken, G.E., Tabler, S.F., Looper, M.L., Brauer, D.K., Strickland, J.R., Shrick, F.N. 2006. Influence of stocking rate and steroidal implants on growth rate of steers grazing toxic tall fescue and subsequent physiological responses. Journal of Animal Science. 84:1626-1632.
- Earing, J.R., During, A.C., Gellin, G.L., Lawrence, L.M., Flythe, M.D. 2012. Bacterial colonization of the equine gut; comparison of mare and foal pairs by PCR-DGGE. Journal of Applied Microbiology. 2:79-86.
- Koontz, A.F., Bush, L.P., Klotz, J.L., Mcleod, K.R., Schrick, F.N., Harmon, D.L. 2012. Evaluation of a ruminally dosed tall fescue seed extract as a model for fescue toxicosis in steers. Journal of Animal Science. 90:914- 921.
|
|