Progress 07/01/09 to 06/30/14
Outputs
Target Audience: Target Audience Researchers, scientists, veterinarians, dairymen, and ranchers Changes/Problems: Changes/Problems We were unable to complete as much work on the chemical forms of selenium in different plant as we had desired. This proved to be a much longer process in the development of the methodology than had been anticipated. What opportunities for training and professional development has the project provided? Opportunities Work product from this overall project has been used to assist in the training of graduate students, as well as used in numerous conferences, veterinary training meetings, and livestock producer meetings. How have the results been disseminated to communities of interest? Dissemination The reproductive study will allow collection of data that can be utilized for the advisement of use or non-use of seleniferous forages in breeding animals. We will also be able to add to the literature regarding reproductive effects of excess selenium. Utilization of the information from the study could result in significant financial benefit to ranchers in seleniferous areas. Inclusion of the long term high selenium group will allow for the evaluation of potential adaptation effects. The dietary intake studies would indicate that naive animals introduced into an environment with seleniferous forages would be at higher risk of acute poisoning that adapted animals. Thus, ranchers should be advised to limit the exposures of naïve animals to limit risks of poisoning. The rayless goldenrod study in horses would suggest that poisoning may be cumulative and lower doses of longer duration are also toxic. Also, the serum indicator cardiac troponin I may be a useful indicator of toxic exposure. Data generated from this study can be used to advise ranchers in areas with rayless goldenrod on the toxic potential , clinical effects, and monitoring of potentially poisoned horses. To ensure wide dissemination of the research data from the studies, results are published in peer reviewed journals. This PI uses data from these studies in numerous presentations to producer groups and veterinarians each year. These presentations often cover elements of mineral excesses and deficiencies and their effects on livestock health and agricultural productivity. IN 2013, the PI did 12 such meetings. At these meetings, the PI takes advantage of questions regarding poisonous plants to provide data from those studies. Research conducted for this project has resulted in data presented in numerous peer reviewed scientific publications. Toxic effects and kinetics of selenium - 5; and toxicity of plants - 5 The data has also been included in seven proceedings publications and five book chapters. And, data from these studies have been used in over 50 invited speaking engagements from 2009-2014, primarily for veterinarians and livestock producers. Most of these meetings are addressing the clinical effects and diagnoses of mineral excesses and deficiencies. What do you plan to do during the next reporting period to accomplish the goals? Plan of Work For the goals and objectives of to identify potentially toxic plants for which data is lacking on toxicity, and delineating the toxicity, toxic effects, and kinetics of different chemical forms of selenium, the following plan of continued work will be followed. 1. Prepare and submit the paper for the comparative toxicokinetics of DL-selenomethioning and L-selenomethionine. 2. Complete the analysis of the hormones from the sheep reproductive studies. 3. Prepare and submit the paper from the sheep reproductive studies. 4. Investigate the potential of doing studies on the reproductive effects at selenium intakes from 1ppm to 10 ppm in sheep. I plan to develop another projects that will allow the furthering of the studies on selenium and toxic plants that have been accomplished to date.
Impacts
What was accomplished under these goals?
Accomplishments For the goals and objectives of identify potentially toxic plants for which data is lacking on toxicity, as well as delineating the toxicity, and toxic effects chemical forms of selenium, the following accomplishments were achieved. Thirty-six ewes were divided into treatment groups that were fed pellets formulated with selenium (Se) contaminated aster during the 2012-2013 breeding-lambing season. Dosing groups included 0, 10, 20, 30 ppm selenium. The 30 ppm group had been fed this concentration of selenium pellets for 1 full year, while the others were started on their respective diets just prior to breeding. Reproductive parameters are being monitored, including breeding efficiency, and reproductive hormones, as well as tissue selenium concentrations and rumen microflora shifts. Additional data to be collected includes lambing rates and ewe/lamb health. Concentrations of 10 ppm and greater had adverse effects on breeding efficiency and lambing rates. Long term exposure had no protective (acclimation) effect on the adverse reproductive effects. Liver selenium concentrations identified have been associated with acute poisoning, although lethality was not observed. The study was a partial replication of the one during the 2011-2012, which verify the adverse effects. Reproductive hormone analyses and rumen microbial analyses for the two studies are still being performed. We investigated the effects of selenium concentrations for both fresh forage and in pellets on the intake/avoidance in both cattle and sheep. The selenium content of fresh forage had no effect on initial consumption by cattle or sheep, but higher concentration forages were decreased on subsequent exposures. With Se pellets, initial responses were variable, but the results indicate that cattle and sheep adjusted their intake over time to avoid excessive intake of Se. These results would indicate that upon initial exposure, cattle and sheep would be more susceptible to selenium poisoning, but with adequate alternative forage types, animals may limit high forage selenium intake and limit poisoning potential. Elk fed similar pelleted rations with increasing concentrations of selenium had poor intake of all high selenium pellets. Neither dose response data nor controlled toxicology studies for benzofuran ketones were available for horses. Horses were fed increasing amounts of rayless goldenrod to obtain doses of approximately 0, 10, 30, and 60 mg benzofuran ketones /kg BW for 14 days. At 60 mg/kg toxic effects were observed by 7 days. Toxic effects included exercise intolerance, increased serum enzymes indicative of muscle damage, increased cardiac Troponin I (indicative of heart muscle damage, and cardiac abnormalities. Lesions consisted of myocardial necrosis, with much lesser skeletal muscle necrosis. The 30 mg/kg treatment had similar but less severe lesions. Goal and objective 1:identify and study potentially toxic plants for which data is lacking on toxicity. 1) Major activities completed - Research on the toxicity and toxic effects of rayless goldenrod in goats and horses has been completed, as well as research on the effects of diet conditioning on the kinetics of pine needle abortion agents. 2) Specific objectives met - We investigated the toxicity and toxic effects of Rayless Goldenrod's benzofuran ketones, for which little published data was available. We also, evaluated conditioning (prior exposure) on the kinetics of ponderosa pine abortion agents. 3) Significant results - In goats, all dosed concentrations of benzofuran ketones greater than 10 mg/kg/day was myotoxic and greater than 20 mg/kg/day was cardiotoxic. In comparison, hoses dosed at 10 mg/kg/day developed no lesions or clinical signs while doses of 30 or greater were poisoned. These stidies were the first time known doses of benzofuran ketone were used in toxicity models. It was also found that plant populations differed significantly in the benzofuran ketone concentrations and types. For the ponderosa pine studies, it was found that rumen adaptation occurs with exposure that results in much faster breakdown of the abortion inducing compounds. 4) Key impacts - Both goats and horses are susceptible to myotoxicity from benzofuran ketones and can be poisoned with sub-acute exposers of 10 and 30 mg/kg/day, respectively. Naïve cattle metabolize abortion agents in pine needles slower that conditioned cattle, rendering naïve cattle more susceptible to abortions. Goal and objective 2: determine chemical speciation of the forms of selenium for differing plant types. 1) Major activities completed - We set up the equipment and initiated the development of methodologies for HPLC-ICPMS determination of the chemical species of selenium. 2) Specific objectives met - We investigated the chemical forms of selenium in mountain aster, a selenium accumulating plant. 3) Significant results achieved - In mountain aster, a selenium accumulating plant, we found that the most abundant chemical form of selenium was as selenate, with much lesser amounts of methyl-selenocysteine, selenomethionine, and selenite. 4) Key impacts - Our findings of predominantly selenate is new, as prior knowledge had suggested that accumulator plants have primarily organic selenium. This finding is important in that different chemical forms pose different toxic potential to ingesting livestock. Goal and objective 3: identify interactive effects of some toxic plants on physiologic mineral balance. 1) Major activities completed - We have measured hepatic mineral concentrations in studies looking at ponderosa pine, and benzofuran ketone containing plants. 2) Specific objectives met - We investigated the effects of plant toxins on mineral balance. 3) Significant results - We found no effects on liver mineral balance for these plants. 4) Key impacts - We can say that neither of these plant types have any direct effect on liver mineral balance in ruminants. Goal and objective 4: delineate the toxicity, toxic effects, and kinetics of different chemical forms of selenium. 1) Major activities completed - We have completed the kinetic analyses of selenium in the chemical forms of selenite, selenate, methyl-selenocysteine, and selenomethionine. We have also completed studies on the effects of selenium concentrations on diet selection in ruminants. And, we have completed studies on the effects of selenium from mountain aster on the reproduction in sheep. 2) Specific objectives met - We have delineate the toxicity, toxic effects, and kinetics of different chemical forms of selenium. 3) Significant results achieved - We have shown that the chemical form of selenium significantly impacts the toxicity and kinetics. We have also proven that mountain aster containing selenium at concentrations of 10 ppm or greater is embryo/neotoxic. And, we found that at high selenium content, ruminants will select away from the higher selenium materials 4) Key impacts - We have, for the first time, published data on the whole body and respiratory elimination kinetics of selenium in sheep, as well as whole body elimination in cattle. We have also characterized the differences in toxicity and lesions for different chemical forms of selenium in sheep.
Publications
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? The reproductive study will allow collection of data that can be utilized for the advisement of use or non-use of seleniferous forages in breeding animals. We will also be able to add to the literature regarding reproductive effects of excess selenium. Utilization of the information from the study could result in significant financial benefit to ranchers in seleniferous areas. Inclusion of the long term high selenium group will allow for the evaluation of potential adaptation effects. The dietary intake studies would indicate that naive animals introduced into an environment with seleniferous forages would be at higher risk of acute poisoning that adapted animals. Thus, ranchers should be advised to limit the exposures of naïve animals to limit risks of poisoning. The rayless goldenrod study in horses would suggest that poisoning may be cumulative and lower doses of longer duration are also toxic. Also, the serum indicator cardiac troponin I may be a useful indicator of toxic exposure. Data generated from this study can be used to advise ranchers in areas with rayless goldenrod on the toxic potential, clinical effects, and monitoring of potentially poisoned horses. To ensure wide dissemination of the research data from the studies, results are published in peer reviewed journals. This PI uses data from these studies in numerous presentations to producer groups and veterinarians each year. These presentations often cover elements of mineral excesses and deficiencies and their effects on livestock health and agricultural productivity. IN 2013, the PI did 12 such meetings. At these meetings, the PI takes advantage of questions regarding poisonous plants to provide data from those studies. What do you plan to do during the next reporting period to accomplish the goals? For the goals and objectives of to identify potentially toxic plants for which data is lacking on toxicity, and delineating the toxicity, toxic effects, and kinetics of different chemical forms of selenium, the following plan of continued work will be followed. 1. Prepare and submit the paper for the comparative toxicokinetics of DL-selenomethioning and L-selenomethionine. 2. Complete the analysis of the hormones from the sheep reproductive studies. 3. Prepare and submit the paper from the sheep reproductive studies. 4. Investigate the potential of doing studies on the reproductive effects at selenium intakes from 1ppm to 10 ppm in sheep.
Impacts
What was accomplished under these goals?
For the goals and objectives of identify potentially toxic plants for which data is lacking on toxicity, as well as delineating the toxicity, and toxic effects chemical forms of selenium, the following accomplishments were achieved. Thirty-six ewes were divided into treatment groups that were fed pellets formulated with selenium (Se) contaminated aster during the 2012-2013 breeding-lambing season. Dosing groups included 0, 10, 20, 30 ppm selenium. The 30 ppm group had been fed this concentration of selenium pellets for 1 full year, while the others were started on their respective diets just prior to breeding. Reproductive parameters are being monitored, including breeding efficiency, and reproductive hormones, as well as tissue selenium concentrations and rumen microflora shifts. Additional data to be collected includes lambing rates and ewe/lamb health. Concentrations of 10 ppm and greater had adverse effects on breeding efficiency and lambing rates. Long term exposure had no protective (acclimation) effect on the adverse reproductive effects. Liver selenium concentrations identified have been associated with acute poisoning, although lethality was not observed. The study was a partial replication of the one during the 2011-2012, which verify the adverse effects. Reproductive hormone analyses and rumen microbial analyses for the two studies are still being performed. We investigated the effects of selenium concentrations for both fresh forage and in pellets on the intake/avoidance in both cattle and sheep. The selenium content of fresh forage had no effect on initial consumption by cattle or sheep, but higher concentration forages were decreased on subsequent exposures. With Se pellets, initial responses were variable, but the results indicate that cattle and sheep adjusted their intake over time to avoid excessive intake of Se. These results would indicate that upon initial exposure, cattle and sheep would be more susceptible to selenium poisoning, but with adequate alternative forage types, animals may limit high forage selenium intake and limit poisoning potential. Elk fed similar pelleted rations with increasing concentrations of selenium had poor intake of all high selenium pellets. Neither dose response data nor controlled toxicology studies for benzofuran ketones were available for horses. Horses were fed increasing amounts of rayless goldenrod to obtain doses of approximately 0, 10, 30, and 60 mg benzofuran ketones /kg BW for 14 days. At 60 mg/kg toxic effects were observed by 7 days. Toxic effects included exercise intolerance, increased serum enzymes indicative of muscle damage, increased cardiac Troponin I (indicative of heart muscle damage, and cardiac abnormalities. Lesions consisted of myocardial necrosis, with much lesser skeletal muscle necrosis. The 30 mg/kg treatment had similar but less severe lesions.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: "Forty-four ewes were divided into treatment groups that were fed pellets formulated with selenium contaminated aster during the 2011-2012 breeding-lambing season. Dosing groups included 0, 10, 20, 30, 45, 60, and 75 ppm selenium, as well as a group that was stepped-up through the concentrations across time. Reproductive parameters are being monitored, including breeding efficiency, and reproductive hormones, as well as tissue selenium concentrations and rumen microflora shifts. Additional data to be collected includes lambing rates and ewe/lamb health. Concentrations of 10 ppm and greater had adverse effects on breeding efficiency and lambing rates. Liver selenium concentrations increased in each treatment group to concentrations that would be associated with acute poisoning, although lethality was not observed. Dietary intake was adversely impacted for dietary concentrations of 45, 60, and 70 ppm, with near complete feed refusal at 75 ppm selenium pellets. The study is being partially replicated during the 2012-2013 breeding-lambing season, at the lower feed selenium concentrations, to verify the adverse effects. This replicate study will also have one group from the previous study that was continuously fed high selenium for the entire year. Reproductive hormone analyses and rumen microbial analyses for the 2011-2012 study are still being performed. We investigated whether cattle conditioned to pine needles metabolize isocupressic acid (ICA), and its metabolites, faster than naive cattle. Agathic acid (AGA) was readily detected in the serum of naive cattle fed ponderosa pine needles, whereas very little AGA was detected in the serum of cattle conditioned to pine needles. We also compared the metabolism of ICA in vitro using rumen cultures from pine-needle-conditioned and naive cattle. In the rumen cultures from conditioned cattle, AGA concentrations were dramatically less than rumen cultures from naive cattle. Thus, an adaptation occurs in cattle conditioned to pine needles such that the metabolism AGA by the rumen microflora is altered." PARTICIPANTS: USDA, Poisonous Plant Research Laboratory TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, other livestock owners, veterinarians, and diagnosticians. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
"The reproductive study will allow collection of data that can be utilized for the advisement of use or non-use of seleniferous forages in breeding sheep. We will also be able to add to the literature regarding reproductive effects of excess selenium. Utilization of the information from the study could result in significant financial benefit to ranchers in seleniferous areas. Inclusion of the long term high selenium group will allow for the evaluation of potential adaptation effects. The findings in the metabolism study of ICA warrant the further investigation of abortion effects in conditioned and naive cattle. Conditioning prior to breeding could prevent later abortions and allow safer use of grazing lands that have been associated with pine needle abortions."
Publications
- Hall, J. O., 2012. Iron, In Michael Peterson and Patricia Talcott (Ed.), Small Animal Toxicology, 3rd edition. W.B. Saunders Company, p. 589-594. (Published).
- Hall, J. O., 2012. Lily Poisoning, In Michael Peterson and Patricia Talcott (Ed.), Small Animal Toxicology, 3rd edition. W.B. Saunders Company, p. 617-620. (Published).
- Hall, J. O., 2012. Iron, In Michael Peterson and Patricia Talcott (Ed.), Small Animal Toxicology, 3rd edition. W.B. Saunders Company, p. 595-600. (Published).
- Welch, K. D., Gardener, D. R., Pfister, J. A., Panter, K. E., Zieglar, J., & Hall, J. O., (2012). A comparison of the metabolism of the abortifacient compounds from Ponderosa pine needles in conditioned versus naive cattle: J Anim Sci, 90(12): 4611-4617. (Published).
- Hall, J. O., 2012. Sulfur, In R Gupta (Ed.), Veterinary Toxicology, 2nd edition. Elsevier Publishing, p. 562-566. (Published).
- Hall, J. O., 2012. Molybdenum, In R Gupta (Ed.), Veterinary Toxicology, 2nd edition. Elsevier Publishing, p. 544-548. (Published).
- Hall, J. O., 2012. Selenium, In R Gupta (Ed.), Veterinary Toxicology, 2nd edition. Elsevier Publishing, p. 549-557. (Published).
- Davis, Z., Stegelmeier, B. L., Panter, K. E., Cook, D., Gardner, D. R., & Hall, J. O., (2012). Toxicokinetics and pathology of plant-associated acute selenium toxicosis in steers: J. Vet. Diag. Invest., 24: 319-327. (Published).
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: We monitored cattle grazing on selenium contaminated mine sites and cohort animals grazed on a similar, but non-selenium contaminated site. Due to heavy precipitation in the test sites, the cattle on the selenium contaminated site did not graze on the more contaminated areas. Higher blood, serum, and liver selenium concentrations were obtained from the cattle on the contaminated site, but adverse concentrations were not identified. Fourty-four ewes were divided into treatment groups that were fed pellets formulated with selenium contaminated aster. Dosing groups included 0, 10, 20, 30, 45, 60, and 75 ppm selenium, as well as a group that are being stepped-up through the concentrations acrost time. Reproductive parameters are being monitored, including breeding efficiency, and reproductive hormones, as well as tissue selenium concentrations and rumen microflora shifts. Additional data to be collected includes lambing rates and ewe/lamb health. PARTICIPANTS: USDA, Poisonous Plant Research Laboratory TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, other livestock owners, veterinarians, and diagnosticians. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The reproductive study will allow collection of data that can be utilized for the advisement of use or non-use of seleniferous forages by breeding sheep. We will also be able to add to the literature regarding reproductive effects of excess selenium. Utilization of the information from the study could result in significant financial benifit to ranchers in seleniferous areas.
Publications
- UTAO+0415 D., S., G., W., P., & Hall, J. O., 2011. Poisoning by Plants, Mycotoxins, and Related Toxins, In Riet-Correa F, Pfister J, Schils AL, and Wierenga T. (Ed.), Acute toxicity of selenium compounds commonly found in selenium accumulator plants. CAB International, Cambridge, MA, p. 525-531. (Published).
- UTAO+0415 Hall, J. O., & D. T., 2011. Reproductive and Developmental Toxicology Selenium. p. 462-467. (Published).
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Fifteen goats were gavaged with rayless goldenrod to obtain benzofuran ketone doses of 0, 10, 20, 40, and 60 mg/kg/day. After 7 treatment days, the goats were euthanized and necropsied. After 5 or 6 days, the higher dosed animals were reluctant to move, stood with an erect stance, and became exercise intolerant. They had increased serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and creatinine kinase activities. All treated animals developed skeletal myopathy with dose-related severity. Goats dosed with 20 mg/kg and higher also developed myocardial degeneration and necrosis. Four lambs each were dosed with 2 or 4 mg/kg of either DL-selenomethionine or L-selenomethionine and monitored via repeated serum and whole blood samplings for selenium content determination. No differences in toxicosis were identified between the two isomeric forms, contradictory to previosly published differences in biological activity of the mixture vs single isomer. Serum, whole blood, and tissue quantification of selenium are to be determined in 2011. PARTICIPANTS: USDA, Poisonous Plant Research Laboratory TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, other livestock owners, veterinarians, and diagnosticians. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The rayless goldenrod study provides data that will be effectively utilized by farmers and ranchers, as well as veterinarians and diagnosticians in the evaluation of clinical disease in goats. As species can vary significantly in susceptibility, this information is important in the evaluation of toxic plant susceptibility. This indicates that goats are highly susceptible to rayless goldenrod poisoning and that characteristic lesions are skeletal and cardiac myonecrosis. The selenium study further verifies that a mineral's chemical form must be individually investigated to determine whether it affects the systemic uptake, kenetics, and its potential toxicity. This is important in determining toxic potential, utility for nutritional balance, and interpreting tissue concentrations with respect to deficient, adequate, or toxic amounts.
Publications
- Hall, J. O., 2010. The Merck Veterinary Manual, 10th edition Selenium Toxicosis. Merck & Co., Inc., Whitehouse Station, NJ, p. 2665-2668.
- Hall, J. O., ZoBell, D. (2010). Common Vitamin and Mineral Deficiencies in Utah. Utah Extension 1-5.
- Stegelmeier, B. L., Davis, T. Z., Green, B. T., Lee, S. T., & Hall, J. O., (2010). Experimental Rayless Goldenrod (Isocoma pluriflors) Toxicosis in Goats: J. Vet. Diagn. Invest., 22(4): 570-577.
- Hall, J. O. 2010. Common Vitamin and Mineral Deficiencies in the AZ Strip and So. Utah. Proceedings of the 32nd Annual Arizona Strip Range Livestock Workshop and Tour.
- Pfister, J. A., Gardner, D. R., Cheney, C. C., Panter, K. E., & Hall, J. O., (2010). The capability of several toxic plants to condition taste aversions in sheep: Small Ruminant Res., 90(1): 114-119.
- Dziba, L. D., Provenza, F. D., & Hall, J. O., (2010). Responses of Lambs to Camphor Highlight Opportunities for Management of Savannas: Options Mediterraneennes Series A, 85: 191-196.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Sheep were randomly assigned to groups and dosed with selenium (Se) as sodium selenate or methylselenocysteine by oral gavage. Selenium was dosed at 0, 1, 2, 3, 4, or 6 Se/kg BW to 4 animals per treatment group. Significant differences in clinical disease phenotype occurred between the different chemical forms. Serum and whole blood selenium concentrations across time were significantly different among all of the doses. In addition, tissue concentrations at 7 days post-dose were dose dependent and differed significantly between the chemical forms. The elimination kinetics were dose dependent, but differed between the methylselenocysteine and the sodium selenate. Terminal elimination was more prolonged in the selenate treatment group than the methylselenocysteine treatments . In another project, sheep were dosed with 6 mg Se/kg BW with Sodium selenate, sodium selenite, selenomethionine, and methylselenocysteine. These sheep had respired air collected at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, and 8 hours post dosing. The respired selenium content was treatment dependent, with methylselenocysteine having significantly greater selenium content in the respired air than any other treatment. Selenomethionine also was significantly greater than the selenite or selenate. A third experiment utilized steers from a group that were naturally poisoned with selenium at a contaminated, reclaimed mine site. Ten steers with the highest blood content were procured and monitored across time as to serum, whole blood, liver, and skeletal muscle selenium content. The whole blood returned to normal content the fastest. Serum and liver paralleled, in that both returned to normal in individual animals at the same time. By 5 months, two steers had deficient selenium content in both serum and liver samples. But, by 5 months, none of the steers had returned to normal skeletal muscle content (all were still slightly greater than the expected normal range for bovine skeletal muscle). PARTICIPANTS: USDA, Poisonous Plant Research Laboratory TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, and other livestock owners. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
These studies verify that a mineral's chemical form significantly affects its systemic uptake, kenetics, and its potential toxicity. In addition, the forms of selenium, organic vs. inorganic, dramatically affect the elimination kinetics and tissue concentrations. This is important in determining toxic potential, utility for nutritional balance, and interpreting tissue concentrations with respect to deficient, adequate, or toxic. These findings will allow better education of farmers, ranchers, and dairy owners as to the potential effects. Two referreed publications were published in 2009. One publication was an invited review article on the appropriate methods of diagnosing poisonous plant problems in livestock. This publication serves to educate individuals on appropriately diagnosing plant poisonings. It provides resource information to contact for additional help, tables of essential information to gather, and tables of samples and procedures that are essential in the diagnosis of poisonous plants. As field personnel often miss needed samples or fail to gather needed history and information, this article serves as an essential guide for persons that are or will investigate cases that may involve poisonous plants. The second article involved evaluation of waterfowl mineral concentrations across time as an indication of heavy metal accumulation from the Great Salt Lake and its associated waterways. This article serves to educate individuals on the high concentations of selenium and mercury that can accumulate in wildlife from this environment. In fact, data from this work was essential in the hunter advisories issues by Utah Fish and Game for potentially harmful concentrations of mercury in Golden Eye and Northern Shovelers during 2004-2006. Concentrations of both mercury and selenium increased across the wintering months on the Great Salt Lake for Green Winged Teal, Golden Eye and Northern Shovelers. This also serves to warn of possible livestock and wildlife exposure to similar heavy metals when pastured in close proximity to the same environments.
Publications
- Vest JL, Conover MR, Perschon C, Luft J, and Hall JO 2009. Trace Element Concentrations in Wintering Waterfowl from the Great Salt Lake, Utah. Arch. Environ. Contam. Toxicol. 56(2)::302-316.
- Stegelmeier BL, Green BT, Panter KP, Welch KD, and Hall JO 2009. Identifying Plant Poisoning in Livestock. Rangelands 31(1):5-9.
- Welch KD, Hall JO, Davis TZ and Aust SD 2007. The Effect of Copper Deficiency on the Formation of Hemosiderin in Sprague-Dawley Rats. Biometals 20(6):829-839.
- Stegelmeier BL, Hall JO, Lee ST, James LF, Gardner DR, Panter KE, Ralphs MH, and Pfister JA 2007. Pheasants Eye (Adonis aestavalis) Toxicity in Livestock and Rodents. In: Poisonous Plants: Global Research and Solutions, 463-467.
- Wilhelm A, Stegelmeier BL, Panter KE, and Hall JO. 2007. Respiratory Elimination of Selenium in Sheep Given the Accumulator Plant Symphyotrichum spathulatum (Western MountainAster). Proceedings of the Western Section of the American Society of Animal Science Annual Meeting, 229-232.
- Hall J, Winger H, Hole P, and Samford R 2007. Investigation of the Bioavailability of Manganese from Organic vs. Inorganic Supplements. Proceedings of the Western Section of the American Society of Animal Science Annual Meeting, 358-363.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Sheep were randomly assigned to groups and dosed with selenium (Se) as sodium selenite, selenomethionine, or plant selenium (Woody Aster) by oral gavage. Treatment groups of 0 and 4 mg/kg BW for sodium selenite and at 0 and 8 mg/kg BW for selenomethionine had 2 animals per group for direct comparison with previous studies. Selenium from the plant material was dosed at 0, 2, 4, 6, and 8 mg Se/kg BW to 6 animals per treatment group. Significant differences in clinical disease phenotype occurred among the different chemical forms. Serum and whole blood selenium concentrations across time were significantly different among all of the plant doses. Histopathologic lesions indicate that the selenium in the woody aster is in a chemical form that causes severe myocardial muscle damage, as compared to significant pulmonary lesions for the selenomethionine dosed sheep. The elimination kinetics were dose dependent for the plant dosed sheep, but differed from both the selenomethionine and the sodium selenite. Terminal elimination was more prolonged in the selenomethionine treatment group, indicating that the plant form may have more inorganic components. PARTICIPANTS: USDA, Poisonous Plant Research Laboratory TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, and other livestock owners. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This study verifies that a mineral's chemical form significantly affects its systemic uptake, kenetics, and its potential toxicity. In addition, the forms of selenium, organic vs. inorganic vs. plant source, dramatically affect the elimination kinetics and tissue concentrations. This is important in determining toxic potential, utility for nutritional balance, and interpreting tissue concentrations with respect to deficient, adequate, or toxic. These findings will allow better education of farmers, ranchers, and dairy owners as to the potential effects. Selenium can be ingested in several chemical forms from natural and man-made sources. Different chemical forms of selenium have unique toxicologic potential. Knowledge of the chemical form is critical for properly evaluating toxic potential, dietary need, adequate body concentrations, and essential for ranchers/nutritionists to achieve optimal livestock health.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Sheep were randomly assigned to groups and dosed with selenium (Se) as sodium selenite, selenomethionine, or plant selenium (Woody Aster) by oral gavage. Treatment groups of 0 and 4 mg/kg BW for sodium selenite and at 0 and 8 mg/kg BW for selenomethionine had 2 animals per group for direct comparison with previous studies. Selenium from the plant material was dosed at 0, 2, 4, 6, and 8 mg Se/kg BW to 6 animals per treatment group. Significant differences in tissue concentrations were observed at equal selenium doses among chemical forms. Serum and whole blood selenium concentrations across time were significantly different among all of the plant doses. Histopathologic lesions indicate that the selenium in the woody aster is in a chemical form that causes severe myocardial muscle damage, as compared to significant pulmonary lesions for the selenomethionine dosed sheep. The respiratory elimination kinetics was dose dependent for the plant dosed sheep, but elimination kinetics
had significantly different curve characteristics at the higher doses than at the lower doses and differed from both the selenomethionine and the sodium selenite. Further evaluation of the kenetics is ongoing.
PARTICIPANTS: USDA, Poisonous Plant Research Laboratory
TARGET AUDIENCES: Ranchers, dairy owners, nutritionists, and other livestock owners.
Impacts
This study verifies that a mineral's chemical form significantly affects both its systemic uptake and its potential toxicity. In addition, the forms of selenium, organic vs. inorganic vs. plant source, dramatically affect the respiratory kinetics and tissue concentrations. This is important in determining toxic potential, utility for nutritional balance, and interpreting tissue concentrations with respect to deficient, adequate, or toxic. These findings will allow better education of farmers, ranchers, and dairy owners as to the potential effects. Selenium can be ingested in several chemical forms from natural and man-made sources. Different chemical forms of selenium have unique toxicologic potential. Knowledge of the chemical form is critical for properly evaluating toxic potential, dietary need, adequate body concentrations, and essential for Livestock owners/nutritionists to achieve optimal livestock health.
Publications
- Stegelmeier BL, Hall JO, Lee ST, James LF, Gardner DR, Panter KE, Ralphs MH, and Pfister JA 2007. Pheasants Eye (Adonis aestavalis) Toxicity in Livestock and Rodents. In: Poisonous Plants: Global Research and Solutions, pp. 463-467.
- Wilhelm A, Stegelmeier BL, Panter KE, and Hall JO. 2007. Respiratory Elimination of Selenium in Sheep Given the Accumulator Plant Symphyotrichum spathulatum (Western MountainAster). Proceedings of the Western Section of the American Society of Animal Science Annual Meeting, 229-232.
- Hall J, Winger H, Hole P, and Samford R 2007. Investigation of the Bioavailability of Manganese from Organic vs. Inorganic Supplements. Proceedings of the Western Section of the American Society of Animal Science Annual Meeting, 358-363.
- Tiwary AK, Stegelmeier BL, Panter KE, James LF, and Hall JO. 2006. Comparative toxicosis of sodium selenite and selenomethionine in lambs. J. Vet. Diag. Invest. 18:60-69.
- Dziba LE, Hall JO, and Provenza FD 2006. Feeding behavior of lambs in relation to kinetics of 1,8-cineole dosed intravenously and into the rumen. J. Chem. Ecol. 32:391-408.
- Hole PS, Schelvan MB, and Hall JO 2006. Effects of Ferrous Chloride on Suckling Calves and on Microbial Growth and Metabolism Using an In Vitro Rumen Culture System. Proceedings of the Western Section of the American Society of Animal Science 78th Annual Meeting 57:313-317.
- Hole PS, Young AJ, and Hall JO 2006. Correlation Between Water Mineral Content and Production Parameters in Dairy Cattle. Proceedings of the Western Section of the American Society of Animal Science 78th 57:318-321.
- Welch KD, Hall JO, Davis TZ and Aust SD 2007. The Effect of Copper Deficiency on the Formation of Hemosiderin in Sprague-Dawley Rats. Biometals 20(6):829-839.
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Progress 01/01/06 to 12/31/06
Outputs
Forty-five lactating Holsteins were randomly assigned to one of 3 dietary manganese treatments for 8 weeks. Fifteen animals each were provided TMRs with mineral source manganese being 100% inorganic, 50% amino acid chelate/50% inorganic, or 100 % amino acid chelate. Serum, Whole blood, milk and true-cut liver biopsy samples were obtained at 0, 4, and 8 weeks. At 4 and 8 weeks, both amino acid chelate treatment groups had significantly higher serum and milk manganese content than the inorganic treatment group, but the two chelate groups did not differ from each other. Whole blood manganese content did not differ among treatments. Liver manganese content was significantly increased in both amino acid chelate treatment groups at 4 weeks, but not at 8 weeks. In a second study, sheep were randomly assigned to groups and given selenium (Se) as sodium selenite, selenomethionine, or plant selenium (Woody Aster) by oral gavage. Treatment groups of 0 and 4 mg/kg BW for sodium
selenite and at 0 and 8 mg/kg BW for selenomethionine had 2 animals per group for direct comparison with previous studies. Selenium from the plant material was dosed at 0, 2, 4, 6, and 8 mg Se/kg BW to 6 animals per treatment group. Sodium selenite at 4 mg/kg, as well as selenomethionine at 8 mg/kg resulted in panting and/or respiratory distress following minimal exercise. Sheep dosed with plant selenium developed tachypnea, weakness, incoordination, and recumbency. Sheep receiving plant selenium died at 4 (1 of 6), 6 (5 of 6), and 8 (6 of 6) mg/kg BW. Deaths occurred very quickly after the observation of weakness then recumbency. Post-mortem evaluation revealed bronchopneumonia, pulmonary edema, and red froth in the trachea of the animals dosed with selenomethionine. Sheep dosed with plant selenium did not have significant pulmonary lesions, but had marked hemorrhages in the myocardium.
Impacts
These studies verify that a mineral's chemical form significantly affects both the nutritional potential and the toxicity of minerals. Amino acid chelated manganese was more bioavailable than the inorganic form. In addition, the forms of selenium, organic vs. inorganic vs. plant source, dramatically affect the clinical toxicosis. This is important in determining both toxic potential and utility for nutritional balance. These findings will allow proper education of farmers, ranchers, and dairy owners as to the potential effects. Manganese is a required mineral for optimal health and reproductive performance. Recent data has shown that dairy cattle often do not have optimal tissue manganese content when it is provided in an inorganic form. Providing manganese as an amino acid chelate improves systemic manganese concentrations. These findings will allow proper education of nutritionists and dairy owners as to the potential of manganese chelates. Preventing manganese
deficiency will improve ruminant health and increase both animal health and overall productivity. Selenium can be ingested in several chemical forms from natural and man-made sources. Different chemical forms of selenium have unique toxicologic potential. Knowledge of the chemical form is critical for properly evaluating toxic potential, dietary need, adequate body concentrations, and essential for ranchers/nutritionists to achieve optimal livestock health.
Publications
- Hole PS, Young AJ, and Hall JO. Correlation Between Water Mineral Content and Production Parameters in Dairy Cattle. Proceedings of the Western Section of the American Society of Animal Science 78th Annual Meeting. 57:318-321 , 2006.
- Hole PS, Schelvan MB, and Hall JO. Effects of Ferrous Chloride on Suckling Calves and on Microbial Growth and Metabolism Using an In Vitro Rumen Culture System. Proceedings of the Western Section of the American Society of Animal Science 78th Annual Meeting. 57:313-317, 2006.
- Dziba LE, Hall JO, and Provenza FD. Feeding behavior of lambs in relation to kinetics of 1,8-cineole dosed intravenously and into the rumen. J. Chem. Ecol. 32:391-408, 2006.
- Tiwary AK, Stegelmeier BL, Panter KE, James LF, and Hall JO. Comparative toxicosis of sodium selenite and selenomethionine in lambs. J. Vet. Diag. Invest. 18:60-69, 2006.
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Progress 01/01/05 to 12/31/05
Outputs
Toxicity evaluation of forage Kochia (Kochia prostrata) plant material was initiated on plants collected from 5 sites in three states in the intermountain west, each month from June to October. Nitrate analysis was performed on all samples and verified non-toxic concentrations in all segments of the plants. Sheep dosed orally with sodium selenite or selenomethionine accumulate selenium in body tissues in a dose dependent manor. Tissue concentrations were 2 to 3 times higher for selenomethionine than for sodium selenite treatments at equal selenium doses. Elimination was much more prolonged in the selenomethionine treated animals indicating much more efficient tissue retention. Rumen fluids from Holstein cows were cultured under nitrogen at 39 C for nine hours using corn as the substrate to evaluate the metabolism and replication of rumen microbes in the presence of increasing soluble iron content. Samples were collected for pH measurement and DNA analysis at the
initiation and at three-hour intervals for nine hours. Soluble free iron significantly inhibited microbial replication and metabolism at concentrations of 50 mg/L or more. Dairy water samples were evaluated for mineral content and modeled against production parameters. Nine percent of the dairies samples had at least one mineral that exceeded recommended maximal concentrations for livestock drinking water. Increasing aluminum concentrations had significantly modeled detrimental impacts on three different reproductive parameters, while increasing silica had significantly modeled detrimental impacts on three different production parameters.
Impacts
Forage Kochia (Kochia prostrata) is not a nitrate accumulator, as is annual kochia. Thus, this forage can be a very efficient and safe forage in semi-arid rangelands to increase the productivity of otherwise poorly utilizable lands. Selenium can be ingested in several chemical forms from natural and man-made sources. Different chemical forms of selenium have unique tissue accumulation and long term elimination. Knowledge of the chemical form is critical for properly evaluating dietary need and adequate body concentrations and essential for ranchers/nutritionists to achieve optimal livestock health. Iron in a reduced chemical state, as can occur in subsurface waters, inhibits rumen microbial replication and metabolism. Microbial growth and death are a primary source of digestable protein in ruminants. These findings will allow proper education of nutritionists, ranchers, and dairy owners as to the potential adverse effects of iron. Preventing excessive iron intake will
improve ruminant health and increase both digestive efficiency and overall productivity. Water is a critical component of dairy production, but many dairies still do not adequately evaluate water components. Aluminum and silica appear to be components in water that at increasing concentrations adversely affects reproduction and productivity in dairy cattle, respectively. Better evaluation of dairy water sources and utilization of better water sources will improve animal health and productivity.
Publications
- Tiwary AK, Panter KE, Stegelmeier BL, James LF, and Hall JO. Evaluation of Respiratory Elimination Kinetics of Selenium after Oral Administration in Sheep. Am J Vet Res. 66:1-7, 2005.
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Progress 01/01/04 to 12/31/04
Outputs
Sheep were studied to evaluate the toxic effects of sagebrush (Artemisia tridentate) terpenes on feeding behavior, absorption kinetics, and elimination kinetics. The lambs were randomly assigned to one of 5 treatment groups of 4 animals each. The sheep were dosed by intraruminal bolus dose with one of three terpenes (camphor, 1,8-cineole, p-cymene), control dosing solution, or a cocktail of the three terpenes after overnight fasting to ensure hunger. Preliminary studies found that the sheep would withdraw from eating their normal diet when the terpenes were administered at a rate of 125 mg/kg BW as a bolus dose. Blood samples were periodically taken for future terpene quantification in order to delineate absorption, distribution, and elimination kinetics. No lamb withdrew from eating the diet with the control dosing. Each lamb was dosed with its respective treatment two times, on weeks 1 and 2 in order to evaluate potential metabolic induction or acclimation to the
treatments. Lambs dosed with camphor , 1,8-cineole, p-cymene or the cocktail withdrew from eating their diets significantly faster than control lambs. The treated lambs ingested significantly less food at 30 min, 1 hour, and 2 hours after the bolus dose than did the control lambs. Cage matched lambs fed at the same times as the treatment lambs continued eating their feed until all was eaten. The lambs dosed with 1,8-cineole ate significantly more and longer with the second dosing than with the first dosing. Sheep were randomly assigned to groups and given selenium (Se) as sodium selenite or selenomethionine by oral gavage. Treatment groups of 0, 1, 2, 3 and 4 mg/kg BW for sodium selenite and at 0, 1, 2, 3, 4, 6 and 8 mg/kg BW for selenomethionine had 4 animals per group. Absorption kinetic rates for the two types of selenium were significantly different and decreased with increasing doses of selenomethionine. And, the elimination rates increased with dose for both forms of selenium.
Impacts
Sagebrush, a terpene containing plant, is common in the intermountain west grazing land of sheep that, when grazed, has a limited intake resulting in poor weight gain or weight loss. The dosing studies verify that sagebrush terpenes have adverse effects on dietary intake. Under field conditions, the adverse effects of sagebrush likely plays a role in both feeding behavior and resultant alterations in the biodiversity of plant types in heavily grazed areas. However, adverse effects on feeding behavior are lessened with adaptation to the plant. Thus, appropriate management of sagebrush grazing will result in less adverse effects on the biodiversity and greater positive utility of sagebrush by sheep. Selenium can be ingested in several chemical forms from natural and man-made sources. Past research has grouped all chemical forms of selenium as being similar in animals. The finding that selenium chemical form differs in absorption and elimination kinetics is critical in
properly evaluating dietary need and adequate body concentrations. The data from these studies is essential for ranchers and nutritionists to achieve better livestock health.
Publications
- Mackowiak, C.L., Amacher, M.C., Hall, J.O., and Herring, J.R. 2004. Uptake of Selenium and Other Elements into Plants and Implications for Grazing Animals in Southeast Idaho. In: Life Cycle of the Phosphoria Formation - From Deposition to the Post-Mining Environment by J. R. Hein. Elsevier. pp. 527-555.
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Progress 01/01/03 to 12/31/03
Outputs
Sheep were studied to evaluate the toxic effects of sagebrush (Artemisia tridentate) terpenes on feeding behavior, blood pH, and elimination kinetics. The lambs (32-35kg) were randomly assigned to one of 5 treatment groups of 4 animals each. The sheep were dosed by intravenous infusion with one of three terpenes (camphor, 1,8-cineole, p-cymene), control infusion solution, or a cocktail of the three terpenes after overnight fasting to ensure hunger. Preliminary studies found that the sheep would withdraw from eating their normal diet when the terpenes were administered at a rate of 1 ml/min at a concentration of 2.1 gm/50 ml of intra-lipid infusion solution. Infusions were maintained in each lamb for the time of 1 min/kg body weight, then stopped and blood samples periodically taken for pH measurement and future terpene quantification in order to delineate elimination kinetics. No lamb withdrew from eating the diet with the control infusion. Each lamb was dosed with
its respective treatment three times, on weeks 1, 2, and 4 in order to evaluate potential metabolic induction or acclimation to the treatments. Lambs dosed with camphor withdrew from eating their diet at 22 to 30 minutes for all three treatment periods. Lambs dosed with 1,8-cineole withdrew from eating their diets at 15 to 24 minutes for all three treatment periods. Lambs dosed with p-cymene withdrew from eating their diets at 24 to 30 minutes. Cage matched lambs fed at the same times as the treatment lambs continued eating their feed until all was eaten. Blood pH was measured immediately after collection and found not to differ when compared across time or to the initial pre-dose blood collection. Rumen fluids from Holstein cows were cultured under nitrogen at 39 C for nine hour using corn as the substrate. Three experiments used rumen inoculum from animals on a concentrate based diet were performed. Manganese in the reduced chemical state was added at 0, 1.5, 3, 6, 12, 24, 48, or 96
ppm to each flask, with two replicates per treatment. Samples were collected for pH measurement and DNA analysis at the initiation and at three-hour intervals for nine hours. Manganese inhibited the increases in microbial DNA at greater than 3 ppm. The overall drop in pH was not different among the treatment groups.
Impacts
These studies verify that sagebrush terpenes have adverse effects on dietary intake, which, under field conditions, likely plays a role in feeding habits and potentially weight gain and growth. This could change the intake of other forages in the environment and alter the biodiversity of plant types in heavily grazed areas, leading to areas that are dominated by sagebrush. The finding that manganese in a reduced chemical state, as can occur in subsurface waters, inhibits microbial replication is very important from a standpoint of ruminant nutrition. Microbial growth and death are a primary source of digestable protein in ruminants. These findings will allow proper education of farmers, ranchers, and dairy owners as to the potential effects of sagebrush and manganese in water.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
High iron content fertilizer (6.8%), aerobically biodegraded sewage, was orally administered to 250 gm rats as seven daily doses to determine the bioavailability and toxic potential of the iron and other minerals. Six rats for each treatment group were dosed with 0, 100, 500, 1000, 1500, or 2000 mg/kg/day. The rats were monitored for one day after the last dose, then killed and tissues collected for analyses. Iron was quantified in each of three tissues (liver, small intestine, and kidney). No treatment associated morbidity or mortality was observed. No treatment associated histologic or serum chemistry abnormalities were identified and no difference between treatment groups occurred. The iron was apparently not bioavailable, as there was not differences between treatment groups for serum iron, serum iron binding capacity, or tissue iron content. Sheep were randomly assigned to groups and given selenium (Se) as sodium selenite or selenomethionine by oral gavage.
Treatment groups of 0, 1, 2, 3 and 4 mg/kg BW for sodium selenite and at 0, 1, 2, 3, 4, 6 and 8 mg/kg BW for selenomethionine had 4 animals per group. Sodium selenite at 2, 3, and 4 mg/kg, as well as selenomethionine at 4, 6, and 8 mg/kg resulted in panting and/or respiratory distress following minimal exercise. Severity and time to recovery (2-3 days) were dose dependent. One animal in each of the 6 and 8 mg/kg selenomethionine groups died (at about 24 and 14 hrs, respectively). Deaths occurred very quickly after the observation of weakness then recumbency. Post-mortem evaluation revealed bronchopneumonia and red froth in the trachea of the animals that exhibited clinical effects. Tissue analysis (liver and kidney) revealed a linear, dose-dependent increase in selenium concentrations. However, tissue concentrations of selenomethionine treated animals were significantly greater than that of animals treated with sodium selenite, at equal Se content.
Impacts
These studies verify that a mineral's form significantly affects the toxic potential of the mineral. The iron in the fertilizer is not bioavailable, thus it is much less toxic. This suggests that it is in the form of a insoluble ferric salt. Likewise, the forms of selenium, organic vs. inorganic, dramatically affect the systemic concentrations of the selenium. This is important in determining toxic potential and nutritional balance. These findings will allow proper education of farmers, ranchers, and dairy owners as to the potential effects.
Publications
- Stegelmeier BL, James LF, Hall JO, Mattix MT. Neurologic disease in range goats associated with Oxytropis sericea (Locoweed) poisoning and water deprivation. Vet Hum Toxicol Oct;43(5):302-4, 2001.
- Pfister JA, Gardner, DR, Stegelmeier BL, Knight AP, Waggoner JW jr., and Hall, JO. 2002. Plains larkspur (Delphinium geyeri) grazing by cattle in Wyoming. J Range Management. Volume 55:350-359
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Progress 01/01/01 to 12/31/01
Outputs
Rumen fluid from Holsteins were cultured under nitrogen at 39 C for nine hours using corn as the substrate. Seven experiments used rumen inoculum from animals on forage based diets and four used that from animals on forage based diets and four used that from animals on a concentrate based diet. Iron, in the form of ferrous sulfate, was added at 0, 25, 50, 100, 200, 400 and 800 ppm to each flask, with two replicates per treatment. Samples were collected for pH measurement and DNA analysis at the initiation and at three-hour intervals for nine hours. Ferrous iron significantly inhibited the drop in pH at greater than 50 ppm for cultures from concentrate based diets, while no difference was observed for any iron concentration with cultures from forage based diets. The overall drop in pH was significantly less for cultures from animals on forage vs. concentrate based diets at all iron concentrations and at all time points after the initial sampling. High iron content
fertilizer (6.8%), aerobically biodegraded sewage, was orally administered to 250 gm rats as a single dose to determine the bioavailability and toxic potential of the iron and other minerals. Six rats for each treatment group were dosed with 0, 100, 500, 1000, 1500, or 2000 mg/kg. The rats were monitored for seven days, then killed and tissues collected for analyses. Twenty eight minerals are to be quantified in each of three tissues (liver, small intestine, or kidney). No treatment associated morbidity or mortality was observed. No histologic or serum chemistry abnormalities were identified and no difference between treatment groups occurred. The iron was apparently not bioavailable, as there was no differences between treatment groups for serum iron, serum iron binding capacity, or tissue iron content.
Impacts
These studies verify that a mineral' s form significantly affects the toxic potential of the mineral. The iron concentration in the water in the ferrous form is much more toxic than dietary iron which is in the ferric form. Since water iron content occurs as a soluble ferrous salt, the occurrence of high iron in ruminant water is of great economic impact. The resultant economic loss from high water iron could be in the form of decreased growth, decreased feed efficiency, and decreased milk production. Similarly, the iron content of the fertilizer is apparently not bioavailable, suggesting that it is in the form of a insoluble ferric salt. These findings will allow proper education of farmers, ranchers, and dairy owners as to the potential effects.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
Studies on the adverse effects of high water iron concentration to in vitro rumen cultures and bovine production parameters were continued. Microbial growth and VFA production in rumen cultures was significantly decreased by (equal to or greater than) 400 ppm ferrous iron. Microbial metabolism, as indicated by pH change, was significantly inhibited by ferrous iron at (equal to or greater than) 50 ppm. Calves administered ferrous iron in drinking water through a nipple delivery system at 0, 20, or 40 ppm had no statistically significant difference in water intake, feed intake, or gain; however, there was a numerical trend towards decreases in each of these parameters with the greater effect noted in the higher treatment group. These numerical effects were more pronounced as the calves got older. Both dosage groups of iron treated calves had significant increases in hemoglobin, hematocrit, and red blood cell counts. These findings are suggestive that the adverse effects
of high iron intake in cattle are primarily associated with ruminal effects, but non-ruminal effects may play a lesser role. Studies to characterize any difference in effects between ferrous and ferric iron to in vitro rumen cultures are in progress. Studies are in progress to further characterize the toxicity of Adonis vernalis in a hamster model. Studies to date have demonstrated that this plant is toxic and that the toxicosis is compatible with cardiac glycoside poisoning. Studies are continuing that involve measurement of systemic mineral balance of cattle fed poisonous plants, including Astragalus bisulcata and Pinus ponderosa.
Impacts
Once the concentrations and types of iron that cause adverse effects on production have been better characterized, this element can be more closely monitored to ensure maximum productivity. This should increase the economic gain of dairy and beef ranching operations. Identification of Adonis vernalis as a toxic plant of Utah hay fields allows us to advise and warn farmers regarding this plant.
Publications
- No publications reported this period
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Progress 01/01/99 to 12/31/99
Outputs
Studies on the adverse effects of high water iron concentrations to in vitro rumen cultures and bovine production were continued. By DNA quantitation, 400 and 800 ppm ferrous iron significantly decreases microbial growth. In addition, inhibited microbial metabolism, as indicated by pH change, was produced by ferrous iron concentrations of 50 ppm or greater. Calves administered ferrous iron in drinking water with a nipple watering system at 20 and 40 ppm had decreased feed intake, water intake, and gain; however, since the project is ongoing, the statisticals significance has not been determined. We are investigating the toxicity of Adonis vernalis in a hamster model. Preliminary studies have demonstrated that hamsters are susceptible to the toxic effects of this plant. The clinical effects are compatible with cardiac glycoside poisoning. Dosing studies to further characterize the toxicity are in progress. Studies are in progress that involve measuring systemic mineral
balance of cattle that have been fed poisonous plants. Plants that are currently being evaluated include Astragalus bisulcata and Pinus ponderosa.
Impacts
Once concentrations that cause adverse effects on prodution have been determined, iron can be monitored to ensure that water and dietary iron concentrations will allow maximimum productivity. This could increase economic gains for dairy and ranching operations. We have identified Adonis vernalis as a toxic plant that occurs in Utah hay fields. In doing so, we are now able to advise and caution farmers and ranchers regarding this plant.
Publications
- No publications reported this period
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