Mineral-salt supplementation to ameliorate larkspur poisoning in cattle.

Larkspurs (Delphinium spp.) are native forbs that are poisonous to cattle and cost livestock producers millions of dollars in losses each year. Macro and micro minerals are required for normal functioning of essentially all metabolic processes in ruminants. The role that mineral status may play in larkspur poisoning in cattle is not clear. In this study, we seek to determine the effects a mineral-salt supplement, commonly used by cattle producers, to potentially reduce cattle losses to larkspur. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen study. Animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than the non-supplemented animals. A separate group of animals were then grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption (P > 0.05). However, overall larkspur consumption was low and averaged 3 ± 1.0% and 2 ± 1.1% for cattle supplemented with mineral and non-supplemented, respectively. Serum was collected from animals once a week during the grazing study. Average and maximum serum concentrations of toxic larkspur alkaloids were numerically higher in mineral-salt supplemented cattle compared with the non-supplemented animals. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, were not observed to consume less larkspur than the non-supplemented animals; however, the mineral-salt supplemented animals had higher concentrations of larkspur alkaloids in their serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing these rangelands as the positive effects can be lost within 30 d post supplementation.

Larkspurs (Delphinium spp.) are native forbs poisonous to cattle and cost livestock producers millions of dollars in losses each year. The role mineral status may play in larkspur poisoning in cattle is unclear. The ability of mineral-salt supplementation to alter susceptibility to larkspur toxicosis was evaluated in a pen and grazing study. In the pen study, animals supplemented with mineral-salt were found to be less susceptible to larkspur poisoning than non-supplemented animals. A separate group of animals grazed on larkspur infested rangelands. One group was supplemented with a mineral-salt mix and the other group did not receive any mineral-salt. Supplementing cattle with the mineral-salt mix did not alter larkspur consumption of grazing cattle. However, overall larkspur consumption was low. Results from the pen study suggest that a good mineral supplementation program will provide a protective effect for animals grazing in larkspur-infested ranges. The mineral-salt supplemented steers, in the grazing study, had higher concentrations of larkspur alkaloids in their blood serum indicating they may be able to tolerate higher larkspur consumption. The data also indicate that mineral-salt supplementation must be continuous throughout the time the animals are grazing as the positive effects can be lost within 30 days after supplementation.

Toxicity of the swainsonine-containing plant Ipomoea carnea subsp. fistulosa for goats and sheep.

In order to determine the toxicity of swainsonine present in Ipomoea carnea for goats and sheep, 12 goats and 12 sheep were divided into 3 groups of 4 goats (G1, G2 and G3) and 3 groups of 4 sheep (S4, S5 and S6) each. Groups G1 and S4 were used as controls; G2 and S5 received 1 mg/kg body weight of swainsonine from plant material and G3 and S6 received 3 mg/kg. Groups G2 and G3 presented the first clinical signs, on average, after the 54th and 39th days of ingestion of the plant, respectively. Groups S5 and S6 presented the first clinical signs, on average, on the 64th and 42nd days of the experiment, respectively. In sheep, in addition to having a longer period of ingestion until the onset of clinical signs, these signs were less severe, being evident only after the animals were forced to move. These results demonstrated that goats are more susceptible to swainsonine poisoning than sheep. Complete regression of clinical signs was observed in 5 goats and 6 sheep. However, three goats and one sheep remained with clinical signs until 120 days of the experiment, suggesting that to control the poisoning the animals should be removed from the pastures immediately after the first clinical signs. There were no significant differences in weight between the different groups, suggesting that for goats ingesting the plant, toxic Ipomoea species can be used as forage for intermittent periods of 15-30 days.

Analysis of rumen contents and ocular fluid for toxic alkaloids from goats and cows dosed larkspur (Delphinium barbeyi), lupine (Lupinus leucophyllus), and death camas (Zigadenus paniculatus).

Larkspurs, lupines, and death camas can be acutely toxic to livestock and are serious poisonous plant problems in western North America. The toxicity of these plants depends on the composition and concentrations of the toxic alkaloids in the plants. In this study, goats and cows were dosed sub-lethal doses of larkspur, lupine, and death camas. Rumen contents and ocular fluid samples were collected, and simple extraction, sample preparation, and analytical methods were developed for the detection of toxic alkaloids in the rumen contents and ocular fluid samples. Toxic alkaloids were detected in the rumen contents and ocular fluid samples from the goats and cows dosed larkspur, lupine, and death camas. In addition, results from a case report where rumen contents were analyzed from a steer that was suspected to have died due to larkspur are reported. This demonstrates the utility of the methods described for the diagnosis of acute plant poisonings.

Clinical and pathological comparison of Astragalus lentiginosus and Ipomoea carnea poisoning in goats.

The indolizidine alkaloid swainsonine, found in some Astragalus and Oxytropis (i.e., locoweed) species, is a potent cellular glycosidase inhibitor that often poisons livestock. Other toxic genera such as some Ipomoea species also contain swainsonine as well as calystegines which are similar polyhydroxy alkaloids. The toxicity of calystegines is poorly characterized; however, they are also potent glycoside inhibitors capable of intestinal and cellular glycoside dysfunction. The objective of this study was to directly compare A. lentiginosus and I. carnea poisoning in goats to better characterize the role of the calystegines. Three groups of four goats each were treated with ground alfalfa (control), I. carnea or A. lentiginosus to obtain daily doses of 0.0, 1.5, and 1.5 mg swainsonine/kg bw per day, respectively, for 45 days. Animals were observed daily and weekly body weights, serum enzyme activities, and serum swainsonine concentrations were determined. At day 45 all animals were euthanized and necropsied. Goats treated with A. lentiginosus and I. carnea developed clinical disease characterized by mild intention tremors and proprioceptive deficits. Goats treated with A. lentiginosus developed clinical disease sooner and with greater consistency. No differences in body weight, serum swainsonine concentrations and serum enzyme activity were observed between goats treated with A. lentiginosus and I. carnea. Additionally, there were no differences in the microscopic and histochemical studies of the visceral and neurologic lesions observed between goats treated with A. lentiginosus and I. carnea. These findings suggest that I. carnea-induced clinical signs and lesions are due to swainsonine and that calystegines contribute little or nothing to toxicity in goats in the presence of swainsonine.

Animal and plant factors which affect larkspur toxicosis in cattle: Sex, age, breed, and plant chemotype.

Larkspur (Delphinium spp.) poisoning is a long-term problem for cattle grazing on rangelands of western North America. Recent research has shown that both plant and animal-based factors are critical in understanding and mitigating larkspur poisoning in cattle. Non-toxicological factors including sex, age, cattle breed, and plant chemotype affect cattle responses to larkspur. For example, Angus heifers are more susceptible to larkspur intoxication than are steers or bulls. Young cattle appear to be more susceptible to larkspur poisoning than mature animals. Beef breeds of cattle are more susceptible to larkspur intoxication than dairy breeds. In addition to animal factors, plant alkaloid composition (chemotype) affects the potential toxicity for cattle because of differences in the ratios and concentrations of highly toxic N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids compared to less lethal non-MSAL-type alkaloids. Animal- and plant-based factors can provide substantial information to inform livestock producers on management to reduce risk and cattle losses to various larkspur species in western North America.

Spontaneous poisoning by Palicourea marcgravii (Rubiaceae) in a sheep herd in southeastern Brazil.

Palicourea marcgravii (Rubiaceae) is considered the most important toxic plant affecting livestock farming in Brazil. This study describes an outbreak of spontaneous poisoning by P. marcgravii in sheep. Forty-nine sheep died while showing clinical signs of sudden death after having access to the plant. During the necropsy, P. marcgravii leaves were observed in the rumens of the animals. Histopathological analysis demonstrated hydropic degeneration of the kidneys. Monofluoracetate concentration obtained in Palicourea samples was 0.53% (5.3 µg/mg). These findings collectively indicate that the affected animals died from poisoning due to P. marcgravii.

Evaluation of noninvasive specimens to diagnose livestock exposure to toxic larkspur (Delphinium spp.).

Larkspurs (Delphinium spp.) are native perennial plants that have a serious toxic potential to cattle on foothill and mountain rangelands in the western United States. Livestock death due to larkspur toxicity is attributed to norditerpenoid alkaloids. Diagnosing plant poisonings in livestock is often challenging. The objective of this study was to evaluate the use of three matrices; earwax, oral fluid, and nasal mucus, as noninvasive specimens to determine livestock exposure to larkspurs. Reversed phase high performance liquid chromatography - high resolution mass spectrometry was used to analyze for norditerpene alkaloids, in all three matrices, in cattle administered a single dose of larkspur. Earwax, oral fluid, and nasal mucus were collected over 6 days post-dosing. Methyllycaconitine (MLA) and deltaline concentrations in earwax ranged from 0.4 ±â€¯0.1 to 0.2 ±â€¯0.06 and 0.6 ±â€¯0.5 to 0.11 ±â€¯0.08 ng/mg, respectively. MLA and deltaline concentrations in oral fluid ranged from 0.08 ±â€¯0.03 to 0.01 ±â€¯0.002 ng/mg and 0.07 ±â€¯0.03 ng/mg to not detected (ND), respectively. MLA and deltaline concentrations in nasal mucus ranged from 0.2 ±â€¯0.13 to 0.03 ±â€¯0.01 ng/mg and 0.2 ±â€¯0.12 ng/mg to ND, respectively. The ability to detect differing norditerpene alkaloid chemotypes from two different Delphinium spp. was also possible in the three matrices. This study demonstrates the potential of earwax, oral fluid, and nasal mucus as noninvasive specimens for chemical analyses to aid in the diagnosis of livestock that may have been exposed to and poisoned by larkspur plants.

The effect of alkaloid composition of larkspur (Delphinium) species on the intoxication of Angus heifers1.

Cattle losses from larkspur (Delphinium spp.) toxicity are a long-term challenge on the rangelands of western North America. In addition to animal factors that affect livestock poisonings, plant alkaloid composition (chemotype) affects the intoxication of cattle because some chemotypes are significantly more toxic. Differences in larkspur chemotype toxicity are due to the ratios of N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids to non-MSAL-type alkaloids and the concentrations of those alkaloids in the plant material. The objective of this study was to compare the responses of 6 Angus heifers to 6 chemotypes of larkspur using a Latin square study design. These Angus heifers from the USDA-ARS, Meat Animal Research Center in Clay Center, NE, were chosen for this research because they are the most larkspur-susceptible cattle observed to date. The 6 heifers were given an oral dose of dried ground larkspur and tested for muscle weakness with an exercise test (i.e., walk time). The 6 chemotypes of larkspur had non-MSAL to MSAL-type alkaloid ratios ranging from 1.4:1 to 6:1 and were administered at an oral dose of 7.5 mg/kg MSAL-type alkaloids BW. There was a treatment effect due to larkspur chemotype (P < 0.0001), and period effects were not significant (P = 0.6). There were also significant correlations between the length of time walking on a dirt track at 5 to 6 km/h, and total alkaloid dose (r = -0.92, P = 0.0045) and alkaloid ratio (r = -0.81, P = 0.0258). Serum alkaloid concentrations at 24 h after dosing were representative of the relative abundance of the alkaloid in the plant material. Results from this work suggest that total alkaloid concentrations in combination with alkaloid ratios can be used together to accurately predict the plant risk component of larkspur poisoning to grazing cattle. Animal factors such as cattle age, breed, and sex must also be considered to comprehensively manage larkspur risk.

Sex-dependent differences for larkspur (Delphinium barbeyi) toxicosis in yearling Angus cattle1.

Larkspur (Delphinium spp.) poisoning is a long-term problem for cattle grazing on rangelands of western North America. Results from preliminary experiments have suggested that differences in larkspur toxicity may exist between heifers and bulls. The objective of this study was to compare the physiological responses of yearling Angus heifers, steers, and bulls with a standardized dose of Delphinium barbeyi and to test the hypothesis that the response is sex dependent. Clinical signs of intoxication, including muscle coordination and function, were measured 24 h after oral dosing with larkspur by walking the cattle at a pace of 5 to 6 km h-1 for up to 40 min on an oval dirt track. Due to the experimental methods used, the variation in susceptibility to larkspur was not quantifiable for walking times of 0 or 40 min or more. Larkspur susceptible animals that were not able to walk (0 min; 36% of the animals) or larkspur resistant animals that walked the entire test period of 40 min (9% of the animals) resulted in censored or truncated data. The statistical methods (censReg and lmec) were used to adjust for data truncation or censoring. The heifers were only able to walk -8.9 ± 3.9 min (65.5% censored on the left) compared with 13.2 ± 3.7 min for bulls and 15.9 ± 2.7 min for steers. When heifers were compared with bulls and steers together, heifers walked 23.4 ± 4.5 min less (P < 0.0001). Serum alkaloid concentrations were measured immediately before walking, and deltaline concentrations averaged 266 ± 28, 131 ± 20, and 219 ± 28 ng mL-1 for all heifers, steers, and bulls, respectively, and serum methyllycaconitine concentrations averaged 660 ± 46, 397 ± 32, and 612 ± 34 ng mL-1 for all heifers, steers, and bulls, respectively. The relative risk of a zero walk time for yearling heifers is 330% that of yearling bulls (P = 0.0008). These results suggest that yearling Angus heifers are more susceptible to larkspur intoxication and, when possible, heifers should be kept from grazing larkspur-infested rangelands as a simple management tool to reduce the risk of fatal poisoning.

Toxicity of the different vegetative stages of Amorimia pubiflora to sheep.

Toxic plants containing monofluoroacetate (MFA) cause sudden death in livestock in Australia, South Africa and Brazil, causing economic losses to producers. The objective of this study was to determine the amount of MFA present in young leaves, mature leaves, senescent leaves, and seeds of Amorimia pubiflora harvested at different times of the year and to determine their toxic effect on sheep. Samples of Amorimia pubiflora were collected during April, August and December of 2015 and March of 2016, separated according to the vegetative stage (young leaves, seeds, mature leaves, and senescent leaves), dried in an oven, and administered in daily doses of 5 g/kg/body weight (bw) of fresh leaves to sheep through ruminal cannulae. The experiment was divided into four stages according to the time of collection of the plant so that each sheep received a different vegetative stage of the plant (young leaves, mature leaves, and senescent leaves). Only in the second stage of the experiment was it possible to collect A. pubiflora seeds, which were administered using the same method used for the administration of the leaves. The sheep were dosed with the plant until they showed clinical signs of toxicosis or until the plant was no longer available. Aliquots of leaves and seeds of A. pubiflora were analyzed for MFA concentration. The seeds and young leaves had higher concentrations of MFA than did the mature (harvested in August and December) and senescent (harvested in December) leaves. However, all vegetative stages of the plant were toxic and caused fatal poisoning. The results of our study showed that A. pubiflora is toxic to sheep even when MFA concentrations are low, demonstrating that the presence of this substance is a risk factor for the occurrence of poisoning. Knowing the toxic principle and its variations allow us to determine the conditions for the occurrence of plant toxicosis as well as possible treatment, control, and prophylaxis methods, contributing significantly to the reduction of economic losses on farms due to plant poisoning.

An Evaluation of Hair, Oral Fluid, Earwax, and Nasal Mucus as Noninvasive Specimens to Determine Livestock Exposure to Teratogenic Lupine Species.

The livestock industry in the western United States loses an estimated $500 million annually from livestock production losses due to poisonous plants. Poisoning of livestock by plants often goes undiagnosed because there is a lack of appropriate or available specimens for analysis. The Lupinus species represent an important toxic plant in western North America that can be toxic and/or teratogenic to livestock species due to the quinolizidine alkaloids. The objective of this study was to evaluate the potential of using earwax, hair, oral fluid, and nasal mucus as noninvasive specimens to determine livestock exposure to the teratogenic Lupinus species. Quinolizidine alkaloids were detected in these four matrices in cattle that were administered a single dose of Lupinus leucophyllus. In addition, quinolizidine alkaloids from lupine were detected in the earwax of cattle that grazed on lupine-infested rangelands. This study demonstrates the potential of earwax, hair, oral fluid, and nasal mucus as noninvasive specimens for chemical analyses to aid in the diagnosis of livestock that may have been exposed to and poisoned by plants.

Plantas cardiotóxicas para ruminantes no Brasil / Cardiotoxic plants affecting ruminants in Brazil

Esta revisão atualiza informações sobre plantas cardiotóxicas que afetam os ruminantes no Brasil. Atualmente, sabe-se que existem pelo menos 131 plantas tóxicas pertencentes a 79 gêneros. Vinte e cinco espécies afetam o funcionamento do coração. As plantas que contêm monofluoroacetato de sódio (Palicourea spp., Psychotria hoffmannseggiana, Amorimia spp., Niedenzuella spp., Tanaecium bilabiatum e Fridericia elegans) causam numerosos surtos de intoxicação, principalmente em bovinos, mas búfalos, ovinos e caprinos são ocasionalmente afetados. A intoxicação por Palicourea marcgravii continua a ser a mais importante devido à ampla distribuição desta planta no Brasil. Novas espécies do gênero Palicourea contendo monofluoracetato de sódio, como Palicourea amapaensis, Palicourea longiflora, Palicourea barraensis, Palicourea macarthurorum, Palicourea nigricans, Palicourea vacillans e Palicourea aff. juruana foram descritas na região amazônica. Na região nordeste, a planta tóxica mais importante para bovinos é Amorimia septentrionalis. No Centro-Oeste, surtos de intoxicação por Niedenzuella stannea foram relatados em bovinos na região do Araguaia e a doença precisa ser melhor investigada quanto à sua ocorrência e importância. Tetrapterys multiglandulosa e Tetrapterys acutifolia, duas plantas que causam fibrose cardíaca, também contêm monofluoracetato de sódio e foram reclassificadas para o gênero Niedenzuella. Essas duas espécies e Ateleia glazioveana, outra planta que causa fibrose cardíaca, continuam sendo importantes no Sul e Sudeste do Brasil. Outras espécies menos importantes e que ocasionamente provocam surtos acidentais de intoxicação são as plantas que contém glicosídeos cardiotóxicos, tais como Nerium oleander e Kalanchoe blossfeldiana. Recentemente, várias metodologias experimentais foram empregadas para evitar intoxicações por plantas que contêm monofluoroacetato de sódio. Estas metodologias incluem a indução de aversão condicionada utilizando cloreto de lítio, a utilização de doses repetidas não tóxicas de folhas para induzir resistência, o uso de acetamida para prevenir as intoxicações e a inoculação intraruminal de bactérias degradantes de monofluoroacetato de sódio.(AU)

This review updates information about cardiotoxic plants affecting ruminants in Brazil. Currently it is known that there are at least 131 toxic plants belonging to 79 genera. Twenty five species affect the heart function. Plants that contain sodium monofluoroacetate (Palicourea spp., Psychotria hoffmannseggiana, Amorimia spp., Niedenzuella spp., Tanaecium bilabiatum and Fridericia elegans) cause numerous outbreaks of poisoning, mainly in cattle, but buffaloes, sheep and goats are occasionally affected. Poisoning by Palicourea marcgravii remains the most important due to the wide distribution of this plant in Brazil. New species of the genus Palicourea containing sodium monofluoracetate, such as Palicourea amapaensis, Palicourea longiflora, Palicourea barraensis, Palicourea macarthurorum, Palicourea nigricans, Palicourea vacillans and Palicourea aff. juruana were described in the amazon region. In the northeast region, the most important toxic plant for cattle is Amorimia septentrionalis. In the midwest, outbreaks of Niedenzuella stannea poisoning have been reported in cattle in the Araguaia region and the disease needs to be better investigated for its occurrence and importance. Tetrapterys multiglandulosa and Tetrapterys acutifolia, two plants causing cardiac fibrosis also contain sodium monofluoroacetate and were reclassified to the genus Niedenzuella. These two plants and Ateleia glazioveana, other plant that causes cardiac fibrosis continues to be important in the southeastern and south of Brazil. Other less important are the plants that contain cardiotoxic glycosides, such as Nerium oleander and Kalanchoe blossfeldiana, in wich poisonings are generally accidental. Recently, several experimental methodologies were successfully employed to avoid poisonings by sodium monofluoroacetate containing plants. These methodologies include the induction of food avertion using lithium chloride, the ministration of repeatedly non-toxic doses of leaves to induce resistance, the use of acetamide to prevent poisonings and the intraruminal inoculation of sodium monofluoroacetate degrading bacteria.(AU)

Transmammary transfer of toxicity to nursing kids from Isocoma pluriflora (rayless goldenrod) dosed to lactating goats.

Rayless goldenrod (RG; Isocoma pluriflora) poisons livestock in the southwestern U.S., west Texas, and northern Mexico. The putative toxin(s) have historically been thought to be benzofuran ketones. Goats have been used successfully as a model of RG poisoning. The transmammary transfer of toxicity to offspring from lactating goats has not been studied, thus the objective of this study was to determine if nursing kids would become poisoned via mother's milk when the dams were dosed with RG. Twelve lactating goats (6 controls and 6 treated; all with twin kids) were dosed via oral gavage with alfalfa or rayless goldenrod at 2% of BW per day for 14 days. Two kids showed overt clinical signs near the end of the study; however, no dams showed clinical signs, and none developed exercise intolerance or muscle weakness. After day 11 of treatment, the RG kids showed increased (P < 0.05) serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatinine kinase (CK) activities until exposure to the plant via mothers' milk ended. Serum CK activity of kids declined rapidly over 7 days after transmammary exposure ended. Histopathology revealed that one kid had extensive myonecrosis that involved both myocardium and skeletal muscles. The other kids from RG-treated does had minimal myocyte degeneration and necrosis characterized by individual myofiber swelling, hypereosinophilia and loss of striation. Benzofuran ketones were not detected in the milk of lactating goats; further, dosing with RG did not alter milk composition. In summary, milk ingestion from does dosed with >300 mg/kg BW of benzofuran ketones from RG over 14 days increased mean CK concentrations in treated kids compared to controls; however kids rapidly recovered when exposure ended. Additional work is needed to better define benzofuran ketone metabolism, toxicity, and animal susceptibility.

Chemical Analysis of Plants that Poison Livestock: Successes, Challenges, and Opportunities.

Poisonous plants have a devastating impact on the livestock industry as well as human health. To fully understand the effects of poisonous plants, multiple scientific disciplines are required. Chemical analysis of plant secondary compounds is key to identifying the responsible toxins, characterizing their metabolism, and understanding their effects on animals and humans. In this review, we highlight some of the successes in studying poisonous plants and mitigating their toxic effects. We also highlight some of the remaining challenges and opportunities with regards to the chemical analysis of poisonous plants.

Toxic plants affecting the nervous system of ruminants and horses in Brazil / Plantas tóxicas que afetam o sistema nervoso de ruminantes e equinos no Brasil

This review updates information about neurotoxic plants affecting ruminants and equidae in Brazil. Currently in the country, there are at least 131 toxic plants belonging to 79 genera. Thirty one of these poisonous plants affect the nervous system. Swainsonine-containing plants (Ipomoea spp., Turbina cordata and Sida carpinifolia) cause numerous outbreaks of poisoning, mainly in goats, but cattle and horses are occasionally affected. The poisoning by Ipomoea asarifolia, a tremorgenic plant, is very common in sheep, goats and cattle in the Northeastern region and in the Marajo island. Poisoning by the pods of Prosopis juliflora are frequent in cattle in Northeastern Brazil; occasionally this poisoning affects goats and more rarely sheep. Some poisonings by plants, such as Hybanthus calceolaria, Ipomoea marcellia and Talisia esculenta in ruminants and Indigofera lespedezioides in horses were recently described and needs to be accurately investigated about its occurrence and importance. Other plants poisonings causing nervous signs in ruminants and equidae are less important, but should be considered for the differential diagnosis of neurologic diseases.(AU)

Esta revisão tem por objetivo atualizar as informações sobre plantas neurotóxicas que afetam ruminantes e equinos no Brasil. Atualmente sabe-se que existe no país pelo menos 131 plantas tóxicas pertencentes a 79 gêneros. Trinta e uma espécies afetam o sistema nervoso. As plantas quem contém swainsonina (Ipomoea spp., Turbina cordata and Sida carpinifolia) causam numerosos surtos de intoxicação, principalmente em caprinos, mas bovinos e cavalos são ocasionalmente afetados. A intoxicação por Ipomoea asarifolia, uma planta tremorgênica, é muito comum em ovinos, caprinos e bovinos na região Nordeste e na ilha de Marajó. A intoxicação pelas vagens de Prosopis juliflora é frequente em bovinos no Nordeste do Brasil; ocasionalmente são afetados caprinos e mais raramente ovinos. Algumas intoxicações por plantas, como Hybanthus calceolaria, Ipomoea marcellia e Talisia esculenta em ruminantes e Indigofera lespedezioides em equinos foram recentemente descritas e precisam ser investigadas com precisão sobre sua ocorrência e importância. Outras intoxicações por plantas que causam sinais nervosos em ruminantes e equídeos são menos importantes, todavia devem ser consideradas para o diagnóstico diferencial de doenças neurológicas.(AU)

Screening for swainsonine among South American Astragalus species.

Swainsonine is a toxic alkaloid found in several plant genera worldwide. The objective of this study was to screen several South American Astragalus species for the toxin swainsonine. Swainsonine was detected in 16 of 30 Astragalus species using liquid and gas chromatography coupled with mass spectrometry. Information in regard to the swainsonine content of these species may provide important information on the risk of grazing these toxic species.

Effects of Elevated CO2 on the Swainsonine Chemotypes of Astragalus lentiginosus and Astragalus mollissimus.

Rapid changes in the Earth's atmosphere and climate associated with human activity can have significant impacts on agriculture including livestock production. CO2 concentration has risen from the industrial revolution to the current time, and is expected to continue to rise. Climatic changes alter physiological processes, growth, and development in numerous plant species, potentially changing concentrations of plant secondary compounds. These physiological changes may influence plant population density, growth, fitness, and toxin concentrations and thus influence the risk of toxic plants to grazing livestock. Locoweeds, swainsonine-containing Astragalus species, are one group of plants that may be influenced by climate change. We evaluated how two different swainsonine-containing Astragalus species responded to elevated CO2 concentrations. Measurements of biomass, crude protein, water soluble carbohydrates and swainsonine concentrations were measured in two chemotypes (positive and negative for swainsonine) of each species after growth at CO2 levels near present day and at projected future concentrations. Biomass and water soluble carbohydrate concentrations responded positively while crude protein concentrations responded negatively to elevated CO2 in the two species. Swainsonine concentrations were not strongly affected by elevated CO2 in the two species. In the different chemotypes, biomass responded negatively and crude protein concentrations responded positively in the swainsonine-positive plants compared to the swainsonine-negative plants. Ultimately, changes in CO2 and endophyte status will likely alter multiple physiological responses in toxic plants such as locoweed, but it is difficult to predict how these changes will impact plant herbivore interactions.

A Screen for Swainsonine in Select North American Astragalus Species.

Swainsonine is found in several plant species worldwide, and causes severe toxicosis in livestock grazing these plants, leading to a chronic condition characterized by weight loss, altered behavior, depression, decreased libido, infertility, and death. Swainsonine has been detected in 13 North American Astragalus species of which eight belong to taxa in four taxonomic sections, the Densifolii, Diphysi, Inflati, and Trichopodi. These sections belong to two larger groups representing several morphologically related species, the Pacific Piptolobi and the small-flowered Piptolobi. The objective of this study was to screen the other 31 species for swainsonine in sections Densifolii, Diphysi, Inflati, and Trichopodi previously not known to contain swainsonine. Furthermore, to broaden the scope further, 21 species within the 8 sections of the Pacific Piptolobi and the small flowered Piptolobi were screened for swainsonine. Swainsonine was detected for the first time in 36 Astragalus taxa representing 29 species using liquid and gas chromatography coupled with mass spectrometry. Several taxonomic sections were highly enriched in species that contain swainsonine while others were not. A systematic examination for swainsonine in these species will provide important information on the toxic risk of these species and may be a valuable reference for diagnosticians and land managers.

Spontaneous poisoning by Prosopis juliflora (Leguminosae) in sheep / Intoxicação espontânea por Prosopis juliflora (Leguminosae) em ovinos

The aim of this paper is to describe the first report of spontaneous poisoning by Prosopis juliflora in sheep. From flock of 500 sheep at risk, four adult male sheep were affected. One died spontaneously and three other were examined, euthanized and necropsied. Neurologic examination focused particularly on motor and sensory-cranial nerve function, complete blood counts, serum biochemistry and urinalysis were done. The evolution of the disease was chronic and to present signs of poisoning, sheep had to ingest a diet containing at least 80% of P. juliflora pods during 21 months. The biochemistry revealed a substantial increase in creatine phosphokinase levels. Clinical signs included drooling of saliva, dropped jaw, tongue protrusion and loss of food from the mouth. Gross and histological lesions were similar to those previously reported in cattle and goats. Sheep are more resistant to poisoning by P. juliflora considering that it took 21 months of pod consumption to show clinical signs. There is no specific treatment for P. juliflora poisoning in ruminants.(AU)

O objetivo deste trabalho é descrever o primeiro caso de intoxicação espontânea por Prosopis juliflora em ovinos. De um total de 500 ovinos sob risco, quatro ovinos machos adultos foram afetados. Um ovino morreu espontaneamente e os outros foram examinados, eutanasiados e necropsiados. Realizaram-se exames clínicos direcionados particularmente para funções de nervos motores e sensoriais-craniais. Avaliou-se hemograma, perfil bioquímico sérico e urinálise. A evolução da doença foi crônica e para apresentar sinais de intoxicação os ovinos tiveram que ingerir uma dieta contendo 80% das vagens de P. Juliflora durante 21 meses. Os níveis de creatinofosfoquinase estavam significativamente elevados. Os sinais clínicos consistiram em sialorreia, mandíbula pendulosa, protusão da língua e perda de alimento pela boca. As lesões macroscópicas e microscópicas foram similares àquelas reportadas previamente em bovinos e caprinos. Ovinos são mais resistentes à intoxicação por P. Juliflora, tendo em vista que foi necessário 21 meses de consumo das vagens para que os ovinos apresentassem sinais clínicos. Não há tratamento específico para a intoxicação por P. Juliflora em ruminantes.(AU)

Comparative oral dose toxicokinetics of sodium selenite and selenomethionine.

Selenium (Se) poisoning by different forms of Se occurs in the United States. However, the toxicokinetics of different selenocompounds after oral ingestion is not well documented. In this study the toxicokinetics of Se absorption, distribution and elimination were determined in serum and whole blood of lambs that were orally dosed with increasing doses of Se as sodium selenite (inorganic Se) or selenomethionine (SeMet, organic Se). Thirty-two lambs were randomly assigned to eight treatment groups, with four animals per group. Se was administered at 1, 2 or 3 mg kg-1 body weight, as either sodium selenite or SeMet with proper control groups. Blood and serum were collected at predetermined time points for 7 days post-dosing. Resulting Se concentrations in both serum and whole blood from SeMet treatment groups were significantly greater than those given equimolar doses of Se as sodium selenite. Se concentrations in serum and whole blood of lambs dosed with SeMet peaked at significantly greater concentrations when compared with lambs dosed with equimolar doses of sodium selenite. Based on the serum and whole blood kinetics, the rate of Se absorption was greater for SeMet than for sodium selenite although rates of absorption for both Se forms decreased with increasing dose. The rates of Se elimination increased with dose. These results demonstrate that SeMet has a greater absorption rate and a similar retention time resulting in a greater area under the curve and thus bioavailability than sodium selenite, which must be considered in both overdose and nutritional exposures. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.