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I. ABSTRACT Swainsona spp. poisoning is a chronic progressive neurologic disorder seen in extensively grazed cattle, sheep, and horses in Australia. There are no macroscopic lesions but microscopically the entity is characterized by widespread neurovisceral ‘watery’ cytoplasmic vacuolation, and in more protracted cases also neuroaxonal dystrophy and pigment deposition. The stored substance is thought to be contained in lysosomes, but its nature is not known. The lesions in this entity are closely similar to those caused by locoweeds in the U.S.A., except that congenitally deformed lambs and calves have not been seen in Australia. The effects of experimental A. lentiginosus intoxication in the pregnant ewe are summarized.

SUMMARY On 6 properties in south-western Queensland an outbreak of nervous disease occurred in horses due to ingestion of Swainsona (Darling pea). Loss of condition, depression, hyperaesthesia and hyperexcitability were seen in affected horses. At autopsy of 2 horses generalised cytoplasmic vacuolation was seen in the neurones of the central nervous system and in the liver, adrenal and thyroid. The clinical and pathological features were similar to those described in horses suffering from Swainsona poisoning in Australia and Astragalus and Oxytropis in North America.

I. ABSTRACT Locoweed poisoning caused by plants of the genera Oxytropis and Astragalus is devastating to livestock, resulting in multi-faceted clinical signs including emaciation, visual impairment, neurological abnormalities (including incoordination), birth defects, abortions, and habituation. All types of range livestock and some wild animals may be affected. Gross lesions of the intoxication are not distinctive, but the neurovisceral cytoplasmic vacuolation of various body tissues observed in light and electron microscopy are characteristic. Sequential development of the lesions, their distribution and correlation with clinical signs are discussed.

The genus Oxytropis DC. is one of the largest genera in the Fabaceae family. The most plant species belonging to the Oxytropis genus have an important medicinal value. Currently the botanical taxonomy of the genus is complicated due to existence of many subgenera and sections that developed based on morphological traits. Also, in the literature there is luck of knowledge on phylogeny of Oxytropis species from Central Asian region. Therefore, the purpose of the present study was the clarification of taxonomic relationship of two Oxytropis species from SouthEast of Kazakhstan (O. almaatensis Bajt. and O. glabra DC.). The study was based on using phylogenetic analysis and haplotype network assessment based on sequences ITS (internal transcribed spacers), which is DNA marker of nuclear genome. Plant materials of O. almaatensis were collected from 2 populations in two neighboring Gorges in Trans Ili Alatau Mountains, O. glabra plant material was obtained from Herbarium of the Department of Biodiversity and Bioresources, al-Farabi Kazakh National University. Based on DNA sequences of ITS the phylogenetic and network relationships were investigated by using Neighbor Joining and Median Joining methods, respectively. The nucleotide sequences of ITS of O. almaatensis and O. glabra were aligned with sequences of 29 Oxytropis references found in the NCBI database. Out of the 601 aligned positions of ITS 33 (5.6 %) sites were found to be polymorphic nucleotides and used in evaluation of the genetic relationship of species. Constructed MJ haplotype network showed a very high congruence with the NJ phylogenetic tree. MJ network provided valuable additional hints in clarification of the taxonomic relationship among species involved in the analysis. In this study phylogenetic NJ tree and MJ network based on the variation of ITS sequences confirmed the monophyletic origin of the genus. The ITS haplotype network suggested that O. glabra is very diverse species and possibly played important role in the evolutionary processes of the genus in Central Asian region. The study is additional contribution in the molecular taxonomy of complex Oxytropis genus.

The indolizidine alkaloids swainsonine and swainsonine N-oxide have been isolated and identified as constituents of spotted locoweed. The inhibition of lysosomal α-mannosidase by these alkaloids su...

Utilization studies conducted on a high mountain range determined the quantity and timing of white locoweed (Oxytropis sericeu Nutt.) consumption by cattle. Paired plots (one caged and one grazed) were clipped at the end of the grazing season to determine seasonal utilization. Biweekly visual appraisals were used to estimate percentage leaf grazed and number of reproductive stalks grazed and thus determine utilization patterns as the season progressed. Loco comprised 26% of the standing crop. Thirty-four percent of the available loco was utilized during the grazing season. Loco flower and pods (heads) were preferred to leaves. Utilization of loco heads increased linearly as the season progressed. LOCO leaves were not consumed until the last 3 weeks of the grazing season. Loco heads also contained the highest concentration of the toxic alkaloid, swainsonhre. Locoweed poisoning of livestock has been the most widespread poisonous plant problem in the western United States (James et al. 1981). Marsh (1909) reviewed reports of locoweed poisoning dating back to 1873 and conducted feeding trials that showed conclusively that white locoweed (Astragalus lambertiinow considered to be Oxytropis sericea Nutt.) and wooly loco (A. mollissimus Torr.) caused locoism in cattle, sheep, and horses. Mathews (1932) conducted further studies to determine quantities of Earle loco (A. mollissimus var earlei Green ex Rydb.) and Garbancillo (A. wootoni Sheld.) required to produce clinical signs of toxicity in domestic livestock. The toxin in locoweeds has been identified as the indolizidine alkaloid swainsonine (Molyneux and James 1982). Desert and semidesert locoweed species (A. lentiginosus Dougl., A. pubentissimus Torr. and Gray, A. mollissimus Torr.) characteristically germinate and become established during a warm, wet fall, remain green over winter, and accelerate growth in early spring. Most livestock losses occur during the winter and early spring when other forage is scarce, or the existing forage is dry and the Authors are with USDA, Agricultural Research Service, Poisonous Plant Research Laboratory, 115OEast 14OONorth, Logan, Utah8432l;and withTexasTechUniversity, Lubbock. The assistance of Steve Fitzwater for his assistance in data collection and Russ Molyneux for alkaloid determination is gratefully acknowledged. This is Journal Paper Number 3103, Utah Agr. Exp. Sta. Manuscript accepted 21 October 1985. 344 locoweed is green (James et al. 1968, James et al. 1969). Due to the habituating properties of loco, livestock that begin eating it will continue to consume it even when good quality green feed is available (Peters and Sturdevent 1908, Marsh 1909, James et al. 1969). White locoweed differs somewhat from other locoweed species. It occurs on the western plains and foothills of the Rocky mountains and up to 3,353 m on some Intermountain ranges (Barneby 1952). It is palatable and livestock graze it throughout the growing season (Marsh 1909). Its population cycles on high mountain ranges apparently are not influenced as much by weather conditions as other locoweed species (James personal observation). Payne (1957) classified it as an increaser species. Recently it has been identified as a predisposing factor in high mountain brisket disease, or congestive right-sided heart failure, in cattle (James et al. 1983). Economic loss occurs annually from the interaction of these two diseases (Barnard 1984). Little is known about why livestock graze locoweeds. Marsh (1909) made some astute observations of livestock grazing white locoweed and made some broad general recommendations to reduce losses (Marsh 1913). However, until we know when cattle eat white locoweed, how much is required to produce intoxication, and what environmental or management factors influence consumption, little can be done to reduce losses other than keeping livestock off infested ranges. The purpose of this study was to describe utilization patterns of white locoweed by cattle on a high mountain range and identify factors that may influence consumption. Once we understand the conditions under which cattle consume white locoweed, management strategies can be developed to reduce losses.

This report includes two new varieties in Astragalus, A. missouriensis var. humi- stratus and A. newberryi var. aquarii, and twelve new combinations in Astragalus, A. allochrous var. playanus, A. australis var. major, A. australis var. olympicus, A. bigelovii var. marcidus, A. episcopus var. lancearius, A. howelii var. pauper, A. iodanthus var. pseudoiodanthus, A. lim- nocharis var. montii, A. lonchocarpus var. hamiltonii, A. missouriensis var. accumbens, A. mono- ensis var. ravenii, and A. monumentalis var. cottamii. New combinations in Orophaca are 0. barriae, 0. hyalina, and 0. proimantha. New combinations in Oxytropis are 0. nana var. argo- phylla, 0. nana var. besseyi, 0. nana var. fallax, 0. nana var. obnapiformis, 0. nana var. sal- monensis, and 0. nana var. ventosa. The taxonomic reasons for these nomenclatural changes are briefly discussed.

Understanding the conditions in which livestock consume poisonous piants is necessary to develop management strategies to reduce losses. Three IO-day grazing trials were conducted to observe consumption of white locoweed (Oxytropis serikea NW.) by cattle. The trials corresponded to the phenological growth stages of white locoweed: (1) flower; (2) immature seed pod; and (3) mature seed pod/seed shatter. Six esophageaily fistuiated Hereford steers were used to collect diet samples. In trial 1, steers selected the locoweed flower only when supplies of grass and other forbs were depleted. In trial 2, steers vohmtariiy selected the immature pod, which comprised 50% of their diet by the middle of the trial. There was very little consumption of locoweed in trial 3. Few locoweed leaves were consumed throughout the experiment. Immature locoweed pods were paiatable and readily selected by cattle. By restricting access at the immature pod growth stage and insuring adequate forage is available at other times, cattle consumption of white locoweed on this site should be minimized.