Location: Poisonous Plant ResearchTitle: A survey of Senecio spp. affecting livestock in Uruguay and their associated pyrrolizidine alkaloid content
|Garcia, Juan - UNIVERSIDAD DE LA REPÚBLICA|
|Garcia Y Santos, Carmen - UNIVERSIDAD DE LA REPÚBLICA|
|Rosas, Juan - NATIONAL AGRICULTURAL RESEARCH INSTITUTE(INIA)|
|Dutra, Fernando - MINISTERIO DE GANADERÍA, AGRICULTURA Y PESCA (MGAP)|
Submitted to: Ciencia Rural
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2017
Publication Date: 2/1/2018
Citation: Garcia, J.A., Garcia Y Santos, C., Rosas, J., Dutra, F., Gardner, D.R. 2018. A survey of Senecio spp. affecting livestock in Uruguay and their associated pyrrolizidine alkaloid content. Ciencia Rural. 48(2):1-7. http://dx.doi.org/10.1590/0103-8478cr20170621.
Interpretive Summary: In Eastern Uruguay there has been a significant increase in livestock being diagnosed with chronic liver disease associated with grazing of Senecio related plant species. The disease is commonly called seneciosis and the toxic compounds in the plants have been identified as pyrrolizidine alkaloids. It appears that the frequency of seneciosis is greater in those regions at or near the Brazilian border with an apparent influx of two Senecio spp that have now been reported to occur that were not previously reported in Uruguay. A survey was thus conducted from 28 farms associated with seneciosis outbreaks from which samples of 50 populations of Senecio plants were collected. The collected plants were submitted for species identification and for analysis of known toxic compounds. Four species of Senecio were identified among the samples taken. All species were found to contain toxic alkaloids. Senecio oxyphyllus however was found to be the most common plant identified being found in 82% of the farms surveyed. Senecio oxyphyllus was also found to contain the second highest concentration of the toxins. Based on the data from the survey it is concluded that S. oxyphyllus is the main species associated with reported outbreaks of seneciosis.
Technical Abstract: In Eastern Uruguay there has been a significant increase of seneciosis in grazing livestock with most affected localities related to counties neighboring the Brazilian border. A survey in 28 farms associated with poisoning outbreaks in grazing cattle in Eastern Uruguay was carried out. Fifty populations of Senecio plants were collected for alkaloid analysis and species identification. Four species were identified: S. oxyphyllus DC, S. madagascariensis Poir, S. brasiliensis (Spreng.) Less., and S. selloi DC. Alkaloids were identified by a combination of GC-MS and HPLC-MS analysis and included: retrorsine in S. oxyphyllus; retrorsine, usaramine, and senecivernine/senecionine in S. selloi; retrorsine, senecivernine/senecionine, integerrimine, and usaramine in S. madagascariensis; and integerrimine, retrorsine and senecionine in S. brasiliensis. Total mean alkaloid concentration was reported to be highest in S. brasiliensis (17.6mg/g) followed by S. oxyphyllus (6.2mg/g), S. selloi (1.8mg/g) and S. madagascariensis (0.6mg/g). Alkaloid concentrations were also reported to be higher in 2015 vs. 2016 probably due to a common environmental factor. The species S. oxyphyllus and S. madagascariensis were not previously recognized as toxic plants in Eastern Uruguay. Particularly, S. oxyphyllus was present in 82% of the farms surveyed and occurred in high density with relative high concentrations of pyrrolizidine alkaloids suggesting S. oxyphyllus may be the main species involved in the reported outbreaks of seneciosis.