Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation
Species-rich pastures naturally contain potentially toxic plants such as common ragwort (<i>Senecio jacobaea</i> L.), whose pyrrolizidine alkaloids (PA) impose a risk, mainly for cattle and horses. Although in vitro studies showed detoxification capacity of PA in sheep, few field data ar...
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MDPI AG
2022-04-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/12/8/1000 |
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| author | Susanne Ohlsen Martin Ganter Peter Wohlsein Bernd Reckels Aiko Huckauf Nikola Lenzewski Sabine Aboling |
| author_facet | Susanne Ohlsen Martin Ganter Peter Wohlsein Bernd Reckels Aiko Huckauf Nikola Lenzewski Sabine Aboling |
| author_sort | Susanne Ohlsen |
| collection | DOAJ |
| description | Species-rich pastures naturally contain potentially toxic plants such as common ragwort (<i>Senecio jacobaea</i> L.), whose pyrrolizidine alkaloids (PA) impose a risk, mainly for cattle and horses. Although in vitro studies showed detoxification capacity of PA in sheep, few field data are available to ascertain whether grazing sheep can both tolerate and reduce ragwort. In a two-year study in a ragwort-rich pasture with a stocking density of 12 sheep/hectare, we documented (1) the extent of voluntarily ingested ragwort, (2) the correlation of nutritional parameters and feeding behavior, and (3) the impact of grazing on the yield proportion and number of flowers of dominant plants. Every six weeks the vegetation underwent a botanical survey and a chemical analysis. Sheep continuously ingested ragwort between 1.2 and 4.9 kg (2020) and 1.0 and 2.2 kg (2021) per individual per day without any impact on animal health. The more biomass ragwort produced, the more it contained sugar (<i>r</i> = 0.59–0.74), and the more sheep ingested it (<i>r</i> = 0.94–0.95). Other herbs increased their yield proportion from 23.3 to 36.5%, while that of ragwort decreased from 26.3 to 18.8% (2020/2021), doubling its flowers. Sheep preferred and tolerated ragwort, making their grazing an option to control ragwort from both an animal health and a nature conservation perspective. |
| first_indexed | 2024-03-09T11:16:18Z |
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| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-03-09T11:16:18Z |
| publishDate | 2022-04-01 |
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| series | Animals |
| spelling | doaj.art-d108772a271b4922ac4b7a508bc677272023-12-01T00:30:45ZengMDPI AGAnimals2076-26152022-04-01128100010.3390/ani12081000Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: VegetationSusanne Ohlsen0Martin Ganter1Peter Wohlsein2Bernd Reckels3Aiko Huckauf4Nikola Lenzewski5Sabine Aboling6Institute of Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, 30173 Hannover, GermanyClinic for Swine, Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Foundation, 30173 Hannover, GermanyDepartment of Pathology, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, GermanyInstitute of Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, 30173 Hannover, GermanyNature Conservation Foundation Schleswig-Holstein, 24113 Molfsee, GermanyInstitute of Plant Science and Microbiology, Universität Hamburg, 22609 Hamburg, GermanyInstitute of Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, 30173 Hannover, GermanySpecies-rich pastures naturally contain potentially toxic plants such as common ragwort (<i>Senecio jacobaea</i> L.), whose pyrrolizidine alkaloids (PA) impose a risk, mainly for cattle and horses. Although in vitro studies showed detoxification capacity of PA in sheep, few field data are available to ascertain whether grazing sheep can both tolerate and reduce ragwort. In a two-year study in a ragwort-rich pasture with a stocking density of 12 sheep/hectare, we documented (1) the extent of voluntarily ingested ragwort, (2) the correlation of nutritional parameters and feeding behavior, and (3) the impact of grazing on the yield proportion and number of flowers of dominant plants. Every six weeks the vegetation underwent a botanical survey and a chemical analysis. Sheep continuously ingested ragwort between 1.2 and 4.9 kg (2020) and 1.0 and 2.2 kg (2021) per individual per day without any impact on animal health. The more biomass ragwort produced, the more it contained sugar (<i>r</i> = 0.59–0.74), and the more sheep ingested it (<i>r</i> = 0.94–0.95). Other herbs increased their yield proportion from 23.3 to 36.5%, while that of ragwort decreased from 26.3 to 18.8% (2020/2021), doubling its flowers. Sheep preferred and tolerated ragwort, making their grazing an option to control ragwort from both an animal health and a nature conservation perspective.https://www.mdpi.com/2076-2615/12/8/1000<i>Senecio jacobaea</i> L.sheepgrazing behavioranimal healthfree-choice conditionsecological impact |
| spellingShingle | Susanne Ohlsen Martin Ganter Peter Wohlsein Bernd Reckels Aiko Huckauf Nikola Lenzewski Sabine Aboling Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation Animals <i>Senecio jacobaea</i> L. sheep grazing behavior animal health free-choice conditions ecological impact |
| title | Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation |
| title_full | Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation |
| title_fullStr | Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation |
| title_full_unstemmed | Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation |
| title_short | Grazing Ecology of Sheep and Its Impact on Vegetation and Animal Health in Pastures Dominated by Common Ragwort (<i>Senecio jacobaea</i> L.)—Part 1: Vegetation |
| title_sort | grazing ecology of sheep and its impact on vegetation and animal health in pastures dominated by common ragwort i senecio jacobaea i l part 1 vegetation |
| topic | <i>Senecio jacobaea</i> L. sheep grazing behavior animal health free-choice conditions ecological impact |
| url | https://www.mdpi.com/2076-2615/12/8/1000 |
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