Ceacero Francisco, Landete-Castillejos Tomás, Olguín Augusto, Miranda María, García Andrés, Martínez Alberto, Cassinello Jorge, Miguel Valentín, Gallego Laureano
Department of Animal Science and Food Processing, Czech University of Life Sciences, Prague, Czech Republic; Department of Ethology, Institute of Animal Science, Prague, Czech Republic.
Sección de Recursos Cinegéticos y Ganaderos, Instituto de Desarrollo Regional (IDR), Albacete, Spain; Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ciudad Real, Spain; Departamento de Ciencia y Tecnología Agroforestal y Genética, Universidad de Castilla-La Mancha, Albacete, Spain.
PLoS One. 2015 Jan 23;10(1):e0115814. doi: 10.1371/journal.pone.0115814. eCollection 2015.
Ungulates select diets with high energy, protein, and sodium contents. However, it is scarcely known the influence of essential minerals other than Na in diet preferences. Moreover, almost no information is available about the possible influence of toxic levels of essential minerals on avoidance of certain plant species. The aim of this research was to test the relative importance of mineral content of plants in diet selection by red deer (Cervus elaphus) in an annual basis. We determined mineral, protein and ash content in 35 common Mediterranean plant species (the most common ones in the study area). These plant species were previously classified as preferred and non-preferred. We found that deer preferred plants with low contents of Ca, Mg, K, P, S, Cu, Sr and Zn. The model obtained was greatly accurate identifying the preferred plant species (91.3% of correct assignments). After a detailed analysis of these minerals (considering deficiencies and toxicity levels both in preferred and non-preferred plants) we suggest that the avoidance of excessive sulphur in diet (i.e., selection for plants with low sulphur content) seems to override the maximization for other nutrients. Low sulphur content seems to be a forgotten factor with certain relevance for explaining diet selection in deer. Recent studies in livestock support this conclusion, which is highlighted here for the first time in diet selection by a wild large herbivore. Our results suggest that future studies should also take into account the toxicity levels of minerals as potential drivers of preferences.
有蹄类动物会选择能量、蛋白质和钠含量高的食物。然而，除了钠之外，其他必需矿物质对食物偏好的影响却鲜为人知。此外，关于必需矿物质的毒性水平对某些植物物种回避行为可能产生的影响，几乎没有相关信息。本研究的目的是每年测试植物矿物质含量在马鹿（Cervus elaphus）食物选择中的相对重要性。我们测定了35种常见的地中海植物物种（研究区域内最常见的物种）中的矿物质、蛋白质和灰分含量。这些植物物种之前已被分类为偏好和非偏好物种。我们发现，鹿更喜欢钙、镁、钾、磷、硫、铜、锶和锌含量低的植物。所得到的模型在识别偏好植物物种方面非常准确（正确分类率为91.3%）。在对这些矿物质进行详细分析后（考虑偏好和非偏好植物中的缺乏和毒性水平），我们认为在食物中避免过量的硫（即选择硫含量低的植物）似乎比其他营养物质的最大化更为重要。低硫含量似乎是一个被遗忘的因素，在解释鹿的食物选择方面具有一定的相关性。最近对家畜的研究支持了这一结论，这在野生大型食草动物的食物选择中尚属首次强调。我们的结果表明，未来的研究也应将矿物质的毒性水平作为偏好的潜在驱动因素加以考虑。
