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Gastrointestinal helminths challenge ruminants in ways that reduce their fitness. In turn, ruminants have evolved physiological and behavioral adaptations that counteract this challenge. Ruminants display anorexia and avoidance behaviors, which tend to reduce the incidence of parasitism. In addition, ruminants appear to learn to self-medicate against gastrointestinal parasites by increasing consumption of plant secondary compounds with antiparasitic actions. This selective feeding improves health and fitness. Here, we review the evidence for self-medication in ruminants, propose a hypothesis to explain self-medicative behaviors (based on post-ingestive consequences), and discuss mechanisms (e.g., enhanced neophilia, social transmission) that may underlie the ontogeny and spread of self-medicative behaviors in social groups. A better understanding of the mechanisms that underlie and trigger self-medication in parasitized animals will help scientists devise innovative and more sustainable management strategies for improving ruminant health and well-being.

A 17-yr grazing trial was conducted in the eastern Galilee of Israel to quantify trade-offs among the responses of pasture and livestock productivity, duration of grazing, amount of supplementary feed, and profitability to higher stocking density during the growing season of a Mediterranean grassland. Treatments included two stocking densities and two grazing protocols. The stocking densities throughout the grazing period were 0.55 animal unit (AU)·ha-1, which is common in this region, and 1.1 AU·ha-1, which is considered high. The grazing protocols were continuous grazing throughout the grazing season and split-paddock grazing in which the herd grazed one subpaddock from the onset of grazing until the pasture was depleted, after which the herd was moved to the second ungrazed subpaddock. Under both protocols, heavier stocking density reduced standing biomass of the whole paddock at the end of the growing season by 43% and grazing duration during the subsequent dry season by 38% but increased the daily consumption of supplementary feed and the weaned live-weight production per unit area. Under continuous grazing the high stocking density of 1.1 AU·ha-1 was maintained throughout the grazing season for 17 consecutive yr with no detectable effect on productivity of the pasture, typical to the resilience of Mediterranean grasslands that have been grazed for thousands of years. The lower pasture biomass production was compensated by higher weaned calf production. At the current local prices, the heavier stocking density was close to the economically optimal stocking density for the pasture in the region. It is concluded that on Mediterranean grassland intensive use of the pasture with high stocking density during the growing season can be economically feasible in those cases where the feed requirement of the herd can be maintained throughout the growing season. [ABSTRACT FROM AUTHOR]

Abstract: The ability to distinguish among diets fed to Damascus goats using excitation–emission luminescence spectra was investigated. These diets consisted of Medicago sativa L. (alfalfa), Trifolium spp. (clover), Pistacia lentiscus, Phyllirea latifolia and Pinus brutia. The three-dimensional luminescence response surface from phosphate buffered saline (PBS) extracts of each material was analyzed using muti-way analysis chemometric tools (MPCA) and parallel factor analysis (PARAFAC). Using three principal components, the spectra from each diet material were distinguished. Additionally, fecal samples from goats fed diets of either alfalfa or clover hays were investigated. The application of MPCA and PARAFAC to these samples using models derived from the pre-digested diet materials was strongly suggestive of the utility of similarly derive training samples for the elucidation of botanical diet composition for animals. [Copyright &y& Elsevier]