Weaning stress in piglets disrupts metabolic and immune homeostasis, limiting growth performance. Here, we show that dietary supplementation with methyl salicylate (MS), the bioactive component of Gaultheria plants, alleviates weaning stress through coordinated effects on host physiology and gut microbiota. In a 28-day trial, 144 weaned piglets received a control diet, MS (1 g/kg), or MS (0.7 g/kg) combined with tributyrin (0.3 g/kg). MS supplementation significantly increased average daily gain and feed intake (P < 0.05), elevated serum total cholesterol and low-density lipoprotein cholesterol, enhanced total antioxidant capacity, and reduced circulating leukocyte counts (P < 0.05). These physiological changes were accompanied by remodeling of the gut microbiota, characterized by enrichment of Prevotella and depletion of Treponema and Clostridium. Notably, Sodaliphilus abundance correlated positively with serum lipid parameters (P < 0.05), suggesting a potential role in host energy metabolism. The combination with tributyrin did not enhance MS effects, indicating that MS alone is sufficient to drive the observed benefits. Our findings identify MS as a functional feed additive that improves postweaning performance by modulating antioxidant capacity, immune activity, and gut microbiota composition, with implications for developing nutritional strategies in swine production.

The enthalpy of freezing of methyl salicylate sorbed by four commercial montmorillonite clays was used to estimate the absorption/adsorption capacity of the clay. Differential thermal analysis was therefore employed to give a quantitative estimate of the sorption capacity of the clay for methyl salicylate. The absorption capacity of the clay depended on the state of hydration and ranged from 30.4% for an 8% water content to 9.7% for a montmorillonite containing 24% water.

Chemicals that stimulate germination of curly dock seed (Rumex crispus L. # RUMCR) and urediniospores of curly dock rust [Uromyces rumicis Schum. (Wint.)], an obligate parasite of this weed, were studied and compared. Methyl salicylate, benzyl cyanide, and benzonitrile were the best stimulators of germination of curly dock seed. The compounds tested were most effective at concentrations ranging from 250 to 1000 μl/L. A 500 μl/L concentration of methyl salicylate caused 99% of the curly dock seed to germinate. Exposure to volatiles from 10 μl methyl salicylate or octyl cyanide for 16 to 24 h was required for maximum stimulation of curly dock seed germination in 10 days. Benzonitrile, methyl-2,4-dihydroxybenzoate, 3-cyanophenol, 2-heptanone, and benzaldehyde were the most effective of 45 compounds tested on urediniospores of curly dock rust. Benzonitrile was most active of 19 compounds tested on both seed and spores. Benzyl cyanide, 4-methoxybenzonitrile, benzaldehyde, and methyl 2,4-dihydroxybenzoate also were active on both propagules.

The behavioural responses of adult female western flower thrips, Frankliniella occidentalis (Pergande) to volatiles from meadow-sweet (Filipendula ulmaria), bay laurel (Laurus nobilis) and sage (Salvia officinalis) were investigated in laboratory bioassays. Volatiles collected by entrainment of a solvent extract of F. ulmaria were more attractive than was the original extract. Frankliniella occidentalis was also significantly attracted to volatiles from L. nobilis and S. officinalis. Analysis by gas chromatography and mass spectrometry identified 1,8-cineole (eucalyptol) as one of the main volatile components of all three plant species. In coupled gas chromatography-electroantennography studies with F. ulmaria, both 1,8-cineole and methyl salicylate elicited responses from F. occidentalis. Eucarvone was identified as the major component of F. ulmaria volatiles, but showed no electrophysiological activity. Behavioural responses of thrips to a range of concentrations of 1,8-cineole and methyl salicylate were tested using a modified Pettersson ‘star’ olfactometer. 1,8-Cineole showed some attractant activity for the thrips at 0.01 mg, but methyl salicylate was repellent at all the concentrations tested.