Effects of exposure to plant‐derived odorants on behavior and the concentration of stress‐related hormones in steers isolated under a novel environment

Abstract

This study was conducted to investigate physiological and behavioral effects of the exposure to plant-derived odorants in Holstein steers (8 month of age) under the acute stress of social isolation in a novel environment. Each steer was tethered in a new room alone and exposed to one of three odorants: a mixture of equal amounts of trans-2-hexenal and cis-3-hexenol (green odor, GO; n = 5), essential oil of grapefruits (EOG; n = 5) and solvent (SOL; n = 6). Behaviors were recorded and blood samples were taken at intervals of 10-15 min for 6 h. Compared with SOL, exposure to GO or EOG decreased the frequency of vocalization (P < 0.05), shortened the latency period before the onset of rumination (P < 0.05) and increased the duration of rumination (P < 0.05). Plasma cortisol concentrations in steers exposed to plant-derived odorants (GO and EOG) during 90-130 min from commencement of sampling were significantly lower (P < 0.05) compared with SOL. These results suggest that appeasing effects of plant-derived odorants on behavioral and physiological stress responses previously reported in laboratory rodents could be also be expected in steers.

Behavior and heart rate variability after intranasal administration of oxytocin in Holstein steers

“…When cattle are exposed to various stressors, such as a new environment, confinement, or isolation, both the frequency and duration of rumination decrease [ 12 ]. Interestingly, the inhibition of rumination under isolation stress was reversed by the use of stress-alleviating plant-derived odorants in sheep [ 46 ]. Therefore, rumination may indicate that cattle are calm and experiencing low levels of stress.…”

Chemical repellents appear non-useful for eliciting exit of brown tree snakes from cargo

“…Several of the essential oils have significant physiological responses in mammals, insects, or microbiota. For example, grapefruit oil has been shown to impact plasma cortisol and prolactin levels in Holstein steers (Sutoh et al 2013) and to interfere with morphological development stages in the yellow-fever mosquito, Aedes aegypti (Ivoke et al 2013). Citronellal, a major component in citronella oil, influences the behavior of mice to mechanical pain reception (de Santana et al 2013) and also has uses as a repellent for A. aegypti (Hsu et al 2013).…”