Origanum vulgare is a natural, less toxic, residue free feed supplement for poultry when compared to other synthetic ingredients. It contains key bioactive components, including as thymol and carvacrol. O. vulgare as a poultry feed supplement has had an antimicrobial, antioxidant, antiviral, immunomodulatory and antiparasitic effect. The potential advantages of utilising oregano extracts, in poultry diets include improved feed intake and feed conversion, enhanced digestion, expanded productive performance, down-regulated disease incidence and economic losses. From the available literature, average inclusions of oregano essential oil up to 600 mg/kg in broiler diets increased body weight gain. Using 1% oregano oil in broiler diets improved feed conversion ratio and feed utilisation. Moreover, oregano can induce a marked improvement on the intestinal microbiota and ileal villus height of broilers when combine with attapulgite by ratio 15 mg/kg of oregano. Broilers fed 300 ppm oregano oil in their diet display higher IgG titres relative to those reared on control (without supplementation) diet. Including 240 mg oregano supplementation per kg diet appears to give an optimum level for protecting broiler chickens from C. perfringens infections. Bioactive components extracted from O. vulgare parts could be used in poultry diets levels of 10 to 30 g/kg. This review includes information on the use of O. vulgare and its derivatives in poultry nutrition. To maximise the overall productivity of poultry, oregano may be used as a natural alternative to antibiotics and drugs due to the absence of side effects and residues.

Ecophysiological aspects of seed germination were investigated in the widely distributed Mediterranean-endemic, aromatic plants thyme (Coridothymus capitatus), savory (Satureja thymbra) and oregano (Origanum vulgare subsp. hirtum). Thyme seed germination is light indifferent, whereas oregano seeds have an absolute light requirement; their germination can be promoted even by green safelight or far-red light. In savory, a portion of the seeds germinates in the dark and germination can be either increased or decreased by the appropriate illumination. All three species show more germination at a relatively low temperature range, a Mediterranean characteristic, with an optimum around 15–20°C. The rate of germination is considerably higher in the tiny seeds of thyme and oregano than in the larger seeds of savory. In the latter species, germination is also dependent upon the age of the seeds; old seeds germinate to a higher percentage than fresh ones, as already observed by Theophrastus, possibly as a result of the volatilization of the essential oils present on the nutlet coat. Seeds of thyme, savory and oregano are dispersed within the persistent fruiting calyces and the seeds eventually germinate within it. Essential oils in the calyx strongly inhibit germination of the enclosed seeds; germination is much suppressed in thyme and to a lesser extent in savory and oregano. This diaspore dormancy caused by essential oils apparently is overcome under natural conditions by leaching of the inhibitors with rainwater. It is suggested that this dormancy operates as an adaptation strategy that delays germination by acting as a rain gauge. In this way, seed germination and subsequent seedling establishment are prevented during the early phase of the rainy period, which is usually interrupted by drought spells in the Mediterranean climate.