Nutritional value and utilization of plants with antimicrobial properties as components of the diet of dairy sheep

The aim of these thesis was to evaluate the nutritional characteristics and the productive and health effects of several aromatic plants with known high antimicrobial activity supplied to sheep.The review of the literature explored the characteristics and nutritional the effects of aromatic plants and of their extracts.In the first chapter, 18 herbs with known antimicrobial activity --Achillea millefoliumL. (aerial parts),Anethum graveolensL. (seeds),Carum carvi L. (seeds),Chamaemelum nobile All. (aerial parts),Coriandrum sativum L.(seeds),Hyssopus officinalis L. (aerial parts),Lavandula angustifolia Mill. (vegetative parts),Lavandula angustifolia Mill. (flowers),Melissa officinalis L. (vegetative parts),Ocimum basilicum L. (vegetative parts),Origanum vulgare L. (vegetative parts),Pimpinella anisum L. (seeds),Pinus Silvestris L. (young shoots),Rosmarinus officinalis L. (vegetative parts),Salvia officinalis L. (vegetative parts),Satureja montana L. (vegetative parts),Thymus serpyllum L. (vegetative parts) andThymus vulgaris L. (vegetative parts) – were evaluated to asses their nutritional characterisitics and values utilizing chemical analysis andin vitrofermentation studies. Based on the results of this Chapter, 7 plant species were selected for further studies. In the second and in the third chapters these 7 species were used in two experiments to assess their palatability when used alone or mixed with other concentrates. Based on the results of these studies, one plant was discarded and 5 plants were used in a productive short term experiment. Indeed, the fourth chapter deals with the experiments carried out on lactating ewes in order to evaluate the intake of the mixes including the plants, and the effects on milk production and composition, health status of the animals, and rumen function. Based on the results of the short term productive experiment, 3 plants were considered superior:Carum carvi,Coriandrum sativumandSatureja Montana.These plants need to further studies to asses their productive and health effects when used in long term studies and to assess their ability to transfer active microbial compounds to the milk and the cheese.