Macro, Micro and Molecular changes of sheep ingestive apparatus related to dry grassland vegetative cycle: a key tool for rangeland management

and functional variability, reached by means of evolutionary steps. In addition, he demonstrated the occurrence of seasonal adaptations of the digestive system in relation to forage availability and climatic conditions. From an ecological viewpoint, the Apennine grasslands show an annual productive trend, with the highest production corresponding to the flowering peak at the end of June. In the summer, the quantity of phytomass available for flock feeding decreases; in addition, a forage biochemical alteration occurs, due to the increase in the percentage of lignin, with a consequent reduction of forage digestibility and nutritional supply. Anatomical research, supporting eco-vegetational investigations focused on the maintenance of pastoral ecosystem biodiversity, performed during two consecutive years, demonstrated molecular, micro- and macroscopic modifications of the sheep ingestive apparatus, related to the vegetative cycle of pasture and to interannual climatic differences. From a molecular viewpoint we observed a different expression of AQP5, a water channel protein, in sheep parotid glands according to the pasture vegetative development and inteannual climatic variations, due to AQP5 involvement in providing appropriate saliva fluidity. At rumen level, four indicative regions were monitored: atrium, dorsal and ventral sac, and dorsocaudal blind sac floor. All regions showed modifications linked to different stages of the pasture vegetative cycle. We observed macroscopic modifications in papillae mean area, which directly affects the SEF (Surface Enlargement Factor) during the pasture vegetative cycle, also linked to interannual climatic variations. Modifications were observed also at microscopical level as rumen epithelium keratinization degree and calibre and number of blood vessels. However, rumen ventral sac was the rumen region showing macro- and microscopical modification mainly related to pasture qualitative and quantitative changes. At the same time, we monitored the animal Body Condition Score (BCS). Obtained results allowed the validation of BCS as representative parameter of morphofunctional modifications, which are strictly related to ecological-productive variations of the grassland systems. The research gave the outputs to provide breeders a simple method for improving farm management and to define the best practices allowing breeders to fulfil European Union aims for biodiversity maintenance through animal husbandry.