Ruminant livestock contribute significantly to global methane production and mitigation of which is of utmost importance. Feed additives represent a cost-effective means of achieving this. A potential target for such additives is rumen Oxidative Reduction Potential (ORP), a parameter which influences CH4 production rates, with methanogenesis occurring optimally at ORPs below −300 mV. Thus, a controlled elevation of rumen ORP represents a potentially benign means of methanogen suppression. This research involved assessing a range of oxygen-releasing compounds for their ability to increase rumen ORP and inhibit methanogenesis, using the in-vitro rumen simulation technique (RUSITEC). Seven potential CH4 inhibitors were tested in a 21-day trial monitoring biogas volume, CH4 content, ORP, digestibility, ammonia, and volatile fatty acids concentration. The additives evaluated included: liquid peroxide (H2O2) and urea hydrogen peroxide (UHP), as well as slower reacting species (calcium and magnesium peroxide), in addition to encapsulated liquid H2O2 for controlled, slow release. Consistent CH4 reductions of >50 % were observed from all additives. Reduced neutral detergent fibre (NDF) digestibility and a reduction in total volatile fatty acids (VFAs) was observed for some treatments, but MgO2 and encapsulated H2O2 reduced CH4 volume by 62 % and 58 %, respectively, and had no detrimental effects on digestibility (p > 0.05) or on VFA production. Ex-situ ORP measurements demonstrated significant increases in ORP upon addition of the additives, with MgO2 and encapsulated H2O2 inducing a more moderate effect suggesting a controlled additive release was achieved with the slow-release format of encapsulated liquid H2O2. Thus, potential slow-release forms deemed suitable to progress to bolus or pellet format in-vivo were identified and could enable a longer-lasting suppression of methanogens within the rumen, facilitating application in both intensive and pasture-based production systems.

Plastic pollution in Special Protected Areas for Migratory Birds and Sites of Community Importance is a growing environmental concern. These areas, often designated to provide safe habitats for migratory bird species, are increasingly threatened by plastic litter. In this study, we conducted the first assessment of plastic litter, ranging from macro to microplastics, in beach sediments from two sites (Montorsoli Beach and Pylon Beach) along the coast of the Strait of Messina, a Special Protected Area, to assess beach quality and ecological risk. The selected beaches for this study are representative example of two different possible source of anthropogenic contaminations. Plastic density ranged from 1.2 pieces/m2 to 0.1 pieces/m2, Montorsoli and Pylon Beach, respectively. The most abundant plastic litter consisted of plastic pieces ranging in size from 0.5 cm to 50 cm. Several anthropogenic microparticles were identified, including Polypropylene, Polyethylene, Polyethylene terephthalate, Polytetrafluoroethylene, cotton fibers and cellulose-based materials. Montorsoli beach had a high percentage (91 %) of Polymethyl methacrylate (PMMA). While in Pylon beach the main polymer was cotton (49 %). Furthermore, calculated pollution indices showed that Montorsoli was very dirty compared to Pylon beach. Furthermore, the presence of PMMA pellets found at Montorsoli beach may endanger marine birds that depend on the resources of these areas, which are designated as Special Protection Areas for rare and vulnerable bird species. This baseline assessment not only provides crucial information on the current status of plastic pollution, but also offers valuable data that can be instrumental in effective regional management efforts.