Intensive pig rearing systems produce several air pollutant emissions, mainly associated with housing and slurry storage. Dietary strategies based on the use of feed additives can effectively mitigate such impacts. This work has been aimed at evaluating the effectiveness of dietary zeolites in mitigating ammonia (NH3), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from piggery and slurry storage on finishing pig farms. An experimental trial, in which three groups of approximately 500 pigs each were reared, has been carried out on a commercial pig farm. The three groups were fed the same diet, with the addition of 0 g/kg (Z0, control), 10 g/kg (Z1), and 20 g/kg (Z2) of micronized clinoptilolite (E567), respectively. The emissions from housing facilities and the live and slaughtering animal performances, were assessed. In addition, manure samples were collected during the rearing period to evaluate, at a laboratory scale, the NH3, CO2, CH4, and N2O emission potential during the subsequent slurry storage phase prior to land application. The results have shown that the addition of dietary zeolite can be considered a valid strategy to reduce gaseous emissions from pig houses without affecting animal performances or the system’s overall productivity. Treatment Z2 gave the best results and resulted in a 25% and 36% reduction of NH3 and CO2 equivalent emission fluxes, respectively, compared to those recorded for the control. The laboratory- scale experiment revealed no significant effect of dietary clinoptilolite inclusion on NH3 or the greenhouse gas emission potential during slurry storage.
Farm tractors are still widely used in many forestry operations. Predicting fuel and lubricant costs is difficult because their consumption depends on a number of factors such as hours worked and operations performed. Fuel and lubricant consumption is important since it can have an impact at both the economic and environmental level. Many fuel models have been studied in the last decades, but few studies have focused on oil consumption. The ASABE (American Society of Agricultural and Biological Engineers) Standard suggested a model for predicting engine oil consumption of farm tractors of the 1980s, which are potentially different from modern tractor engines. In addition, the recent widespread application of semi- and full-power-shift and continuous variable transmissions and the high number of hydraulic applications increased the amount of lubrication oil for transmission and hydraulic systems.For these reasons, we analysed 133 4WD recent model farm tractors used in forest operations with the aim to study:Þ engine, transmission and hydraulic system oil capacitiesÞ engine oil change intervals as recommended by the manufacturers.A new equation for engine oil consumption, as a function of the rated engine power, was first used and statistically analysed. It was similar to the equation developed by other authors (with a mean difference of 28%, decreasing to 11% at the highest engine power), but well below the ASABE model (with an average engine oil consumption three times higher). Another equation of total oil consumption related to the rated engine power was then studied and compared with a recent study. The results showed an average difference of 18%, decreasing to 8% at the highest engine power. The differences, due to a different machine dataset (only 4WD farm tractors that can be used for forestry operations were analysed) are, however, minimal also in the engine oil consumption model if compared with the oldest ones: a new proposal is therefore necessary, with new and affordable models for correctly evaluating economic and environmental forestry operation costs when using farm tractors.
