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Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be the equivalent to approximately 1000 kg N ha−1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of the effect different wetting and drying conditions mimicking the variation in weather conditions on the nitrification process from urea to NH4+ and total oxidized nitrogen (TON) over time. In addition, the inhibition of nitrification driven by the accumulation of NH3 at high rates of N applied to Andisol has not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N ha−1 (Low N), 461 kg N ha−1 (Medium N), and 921 kg N ha−1 (High N), as well as deionized water as a control. Further, three moisture conditions were imposed: constant moisture (CM), drying–rewetting (DRW) cycles at 7-day intervals, and soil drying (SD). Destructive soil core samples were evaluated for top and bottom halves individually every 7 days over a 36-day period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was variable over time. High N was associated with elevated NH3 concentrations and could explain why total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in soil under different chemical and physical conditions determines nitrification, and thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils. [ABSTRACT FROM AUTHOR]

Simple Summary: The livestock sector contributes a considerable proportion of greenhouse gas emissions. Mechanisms must be developed in this sector to reduce these gases' emissions. This generates a demand for studies that evaluate plant species or their extracts to define their potential in modulating ruminal fermentation with the objective of reducing enteric methane emissions. The yerba mate extract (YME) is obtained from a plant widely consumed in the southern region of Brazil for its biological properties, with few studies on rumen fermentation, meat quality, and production parameters. For this reason, this study sought to evaluate the inclusion of different levels of YME and analyze its effects on ruminal fermentability, methane emissions, and animal performance. Our results show that the inclusion of YME does not affect ruminal fermentation parameters or apparent digestibility. The inclusion of plant extracts that contain secondary compounds with the potential to modulate rumen fermentation and improve animal performance has gained attention in recent years. The aim of this study was to evaluate the effect of the inclusion of yerba mate extract (Ilex paraguariensis ST. Hilaire) (YME) on the ruminal parameters. Eight castrated cattle were divided into four groups, a control without YME (0%) and three treatment groups with 0.5, 1 and 2% inclusion of YME in the dry matter. The inclusion of YME did not show differences in ruminal methane emissions (CH4), and total apparent digestibility (p = 0.54). Likewise, YME did not modify ruminal pH, but positively affected NH3-N, which decreased linearly as the extract level in the diet increased (p = 0.01). No short chain fatty acids (SCFA) were influenced by YME, except isovaleric acid (p = 0.01), which showed a lower concentration in the inclusion of 2% YME. Our results show that up to 2% YME does not affect digestibility, ruminal fermentation parameters, or the concentration of short-chain fatty acids in the rumen. [ABSTRACT FROM AUTHOR]

Understanding the behaviour of grazing animals at pasture is crucial in order to develop management strategies that will increase the potential productivity of grazing systems and simultaneously decrease the negative impact on the environment. The objective of this review was to summarize and analyse the scientific literature that has addressed the site use preference of grazing cattle using global positioning systems (GPS) collars in the past 21 years (2000–2020) to aid the development of more sustainable grazing livestock systems. The 84 studies identified were undertaken in several regions of the world, in diverse production systems, under different climate conditions and with varied methodologies and animal types. This work presents the information in categories according to the main findings reviewed, covering management, external and animal factors driving animal movement patterns. The results showed that some variables, such as stocking rate, water and shade location, weather conditions and pasture (terrain and vegetation) characteristics, have a significant impact on the behaviour of grazing cattle. Other types of bio-loggers can be deployed in grazing ruminants to gain insights into their metabolism and its relationship with the landscape they utilise. Changing management practices based on these findings could improve the use of grasslands towards more sustainable and productive livestock systems. [ABSTRACT FROM AUTHOR]

Ensuring energy security, stopping climate change, and improving urban air quality are the three main challenges of this century that are being addressed by governments globally. The transportation sector contributes significantly to these issues. Sustainable transport involves the consideration of three dimensions—economic development, environmental preservation, and social development—and one of its aspects is the focus on the transition towards electric vehicles. The sustainable transportation is a complex system with multiple relationships and feedback between their elements. Understanding this complexity in an integrated and holistic manner is a challenge that must be addressed. To obtain insight into this complexity, we perform a systematic review of studies in which the demand and supply components of the passenger transportation sector were modelled in an integrated manner along with the dimensions of sustainability. All the reviewed previous studies had taken into consideration both the economic and environmental dimensions; however, only a few had also considered social development. The holistic and systematic integration of the dimensions of sustainability along with their relationships and feedback would facilitate a better understanding of the transportation sector and promote the development of better policies for improving the diffusion of passenger electric vehicles. [ABSTRACT FROM AUTHOR]