16 research outputs found

    The Correlation between Thermal and Noxious Gas Environments, Pig Productivity and Behavioral Responses of Growing Pigs

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    Correlations between environmental parameters (thermal range and noxious gas levels) and the status (productivity, physiological, and behavioral) of growing pigs were examined for the benefit of pig welfare and precision farming. The livestock experiment was conducted at a Seoul National University station in South Korea. Many variations were applied and the physiological and behavioral responses of the growing pigs were closely observed. Thermal and gas environment parameters were different during the summer and winter seasons, and the environments in the treatments were controlled in different manners. In the end, this study finds that factors such as Average Daily Gain (ADG), Adrenocorticotropic Hormone (ACTH), stress, posture, and eating habits were all affected by the controlled environmental parameters and that appropriate control of the foregoing could contribute to the improvement of precision farming and pig welfare

    Origin and age of porewaters in low permeability Ordovician sediments on the eastern flank of the Michigan basin, Tiverton, Ontario, Canada

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    Porewater extractions and acid leachates of rock core from a 250 m thick sequence of low-permeability Ordovician-age shales and limestones, on the eastern flank of the Michigan Basin, were analysed for strontium isotope ratios in an attempt to infer porewater ages from observed 87Sr/86Sr enrichments. The porewaters originated as Ordovician seawater, which subsequently mixed with evaporated Silurian seawater infiltrating from above, and, to some extent, with a deep brine—with an enriched 87Sr/86Sr signature—from the underlying crystalline shield or deep basin. The porewater 87Sr/86Sr ratios are more radiogenic than contemporaneous seawater but show no obvious correlation to those leached from the solid rock phases. Accepting that the initial 87Sr/86Sr signatures in porewaters were dominated by Late Silurian brine, potentially with an additional deep brine component, the excess of radiogenic 87Sr appears to represent ingrowth from 87Rb decay over a time span of some 420 million years, approaching the depositional age of the rocks. Similarly, Rb/Sr errochron ages of acid leachates of solid phases, and the calculated initial 87Sr/86Sr isotopic ratios, are consistent with a proposition that the calcites inherited their Sr from Ordovician seawater and were dolomitized shortly afterwards by infiltrating Mg-enriched evaporative brine, indicating long-term conservative behaviour for the enclosing carbonate rocks. The errochron for leachates from (alumino)silicates yields a high initial 87Sr/86Sr, but with an errochron age of about 340 ± 48 Ma, likely owing to variable admixtures of diagenetic illite in the shales. Overall, the data provide evidence for a stable hydrologic regime since Paleozoic time.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
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