Journal of the Society of Agricultural Structures, Japan
Online ISSN : 2186-0122
Print ISSN : 0388-8517
ISSN-L : 0388-8517
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Volume 50, Issue 1
Vol. 50, No. 1 (Ser. No. 160)
Displaying 1-3 of 3 articles from this issue
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  • Effect on Water Intake and Milk Production of Supplemental Warmed Water for Dairy Cows in Winter
    Yoichiro KOJIMA, Hiroki MATSUYAMA, Yoshiyuki ABE, Makoto MIYAJI, Koich ...
    2019 Volume 50 Issue 1 Pages 1-6
    Published: 2019
    Released on J-STAGE: September 07, 2023
    DOIhttps://doi.org/10.11449/sasj.50.1_1
    JOURNAL OPEN ACCESS
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    This paper describes the impact on water intake and milk yield of supplemental warmed water for dairy cows in winter. Twenty four Holstein cows were used in a crossover design with two supplied water treatments: water warmed to 35 °C and water of below 10 °C as a control. The mass of water intake increased by 9.9 % and milk yield increased by 3.8 % by supplying warmed compared with cold water (p < 0.01) without increasing feed intake or altering milk components. Moreover, cold-water supplement had a water-intake frequency of 2.1 times and a duration of water-intake 2.4 times that for warmed-water (p < 0.01). Therefore, the warm-water supplement increased water intake within a short period and reduced the intake time, and resulted in higher milk yield without increased feed intake.
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  • Wind Load Reduction of Steel Greenhouse with Wing-like Cross Section by Controlling Internal Pressure
    Namseok KIM, Tomoaki MAZAKI, Yasushi UEMATSU
    2019 Volume 50 Issue 1 Pages 7-15
    Published: 2019
    Released on J-STAGE: September 07, 2023
    DOIhttps://doi.org/10.11449/sasj.50.1_7
    JOURNAL OPEN ACCESS
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    We proposed a steel greenhouse with wing-like cross section in previous study (Kim et al., 2016). The present paper discusses the reduction of load effect (bending moment, in practice) by making openings (slits) in the side walls and thereby controlling the internal pressure. 　　First, we measured external pressures at the location of the openings with a scale model in a turbulent boundary layer. The external pressures were used for simulating the internal pressure. The effects of various parameters on the internal pressure coeffi cient were made clear. The distributions of external wind pressures in some cross-sections were also measured. Then, we carried out a two-dimensional frame analysis using the time history of wind force coeffi cients provided by the difference between the external and internal pressure coeffcients. Focus was on the bending moments induced in the frame members as the most important load effect. The effect of the width of slits in the side walls on the bending moments was investigated under various conditions, e.g. frame location and wind direction. Based on the results, an optimum combination of the slit width was derived, which could reduce the maximum bending moment by approximately 20 %, compared with the enclosed type of structure.
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  • Solid-liquid Separation Process by Using Screw Press to Treat Semi-solid Dairy Manure from Free-barn Cowshed for Anaerobic Digestion and Composting
    Kenichi FURUHASHI, Akihiro TANAKA, Kazutaka KURODA
    2019 Volume 50 Issue 1 Pages 16-23
    Published: 2019
    Released on J-STAGE: September 07, 2023
    DOIhttps://doi.org/10.11449/sasj.50.1_16
    JOURNAL OPEN ACCESS
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    The semi-solid dairy manure from the loose housing system contents relatively large amount of sawdust as bedding material. In this study, the introduction of solid-liquid separation process by screw press in wet anaerobic digestion treatment system, which can treat the semi-solid manure, was investigated for composting the solid fraction without adding any secondary material and increasing the concentration of organic matter in the liquid fraction to improve fermentation effi ciency. The manure was mixed in digested liquid to pump easily to the separator in advance. The water content of the solid fraction decreased with either decreasing total solids in the mixture or increasing back pressure, and was easily achieved under 73.0 %, suitable for composting. EC was decreased by 30 %. The separation effi ciency of dry matter from the semi-solid or the slurry manure was at 79.3 % or 58.5 %. This was caused by sawdust almost completely removed. The ratio of easily decomposable organic matter to volatile solids in the liquid fraction was at 79 %, compared with 40 % in the initial manure. Moreover, the concentration of easily decomposable organic matters estimated to be more than twice by repeating mix of the manure in liquid fraction and separation three times.
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