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緩解奶牛熱應(yīng)激的噴淋水滴粒徑研究

發(fā)布時(shí)間:2018-06-23 02:55

  本文選題:奶牛 + 噴淋水滴粒徑。 參考:《農(nóng)業(yè)機(jī)械學(xué)報(bào)》2017年09期


【摘要】:為探討夏季緩解奶牛熱應(yīng)激噴淋水滴粒徑對(duì)降溫效果的影響,通過(guò)現(xiàn)場(chǎng)實(shí)驗(yàn)測(cè)試了3種平均噴淋水滴粒徑(0.829、0.947、1.127 mm)緩解奶牛熱應(yīng)激效果。實(shí)驗(yàn)中利用熱像儀采集奶牛體表溫度,同時(shí)測(cè)定呼吸頻率、直腸溫度生理指標(biāo),并在此基礎(chǔ)上利用Merkel焓差理論分析計(jì)算奶牛噴淋降溫?fù)Q熱量。結(jié)果表明,噴淋過(guò)程中,3種粒徑(0.829、0.947、1.127 mm)在奶牛脖頸區(qū)域平均降溫為0.7、1.1、0.9℃,腹部區(qū)域平均降溫為0.7、1.4、1.5℃,平均呼吸頻率分別降低0.6、4.2、2.1次/min;噴淋結(jié)束后,3種粒徑在奶牛脖頸區(qū)域平均降溫為0.2、0.4、0.6℃,腹部區(qū)域平均降溫為0.1、0.5、0.6℃,平均呼吸頻率降低-0.4、1.4、1.2次/min。噴淋前后奶牛直腸溫度均控制在穩(wěn)定范圍內(nèi),且平均噴淋水滴粒徑0.947 mm和1.127 mm低于0.829 mm時(shí)的奶牛平均直腸溫度。3種平均噴淋水滴粒徑對(duì)應(yīng)的奶牛單位時(shí)間換熱量分別為417.4、469.9、430.4 W,其中0.947 mm平均噴淋水滴粒徑下?lián)Q熱量最大。因此,平均噴淋水滴粒徑0.947 mm更適用于夏季奶牛噴淋降溫。
[Abstract]:In order to investigate the effect of sprinkling water droplet size on cooling effect in summer, three kinds of average spray water droplets diameter (0.829 ~ 0.947 ~ 1.127 mm) were tested in the field. In the experiment, the body surface temperature of dairy cattle was collected by thermal imager, and the physiological indexes of respiratory frequency and rectal temperature were measured simultaneously, and based on this, the heat transfer was calculated by using the theory of Merkel's enthalpy difference. The results showed that during the spraying, the average temperature of the three diameters (0.829, 0.9471.127mm) in the neck area of dairy cattle was 0.71.1kW 0.9 鈩,

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