کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
11000010 | 1421095 | 2018 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Comparison of a laser methane detector with the GreenFeed and two breath analysers for on-farm measurements of methane emissions from dairy cows
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کلمات کلیدی
DMINDIRLinear mixed effect modelLMELMDIQRAMSTMRCCCRMSECH4CCRCThreshold - آستانهMethane emission - انتشار گاز مگنfirst quartile - اولین بارSniffer - بیگانهRepeatability - تکرارپذیریCarbon dioxide - دیاکسید کربنRoot mean square error - ریشه میانگین خطای مربعthird quartile - سومین تخت جمشیدCIA - سیاconcordance correlation coefficient - ضریب همبستگی سازگاریFTIR - طیف سنج مادون قرمزFourier transformed Infrared - فوریه تبدیل مادون قرمزNon-dispersive infrared - مادون قرمز غیر مشتق شدهMethane - متان interquartile range - محدوده بین محدبdry matter intake - مصرف ماده خشکrespiratory rate - نرخ تنفسRep - هرزهCO2 - کربن دیاکسیدtotal mixed ration - کل جیره مخلوط شده
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی کامپیوتر
نرم افزارهای علوم کامپیوتر
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Comparison of a laser methane detector with the GreenFeed and two breath analysers for on-farm measurements of methane emissions from dairy cows Comparison of a laser methane detector with the GreenFeed and two breath analysers for on-farm measurements of methane emissions from dairy cows](/preview/png/11000010.png)
چکیده انگلیسی
To measure methane (CH4) emissions from cattle on-farm, a number of methods have been developed. Combining measurements made with different methods in one data set could lead to an increased power of further analyses. Before combining the measurements, their agreement must be evaluated. We analysed data obtained with a handheld laser methane detector (LMD) and the GreenFeed system (GF), as well as data obtained with LMD and Fourier Transformed Infrared (FTIR) and Non-dispersive Infrared (NDIR) breath analysers (sniffers) installed in the feed bin of automatic milking systems. These devices record short-term breath CH4 concentrations from cows and make it possible to estimate daily CH4 production in g/d which is used for national CH4 emission inventories and genetic studies. The CH4 is released by cows during eructation and breathing events, resulting in peaks of CH4 concentrations during a measurement which represent the respiratory cycle. For LMD, the average CH4 concentration of all peaks during the measurement (P_MEAN in ppmâ¯Ãâ¯meter) was compared with the average daily CH4 production (g/d) measured by GF on 11 cows. The comparison showed a low concordance correlation coefficient (CCC; 0.02) and coefficient of individual agreement (CIA; 0.06) between the methods. The repeated measures correlation (rp) of LMD and GF, which can be seen as a proxy for the genetic correlation, was, however, relatively strong (0.66). Next, based on GF, a prediction equation for estimating CH4 in g/d (LMD_cal) using LMD measurements was developed. LMD_cal showed an improved agreement with GF (CCCâ¯=â¯0.22, CIAâ¯=â¯0.99, rpâ¯=â¯0.74). This prediction equation was used to compare repeated LMD measurements (LMD_val in g/d) with CH4 (g/d) measured with FTIR (nâ¯=â¯34 cows; Data Set A) or NDIR (nâ¯=â¯39 cows; Data Set B) sniffer. A low CCC (A: 0.28; B: 0.17), high CIA (A: 0.91; B: 0.87) and strong rp (A: 0.57; B: 0.60) indicated that there was some agreement and a minimal re-ranking of the cows between sniffer and LMD. Possible sources of disagreement were cow activity (LMD: standing idle; sniffer: eating and being milked) and the larger influence of wind speed on LMD measurement. The LMD measurement was less repeatable (0.14-0.27) than the other techniques studied (0.47-0.77). Nevertheless, GF, LMD and the sniffers ranked the cows similarly. The LMD, due to its portability and flexibility, could be used to study CH4 emissions on herd or group level, as a validation tool, or to strengthen estimates of genetic relationships between small-scale research populations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computers and Electronics in Agriculture - Volume 153, October 2018, Pages 285-294
Journal: Computers and Electronics in Agriculture - Volume 153, October 2018, Pages 285-294
نویسندگان
Diana Sorg, Gareth F. Difford, Sarah Mühlbach, Björn Kuhla, Hermann H. Swalve, Jan Lassen, Tomasz Strabel, Marcin Pszczola,