| Autor: |
Moate PJ; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia.; Centre for Agricultural Innovation, Faculty of Veterinary and Agricultural Sciences, School of Agriculture and Food, The University of Melbourne, Victoria 3010, Australia., Pryce JE; Agriculture Victoria Research, La Trobe University, Bundoora, Victoria 3083, Australia., Marett LC; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia.; Centre for Agricultural Innovation, Faculty of Veterinary and Agricultural Sciences, School of Agriculture and Food, The University of Melbourne, Victoria 3010, Australia., Garner JB; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia., Deighton MH; Cropmark Seeds Ltd., Christchurch 7677, New Zealand., Ribaux BE; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia., Hannah MC; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia., Wales WJ; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia.; Centre for Agricultural Innovation, Faculty of Veterinary and Agricultural Sciences, School of Agriculture and Food, The University of Melbourne, Victoria 3010, Australia., Williams SRO; Agriculture Victoria Research, Ellinbank, Victoria 3821, Australia. |
| Abstrakt: |
Despite the fact that the sulphur hexafluoride (SF 6 ) tracer technique was developed over 25 years ago to measure methane production from grazing and non-housed animals, no studies have specifically investigated whether ambient wind speed, temperature, relative humidity and rainfall influence the accuracy of the method. The aim of this research was to investigate how these weather factors influence the measurement of enteric methane production by the SF 6 technique. Six different cohorts of dairy cows (40 per cohort) were kept outdoors and fed a common diet during spring in 3 consecutive years. Methane production from individual cows was measured daily over the last 5 days of each 32-day period. An automated weather station measured air temperature, wind speed, relative humidity and rainfall every 10 min. Regression analyses were used to relate the average daily wind speed, average daily temperature, average daily relative humidity and total daily rainfall measurements to dry matter intake, average daily methane production and methane yield of each cohort of cows. It was concluded that the modified SF 6 technique can be used outdoors during a range of wind speeds, ambient temperatures, relative humidities and rainfall conditions without causing a significant effect on the measurement of methane production or methane yield of dairy cows. |
