| Autor: | Martin, Cécile, Rochette, Yvanne, Humphries, David, Renand, Gilles |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| DOI: | 10.5680/mcpb012 |
| Popis: | The GreenFeed (GF) system spot samples the breath of individual animals for short periods (3–7 min), at various times of the day, over several days, weeks, or months to measure methane production. To obtain a diurnal CH4 emission pattern from the GF system, the animal visits need to be appropriately distributed over a 24 h feeding cycle. This can be difficult to achieve as the number of visits is greater during certain hours of the day. However, visits can be manipulated to some extent by the type of ration provided. Arthur performed a field study using beef cattle, and concluded that 30 observations per animal (15 d, cattle fed an ad libitum roughage diet) were sufficient to produce a reliable CH4 emission outcome from the GF system, if the durations of each visit are sufficient (minimum of 3 min). Others have stated that 50 spot measurements per animal were needed over a 17 d period to obtain a high repeatability (R=0.7) for dairy cows. Manafiazar concluded that a minimum of 20 spot samples over a 7- to 14-d period would be highly repeatable as well as highly correlated with feed intake. Ultimately, accurate outcomes from the GF system can be obtained when the operator strictly controls the number and timing of animal visits. This can be easily managed in tie-stalls but is more difficult in grazing systems Chapter of the Living Handbook Methods in cattle physiology and behaviour – Recommendations from the SmartCow consortium |
| Databáze: | OpenAIRE |
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