EvaluatingCattleEmissionSamplingSchemes

This study evaluated the accuracy of daily enteric H2 and CH4 production from dairy cattle using various sampling schemes for collection of emitted gases. Gas emission data from climate respiration chambers were available from 2 experiments covering both restricted and ad libitum feeding. Generalized additive models were fitted to the data for predicting diurnal H2 and CH4 emission rates. Sampling based on 9 predetermined sampling schemes had a major impact on estimated daily H2 production, in particular with restricted feeding, whereas daily CH4 production was moderately affected by sampling scheme with restricted feeding and not with ad libitum feeding.本研究针对奶牛肠道源性每日氢气（H₂）与甲烷（CH₄）产生量，采用多种气体采样方案采集排放气体，评估了其估算精度。本研究从两项涵盖限制饲喂与自由采食两种饲喂模式的实验中，获取了气候呼吸代谢舱内的气体排放数据。本研究针对该数据集拟合广义相加模型（Generalized Additive Models），以预测昼夜变化的氢气与甲烷排放速率。研究结果显示，基于9种预设采样方案开展的采样，对估算的每日氢气产生量存在显著影响，其中在限制饲喂模式下该影响尤为突出；而在限制饲喂模式下，采样方案对每日甲烷产生量仅存在中等程度影响，在自由采食模式下则无显著影响。