Pereira Ana Margarida, Peixoto Pedro, Rosa Henrique J D, Vouzela Carlos, Madruga João S, Borba Alfredo E S
Faculdade de Ciências Agrárias e do Ambiente, Instituto de Investigação em Tecnologias Agrárias e do Ambiente (IITAA), Universidade dos Açores, Campus de Angra do Heroísmo, Rua Capitão João d'Ávila, 9700-042 Angra do Heroísmo, Portugal.
Animals (Basel). 2023 Mar 8;13(6):974. doi: 10.3390/ani13060974.
Reversing climate change requires broad, cohesive, and strategic plans for the mitigation of greenhouse gas emissions from animal farming. The implementation and evaluation of such plans demand accurate and accessible methods for monitoring on-field CH concentration in eructating breath. Therefore, this paper describes a longitudinal study over six months, aiming to test a protocol using a laser methane detector (LMD) to monitor CH emissions in semi-extensive dairy farm systems. Over 10 time points, CH measurements were performed in dry (late gestation) and lactating cows at an Azorean dairy farm. Methane traits including CH concentration related to eructation (E_CH4) and respiration (R_CH), and eructation events, were automatically computed from CH measured values using algorithms created for peak detection and analysis. Daily CH emission was estimated from each profile's mean CH concentration (MEAN_CH). Data were analyzed using a linear mixed model, including breed, lactation stage, and parity as fixed effects, and cow (subject) and time point as random effects. The results showed that Holsteins had higher E_CH than Jersey cows ( < 0.001). Although a breed-related trend was found in daily CH emission ( = 0.060), it was not significant when normalized to daily milk yield ( > 0.05). Methane emissions were lower in dry than in lactation cows ( < 0.05) and increased with the advancement of the lactation, even when normalizing it to daily milk yield ( < 0.05). Primiparous cows had lower daily CH emissions related to R_ CH compared to multiparous ( < 0.001). This allowed the identification of periods of higher CH emissions within the milk production cycle of dairy cows, and thus, the opportunity to tailor mitigation strategies accordingly.
扭转气候变化需要制定广泛、连贯且具有战略意义的计划，以减少畜牧业的温室气体排放。此类计划的实施和评估需要准确且可操作的方法来监测反刍呼出气体中的甲烷浓度。因此，本文描述了一项为期六个月的纵向研究，旨在测试一种使用激光甲烷探测器（LMD）监测半粗放式奶牛养殖系统中甲烷排放的方案。在亚速尔群岛的一个奶牛场，在10多个时间点对干奶期（妊娠后期）和泌乳期奶牛进行了甲烷测量。利用为峰值检测和分析创建的算法，从甲烷测量值中自动计算出与反刍（E_CH4）和呼吸（R_CH）相关的甲烷特征以及反刍事件。根据每个记录的平均甲烷浓度（MEAN_CH）估算每日甲烷排放量。使用线性混合模型对数据进行分析，将品种、泌乳阶段和胎次作为固定效应，将奶牛（个体）和时间点作为随机效应。结果表明，荷斯坦奶牛的E_CH高于泽西奶牛（<0.001）。尽管在每日甲烷排放中发现了与品种相关的趋势（=0.060），但在按每日产奶量进行标准化后并不显著（>0.05）。干奶期奶牛的甲烷排放量低于泌乳期奶牛（<0.05），并且随着泌乳进程的推进而增加，即使按每日产奶量进行标准化也是如此（<0.05）。与经产奶牛相比，初产奶牛与R_CH相关的每日甲烷排放量较低（<0.001）。这使得能够确定奶牛产奶周期内甲烷排放较高的时期，从而有机会相应地调整减排策略。
