Interventions to reduce enteric methane emissions in early life of cattle

为减少畜牧生产产生的温室气体（GHG）排放，提出了几种干预措施。特别是，有一些甲烷抑制剂（例如，3-硝基氧丙醇（3-NOP），来自海藻的活性化合物，单宁），当喂给牛时，具有减少碳足迹的潜力。最近的一项研究表明，在奶牛生命的早期阶段施用一些抗甲烷化合物，在施用3-NOP的同时，使小牛的甲烷排放量减少了11.6%，而且具有持久的效果，在停止施用3-NOP一年后，排放量减少了17.5%。然而，之前的研究是在犊牛饲喂代乳品或全混合日粮（TMR）的乳制品条件下进行的，随后的研究表明，3-NOP抗产甲烷菌的性能在牧场条件下效果较差。这些抗产甲烷菌干预措施可能会影响瘤胃微生物种群，并可能对减少甲烷排放产生中长期影响。此外，如果这些干预措施与生命后期的其他缓解战略相结合，例如，将呼出的甲烷氧化成二氧化碳（CO2）和水蒸气（H2O）的可穿戴设备，它们的共同作用可能会大大减少畜牧业的温室气体排放。因此，本项目的目的是评估在犊牛出生后两周内施用抗产甲烷化合物是否能减少犊牛不同生命阶段（即犊牛、生长公牛或肥育期）以及不同喂养方式（如断奶前、青贮喂养和放牧条件下）的甲烷排放。此外，该项目旨在评估ZELP可穿戴设备等农业技术工具的潜力，这些工具能够将呼出的甲烷氧化成二氧化碳和H2O，特别强调其减少幼鱼甲烷排放的潜力。所有这些干预措施将通过生命周期评估（LCA）在系统一级全面评估其对碳足迹的影响。博士论文将涉及以下任务进行评估：T1：抗产甲烷技术对犊牛早期肠道甲烷排放的短期影响。T2：早期抗产甲烷剂干预对犊牛放牧或食用青贮饲料时肠道甲烷排放的中长期影响T3：干预如何影响Zelp可穿戴设备作为第二种甲烷排放抑制剂的潜在使用T4：对上述条件进行LCA，以进行比较并确定最佳缓解策略

Several interventions have been proposed for mitigating greenhouse gas (GHG) emissions arising from livestock production. In particular, there are some methane inhibitors (e.g., 3-nitrooxypropanol (3-NOP), active compounds from seaweeds, tannins) that possess potential reductions to carbon footprints when fed to cattle. A recent study has shown that some anti-methanogen compounds administrated at early stages of dairy calves' life reduced the calves methane emissions by 11.6% while the 3-NOP was administered, but also had a lasting effect, reducing the emissions by 17.5% after one year of ceasing 3-NOP administration. However, the previous study was undertaken under dairy conditions where calves were feed either milk replacer or a total mixed ration (TMR), and subsequent research has shown that the 3-NOP anti-methanogen properties are less effective under pasture-based conditions. These anti-methanogen interventions may affect the microorganism populations inhabiting the rumen and could have a mid- or long-term effect in reducing methane emissions. Moreover, if such interventions are combined with additional mitigation strategies later in life, e.g., wearable devices to oxidise the methane exhaled into carbon dioxide (CO2) and water vapour (H2O) their joint effect might produce substantial reductions in GHG emissions from the livestock sector. Therefore, the objective of this project is to assess whether anti-methanogen compounds administrated within the first two weeks of life to calves reduce methane emissions at different life stages, i.e., calf, growing steer or finishing stage and under different feedings regimes: e.g., until weaning, silage feeding, and under grazing conditions. Moreover, this project aims to assess the potential of agritech tools like ZELP wearables, capable of oxidising methane exhaled into CO2 and H2O, with a particular emphasis on its potential to reduce methane emissions of young stock. All these interventions will be assessed in a comprehensive way with regard to their impact on the carbon footprint at a system level through Life Cycle Assessment (LCA).The PhD thesis will involve the following Tasks to assess: T1: The short-term effect of anti-methanogen technologies on calves' early life enteric methane emissions. T2: The mid/long-term effect of the early anti-methanogen intervention on calves' enteric methane emissions whilegrazing or consuming silage T3: How the intervention affects the potential usage of Zelp wearables as a second methane emissions inhibitor T4: To undertake a LCA of the aforementioned conditions for comparative purposes and identification of optimalmitigation strategies