Interventions to reduce enteric methane emissions in early life of cattle

已经提出了若干干预措施，以减少畜牧业生产产生的温室气体排放。特别地，存在一些甲烷抑制剂（例如，3-硝基氧丙醇（3-NOP）、来自海藻的活性化合物、单宁），其在饲喂牛时具有减少碳足迹的潜力。最近的一项研究表明，在乳牛生命的早期阶段施用一些抗产甲烷菌化合物，在施用3-NOP时，使乳牛甲烷排放量减少11.6%，但也具有持久的效果，在停止施用3-NOP一年后，使排放量减少17.5%。然而，先前的研究是在奶牛条件下进行的，其中小牛被喂食牛奶添加剂或全混合日粮（TMR），随后的研究表明，3-NOP抗产甲烷菌特性在基于牧场的条件下效果较差。这些抗产甲烷菌的干预措施可能会影响瘤胃内的微生物种群，并可能对减少甲烷排放产生中期或长期影响。此外，如果这些干预措施与生命后期的其他缓解策略相结合，可穿戴设备将呼出的甲烷氧化成二氧化碳（CO2）和水蒸气（H2O），它们的共同作用可能会大幅减少畜牧业的温室气体排放。因此，本项目的目的是评估在小牛出生后的前两周内给予抗产甲烷菌化合物是否会减少不同生命阶段的甲烷排放，即，犊牛、生长期阉牛或肥育期以及在不同的喂养方案下：例如，直到断奶、青贮饲料喂养和放牧条件下。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为CO2和H2O，特别强调其减少幼龄牲畜甲烷排放的潜力。所有这些干预措施都将通过生命周期评估（LCA）在系统层面上对碳足迹的影响进行全面评估。博士论文将涉及以下评估任务：T1：抗产甲烷菌技术对小牛早期肠道甲烷排放的短期影响。T2：早期抗产甲烷菌干预对放牧或食用青贮饲料时小牛肠道甲烷排放的中期/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用途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