Future forages: Implications of forage response to climate change for ruminant production

未来饲料：饲料应对气候变化对反刍动物生产的影响

• 批准号: BB/R019185/1
• 负责人: Alison Kingston-Smith
• 金额: $ 60.5万
• 依托单位: Aberystwyth University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FR019185%2F1
• 关键词: Future; forages; Implications; forage; response

Are our current forage-grass varieties fit for the future? Ruminant farming enables production from marginal land that cannot be used to grow human food, thus contributing to global food security. Grazing land makes up ~60 % of the world's agricultural land supporting 360 million cattle and > 600 million sheep and goats. Continual improvement of the forage grasses used as animal feed has underpinned increases in ruminant production in an industry sector worth over £6 billion a year to the UK. Continued development of forage varieties for livestock production is essential to keep up with future demands of the growing human population. Forage grass varieties currently under development are grown and assessed under current field conditions, Our preliminary research indicates that a change in growing conditions can affect how grass is digested and impact on animal production. Climate models predict near future (2050) increases in atmospheric CO2, increases in average temperatures, increased average precipitation, and increased frequency of extreme events. These trends are particularly pertinent to western England and Wales that are the primary sites of UK ruminant production. As it takes at least 10 years of selective breeding to go from concept to marketable product we need to know now if we are targeting the correct traits for forages of the future. Previous work at Aberystwyth has shown that following ingestion by the animal, fresh forage feeds are degraded by enzymes of both microbial and plant origin. Grazed ryegrass entering the rumen of the animal is colonised by a subset of the microbial species present. These microbial communities are associated with the production of hydrolases, enzymes that break down plant cell walls. Efficient break down of plant cell walls in the forage is the key to energy provision for microbial growth in the rumen. If energy is limiting and plant protein breakdown is rapid, amino acids are used as an energy source generating levels of ammonia that cannot be assimilated by the animal and are excreted. This results in a loss of up to 70% of feed protein. Grazed grasses contribute to these protein losses because of stress responses to the rumen conditions. Modification of forage quality by exposure of the grass to stress during growth (eg drought) affects the process of early digestion in the rumen through stress memory; the effect of pre-exposure to a stress on the response to a subsequent stress. Hence, growth of current ryegrass varieties in a changed climate will alter the plant's response to stresses in the rumen. This will change the microbial colonisation in the rumen, which in turn will affect animal production and the environment through increased waste. We will test the hypothesis that the response of grass leaves to climate change affects post-ingestion metabolism in plant and microbial cells, thus altering rumen system efficiency. In vitro fermentation of 10 ryegrass varieties will be assessed under current (2020) and 4 future (2050) conditions of elevated CO2 and temperature. These include scenarios that involve exposure to acute stress (drought, flooding or heat). Two varieties showing maximum and minimum differential response to at least one 2050 condition will be studied in detail to assess changes in the chemistry, protein content and composition of the forage, changes in the response of their genes to the rumen environment and how this affects the development and function of the rumen microbial communities. Predictions formed by in vitro experimentation will be confirmed with small ruminant trials to verify the whole animal effect focusing on decreasing methane and nitrogen release. The key output of our work will be to inform plant breeders on optimal targets to ensure forage grasses are fit for the future.

我们现在的牧草品种适合未来吗？ 反刍动物养殖使不能用于种植人类粮食的边际土地能够生产，从而促进全球粮食安全。牧场占世界农业用地的60%左右，饲养着3.6亿头牛和6亿多只绵羊和山羊。作为动物饲料的牧草的不断改进支撑了反刍动物产量的增长，该行业每年为英国创造了超过60亿英镑的价值。持续开发用于畜牧生产的饲料品种对于满足不断增长的人口的未来需求至关重要。 目前正在开发的饲草品种是在当前的田间条件下种植和评估的，我们的初步研究表明，生长条件的变化会影响草的消化方式，并影响动物生产。气候模型预测，在不久的将来（2050年），大气中的二氧化碳会增加，平均气温会上升，平均降水量会增加，极端事件的频率会增加。这些趋势与英国反刍动物生产的主要地点英格兰西部和威尔士特别相关。由于从概念到可销售的产品至少需要10年的选择性育种，我们现在需要知道我们是否针对未来牧草的正确性状。 阿伯里斯特威斯先前的工作表明，在动物摄入后，新鲜的草料饲料会被微生物和植物来源的酶降解。进入动物瘤胃的放牧黑麦草被存在的微生物物种的子集定殖。这些微生物群落与水解酶的产生有关，水解酶是分解植物细胞壁的酶。饲料中植物细胞壁的有效分解是为瘤胃微生物生长提供能量的关键。如果能量是有限的，植物蛋白质分解是快速的，氨基酸被用作能量来源，产生的氨水平不能被动物同化，并排出体外。这导致高达70%的饲料蛋白质损失。放牧牧草由于对瘤胃条件的应激反应而导致这些蛋白质损失。通过在生长过程中将牧草暴露于应激（如干旱）来改变牧草质量，通过应激记忆影响瘤胃中的早期消化过程;预先暴露于应激对随后应激反应的影响。因此，当前的黑麦草品种在变化的气候中的生长将改变植物对瘤胃应激的反应。这将改变瘤胃中的微生物定殖，从而通过增加废物影响动物生产和环境。 我们将测试这一假设，即牧草叶片对气候变化的反应影响了植物和微生物细胞的摄食后代谢，从而改变了瘤胃系统的效率。将在当前（2020年）和4个未来（2050年）CO2和温度升高的条件下评估10个黑麦草品种的体外发酵。这些包括涉及暴露于急性应激（干旱、洪水或高温）的情景。将详细研究对至少一种2050条件表现出最大和最小差异反应的两个品种，以评估饲料的化学、蛋白质含量和组成的变化，其基因对瘤胃环境的反应变化，以及这如何影响瘤胃微生物群落的发育和功能。将通过小型反刍动物试验证实体外实验形成的预测，以验证整个动物的效果，重点是减少甲烷和氮的释放。我们工作的关键成果将是告知植物育种者最佳目标，以确保牧草适合未来。

项目成果

Improving orthologous signal and model fit in datasets addressing the root of the animal phylogeny

改善数据集中的同源信号和模型拟合，解决动物系统发育的根源

• DOI: 10.1101/2022.11.21.517274
• 发表时间: 2022
• 作者: McCarthy C

Improving Orthologous Signal and Model Fit in Datasets Addressing the Root of the Animal Phylogeny.

• DOI: 10.1093/molbev/msac276
• 发表时间: 2023-01-04
• 期刊: MOLECULAR BIOLOGY AND EVOLUTION
• 影响因子: 10.7
• 作者: McCarthy, Charley G. P.;Mulhair, Peter O.;Siu-Ting, Karen;Creevey, Christopher J.;O'Connell, Mary J.
• 通讯作者: O'Connell, Mary J.

Forage grass growth under future climate change scenarios affects fermentation and ruminant efficiency.

• DOI: 10.1038/s41598-022-08309-7
• 发表时间: 2022-03-15
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Hart EH;Christofides SR;Davies TE;Rees Stevens P;Creevey CJ;Müller CT;Rogers HJ;Kingston-Smith AH
• 通讯作者: Kingston-Smith AH

Enriching for orthologs increases support for Xenacoelomorpha and Ambulacraria sister relationship

丰富直向同源物增加了对 Xenacoelomorpha 和 Ambulacaria 姐妹关系的支持

• DOI: 10.1101/2021.12.13.472462
• 发表时间: 2021
• 作者: Mulhair P