Improving livestock productivity and sustainability through management and genetics

Challenges

The interactions between livestock productivity, climate change and biodiversity are multi-factorial. Livestock certainly contributes to greenhouse gas (GHG) emissions and uses a significant proportion of available land, but they are also an integral part of the solution to both the climate change and biodiversity crises. Improving livestock health is a key priority for important stakeholder groups. The control of endemic disease has frequently been shown to correlate with improved livestock productivity, in terms of improving reproductive success, optimising growth rates, and reducing waste and losses.

Helminth parasites (worms and fluke) are a major constraint on efficient livestock production worldwide. They are directly affected by changing climatic conditions and farm management practices and contribute to livestock’s carbon footprint through reduced biological efficiency and increased emissions. Helminth parasites influence many factors that directly affect methane emissions, including feed conversion efficiency and nutrient utilisation. Effective worm control in sheep has been shown to lead to a 10-33% reduction in GHG emissions intensity, whereas, in abattoir studies, liver fluke has been shown to increase emissions from beef cattle by a small but statistically significant 2%, which is likely an underestimate.

The benefits of ‘farming with nature’ have been advocated to help achieve climate change targets and redress biodiversity loss on farmland. While initiatives such as wetland creation, woodland expansion and peatland restoration help in this regard, they require livestock grazing to function optimally, bringing with them potential risks to animal health. In addition, improved pasture management strategies may help to increase grass production, improve livestock productivity, reduce disease incidence, and promote sustainability on pasture. When considering all these options, we need further evidence on how to achieve a balance between improving biodiversity, reducing climate impact, sustainable intensification and food security whilst maintaining a healthy and vibrant rural economy.

Questions

Solutions

Grazing livestock are continually exposed to infection with helminth parasites (worms and fluke), which has a significant negative impact on their health, welfare, productivity and carbon footprint. This project aims to better understand key life-history characteristics of sheep, specifically (i) how animal performance changes with age, (ii) how animals differ in their tolerance of parasite infection, and (iii) the implications of early life events on future productivity. We are also investigating how livestock productivity can be improved through grazing management, specifically through improved pasture management to reduce gastrointestinal nematode (worm) burdens and to better understand the risk of liver fluke infection under wetland, woodland and peatland agri-environmental scenarios.

Quantifying age-specific variation in animal performance

As organisms age, their health and performance decline due to senescence. Increasing the healthy lifespan of livestock through nutrition or breeding may be a way to improve the efficiency of production. This may, however, come with costs, such as antagonistic associations between early and later-life performance or antagonistic associations between traits such as breeding ability and resistance to infection. We follow animals for four years from 18 months of age, to quantify ageing patterns in traits such as breeding performance and parasite resistance and identify the contribution of between- and within- individual processes to these patterns; identify how associations between traits change with age; and whether there are synergistic or antagonistic associations between traits across ages.

Tolerance of gastrointestinal nematode infection (GIN) in sheep

We are exploring tolerance of GIN in sheep. Infected hosts have two broad mechanisms for dealing with the impact of infection: resistance or tolerance. Resistance has been well-studied in the context of GIN-sheep interactions but tolerance has not. Without understanding how much tolerance varies, what its physiological basis is, or how it is associated with resistance and performance, optimising its use against GIN cannot be realised.

Understanding the consequences of early life events for future productivity

Livestock faces myriad challenges in early life, but we have little information about how these affect long-term productivity. Animals may show “predictive adaptive responses,” whereby health and performance are highest in animals whose later-life conditions mirror those experienced in early life, or “silver spoon” effects, where poor conditions in early life are associated with low performance in later life. We are estimating the impact of early life events on ewe traits and identifying key factors for important diseases/issues to introduce appropriate mitigations.

Impact of improved pasture management, grazing strategies and sustainable helminth control for livestock improvement

Improved pasture management may help to increase grass production, improve livestock productivity, reduce disease incidence, and promote sustainability in terms of GHG emissions, biodiversity, and resilience to climate change. However, evidence for these benefits is anecdotal. We aim to show how pasture management tools can improve livestock in Scotland. Combining rotational grazing with targeted selective treatment (TST) wormer use strategies will are testing management strategies that will be beneficial for livestock health and welfare, sustainable production, and climate change.

Evaluating fluke risk under agri-environment schemes, specifically wetland, woodland, and peatland

Lastly, we are evaluating fluke risk under agri-environment schemes, specifically wetland, woodland, and peatland. These environments bring potential benefits and risks from an animal health and environmental health/biodiversity perspective. We are monitoring the animal health implications of grazing such systems, specifically concerning fluke infections. We are assessing the liver fluke risk in these environments through analysis of the mud snails themselves, as these are the intermediate hosts for several important trematode (fluke) parasites of livestock and wildlife and hence function as sentinels of the fluke infection risk. We are also assessing the impact of these grazing systems on the requirement for anthelmintic treatment and the possible implications of such treatment for the ecology of these sensitive sites.

Project Partners

Progress