Future-proofing our breeding goals - Breeding for climate resilience in UK dairy systems

Lead Research Organisation: SRUC
Department Name: Research

Abstract

Our climate is changing, and we can expect to see increases in temperature and the frequency of extreme weather events, such as heat waves, flooding and drought, over the coming century. Previous work on the effects of weather on livestock has focused on animals' responses to heat stress. Dairy cows produce less milk under high temperatures and humidities and the quality of their milk is reduced. In addition, heat stress can interfere with cows' abilities to conceive and can increase susceptibility to disease and early mortality. Our preliminary analyses show that dairy cows are not only affected by heat stress under current UK weather conditions but also by a range of other weather elements, such as precipitation, wind speed and solar radiation, sometimes even while they are housed. Further preliminary work estimated the cost of the UK's future climate (2050-2080, UKCP09) on the UK dairy industry at up to £80 million/yr in net present terms based on lost milk production and female fertility and increased mortality. The need to address production losses will become increasingly important as the global population continues to grow.

For many decades, agriculture has benefited from knowledge of the genetic quality of livestock, whereby genes associated with high productivity are identified, and animals with those genes are selected for breeding. Livestock breeding is a globalised industry controlled by multinational companies that disseminate semen (and therefore genetic improvements) across continents. Breeding plans have traditionally focused on improving productivity without attention to other characteristics, such as the ability of animals to cope with heat stress. High producing dairy cattle are usually poor at tolerating heat, especially those bred for temperate climates. Furthermore, dairy cattle are becoming more sensitive to heat stress as the pressure to produce more milk from fewer animals rises. The health and performance of high yielding cows can only b maintained if they receive an adequate intake of feed and water. However, little is known about how unfavourable weather conditions and extreme events will affect their requirements for nutrients and water. For example, cows might change the overall quantities of food and water they consume, and also aspects of feeding and drinking behaviour. An understanding of animal requirements for water under increasing temperatures will be a key component of efficient water management, especially given that water shortages are predicted to become more frequent over the next century.

Here we aim to identify the characteristics that indicate how well dairy cows cope with the challenges of a changing climate, along with the genes that control the various aspects of this ability. We will also assess the economic costs and benefits of breeding for cows with an improved tolerance to unfavourable weather to ensure that our findings can be applied in a cost-effective way . Our team at SRUC consists of experts in livestock genetics, climate change, animal behaviour and environmental economics with a strong track record of successful projects. We will work closely with established contacts within the dairy industry (e.g. Genus) to ensure that the knowledge generated from this project is of practical value to farmers in helping them to maintain or improve livestock productivity, health and welfare, and thus farm profitability. This work will provide clear benefits to the farming community, the broader UK dairy industry and consumers, helping to maintain productivity through sustainable, socially-acceptable means in the face of climate and food security risks.

Technical Summary

Climate change will impact livestock directly through increases in heat stress and the frequency of extreme weather events (e.g. drought). In dairy cows, heat stress can reduce milk yield and quality, and fertility, and increase susceptibility to disease. Our preliminary analyses show that cows are not only affected by heat stress under current UK conditions but also by a range of other weather elements, such as precipitation, wind speed and solar radiation. Here we aim to develop tools that will increase the capacity of dairy cows to maintain productivity and fitness in the face of stresses associated with climate change. We will thus:
1. Quantify the effects of weather and extreme events on a range of phenotypic traits (e.g. milk yield, health, survival, fertility) on a local (research farm: >25 years of fine-scale data) and national (UK-wide, commercial) scale using UK Met Office data.
2. Evaluate the potential for novel phenotypes (e.g. feeding/drinking patterns, mid-infrared (MIR) spectral measurements of milk) to be used as indicators of climate resilience.
3. Estimate genetic parameters for climate resilience to assess the potential to breed for it, and conduct a genome wide association scan (GWAS) for the resilience traits.
4. Perform cost-benefit and quantitate risk analyses for climate resilience to select breeding strategies that are cost-effective, socially acceptable and policy-relevant, resulting in a prototype 'Climate Smart' breeding programme.
The project team consists of experts in livestock genetics, climate change and environmental economics with a strong track record of successful projects. We will work closely with dairy industry contacts to ensure that this knowledge is of practical value to farmers. In helping to maintain productivity, animal health and welfare through sustainable means in the face of climate and food security risks, the project will benefit the farming community, the broader UK dairy industry and consumers.

Planned Impact

The sustainability of the UK dairy industry hinges on the ability of farmers to respond to key challenges, such as those arising from climate change and extreme weather events. This project aims to characterise the phenotypic and genetic traits that enable dairy cows to cope with weather-related stresses. By combining animal science and environmental economics, it offers an innovative approach to equipping the UK dairy industry with the tools necessary to breed more resilient animals in a sustainable and profitable manner. We will work closely with contacts within the dairy industry to ensure that this project is of practical value to farmers. The PI has previously worked with the dairy industry to successfully deliver genetic improvement tools to dairy farmers to enhance animal fertility, health, welfare and survival. These tools have helped UK dairy producers become more sustainable by adapting to a range of challenges. Adoption of new indices have improved animal health and profitability compared to continued use of previous selection practices, and have cumulatively reduced greenhouse gas emissions per breeding cow per year by 1.4% (reduction in CO2 equivalents). The overall economic benefits of the genetic improvement that took place in the years 1980-2009 is worth £105.7 million/year to the UK dairy industry. A large proportion (~50%) has been realised by including health, fertility and longevity traits in UK dairy breeding goals.

Our project is expected to benefit the scientific community, the farming community, the broader UK dairy industry, consumers and public policy.

DAIRY FARMERS AND INDUSTRY
1. Better understanding of the response of animals to extreme weather events and the genetic basis of resilience,
2. Novel indicators of climate resilience (e.g. mid-infrared spectral measurements from milk),
3. Calibration of breeding goals to future climates, including prototype Climate Smart breeding goal geared to a temperate climate. Such a tool can be imlemented into dairy breeding programmes (e.g. Genus' Genetic Management System offers customised programmes based on farmers' individual breeding goals - letter of support). Incorporating resilience traits into these programmes would minimise economic loss due to climate change balancing farmer profitability and sustainability.
4. Improved farm management strategies. For example, a better understanding of changes in water intake patterns by cattle under different weather conditions will be particularly important given predictions for increases in drought intensity and spatial extent.

CONSUMERS AND POLICY
5. Improved farm welfare from minimising weather-related stress. This should improve consumer image
6. Projections for future dairy performance. These will help us to predict cost of climate change to the UK dairy industry and identify geographic regions where productivity will decline or increase over the next decades. Such projections could help the UK prepare for potential changes in productivity and economic viability in different regions. In addition, the project will quantify the economic costs and benefits of resilience to climate, which will be an important tool for informing policy.

SCIENTIFIC DEVELOPMENT
7. Training for two postdoctoral researchers in interdisciplinary approaches to addressing societal challenges
8. Collaboration with INIA, Spain will enable methods to be shared to provide broader knowledge on genetics of thermal stress in cattle

All members of society who work to improve or depend upon the competitiveness and sustainability of agriculture will benefit from the downstream applications. The application of the research by breeding companies will lead to faster and more sustainable genetic progress, producing food that is more resource-efficient and affordable. Increased efficiencies in agriculture have direct societal benefits in greater food security with less environmental impact.

Publications

10 25 50
 
Description 1. using UK Meteorological Office data to investigate the effects of weather events on phenotypic traits encompassing different management systems on a local and national scale
We secured and matched weather data from UK Met Office to both research farm data (SRUC dairy research centre) and national dairy farm data secured from National Milk Records. Data extraction systems were developed to match the weather station location (long:lat) with farm location data by calculating the distance of the weather station to the farm location taking account, where relevant, with the altitude of the site of the farm (main steading) and the weather station. A subset of the national farm data based on only including farms having a met office weather station within 5km or 10km of the farm main steading, ensuring that we have sufficient representative coverage across the UK. These algorithms were developed in line with the system for extracting information on animal and farm performance used in national genetic evaluations such that if we find relevant animal climate resilience phenotypes and/or weather effects on animal performance that impacts on estimated breeding values we will be able to incorporate this information into routine genetic evaluations.
To test the impact of weather variables on production and health traits we extracted regionally blocked animal performance data (minimum of 50 herds within a NUTS2 region) with 202 farms selected, with a minimum of two years of monthly milk testing data, including milk mid infrared analysis. Results showed that milk production decreased at both higher and lower temperature humidity index with a larger and longer depression of yields at higher rather than lower THI (up to 14% reduction under highest THI levels). There was a small and significant increase in somatic cell scores, an indicator of animal health, at higher THI.
OUTCOME: a detailed understanding of the relationship between weather and livestock phenotype, identification of resilient individuals for key production and fitness traits that can be incorporated into breeding programmes. COMPLETED
2. quantify the value of potential indicator traits to predict resilience in animals
The animal phenotypic indicators were primarily explored by analysing the richer phenotypes from the SRUC research centre. We have demonstrated animals' production and feeding is impacted by climate change. Using >73,000 dry matter intakes (DMI) and feed efficiency (FE) records from 328 cows over 8 yr, we found that select cows produced more fat- and protein-corrected milk, and had higher DMI and FE than controls. Cows of both lines decreased DMI and fat- and protein-corrected milk but, importantly, increased FE as THI increased. This suggests that improvements in the efficiency of converting feed to milk may partially offset the costs of reduced milk yield owing to a warmer climate, at least under conditions of mild heat stress. The rate of increase in FE with THI was steeper in select cows than in controls, which raises the possibility that select cows use more effective coping tactics. Analysis of milk MIR data using the national data described earlier could not identify a significant difference between milk MIR under higher THI conditions modelling all of the data. We also explored the differences in milk MIR under extreme events (heat wave and snow events) and there was suggestion of a differences in MIR during the event but no useful predictor of failure to recover in subsequent milk test results.
OUTCOME: the development of novel biomarkers for 'resilience' traits (RT). COMPLETED
3. undertaking genetic and genomic studies on resilience traits and their relationships with other cattle productivity, fitness, and resource-use-efficiency traits
WP4. Genetic and genomic analysis of resilience traits (90% complete): Over 463,000 daily records from approx. 90,000 cows across 10 years were extracted and matched with a weather station within 10km. Using reaction norms, we modelled the response in milk production across different THI levels and time. Low THI reduced production levels by 2.3% during periods of low THI. High THI reduced production levels with between 2.7% and 5+% reduction in fat and protein percentage. The heritability of "tolerance" to high THI using reaction norm modelling was estimated to be 9%. There was no significant heritable effect when looking at response in SCC under high THI conditions. However, when fitting SCC as an addition al effect in the model for milk production the heritability rose in 11.5%. We selected ~900 bulls with sufficient UK daughters and genomic information to explore genetic links to international studies of resilience in warmer climates. We explored the common bulls between Spanish and UK Holstein populations and that failed to yield sufficient bulls in common to combine genomic predictions across countries. We have initiated discussions with partners in Australia who have been undertaking similar studies using national data to compare genomic hits from within the different populations. .
Outcome: Identify benefit of utilising information from more extreme production scenarios in developing genetic evaluations for climate resilience. Identify bull genetics that are more/less resilient within and between countries to help selection and marketing routes for different bulls.
Exploitation Route New phenotypes/models of current phenotypes: Although the project is in the initial phases we have already identified that weather significantly influences individual animal performance across time. These results indicate that for traits that are analysed temporally, such as milk production over a cows lifetime, that fitting the coincidental weather conditions will increase the precision of the animal model. This is not, as such, a climate resilient phenotype, but rather a potential improvement to the precision of the evaluation system. This will be further tested in national data and results feedback to industry stakeholders in discussion with AHDB.
Sectors Agriculture, Food and Drink

 
Description BBSRC Impact Accelerator
Amount £150,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 08/2017 
End 03/2018
 
Description Grant Award
Amount £10,000,000 (GBP)
Organisation Bill and Melinda Gates Foundation 
Sector Charity/Non Profit
Country United States
Start 09/2015 
End 09/2020
 
Description Horizon 2020
Amount € 7,000,000 (EUR)
Funding ID 727213-2 
Organisation European Union 
Sector Public
Country European Union (EU)
Start 05/2017 
End 04/2022
 
Description Horizon 2020
Amount € 7,000,000 (EUR)
Organisation European Union 
Sector Public
Country European Union (EU)
Start 02/2016 
End 01/2020
 
Description RESAS Strategic Reserach Portfolio
Amount £25,000,000 (GBP)
Funding ID Work package 2.3 Agricultural Systems 
Organisation Government of Scotland 
Department Scottish Government Rural and Environment Science and Analytical Services Division (RESAS)
Sector Public
Country United Kingdom
Start 04/2016 
End 04/2021
 
Description Dairy Australia MoU 
Organisation Dairy Australia
Country Australia 
Sector Public 
PI Contribution This Memorandum of Understanding agrees to jointly work on the development of milk mid-infrared prediction tools to help dairy farmers manage and select their cows, combining of genomic information and the integration of genomic and milk mid-infrared data.
Collaborator Contribution The partners, by sharing of data, will help to further improve the impact of the original BBSRC project(s) after the projects have ended
Impact No outputs as yet. Not multidisciplinary
Start Year 2017