Breeding and management strategies for sheep in the Scottish hills and uplands to meet future economic, environmental and climatic challenges
Project Lead
Challenges
Scottish agriculture faces significant challenges associated with changing policy, markets, environment, and technology. The agriculture sector needs to maintain and increase profitability by responding to changing market conditions while contributing to Scottish Government commitments on greenhouse gas (GHG) emissions and biodiversity. There is an opportunity to transform Scottish hill farming systems to adapt to climate change, reduce its environmental impact and promote biodiversity. This requires a change in the way livestock use available resources. System-wide adaptation is crucial, considering the genetics, grazing and management strategies for livestock, alongside other land-use, and environmental and public good goals.
Previous research, focussing on Scottish Blackface (SBF) as the most numerous UK hill sheep breed, has shown the benefits of within-breed genetic selection for maternal and lamb production traits to meet current hill sheep system economic drivers. However, hill sheep research has also identified some limitations within traditional hill breeds for traits related to GHGs and feed efficiency. Pilot trials considering individual feed intake of finishing lambs suggest variation in feed efficiency within-breed. The trials also found that SBF has higher feed intake and poorer feed efficiency when fed indoors on concentrates compared to Lleyn lambs managed in the same way.
There may be trade-offs, due to differences in rumen physiology, to animals that are inefficient at digesting fibre and produce less methane. Hill sheep are adapted to survive and reproduce over winter on rough hill ground, eating poor-quality vegetation. This enables high-quality animal protein for human consumption to be produced from these land areas that are unsuitable for many other forms of agricultural production, reducing competition for good quality land suitable for cropping, or potentially for initiatives to increase biodiversity. Research is needed to determine if it is possible to select resilient hill sheep that use hill grazing resources efficiently, but with reduced environmental impact either through within-breed selection, or crossbreeding.
In parallel, there is a requirement to maintain biodiversity in these fragile hill systems and to develop livestock breeding and management strategies that will promote biodiversity. Grazing strategies can impact biodiversity on hill sheep farms. Different breeds can show different patterns of foraging behaviour and diet selection. Differences in the home range and time spent foraging on habitats, during different times of the year, can have an impact on the vegetation structure and composition across the grazed area, and on the overall biodiversity of a site.
Questions
- How can we improve livestock for the biodiversity and climate change crises through genetics and nutrition, feeds, and management?
- How can we protect genetic diversity in livestock whilst promoting wider biodiversity in agriculture?
Solutions
The project is identifying the best genetics for future hill sheep systems by blending state-of-the-art phenotyping for efficiency and resilience traits with genetic selection. We are evaluating within-breed genetic selection and crossbreeding to enhance climate resilience. We are also investigating the most appropriate management and grassland strategies to be used alongside these breeding strategies to promote biodiversity and resilience to climate change in Scottish hill sheep systems.
Genetic improvement of resilient hill sheep
We are exploring the genetic improvement of resilient hill sheep using new technologies to make them relevant for future challenges. Breeding sheep specifically for high altitude (hill), low resource availability (extensive grazing) and harsh conditions (cold and wet). We are also combining improved genetics with management strategies to optimise feeding and grazing resource management and promote biodiversity.
A flock of six hundred breeding ewes form the livestock platform for this research and is comprised of crossbred ewes (including SBF and Lleyn genetics), and ewes from the previously established high-index Scottish Blackface selection line. The flock are managed primarily on extensive hill ground, with some use of in-bye, semi-improved pastures.
The flock are recorded for:
- Maternal traits – mature size, lamb production, lamb losses
- Ewe longevity and lamb survival
- Health and welfare traits – health treatments, disease, condition scores, lambing ease
- Production and product quality traits – growth, carcass composition (CT and ultrasound), carcass quality
- Feed-efficiency and GHG predictors – individual feed intake measurements, group feed and grazing records; CT-measured rumen volumes
- Resilience to climate change – combining environmental and flock production data
We are estimating genetic parameters that incorporate relevant traits with appropriate weightings to breed hill sheep for sustainable production improvements, climate change resilience and reduced environmental impact on hill ground.
Combining improved genetics with management strategies
Grazing and grassland management strategies are being designed to minimise the negative environmental impacts of livestock and to promote biodiversity. Further on-farm recording, which allows an assessment of biodiversity impacts to be made, includes:
- Animal tracking (using a combination of observation and sensor data to identify habitats being used
- Grazing resource monitoring - amount and quality to identify the condition of those habitats
- Environmental sensors to identify climatic factors affecting grazing locations
Coupled with the performance data, this enables the investigation and comparison of how the different genetic lines are using the available grazing resources during different times of the year or in different conditions.
Using data from previous years on biodiversity on the site, we are investigating the implications of using different areas of land for strategies to promote biodiversity, rather than for livestock production. A desk-based study is focusing on the system-level consequences for biodiversity of making the proposed changes to genetics and management of hill sheep systems. Carbon-foot printing is also being performed to compare different outcomes.
Project Partners
Progress
Objective 1: Genetic improvement of resilient hill sheep using new technologies to make them relevant for future challenges
Objective 1.1 Identify the genetic merit for maternal and lamb performance traits in a key hill bred and crossbred flock
Scottish Blackface (SBF) and crossbred ewes (~600) and lambs (~845) have been recorded for pedigree and production traits linked to maternal and lamb performance throughout the production year. This data has been incorporated into the national hill sheep genetic evaluation to produce estimated breeding values for each trait and a combined selection index value for all sheep in the flock. Breeding stock was selected using this index.
Objective 1.2 Identify the genetic merit of new traits (with a focus on climate resilience, feed efficiency and GHG predictors) for incorporation into breeding goals
Data has been collected on a representative sub-set of SBF and crossbred lambs for individual feed intake and associated growth, using feed intake recording equipment. CT scans were performed on the same animals, before and after the feeding trail, allowing calculation of carcass composition and rumen volume (a predictor of methane emissions). Feed efficiency phenotypes were calculated using feed intake, growth and CT composition data. Environmental data collected from numerous sensors throughout the farm will be combined with the production data to develop phenotypes conferring resilience to climate fluctuations. This dataset will be expanded in coming years to collect sufficient records to estimate genetic parameters for these new traits.
Objective 1.3 Estimation of genetic parameters and development of an index incorporating production, health/welfare and environmental breeding goals
Datasets collected in Objectives 1.1 and 1.2 will be expanded in the coming years to allow genetic parameter estimation and index development in the later project years.
Objective 2: Combining improved genetics with management strategies to optimise feeding and grazing resource management and promote biodiversity
Objective 2.1 Assessment of metrics affecting biodiversity
Data have been continually collected from various weather and environmental sensors located around the farm. To assess grazing patterns and resource use, individual animal locations have been monitored, and the flock gathered from the hill in sections to record more precise locational information. Group feed levels were recorded and grazing resources monitored using biomass measurements at key times. This can be related to drone footage of vegetation types. GPS collars have been tested for wider deployment in year 2.
Objective 2.2 Carbon footprinting to compare breeding and management strategies
Datasets are amassing to enable carbon footprinting in later years of the project.
Objective 3: Knowledge exchange with stakeholders
A stakeholder group has been established with members including hill sheep farmers, consultants and industry representatives (Quality Meat Scotland (QMS), National Sheep Association (NSA) and National Park). An on-farm meeting has been held, discussing project progress and presenting the equipment and stock during a farm tour. The project has been presented at over 30 industry, science and student events/visits.
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