Project Team: Aurelie Aubry, Francis Lively, Melanie Flexen and John Archer

Background: 

The sheep industry is a major contributor to the Northern Ireland GDP accounting for 19,511 farms, 78% of the total number of farms recorded in 2015 (DARD, 2015).  However, low profitability in sheep production enterprises is a real threat to the sustainability of this industry in NI.  The main factors that directly affect the economic and biological efficiency of sheep production are (1) feed requirements, (2) reproductive performance and (3) progeny growth rate.  Grazed grass is the cheapest form of feed currently available for ruminant livestock in NI. However grazed grass is often poorly utilised on many sheep farms.  NI lamb is marketed worldwide as being grass fed and as such has a green image.  Previous research has shown how the performance of sheep could be improved via changes in grazing strategies in terms of target sward height and sward type. However, further work is required to reflect how modern, productive breeds and pasture types respond to contrasting grazing strategies. The difficulty in installing paddocks within a field to graze sheep has meant that sheep normally graze full fields within lowland pastures and freely roam hill pastures.  Increasingly more concentrates are being offered to sheep to enhance progeny performance during the finishing period. It is key that research is undertaken to drive improved physical performance in sheep production from grassland, thereby improving the financial performance and sustainability of the industry as well as its environmental footprint.   

Almost 60% of breeding ewes in NI are found in hill and upland areas.  Within these areas, sheep grazing also plays an important role in managing upland habitats to maximize biodiversity, prevent encroachment by unwanted species, and maintain the aesthetic value of the countryside.  Ensuring a vibrant and profitable hill livestock sector is therefore crucial for a strong rural economy and food security.  However, the key challenge for sustainability of hill areas is to maximize production of both economic goods (food, tourism) and environmental goods (biodiversity, ecosystem services).   

A recent DARD E&I project evaluated the impact of grazing beef and sheep on NI uplands (Aubry et al 2016).  This short-term project identified a number of important issues regarding the impact of sheep grazing within the uplands on animal performance and environmental aspects. In particular, a major limitation identified within the study was that, under the most recent countryside management guidelines, the limits imposed in terms of grazing periods and stocking rates could have led to significant detrimental effects on pasture quality.  For example, inability for winter grazing and low stocking rates were identified by farmers as having a negative impact on the ability to manage heather and rush within uplands. The detailed vegetation surveys undertaken as part of this previous work indicated an important variability between sites and years, and suggested that site-specific prescriptions may be necessary to ensure that heather or rush dominated areas are more utilised by sheep. More recently, the Sustainable Agricultural Land Management Strategy also recognises the need for more flexible management plans for upland areas.  It is proposed within this study to undertake a scoping exercise to identify potential sheep grazing strategies within upland pastures, and associated research needs, that will assist policy makers to develop future environmental schemes for upland farms.  Part of this work will also establish the issues and major constraints facing upland sheep farmers, to ensure that those are taken into account in the development of future strategies.  

Recent interest in sheep breeding has led to the production of composite genotypes which have been bred for functional traits including parasite resistance and the ability to make maximal utilisation of forage.  Recent research at AFBI demonstrated the benefits that such cross breeding programmes can represent for our sheep industry (Annett et al 2011, Aubry et al 2016), in particular in terms of lamb growth and output.  Novel breeds and selection strategies using breeding values and/or genomic tools may be suitable for the NI industry to maximise animal performance and improve parasite resistance.  In the current study, it is planned to implement such strategies to evaluate their suitability for both upland and lowland production within NI, and assess how different genotypes respond to contrasting grazing strategies.

 

Objectives:

The overall objective of this project is to identify and test sheep grazing strategies that can maximise the use of grass on both hill and lowland production systems.  Specifically, the project has 4 main objectives: 

Objective 1- Identify, implement and monitor i) grazing strategies suitable for Northern Ireland’s upland sheep production systems and ii) monitoring tools to assess their efficacy 

A recent DAERA funded study reported a number of detrimental effects on pasture associated with restrictions imposed to farmers participating in environmental schemes.  It is proposed to undertake a review of the scientific literature to evaluate sheep upland grazing systems, taking account of stocking rates, grazing periods, herd and land types and biodiversity. This work will be done in consultation with DAERA (Countryside Management and Environmental Policy teams and CAFRE), animal scientists and other stakeholders (levy boards, producers). Grazing strategies will then be implemented at 5 hill farms and their effects on both vegetation and animal performance will be monitored. This work will also evaluate how useful, easy to use and reliable some of the monitoring tools can be for producers to evaluate the effects of their grazing strategy on grass and animal performance. Those monitoring tools are likely to include the use of a ‘habitat health’ checklist. This information will be used to identify long-term research needs that will inform the development, delivery and assessment of new grazing guidelines for NI upland areas. 

Objective 2 – Develop a blueprint for lowland sheep grazing systems 

After identifying targets for sustainable lowland sheep grazing systems in terms of grass utilisation, outputs per hectare, a series of complementary grazing experiments will be undertaken at AFBI to validate the achievability and to fine tune those targets and form a deliverable blueprint for achieving these levels of performance.  

Objective 3 – Implement and monitor the effects of grazing strategies on grass and animal responses in lowland production systems 

Different grazing strategies will be implemented and monitored on 5 lowland flocks to evaluate their effect on grass and animal performance and overall lamb production per hectare.  Breeding strategies implemented at each of the co-research farms as part of this objective will be defined following a consistent approach across farms, and therefore provide the opportunity to investigate how different breeds/genotypes respond to similar grazing strategies implemented at the farms. This work will also evaluate how useful, easy to use and reliable some of the monitoring tools can be for producers to evaluate the effects of their grazing strategy on grass and animal performance. Those monitoring tools are likely to include estimates of grass production and animal growth using rising plate meters, small grazing exclosures, grass clips and regular animal weighing. Software such as AgriNet and information on the nutritional values of the grass will also be used to inform grazing management.