SusSheP - Sustainable Sheep Production

Aim of the project:

To increase the sustainability and profitability of European sheep production, by addressing key industry focused problems to better understand fundamental mechanisms influencing on-farm efficiencies.

Introduction

The overall aim of SusSheP is to increase the sustainability and profitability of European Sheep Production by addressing key industry focused problems.

Sheep are unproductive (but carbon productive) until they produce their first lamb crop, normally at 2 years of age and, on average, ewes only produce 4 crops of lambs in their lifetime. Despite its importance both from an economic and environmental perspective ewe longevity is not included in sheep breeding indexes across Europe. SusSheP will establish the genetic factors controlling ewe longevity, under different Sheep Production Systems (SPSs) and assess if early life predictors (eg reared as single, twin etc) can be used to predict longevity. Parallel to this, SusSheP will identify the most carbon and labour efficient SPSs under different management systems (eg prolific vs non-prolific sheep breeds) in order to enable the development of strategies to reduce the labour input and carbon hoof print per kg of output.

The breeding of more efficient sheep has been hampered internationally by the lack of sheep artificial insemination, as the only effective method for use with frozen-thawed semen is a laparoscopic procedure, whereby, semen is injected directly into the uterus but this requires veterinary expertise, is welfare unfriendly and sociable unacceptable. The only exception to this is in Norway, in which vaginal deposition of frozen-thawed semen yields good pregnancy rates. Research in Ireland has demonstrated this is due to the breed of the ewe used in Norway, whereby sperm can transverse the cervix in greater numbers than in other breeds, leading to higher pregnancy rates. SusSheP will interrogate the differences across breeds in cervical physiology and its secretions (genes, proteins and glycans) with a view of developing a more sociably acceptable AI method. Finally, through the participation of strategically chosen SME’s, SusSheP will maximise knowledge transfer to industry, farmers and the scientific communities.

What: The focus lies on genetics, animal welfare and ethical breeding practices, while being cognisant of labour input and the economics of SPSs. Through the participation of strategically chosen SMEs, the knowledge transfer to industry, farmers and scientific communities.is maximised.

Why: Sheep have a relatively short productive life and the identification of the genetic factors controlling ewe longevity (EL), under different Sheep Production Systems (SPSs) would facilitate breeding for healthier sheep. Sheep genetic improvement schemes across Europe are hampered due to low pregnancy rates that result from cervical insemination with frozen-thawed semen. The exception is in Norway and the challenge is to identify the reasons why cervical artificial insemination (AI) works well in Norwegian ewe breeds but no other European breeds. In addition, there is a requirement to develop strategies to reduce the labour input and carbon hoof print per kg of output.

Where: The research is been done in five academic centres located in France, Ireland, Norway and the United Kingdom.

Main project activities:

SusSheP will establish the genetic factors controlling EL, under different SPSs and assess if early life predictors can be used to predict EL. Parallel to this, the most carbon and labour efficient SPSs will be identified. Another objective is to interrogate differences across breeds in cervical physiology and its secretions with a view of developing a sociably acceptable AI method.

Interim research findings:

 SusSheP utilises a range of research methods. It uses existing databases in Ireland, UK and Norway to identify early life predictors of ewe longevity and to calculate heritabilities on key traits. On-farm labour as well as farm input/output data have been collected and modelled for varying SPSs, and this data will be used to complete a carbon hoofprint and life cycle assessment of each system. Surveys will be used to identify farmers views on alternative SPSs. Detailed characterisation of cervical tissue and its secretions (Genes, Proteins and Gycans) of six ewe breeds (across Ireland, France, Norway), known to have divergent fertility following cervical AI with frozen-thawed semen is ongoing.

 The main reasons for involuntary culling is tooth loss in the UK while it is mastitis in Ireland and Norway. Ewe longevity is influenced by a range of different factors and the early life predictors investigated could not be used to provide consistent recommendations across countries. The use of precision livestock farming (PLF) improved labour efficiency but did not show an improvement in terms of carbon hoofprint while at sheep flock level, the performance recording was the best for reducing carbon hoofprint (a reduction of 3.9 kg CO2e per kg liveweight produced), as was the use of prolific breeds (reduction of 1.6 kg CO2e per kg produced). In contrast, implementing high genetic gain through breeding, tends to increase labour but greatly reduces carbon hoofprint. Size or gross morphology of the cervix does not explain ewe breed differences in sperm transport (or pregnancy rates). While mucus production varies with stage of the oestrus cycle, irrespective of whether exogenous hormones are used to synchronise oestrus, there are no clear biological patterns relating mucus volume, colour or viscosity, to ewe breed differences in sperm transport across the cervix. The biology of the cervix and its secretions are now being characterised at the molecular level. Preliminary results are suggesting lower expression of some genes involved in sialic acid synthesis (a sugar in cervical mucus which binds sperm) as well as a lower inflammatory response within the cervix in high fertility Norwegian ewe breeds compared to low fertility breeds such as the Suffolk. The team are currently mining their way through the proteomic, transcriptomic and glycomic data.     

Recording labour on varying sheep production systems has been a useful exercise, especially for farmers. For example, looking at the various tasks conducted during lambing has allowed some farmers to change their management practices (e.g. modifying layout of fences). Farmers were also keen to know how other farmers are conducting their everyday practices, to be better informed and potentially adapt or change their own practices. For instance, the French farmers were very interested to know how the Norwegian farmers conduct their AI. Likewise, initial information from the carbon hoofprint has led some farmers to start questioning their actual management practices. Labour efficiency using PLF has also raised great interest in the farming community (and perhaps dispelled some misconceived ideas) and has stimulated farmers to consider the scale of investment needed to implement such technologies.

Project consortium:

Coordinated by: Dr. Sean Fair - University of Limerick (IRELAND)

  • FRANCE: Institut National de Recherche Agronomique
  • IRELAND: Sheep Ireland and Teagasc
  • NORWAY: The Norwegian Association of Sheep and Goat Breeders and Norwegian University of Life Science
  • UNITED KINGDOM: Scotland’s Rural College and Maternal Sheep Group