Genetic improvement of pea to replace soyabean in the diets of poultry and monogastric livestock (PeaGen)

Higher agricultural productivity and sustainability is critical to meeting the global challenges of food security in the presence of climate change. Legume crops are a critical source of plant-based proteins for people and animals. As the world demand for animal products increases, the demand for vegetable proteins as animal feedstocks also rises and the UK in common with other countries faces a shortfall in domestic vegetable protein production capability. In the EU 70% of the protein fed to animals is imported, mostly soyabean or soya meal with soya meal accounting for 33% of the protein in UK livestock feeds. In 2011-12 UK imports of soya products reached 1.83 million tonnes, the majority of this being transgenic soya imported from South America. Increasing the amount of UK grown protein to replace imported soya products is recognised as a major challenge for the UK animal feed sector.

In this LINK proposal we will develop and apply new genetic approaches to enhance the nutritional value (protein and water soluble carbohydrate) of the pea (Pisum sativum L.) seed, to increase the use of pea as a high quality feed in animal diets, reducing the UK protein deficit from the import of soya products and also delivering environmental benefits to livestock production systems. The proposal builds on knowledge gained in BBSRC, EU, Defra, Innovate UK and levy board-funded research on the genetics and agronomy of pulses that have led to the development of novel lines of pea with higher protein content. We will use our expertise in plant genomics, pea genetics and breeding, agronomy, plant chemistry and animal nutrition to integrate the germplasm with improved grain composition into improved pea varieties. With industry partners from the poultry and pig sector as well as crop developers, we will analyse the impact of replacing soya with these new pea varieties in feed rations on the growth of monogastrics and poultry and the economic and environmental impact of their inclusion. Although the focus is on poultry and monogastrics, the project will provide information on the value of including these new pea lines for other sectors (ruminants and aquaculture).

A challenge faced by the UK and EU livestock sector is the current shortfall in domestically produced protein for animal feed. The UK is almost completely reliant on imported soyabean and soya meal to make up this deficit. We propose to address this issue by developing and applying new genetic approaches to improve the nutritional value of pea (protein quality and content), allowing us to develop new varieties of pea that can replace soya products in UK agriculture, improving the efficiency and sustainability of UK livestock production.

Null mutants for the production of the vicilin family of globular storage proteins have been developed at JIC. It is hypothesised that, in combination, these mutants will either reduce the overall production of storage proteins in the seed or divert available amino acids into the production of other proteins, namely legumins. Preliminary investigations have demonstrated that these mutants exhibit no penalties in growth or germination. Protein content is equal to the wild type in all but one line where the protein content is elevated by 3-4%. These mutants have been generated in research lines that are agronomically poor and not suited for agricultural use. A breeding programme using marker assisted selection and speed breeding will be used to combine these mutations into an agronomic background suited for animal feeding.

The advanced lines will be phenotyped to assess the impact, if any, of these mutations on performance, including pest and disease tolerance, vigour, crop development, lodging, maturity and yield, and to determine their protein content and quality. The most promising lines will then be assessed in animal feeding trials to evaluate their effect on the growth rate of pigs and poultry. Economic and life cycle analyses will be carried out to fully quantify the value of replacing soya based feed with the improved pea varieties. Material developed in this project will be developed further as commercial pea varieties.

The major beneficiaries of this research will be:

Animal feed industry: Replacing the imports of soya with home grown protein that can be utilised within animal feed is a major objective of the animal feed sector. Development of pea varieties that combine increased seed protein whilst maintaining agronomic performance provides a major opportunity for the different animal feed sectors to increase the proportion of protein produced in the UK. Although this project is primarily focused on the pig and poultry sectors the outcomes from the project will also have direct relevance for the ruminant and aquaculture sectors.

Arable sector: The project will have a significant economic and environmental benefit on the arable sector. Grain legumes such as pea can be grown in arable rotations across the UK, are an excellent break crop and have a major role in sustainable arable rotations. Application of the different technologies within this project to breed pea varieties that have improved seed quality that meet the feed requirements of the different animal feed sectors, whilst ensuring that they have the agronomic performance that will maintain the economics of growing the crop, will enhance the value of peas to the arable sector. This will ensure that peas remain a competitive crop for arable production and that the benefit of growing peas in arable rotations is realised.

Plant breeding community: Information on the use of the Taqman assay for validation of genetic material and the use of microsatellites and other markers to eliminate the introgression of undesirable genetic traits into elite pea lines will be of value to plant breeders. Specifically the integration of pea germplasm with improved seed quality (protein) into a commercially facing pea breeding programme will be of value to other breeders of pea and other pulses.

Society: Direct benefit will be gained from the development of an economically sustainable protein crop that can be grown within the UK and which can replace some of the imported soya that is currently used as the protein source in many animal feedstuffs. Increasing the proportion of protein used in animal feedstuffs that can be grown within the UK will have direct benefits in terms of improved food security but will also help to broaden and diversify arable cropping within the UK.