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The Deffilait project aims to improve the dairy cows feed efficiency without affecting their robustness

Deffilait project
Improving feed efficiency in dairy cows: understanding its key determinants using precision phenotyping, to allow tailored genetic selection strategies according to environment.

Understanding the major determinants of feed efficiency

The livestock sector is highly concerned by the global food system, both by an expected increase in the demand for animal products such as milk, and by the ecological footprint of animal production, which must be minimized. Increasing feed efficiency in dairy cows would reduce some of the direct emissions (methane and ammonia) from livestock production but would also have a substantial positive impact on the induced emissions associated with crop production, due to the better feed conversion. Genetic improvement of feed efficiency is a particularly attractive strategy because it would impact most of the dairy farms for a limited cost. The decreased use of feed inputs implied by such an efficiency gain would give a competitive advantage to dairy production, but will also contribute to reducing environmental impacts. Thus, this project is expected to provide the essential elements needed for genetic selection strategies to improve feed efficiency in dairy cows.

Developing new phenotyping tools

Deffilait aims to elucidate ways by which to improve the feed efficiency of dairy cows without decreasing their robustness, to build strategies for doing this, and models to predict the future increases in feed efficiency attainable by selection programs, and directly on farm. The project will first involve developing new tools for large-scale phenotyping of the major biological characteristics that are directly involved in feed efficiency. The project will produce new tools to better estimate body condition, morphology, and digestive efficiency in large scale studies. These phenotypic measures will also impact on our capabilities for on-farm advising, and monitoring in livestock, which are also levers for improving efficiency at farm level. Then, to study the major determinants of feed efficiency, the project will also build an original database of dairy cow lactations with a large set of phenotypes to describe the main sources of energy transformation, thus explaining the observed between-animal variability in feed efficiency. This dataset will then be used to quantify the contribution of the different mechanisms to the variability in feed efficiency, and to test different indicators and strategies to improve feed efficiency. A specific focus will be made on body reserves mobilization in early lactation to assess its genetic components and correlation with other traits with a larger dataset involving commercial farms. The project will then develop simulation tools to predict the short- and long-term consequences of different selection strategies in different environments.

Innovation in livestock precision farming systems

The project will provide a coherent framework to undertake a balanced genetic selection on these traits, and thereby make a significant - and lasting - contribution to improving feed efficiency. It will propose also an original dataset of  lactations of dairy cows with new large scale phenotyping strategy to better characterize individual variability including most of the important traits associated to feed efficiency. The improvement of phenotyping will also give new opportunities to innovate in livestock precision farming systems.

Paturage Deffilait

The expected results will contribute to the definition of strategies of selection to combine efficiency and robustness. The results concerning mobilization of body reserves can be integrated in the equation of genomic selection. In addition to the communication on the results of the project through a website and different communications, the large partnership with many actors of the dairy industry of the project guarantees a rapid transfer of the main results of the project.
The consortium of Deffilait brings together the scientific teams currently working in France on dairy cow breeding with the different disciplines of nutrition, physiology, genetics and farming systems. It will use animal experimental facilities of Inra (UMR Pegase, UE le Pin) and agricultural chambers 49 (Trinottières). It will also associate the partnership of FCEL to collect information and samples from many dairy farms. The consortium also includes other partners from applied research and private companies (3D Ouest, Apis-Gene with Unceia, Cniel, Interbev, CNE, Invivo SA and Idele) and advisory services to provide a rapid transfer of the scientific results of Deffilait. This large project is funded for 4 years by ANR (703 k€) and Apis Gène (360 k€) for a total cost of 3100 k€.