The meat quango appointed the Havas-owned agency after a three-way pitch against the incumbent, OMD UK, and Universal McCann.
MPG's appointment, which covers an initial two-year period, follows a change in EBLEX's creative agency arrangements last year.
EBLEX appointed TBWA\London to replace Leo Burnett and dropped TV activity featuring the "Beefy" and "Lamby" characters, based on the cricketers Sir Ian Botham and Allan Lamb, in favour of print activity highlighting the quality standards applied to British beef and lamb.
The meat body is a division of The Agriculture and Horticulture Development Board and raises around £12 million each year from a levy paid by farmers. It is responsible for marketing beef and lamb under the Quality Standard and Red Tractor labels.