He was first elected in 2012 and re-elected in 2014.
Mr Raymond was NFU dairy board chairman from 2010-2014.
The new chairman of the Copa Milk Group is Thierry Roquefeuil from France. He is from the French Farm Organisation FNSEA and has been vice chairman since 2014.
Mr Roquefeuil is also President of the French inter-branch dairy organisation CNIEL. He will be supported by two vice chairmen - Tommaso Mario Abrate, of ACI, Italy and Dorota Smigielska, of FBZPR, Poland.
NFU dairy board chairman Michael Oakes said: “Mansel has been a true advocate for British dairy farming. I worked closely with him on the NFU dairy board when he was chairman between 2010 and 2014, a role that I’ve now held since March this year. During this time he made a vast number of contacts and colleagues which led to him being elected as Copa Milk chairman in 2012.
“As Copa chairman, I know he has flown the flag for British and EU dairy farmers in troublesome times – probably the most extreme that most of us dairy farmers ever remember - reaching difficult compromise positions on a number of issues, especially over the past two years.
“With the referendum result in June we now have to focus our efforts on getting the best deal for agriculture and dairying with the UK and devolved governments. Mansel’s vast knowledge and passion for British dairying will be valuable to the industry when it looks to the future out of Europe.”