Houghton-Parkhouse, the designer and manufacturer worked closely with Defra to improve the welfare of the 600 lambs that can be carried at any one time. Measures include improved head room and access to water in every pen. The transporters bear the Asda logo.
Trevor Hanger, managing director of Welsh Country Foods, said: "The Asda LambLink scheme has gained terrific momentum since its launch in 2002 with over 5,000 farmers from Scotland down to Devon now supplying lambs direct to Welsh Country Foods.
"Introducing a fleet of livestock transporters is the next step in the evolution of the Asda LambLink scheme which continues to gain new lamb suppliers from across the UK week after week."
He added: "Today's discerning ASDA consumers demand top quality products produced with first-class husbandry and the highest welfare standards and traceability. Investing in these six new transporters ensures that we achieve top welfare standards for our stock."