The figures show that over 10 per cent of the lamb carcases classified achieved an E conformation - the highest class possible on the current EUROP classification grid - almost double the number of four years ago.
There was also an increase in the U class and reductions in the lower O and P grades.
According to John Richards, the industry information executive at Hybu Cig Cymru (HCC) – Meat Promotion Wales, the results were mainly a consequence of increased use of rams and ewes with superior genetics for conformation traits.
“These results show that producers can change the genetic make-up of their flocks in a relatively short period of time,” he said.
“The use of terminal sires has improved genetic traits for conformation over the last decade and we are now seeing the results of this.
“While the improvement in conformation results is encouraging, particularly the decline in those achieving the lower classes, the main consideration for farmers when selecting lambs for slaughter should be the market’s requirements and desired specification.”
The results also showed that there was an increase in the number of slightly over-finished lambs being marketed, possibly as a result of farmers trying to maximise carcase weight given the subdued prices witnessed last year.
“Understanding a market’s required specification should be a key target for every farmer. Different outlets such as supermarkets, export and catering may, and do require different types of lambs,” added Mr Richards.
“In order to achieve the highest return farmers should ensure that the lambs sold are the correct type for those markets.
“Over the coming weeks, many farmers across Wales will be selecting their first lambs of the season.
"Before doing this we would encourage them to select lambs based on the weight and finish that meet their market requirements.”