Lambs sired by performance recorded rams were heavier than lambs sired by non-performance recorded rams, according to Wales's Hill Farm Scheme.
These results showed that lambs sired by performance recorded rams were on average 1.6kg heavier at 8 weeks than their non-performance recorded equivalents.
Additionally, there were 13% less lambs under 20kg at 8 weeks when recorded sires were used, with 76% of the performance recorded lambs being over 20kg at 8 weeks.
Furthermore, 22% more lambs sired by recorded rams were over 30kg at weaning, Hybu Cig Cymru - Meat Promotion Wales (HCC), the scheme's creators, said.
Compared with non-recorded sired lambs, the lambs sired by performance recorded rams were on average 2.4kg heavier.
In monetary terms, this means lambs sired by performance recorded rams could be worth approximately £4.00 more each.
Gwawr Parry, HCC’s Flock Genetics Executive who co-ordinates the scheme, said initial results are 'very exciting'.
"The use of genetic performance recording will allow hill farmers to produce lambs for a wider range of markets by using genetics," she said.
"The concept of the Hill Ram Scheme was created in order to help hill farmers become more resilient in their businesses; allowing them to target various aspects of flock performance to produce lambs efficiently and within a wider range of market specifications.’
"In a hill environment it is difficult to target growth and finishing in lambs. However, these results show that small genetic differences can have a big impact on margins without fundamentally changing farmers’ systems."
A second expression of interest window to join the scheme ended in March this year, with a third and final wave of new flocks set to join autumn.