Female lambs born to Inverdale gene-carrying sires are less affected by the pregnancy diet of their dams than their male counterparts, according to the initial results of a Scottish trial.

The study found single ewe lambs sired by Inverdale-carrying semen and born to Blackface ewes fed a restricted diet during pregnancy were 0.18kg lighter than Inverdale-sired lambs born to Blackface ewes fed a full diet, explained Frances Alink of SAC.

“Single male lambs sired by Inverdale-carrying semen and born to Blackface ewes fed the restricted diet were 0.51kg lighter than their counterparts born to Blackface ewes fed the full diet.”

“Female Inverdale-sired lambs were also less affected than non-Inverdale-sired single male and female lambs and also Inverdale- and non-Inverdale-sired twin lambs of both sexes.”

Since male lambs cannot inherit the Inverdale gene from their sire, the results suggest that pre-natal growth of lambs carrying the Inverdale gene was less compromised than that of their male counterparts by the same sire.

The suspicion is that placental function could be partly to play in these results, but further investigation is required, said Miss Alink.

But, speaking from the floor, Jo Connington, also of SAC, cautioned against the widescale use of Inverdale carriers in UK sheep flocks without improved understanding of their management and nutritional needs.