Abstract

The Inverdale gene (FecX) offers the sheep industry the potential to markedly increase production at little cost. However, the characteristics of the gene mean that appropriate breeding structures are essential. The recommended structure is a stratified crossbreeding system. The three tier breeding structure consists of: (1) a ram breeder producing rams known to carry the Inverdale gene; (2) a ewe breeder producing carrier ewes by mating carrier rams across dual purpose breed ewes; and (3) a lamb producer who mates a meat breed ram with carrier ewes to produce lambs for slaughter. Some farmers may choose to have two, or all three tiers on a single property. If the gene was used to maximum extent possible in Romney and Romney derived breeds, some 40% of all breeding ewes would contain a single copy of the gene and these would produce 31% more lambs for sale per ewe mated. Conservative estimates of the benefits to the New Zealand farmer are approximately $29m per annum.

JC, McEwan, GH Davis, PF Fennessy, and KG Dodds

Proceedings of the New Zealand Society of Animal Production, Volume 55, , 298-300, 1995