SRS® breeding technology allows meat and milk breeds of sheep, that produce no wool, or inferior wool, to be transformed into valuable wool-producing animals without any loss of meat or milk production.

And vice versa. We can transpose into Merino sheep, which are renowned for producing quality wool, new gene sets from non-Merino sources which greatly increase fecundity and meat value of the Merino whilst lifting wool quality to even greater levels. This is the approach we have taken to develop the Australian Meat Merino® (AMM®).

AMM® ewes and lambs.

Eight week old AMM® lamb.

Nine months wool growth on an AMM® ewe.

Selection for low primary fibre diameter and high levels of fibre density and length underpins this whole genetic development. The photomicrographs below, which are magnified views of horizontal skin sections from a foundation sire and a current sire, show the enormous changes in density and fibre uniformity that have been achieved.

The follicle and fibre patterning in the skin of the AMM® sheep has advanced from one of low density and irregular fibre size (left) to high density of uniform and fine fibres (right).

The strategy has been to infuse the high feed converstion and muscling pattern of the White Suffolk/White Dorper into the Merino. The work has been ongoing since 1994. The flock comprises animals which are now at least 4 generations removed from this infusion.

The Keri Keri Merino sheep have provided an ideal breeding base for developing the AMM® sheep. These sheep already have most of the required body and fertility traits and bring to the new equation, exceptionally high levels of wool fibre density and length.

Keri Keri maiden ewes in a drought.

Wool on a 12 month old Keri Keri Merino ewe with a lamb at foot.

Keri Keri Merino ram 8107.

Keri Keri Merino Ram 8107, shown above right following shearing, has breeding values of + 12 kgs for body weight at day 200 and carries the 4 teat high milking trait.

We knew from trial work (see table below) that the Keri Keri Merino ewes were capable of producing heavier carcase weights on prime lambs than crossbred (Merino x Border Leceister) ewes.

Merino ewes can be excellent prime lamb dams.

Carcase Evaluation trial. Source: MLA, 2000.

The White Suffolk/White Dorper sires used to establish the AMM® sheep, in addition to having exceptional breeding values for body growth, muscling and fat cover, were quite rare individuals for this meat type in having relatively fine primary fibres, no medullated fibres and moderate (rather than low) follicle density.

One of the White Suffolk x White Dorper rams used. His postweaning breeding values are +10.9kgs for 200 body weight, and +1.1mm for eye muscle depth.

Andrew is the owner of the Keri Keri Merino Stud (see www.kerimerinos.com.au). Like his father, Peter, Andrew's lateral thinking regarding sheep breeding is remarkably ahead of its time. He has a great eye for being able to identify in a sheep the traits of fertility, survival and reproduction.

Andrew Dowling

Jim Watts is the founder of the SRS® breeding system. He is a veterinarian who has specialised in the genetics of wool fibre growth. This expertise has allowed sheep, alpacas and goats to be bred with advanced fleeces.

The AMM® sheep epitomise the revolutionary changes to animal production that can be invoked by applying the selection principles he has developed.

Jim Watts