Gates Maternals - Understanding ASBV's

Buying the right ram is an integral part of all sheep breeding businesses. Rams breeding decisions made today will impact the profitability of your sheep enterprise in the short and long term future, depending on the enterprise characteristics. 

The detailed overview of each relevant ASBV (Australian Sheep Breeding Value) below will ensure a clear understanding of the traits one should be selecting rams with at the next sale day.

Birth Weight (kg) BWT

Indicates the genetic merit of lamb birth weight. Terminal sires should be selected with a BWT of <0.3 for merino and maiden ewes and <0.45 for crossbreds and maternal composite ewes.

Weaning Weight (kg) WWT

Indicates the genetic merit of animals for liveweight growth at 100 days of age. A more positive value is desirable.

Post Weaning Weight (kg) PWWT

Indicates the genetic merit of animals for liveweight growth at 225 days of age. A more positive value is desirable.

 Adult Weight (kg) AWT

Indicates the genetic merit of animals for their mature adult liveweight.

Post Weaning Fat Depth (mm) PFAT

Indicates the genetic merit of animals for GR fat depth at 45kg liveweight. Fat depth should be selected for according to the type of finishing system, ewe base and lamb target market.

Post Weaning Eye Muscle Depth (mm) PEMD

Indicates the genetic merit of animals for eye muscle depth at the C site on a 45kg liveweight animal. A more positive value is desirable and indicates the animal will have more muscle on the high value loin area.

Yearling Greasy Fleece Weight (%) YGFW

Indicates the genetic merit of animals for their wool growing ability.

Post Weaning Worm Egg Count (%) PWEC

Indicates the genetic merit of animals for their ability to carry worm burdens. A combination of being genetically less likely to pick up worms & being able to cope immunologically with the worm burden.

Lambing Ease Direct (%) LE DIR

Describes how easily a sire’s lambs will be born, with a positive number preferred.

Lambing Ease Daughters (%) LE DTR

Describes how easily a sire’s daughters will give birth, with a positive number preferred.

Number of Lambs Weaned (%) NLW

Indicates the genetic merit of animals for number of lambs weaned at each lambing opportunity.

Maternal Weaning Weight (kg) MWWT

Indicates the genetic merit of animals for their ability to milk.

Maternal$ Index ($) MAT$

Indicates the genetic merit of animals for their overall profitability per ewe joined. The MAT$ index balances the key economic traits relevant to most maternal breeds. A dollar index of 105 indicates that a ram will produce $5 extra value for every ewe joined compared to a ram with an index of 100. Therefore over four years, if a ram produces 200 progeny, the extra value produced by that ram will be$5 x 200 = $1000.