New indexes to dial up genetic gain

Rather than overwhelming yourself by inspecting every ram at the sale, you can use the Sheep Genetics MERINOSELECT indexes to do some presale homework and rule out the rams that don’t meet your requirements, leaving yourself with a shortlist of all the ones that do.

Meat & Livestock Australia’s Sheep Genetics manager, Peta Bradley, shares her tips and tools to help sheep producers target genetics that align with their production goals.

“I like to use the cereal aisle in your local grocery store as an analogy of how to use these indexes. If having a healthy breakfast is most important to you, you can look at the health star rating on each box to condense your shortlist,” she explains.

“The indexes continue to drive genetic progress in the key production traits such as reproduction, growth and fleece traits.”  – Peta Bradley, Meat & Livestock Australia’s Sheep Genetics manager

“The next most important factor may be having a tasty breakfast, so from the shortlist, you may then look at the individual ingredients to find something you know you will enjoy.

“Ultimately, you’re left with a drastically refined list of cereals you would buy, allowing you to make the final call based on value for money,” Peta says.

How to use the indexes

Step One: Set your flock production goals and breeding objectives:

• What is your flock’s current performance and where do you want it to improve?
• What is your target market i.e. fine wool, volume of wool, heavier lambs?
• What are your profit drivers to reach your goals?
• What is the operational environment you are working with?
• For some indexes, wool traits are a main focus as for some sheep production systems a majority of the income is derived from wool production, whereas other Merino systems achieve more profit from lamb and surplus sheep sales.

Step Two: Choose the right index that best fits your goals. MERINOSELECT provides four standard indexes covering a broad range of production systems
for producers:

• Fine Wool Index (FW) – Aiming to go finer while increasing wool production
• Wool Production (WP) – Greater emphasis on wool cut
• Sustainable Merino (SM) – Systems deriving more balanced income from wool and sheep sales with a focus on sustainability traits
• Merino Lamb (ML) – Prime lamb production from Merino ewes

The following flowchart (right) helps producers determine the best index for their Merino production system.

How to use the chosen index to assist in purchasing decisions:

Before the sale:

• Rank animals in the sale on the value of your chosen index.
• Consider the individual ASBVs that are important to you to create a shortlist of rams to look at on sale day. (ASBVs – Australian Sheep Breeding Value is a prediction of an animal’s genetic merit for a particular trait)

At the sale:

• Look through your shortlist of rams to find the ones that meet your structural and type requirements.

What are the key changes in 2024?

Following on from last year’s release of the new research indexes for Merinos, Sheep Genetics has refined the four indexes. Across all four indexes there is an emphasis on the health and welfare traits that are appropriate for the production system.

For example, the Sustainable Merino (SM) Index includes a focus on health traits such as:

• reducing breech wrinkle
• reducing worm egg count
• reducing dag score.

“The indexes also continue to drive genetic progress in the key production traits such as reproduction, growth and fleece traits,” Peta says.

“Indexes allow genetic improvement for a range of traits even if antagonistic relationships exist. For example, the new indexes yield favourable responses simultaneously for fleece weight and breech wrinkle.” Updated modelling that best captures the different types of Merino production system has been a focus during the development of the new indexes.  Peta says feed intake is modelled and accounted for in the new indexes. The updated software also enables methane output to be incorporated in the future when there is an Australia Sheep Breeding Value (ASBV) available for that trait.