Selecting rams with €uro-star index

WE are at that time of the year again when lambs should be either sold or weaned, depending on your system, so that ewes will have a chance to gain some body weight in advance of this year’s breeding season.

Allowing ewes adequate time and good nutrition before the breeding season should help to maximise next year’s lamb crop.

Identifying cull ewes is also a job that should be completed now.

With lambs weaned and cull ewes identified or sold, the next focus will be on the rams.

You might be considering purchasing some additional rams this autumn.

There are now two genetic indexes available on a large proportion of pedigree rams, to aid your purchase decision.

These indexes allow farmers to rank animals based on their genetic potential across a range of terminal and replacement traits.

So what do these indexes mean and what will they do for me?

The first is a terminal index; this ranks animals based on their ability to produce live, fast-growing terminal progeny with little lambing difficulty.

This takes into account the progeny’s growth rate, carcass characteristics, days to slaughter and also lamb survival and lambing difficulty.

The second is the replacement index, which ranks animals on the expected maternal performance such as milk yield, lamb survival and the ease of lambing.

However, it also includes some terminal traits to account for the efficiency by which an animal’s progeny is finished.

A thorough visual assessment will always be part of the purchasing process, but before selecting a breeding ram, each farmer should focus on a couple of key aspects of the €uro-star indexes of each ram. These will include:

• Index of choice: Farmer should pay particular attention to the index of choice. For example, if farmers are interested in finishing all their lambs, then they should focus on the terminal index.

On the other hand, if a farmer is looking to retain replacements from a ram, then they should focus on the replacement index.

• €uro-star value: From 2019 onwards, the €uro-value with each ram is now presented across all breeds, which allows any two breeds to be compared to each other.

For example a ram with an €uro-value of €1.15 is expected, on average, to produce progeny that will generate €1.15 more profit compared to their average contemporaries.

Assuming that a ram produces 100 progeny per year and survives within a flock for four mating seasons, this ram is expected to generate €460 more profit across his lifetime compared to the average ram.

• Star rating: Within each index, animals are ranked on a scale of one to five stars within breed; a one-star rating indicates that the animal lies within the bottom 20 per cent of ranked animals. On the other hand, a five-star-rated animal is within the top 20 per cent of animals

• Accuracy: Irrespective of the type of animal that is needed, careful attention should be placed on the accuracy associated with the index or trait of interest.

The higher the accuracy, the more information that is known about the animal, and the greater the confidence we have that their index value will reflect their true performance potential.

For ram lambs, farmers should aim to select animals with an accuracy value of at least 30 per cent.

• DQI: The data quality index (DQI) index rates flocks based on the quality and quantity of the data recorded on the flock over the previous year.

This index can be used to help pedigree farmers identify the areas where their data recording needs the most attention in the year ahead.

When selecting rams from pedigree flocks, farmers should aim to purchase rams from flocks with a high DQI (in other words, 65 per cent or greater).

Similar to the Economic Breeding Index (EBI) and star ratings in cattle, Sheep Ireland have created the €uro-star indexes for breeding rams with the overall aim of identifying and breeding the most efficient sheep in the industry.

So, if you are in the market place for a ram this autumn, get familiar with these indexes, and use the information that is available to get the best return out of your purchase by aiming for high-index rams.