Performance Recording

Data-Driven Sheep Farming

How we use EID tagging, LambPlus recording, and weekly EuroStar indices to produce verifiably better EasyCare rams.

What performance recording means in practice

Performance recording is the systematic collection of weight and lambing data from every animal in the flock. This data is submitted to Sheep Ireland's LambPlus programme, which calculates EBVs (Estimated Breeding Values) for each animal relative to the entire national recorded population.

The result is an EuroStar report — a set of indices that tell you, in plain numbers, how an animal is likely to perform as a breeding sire compared to every other recorded animal in Ireland. This removes guesswork from ram selection.

Our recording system

01

EID tagging at birth

Every lamb born on Tír na nÓg Farm receives an Electronic ID (EID) tag within 24 hours. All data is linked to the individual animal for its entire life.

02

Weighing at 40, 100, and 150 days

Lambs are individually weighed at 40, 100, and 150 days of age. These three data points form the backbone of the LambPlus growth indices.

03

LambPlus data entry

Weights and lambing data are submitted via the LambPlus app and website. Sheep Ireland processes these submissions to update EBVs.

04

Weekly EuroStar index updates

Sheep Ireland publishes updated EuroStar indices on a weekly basis. Our website pulls the latest file automatically so buyers always see current data.

Reading EuroStar indices

A plain-English guide to the six most important indices — and who should prioritise each one.

REP Replacement Index
Prioritise if: All flocks retaining their own replacements

The aggregate index for producing replacement females. A high REP ram will produce daughters that are more efficient, have better survival, and produce more lambs over their lifetime. This is the most important index for most commercial producers.

TER Terminal Index
Prioritise if: Producers selling all lambs as stores or deadweight

Focuses on growth rate, muscle depth, and carcase conformation. Prioritise TER when crossing ewes with a terminal sire and selling all offspring — it directly predicts factory returns.

NLB Number of Lambs Born
Prioritise if: Producers wanting to increase scanning percentage

Measures genetic potential for multiple births. In a breed already selected for ease of lambing and strong maternal instinct, a higher NLB compounds the advantage — more lambs born and more lambs reared without extra labour.

DM Daughters Milk
Prioritise if: Producers retaining ewe lambs

Predicts the milking ability of daughters. Higher DM means lambs grow faster pre-weaning on grass alone — no creep feeding, no supplementary milk, and a ewe that keeps her body condition without extra concentrate.

SUR Lambing Survivability
Prioritise if: Any flock with lambing losses above 5%

Measures genetic potential for lamb survival from birth to weaning. A key index for improving flock profitability as every extra lamb saved goes straight to the bottom line.

DTS Days to Slaughter
Prioritise if: Producers selling prime lambs on a tight window

Predicts how quickly progeny will reach slaughter weight. A positive DTS means progeny reach slaughter earlier — important for producers with a narrow marketing window.

Genotyping

Genotyping involves analysing an animal's DNA to directly measure thousands of genetic markers. When combined with performance data, genotyping significantly increases the accuracy of EBV estimates — particularly for young animals with limited progeny records.

On Tír na nÓg Farm, we genotype our top rams and selected females. A genotyped animal will have higher accuracy figures on its EuroStar report, meaning you can have greater confidence that its index reflects its true genetic merit. Look for the green "Genotyped" badge on each ram profile.

Rule of thumb: when accuracy is low (<50%), the index is a less reliable predictor. Genotyped animals typically show accuracy of 70–90%+ even at a young age.

See the data behind every ram

Every ram profile shows live EuroStar indices from Sheep Ireland LambPlus.