Producing the future suckler cow: balanced genetics for profitability and sustainability

Aisling Molloy Martina Harrington

Improving the efficiency of the national suckler herd is a key priority for the Irish beef industry. Research and on-farm evidence consistently show that cows with strong maternal traits and of moderate size deliver superior lifetime performance. Balanced genetic selection is essential to produce a suckler cow capable of meeting both profitability and sustainability targets. This paper outlines how tools such as beef indexes, breeding values, genomics, and Irish Cattle Breeding Federation (ICBF) data can be used to breed a more efficient suckler cow for grass-based production systems.

What does the “future suckler cow” look like?

Before selecting sires or analysing data, it is essential to clearly define the type of cow required. The most profitable suckler cow is the one that consistently delivers a quality calf each year, while maintaining herself largely from grass, either grazed or conserved.

A ‘balanced’ suckler cow combines several traits that together drive lifetime efficiency:

1. Fertile

This is the cornerstone of any suckler system. A cow must produce one live calf every 365 days. To achieve this, she must go in calf within a defined breeding season and return to heat quickly after calving. Poor fertility increases empty rates and reduces output through longer calving intervals. It is one of the biggest drivers of inefficiency on suckler farms.

2. Good milk yield

Adequate milk is essential to support good calf growth pre-weaning and reduce reliance on concentrate supplementation for the calf. However, excessive milk can increase the cow’s energy demand, making it harder to maintain body condition on grass alone. The goal is optimal, not maximum, milk production. The target predicted transmitting ability (PTA) on the Future Beef Programme is eight kilogrammes for milk.

3. Functional

A good suckler cow should be docile, have good feet and legs and have a good udder. She should suit the production system on the farm and have good survivability in the herd.

4. Moderate mature size

Larger cows have higher maintenance energy requirements and require more feed. Moderate-sized cows (~650 kg live weight) are generally more efficient in grass-based systems, as they cost less to maintain and can allow higher stocking rates per hectare.

5. Good calving ability

Difficult calvings have short- and long-term negative effects through increased labour and veterinary costs, higher calf morbidity and mortality and delayed oestrus after calving, which impacts the subsequent calving date. Selecting for calving ease improves both animal welfare and overall system efficiency.

Breeding a ‘balanced’ cow with the traits outlined above is the foundation of a successful suckler system. While other desirable traits in the progeny can be bred via sire selection, such as carcass conformation, age at finish, carcass fat and tuberculosis resistance, the suckler cow is responsible for conceiving, calving and rearing a live calf for sale every year.

Using beef indexes to drive profitability

The Euro-Star Index was designed to aid in the selection of more profitable breeding animals for the suckler herd. This provides farmers with more information to select better males and females to breed for either replacement or terminal traits.

The Euro-Star rating system ranks animals based on a star system, with 1-star animals being in the bottom 20% and 5-star animals being in the top 20%. The indexes show two Euro-Star ratings; one for within-breed and one for across-breed. Within-breed stars rank an animal against other animals of the same breed, while across-breed stars rank an animal against other animals across all beef breeds.

There are two Euro-Star Indexes for use on suckler farms; the Replacement Index and Terminal Index. The Replacement Index looks at the maternal traits such as milk and fertility, whilst maintaining or improving beef traits, and is used for breeding heifer replacements. Calf traits account for 41% of the index, while the cow’s traits contribute to 59%. The Terminal Index looks at the beef traits of an animal such as carcass weight and conformation for farmers wanting to breed animals for finishing or live sale.

While the overall indexes combine multiple traits into one decision-making tool, it is important to assess the individual traits within each index.

Replacement Index

The Replacement Index is an overall indication of the maternal genetics in a beef animal. The current index valuation is over €111 for 4-stars on the replacement index and over €132 for 5-stars (based on March 2026 evaluations). Within this index, target maternal traits include:

Daughter milk

The milk ability of progeny from the animal. Target predicted transmitting ability (PTA) of 8 kg for replacement heifers.

Daughter calving interval

The number of days between successive calvings which indicates fertility. Target a minus PTA value to reduce the calving interval.

Carcass weight

The expected carcass weight of progeny. Target a PTA of 18-20 kg for suckler cows to balance cow size with carcass potential and cull value.

Docility

This indicates how quiet an animal is expected to be. Target a positive PTA value.

These figures are available for all SCEP and ICBF HerdPlus herds to access through ICBF. When stock bulls or AI bulls are selected to breed replacement heifers in the herd, the traits outlined above can be used. The remainder of the herd can be bred to more terminal bulls using the Terminal Index.

Terminal Index

This provides an overall indication of the ‘terminal’ genetics in a beef animal. The current index valuation is over €105 for 4-stars and over €132 for 5-stars (based on March 2026 evaluations). Within this index, target terminal traits include:

Calving difficulty

This trait provides an indication of the potential percentage of calving issues; these are divided into heifer and cow figures. Targets are less than 7% on heifers at over 90% reliability, and less than 6% for first- and second-calvers, less than 7% for average size cows and less than 9% for ‘strong’ mature cows, at over 80% reliability to help avoid difficult calvings.

Carcass conformation

This trait provides an indication of expected conformation or ‘shape’ of an animal based on the EUROP scale. The higher the value, the higher the expected grade. This is important for weanling sellers, particularly where they are selling export stock and for finishers.

Age at finish

This trait gives an indication of how quickly the animal will finish which can help to reduce the overall age at finish in a herd. A minus PTA value means a reduction in days to finish from birth.

Carcass fat

This trait gives an indication of the expected carcass fat of an animal; for example, the potential to finish from grass. Selecting sires with 1- and 2-star values for carcass fat means that they have improved fleshing ability.

Tuberculosis (TB)

The TB trait allows farmers to identify animals which are genetically more resistant to TB. A figure of less than 6.69% means that an animal is in the top 20% for TB resistance (based on March 2026 evaluations).

Using ICBF data for better decisions

ICBF reports are available to identify key performance indicators in a breeding herd and allow farmers to benchmark their own farms against others. It is a simple way of identifying underperforming cows in the herd for culling and the good performing females for breeding. Some of the reports include:

1. Beef calving report

Among other key performing indicators (KPIs) it shows the calving interval, calves per cow per year, mortality, 6-week calving rate and heifers calved at 22-26 months of age.

2. Weaning performance report

This report predicts the 200-day weaning weights and lists the top and bottom five female and male calves in the herd. It also produces a weaning efficiency figure for the cows to show the calf 200-day weight as a percentage of their body weight (target 42%) and ranks calf performance based on sire.

3. Suckler cow report

Outlines the ancestry and fertility details of the cows, followed by the lifetime performance of their progeny.

4. Beef Eurostar report

Gives an overview of the herd. Ranks the highest and lowest heifers and cows on the Replacement Index and provides details of their carcass weight, daughter milk and daughter calving interval.

Conclusion

Visual assessment, genetic information and performance data can be used together to make decisions about the herd. Producing a ‘balanced’ suckler cow means avoiding extremes in most traits and helps to produce a uniform set of calves for the farm system. The most profitable suckler cow is the one that consistently delivers a quality calf every year with minimal inputs.

Compiled and edited by Mark McGee and Paul Crosson, Teagasc, Grange Animal & Grassland Research and Innovation Centre, and first published in BEEF2026 – Driving Sustainable Performance, additional reading from BEEF2026 is available here.