How suckler herds can reduce carbon footprint by 40%

Research conducted by the Stabiliser Cattle Company and Alltech E-CO2 has revealed that suckler producers can achieve a near 40% reduction in carbon footprint while saving £350 per cow place through a series of incremental system changes. 

The companies have used a computer-based modelling tool to assess 12 different variables in suckler herd management and their impact on the carbon footprint of the system.

Results showed that most of the changes would decrease carbon footprint when implemented as a standalone change, and then when combining all of them in a bull-finishing system, a carbon reduction of 39.7%/kg of beef produced was achievable.

See also: Why the carbon reduction goal makes good sense

The combined changes would also increase profitability as well as reducing carbon footprint due to the efficiencies achieved.

“We need to move away from seeing carbon footprinting as a burden or simply a tick-box exercise and see that this is beneficial, as a proxy measurement for efficiency and profitability of a farm as well as simply a measure of waste,” said Dr Stephen Ross, senior sustainability specialist at Alltech E-CO2.

Anywhere you can identify inefficiency in the life cycle of an animal or on the farm will have a resounding impact further up the supply chain and reduce the emissions of meat, Dr Ross explains. 

“You have to ask if we can improve 100 things by 1% rather than focusing on one thing 100%.”

Seth Wareing, Stabiliser Cattle Company business manager, acknowledges while there are some quick wins, such as reducing age at first calving or feeding forage-only, completely changing system to incorporate all of the more efficient management practices will take time.

How the trial worked

The research took average suckler herd data from AHDB Stocktake 2017 figures and the latest edition of the John Nix Farm Management Pocketbook.

This data was put into Alltech E-CO2’s Beef Environmental Assessment tool so that a carbon footprint could be determined for the average UK suckler herd.

The trial then changed one management factor at a time (for example, cow size) to see what the impact was.

Aside from the individual variable, all other inputs remained fixed, such as electricity use, fuel use).

A total of 12 different scenarios were tested. These were all based on achievable management practices seen in Stabiliser Cattle Company data, which comes from more than 100 farmers a year, recording 12,000 cattle a year.

Research assumptions

The assumptions of the model were:
• A UK-based, spring-calving 100-cow herd
• Housed during winter – six months bedded on straw
• Grazed for summer – six months
• All offspring taken to slaughter
• Slaughter weights: steers – 370kg, bulls – 370kg, heifers – 330kg
• Replacements are home-bred females

The KPI figures for the average system (AHDB stocktake) were:
• 33% conception rate
• 36 months first calving age
• 15-week calving period
• 93% in-calf rate
• 89 live calves born for every 100 cows
• 47kg birthweight of calves
• 750kg cow weight
• 16% replacement rate
• 24.8 months slaughter age of females
• 23.1 months slaughter age of males

Trial results

Impacts of cow efficiency changes

Scenario 1: Smaller cow size

  • Variable: Based on a 600kg cow (AHDB average – 750kg).
  • Effect on carbon footprint (CF): 7.3% reduction.
  • Causes: Smaller cows require less feed.

Scenario 2: Earlier calving

  • Variable: Calving at 24 months (AHDB average – 36 months).
  • Effect on CF: 3.8% reduction.
  • Causes: Heifer is on farm for one year less before she starts production, requiring less input spend, such as feeding and bedding.

Scenario 3: Smaller calf size

  • Variable: 37kg birthweight (AHDB average – 47kg).
  • Effect on CF: 4.1% reduction.
  • Causes: In theory, a smaller calf involves less complication at calving, with less intervention required, resulting in a higher number of live calves born. In this scenario, there were 92 live calves born for every 100 (AHDB average – 89).

Scenario 4: Nine-week bulling period

  • Variable: Bulling period of nine weeks (AHDB average – 15-week calving period).
  • Effect on CF: 9.3% increase.
  • Causes: In this scenario, the only variable was the length of bulling period and the conception rate (33%) and fertility levels remained the same. Therefore, it resulted in 79% of females in-calf (compared to AHDB average of 93%). This decrease in efficiency and productivity increases the carbon footprint. What this shows is that in order to pursue a nine-week bulling period and then assess its impact on carbon footprint, focus on male and female fertility needs to happen before the length of bulling period is changed.

Scenario 5: Improved fertility on a nine-week bulling period

  • Variable: Conception rate of 65% (AHDB average – 33%).
  • Effect on CF: 4.6% reduction.
  • Causes: This resulted in 96% cows in-calf after bulling (AHDB average – 93%), which would calve over a nine-week calving period. This increase in efficiency reduces the carbon footprint.

Scenario 6: Reducing the replacement rate

  • Variable: 12% replacement rate (AHDB average – 16%).
  • Effect on CF: 2.0% reduction.
  • Causes: By focusing on good feet and udders, good temperament and fewer calving issues, replacement rate can be reduced, so there are fewer heifers running in the herd.

Scenario 7: Forage-fed cows

  • Variable: No concentrate fed after 15 months of age (AHDB average – 130kg a head a year).
  • Effect on CF: 3.6% reduction.
  • Causes: With the right genetics, heifers should not require concentrates once at bulling age. Reduced concentrates fed decreases carbon footprint.

Impacts of youngstock system changes

Scenario 8: Improved growth rate in a steer finishing system

  • Variable: Heifer slaughter at 20 months old and steer slaughter at 18 months (AHDB averages: female – 24.8 months, and male – 23.1 months).
  • Effect on CF: 10.1% reduction.

Scenario 9: Improved growth rate in a bull finishing system

  • Variable: Heifer slaughter at 20 months and bull slaughter at 13 months (AHDB averages: female – 24.8 months, and male – 23.1 months).
  • Effect on CF: 16.3% reduction.

Scenario 8 and 9 causes: Animals are on farm for a shorter period of time, which requires less feed and other inputs, therefore, reducing carbon footprint.

Scenario 10: Improved feed efficiency

  • Variable: 12% better feed efficiency in youngstock.
  • Effect on CF: 7.3% reduction.
  • Causes: Animals still reach same age and weight, but use less feed to do it.

Combining effects

 Scenario 11: Stacking all of the cow and youngstock changes in a steer finishing system

  • Effect on CF: 31.7% reduction.

 Scenario 12: Stacking all of the cow and youngstock changes in a bull finishing system

  • Effect on CF: 39.7% reduction.

 “These management practices are things that don’t only reduce carbon footprint, but things that improve the profitability of the farm, the resource use of the farm,” says Mr Wareing.

“What we see is if you stack all of these on top of each other, for the farmer going from the AHDB average system to the bull-finishing system with a Stabiliser herd, is a saving of about £350 per cow place.”

That comes from increased output and the savings associated with the smaller cows and the easy-management cows, Mr Wareing explains.

Implementation on farm

Independent beef agricultural specialist Jimmy Hyslop says that when considering which of these learnings to implement on farm and how, you need to work out what the limiting factor in the system is then establish how to maximise profit per limiting feature.

Two of the most common examples of limiting factors on farm are:

  • Shed space for winter housing
  • Summer grazing available

Based on the results of scenario 12 (making all of the cow and youngstock efficiency changes and finishing all males as bulls), Mr Hyslop explained what that would mean in terms of shed and grazing space requirements, and how that could actually allow herd expansion.

“By making these changes to the efficiency of the system, achieving the greater output and finishing cattle as quickly as possible, it’s possible to make most efficient use of the same fixed costs, in this case land, in your farming business,” Mr Hyslop explains.

Winter housing

Comparing the shed space requirements of the bull beef stabiliser system that had the stacked changes to reduce carbon footprint with the AHDB average shows that less shed space is required because finished cattle are off the farm sooner.

This would allow the system with a lower carbon footprint to carry 30 more cow-and-calf units.


Shed space for AHDB Average (sq m)

Shed space for stabiliser system with stacked changes to decrease CF (sq m)

Change in shed space required (sq m)

Pregnant cows (100 and 100 at 7.5sq m a cow)



Weaned calves (89 and 95 at 5.5sq m a calf)




Finishing cattle (73 and 0 at 6sq m a head)




Total shed space used




Extra shed space available


Additional cows and calves that can be carried in herd with extra shed space (13sq m a cow and calf unit)


Summer grazing

A similar analysis reveals you can keep another 38 cows on the same area of grazing in the stabiliser system with stacked changes, compared to an average herd.


Summer grazing requirements of AHDB average (Livestock units – LSU – at grass)

Summer grazing requirements of stabiliser system with stacked changes to decrease CF (LSU at grass)

Change in summer grazing requirements (LSU at grass)

Lactating cows with calves (100 and 100)



Replacement heifers (20 and 15)





Finishing cattle (69 and 0)




Total LSU at grass




Extra LSU that can be carried


Extra cows in the herd (inc calves and replacements)


Greenhouse gases from ruminant systems

Carbon dioxide
• Possible sources: Fossil fuel use and energy consumption
• Relative global warming potential: one

• By-product of enteric fermentation
• Possible sources: Manure and waste management
• Relative global warming potential: 25

Nitrous oxide
• More complex emission – arises from direct and indirect processes, such as volatilising and leaching in fields
• Possible sources: Urine and manures, applied fertiliser, crop residues
• Relative global warming potential: 298

Embedded emissions from pre-farm processes and inputs
Possible sources: purchased feeds, bedding, fertilisers, transport, machinery and replacement animals