Review of productivity and comparison of breeding evaluations of Wagyu on Pastures in Northern Ireland, UK.
Introduction
Wagyu cattle are raised globally and practices that are applied in Japan are generally followed. A mandate that was imposed ten years ago is affecting domestic policy there. The Japanese Government’s basic plan for Food, Agriculture and Rural Areas is revised every five years. In March 2015, the move away from the heavy reliance on imported feed grains was a big step on the push towards feed self-sufficiency with the setting of targets over ten years through to 2025.
Some grain consumption projections and production targets (million metric ton) |
||||
Grain |
Total supply = |
Domestic production as percentage of Total supply |
||
FY 2013 |
FY 2025 |
FY 2013 |
FY 2025 |
|
Barley |
2.08 |
2.13 |
8.7% |
10.3% |
Soybeans |
3.01 |
2.72 |
6.6% |
11.8% |
Wheat |
6.99 |
6.11 |
11.6% |
15.5% |
The focus for research changed and the number of days to finish Wagyu cattle has been decreasing more noticeably. Encouragement to produce beef in Japan from less productive land such as on hillsides has also been encouraged.
Most of the Fullblood and Wagyu-cross beef produced in Australia is finished on grain and exported. Breeding values and indices in Australian BreedPlan are focused on highest marbling from intensive production and Wagyu there have been branded to be the “luxury Breed”.
For fifteen years Wagyu International has been studying genomics and nutrition in Japan and applying commercial programs in Australia.
After exporting genetics from Australia to Europe, an interest in production of Wagyu from pastures developed. A collaboration with a producer finishing Fullblood and Wagyu-cross on pastures in Northern Ireland commenced five years ago. Monitoring of progress was slow initially because of environmental constraints but the drivers for productivity have become more evident.
The Australian Wagyu Association turned off access to the Estimated Breeding Value (EBV) database at 9:30pm on 2nd February 2026. After recalibration of several traits, Wagyu Breeding Values (WBV) have replaced them, and they are displayed on the Helical website. Predictions of WBVs for all Fullblood, F2 and F3 Wagyu cross steers that have been processed at Riversdale Wagyu have been determined.
A comparison has been made of the associations between EBVs as posted on 31st January 2026 and the WBVs as posted since 1st February 2026 with Margin of Fullblood steers during finishing on Pastures at Riversdale Wagyu.
Production from Fullblood and crosses on pasture at Riversdale Wagyu
Shorthorn, Angus and Angus/Friesian base females have been upgraded, and the first Fullblood females are from Australian embryos.
Recently more Fullblood embryos have been imported. Sires for beef production are home-raised and from EU and Australia.
Prices are set at retail by weight of sub primal and retail cuts.
There is no official beef grading in the UK so Wagyu International allocates scores from photographs of ribeye and sirloin steaks for each steer for the internal analysis.
Mid-parent estimated breeding values are prepared from Australian BreedPlan.
Pastures are supplemented with grain.
Financial performance is tabled, as a percentage of Full blood averages:
Financial performance by grade from pasture |
|||
Measurement/ |
Fullblood |
F3 cross |
F2 cross |
Number by grade |
10 steers |
3 steers |
12 steers |
Retail value (£) |
- |
+ 2.7% |
-7.9% |
Net profit (£) |
- |
-4.7% |
- 7.2% |
Despite a lower Slaughter Weight, Fullblood steers have a heavier Retail Weight after processing. They also have a higher proportion of higher value cuts. Wagyu crosses have a higher weight of Burgers. These factors culminate in a higher Retail Value for Fullblood steers.
Slaughter Weight and Retail Weight are charted to illustrate the breed differences of “waste” in columns in red. The sub primal/retail cuts (Retail Weight) are shown in different shades of blue colour.
Carcasses with the highest proportion of higher value retail cuts – such as fillet, sirloin and ribeye – yield highest revenue. Carcasses with a heavier weight of the high-volume burgers have lower total retail value. These are the fundamental differences between Fullblood and Wagyu cross steers - and within breed.
Average Birth weight is 10.9% lower for Fullblood steers when compared with average Wagyu crosses. Fullbloods are processed at a 5.6% higher Age with an average Slaughter weight that is 2.1% lighter than the average crosses.
Because of a higher yield from Fullblood steers, Retail weight is 3.0% higher. Fullblood Retail value per Retail weight is also 3.0% higher than crosses so Retail Value for Fullbloods is 5.8% higher. Grain supplements provided on pasture cost 17.6% more for Fullbloods and total costs overall are 4.8% higher for Fullbloods. With higher yield, Fullbloods have 5.2% lower Waste at Retail.
Overall, average Net profit per head is 6.7% higher for Fullblood steers in this dataset when compared with Wagyu cross steers finished on pasture.
Wagyu cross retail value is lower than that from Fullblood steers, so the same profit can only be realised at a higher Slaughter Weight. Ideal weight for processing Fullblood Wagyu steers at Riversdale Wagyu is between 660 and 740 kg Live Weight. Ideal Slaughter weight for Wagyu crosses is from 720 to 825 kg.
Highest marble score has been scored to a son of Trent Bridge F115. Until harvested, progeny from F115 had been unpopular across Europe because of moderate growth and smaller size. However, they were subsequently found to yield higher grades and to bring heavier high-value primal cuts with higher marbling.
Fernando, son of Trent Bridge F115, maintained modest growth for almost three years on pasture then gave a growth spurt during one summer. During waterlogging he lost 76 kg over the next 28 days. He was processed at 37 months of age before recovering the lost liveweight. Two years later Fernando still has highest marble score and the lowest growth rates.
Fat Intrusion (Intermuscular fat within the muscle) is common during finishing on pasture. F3s Hardy, sired by Arubial Anticipated, weighed 800kg at 39 months.
F3a Hans, from Wyndford Sonic, weighed 825 kg at an age that two months longer.
Fullblood son from Circle 8 Bulls Q122, recorded the highest margin at 800kg at the age of 44 months.
Typically, the higher maintenance requirements for heavy steers erode the return but the yield from high value cuts from Q122 has compensated to realise highest profit.
A review of the incidence of Fat Intrusion has been undertaken from the dataset. No statistical differences were identified between traits and Fat Intrusion from internal scoring. However, there are indications that Live Weight, Marble Fineness and grain supplementation may individually or in combination have some influence on the incidence.
Association of breeding values with returns on grass.
Frequent monitoring of live weight revealed fluctuations that become more pronounced from the age of 200 days.
These variances that are caused by seasonal effects were amongst the environmental effects that appeared initially to suppress genomic expression on the pasture.
After accumulating data from five year’s production from pastures, the association in Wagyu Fullblood steers of Margin was highest with Eye Muscle Area (EMA) Estimated Breeding Value (EBV), then Carcass Weight (CW), Marble Fineness (M fine), then Marble Score (M score) EBVs. The association of Growth EBVs were weakly positive and Milk EBV was strongly negative with Margin.
The Fullblood Terminal Index has the strongest association with Margin amongst the production indices.
Re-calibrated BreedPlan breeding values called Wagyu Breeding Values (WBV) replaced EBVs in February 2026. Associations of mid-parent predictions with Margin from steers that have been processed by Riversdale Wagyu have been charted (yellow bars) alongside the discontinued EBVs (red bars).
The associations between the new carcass trait WBVs with Margin are all reduced from the former carcass traits EBVs. The new calibrations in Australian BreedPlan do not appear to enhance the measurement of breeding values for finishing Wagyu from pasture in Northern Ireland.
Wagyu International has been developing new estimated breeding values. The association of Fillet weight, Ribeye weight, Sirloin weight, Marble fineness, Marble coarseness and Fat intrusion with Margin for Wagyu Fullblood steers that were finished on pasture are charted:
The association of Margin with EMA EBV has dropped from +0.43 to +0.29 with the new EMA WBV. The demise of a breeding value from AWA for the pasture industry makes way for the launch of Wagyu International Fillet weight and Ribeye weight EBVs. They are based on actual primal weights and the associations with Margin are +0.65 and +0.58. However Sirloin weight is heavier than the other two but there is no association between this EBV with Margin at this preliminary stage.
More than half of the production at Riversdale Wagyu is from Wagyu crosses. There are no EBVs for crossbreds so Wagyu International developed Marble fineness EBV when the Marble Coarseness EBV and Fat Intrusion EBVs were being developed. Marble fineness WBV that has replaced Marble fineness EBV by AWA does not have an association with Margin on Pastures so the new Wagyu International Marble fineness EBV will be used internally.
The association of Fat Intrusion EBV is negative with Margin so this indicates that there is a negative association between Margin and Fat Intrusion Score and that amongst other causes, there may be some genomic influence.
There is a compromise of quality from sustainable production of Wagyu on pastures. However, the supply of high-quality Wagyu that is offered to the market from grass by Riversdale Wagyu is held in high regard because it usually is of the standard that would grade AUS-MEAT 9, and higher. The average Marble Score for Fullblood steers is 9.45 and 8.93 for F2 and F3 Wagyu cross steers.
Acknowledgement is given to Riversdale Wagyu for providing performance data to enable Wagyu International to undertake this review.
References
AWA Estimated Breeding Value database, until 2nd February 2026.
Fujibayashi, K., 2015. Japan's Basic Plan for Food Agriculture and Rural Areas. USDA Foreign Agricultural Service, Global Agricultural Information Network. Public. 4th October 2025.
Helical Company Limited, Wagyu Breeding Values, from 1st February 2026.