The original Beef Value measured the improved financial return by improving carcass weight, fat and conformation scores adjusted for any additional costs due to increased calving difficulties.

The new Beef Value EBV

When the EBVs for Calving Ease and the index Calving Value were introduced the Beef Value was changed to measure only the improved financial return by improving carcass weight, fat and conformation scores.

In both cases, the main factor inflluencing Beef Value is 400 day weight. As a result by selecting entirely on Beef Value breeders have bred faster growing, larger and leaner cattle. These produce significantly heavier carcasses when taken to the same level of fat finish eg fat class 4L.

As a result in some of the larger later maturing breeds the top bulls in Beef Value are beginning to produce what the index suggests ie much heavier carcasses but:

- with reductions in carcass fatness being greater than increases in daily liveweight gain, these animals are taking longer to reach finished condition.

- the increased carcass weight produced is incurring penalties of around 4 p/kg for overweight carcasses even though they grade well in terms of carcass conformation/fat class.

An indication of this can be seen in the result of Charolais X bull calves sired by three different Charolais bulls in our spring calving herd which were intensively finished last winter.

+13                   329                 0.85                      571                     386                   148

Calves sired by the bull with the highest Beef Value produced the heaviest carcass weights but as they had similar lifetime growth rates they took longer to reach finished condition - our target being fat class 4L. In addition around half of his carcasses were overweight ie over 380kg dead weight and received a penalty of 4 p/kg. The combination resulted in animals sired by the bull with the highest Beef Value leaving little benefit in terms of carcass income per day of age!

The problem would be even more extreme had we castrated his calves and grown them on to two years of age to claim the second BSPS premium. In order to get sufficient fat cover it is likely that we would have to have taken steers to carcass weights well in excess of 440kg.

Conclusions

1 For each breed there will be an optimum Beef Value EBV, above which profitability will fall due to the penalities imposed on overweight carcasses.

2 For each breed there will be different optimum Beef Values depending on the system in which the progeny will be fin ished. The more intensive the finishing system the higher the optimum Beef Value.

3 The optimum Beef Value will also depend upon the cross of cow with which the bull is mated, the optimum being lower, the more continental breeding there is in the cow.