While the majority of dairy-beef calves are bred of Angus and Hereford sires, suckler-bred cattle in Ireland are predominantly bred from continental breed sires with the target of achieving a higher beef carcass weight.
These breeds generally take longer to mature than traditional breeds of cattle and it can be harder for these cattle to reach the right level of fat cover (a score of 2+ or higher) at a young age, especially when they’re raised mainly on grass. This is especially true when compared to early maturing breeds of cattle.
Research completed by Sarah Burke, Edward O’Riordan, Paul Crosson and Mark McGee from Teagasc Grange recently looked at how genetics affected carcass fat score, growth, and conformation (shape) of Charolais crossbred steers finished from grass-based systems at 19, 23, and 26 months of age.
The study, published in the Teagasc November Beef Newsletter compared cattle that were bred to be leaner versus those bred to gain more fat.
The researchers found that cattle bred to gain fat had higher carcass fat scores at all
ages. The fat scores were higher by 1.7, 2.4, and 2.0 points (15-point scale) at 19, 23, and 26 months of age respectively, compared to the leaner cattle.
The research found that the cattle with the higher fat scores had slightly lower carcass
conformation scores (-1.0 point) and their carcasses weighed approximately 9kg less on average at 19 and 23 months of age.
Interestingly, the research found that there was no weight difference in the cattle at 26 months of age.
The key findings of the research is that late-maturing cattle that are bred to gain more fat can still reach the right fat level at a younger age.
The slight drop in shape and carcass weight isn’t as much of a concern in these types of cattle as it would be in breeds that mature earlier, according to the researchers.