carbon sub-index<\/a>, there has also been a number of updates to the beef sub-index within the economic breeding index (EBI).<\/p>\n\n\n\nThis is the first time since 2014 that changes have been made to the beef sub-index. <\/p>\n\n\n\n
The updated beef sub-index will account for 10% of the total EBI, rather than the previous 8%. <\/p>\n\n\n\n
Updates to the beef sub-index are important for a number of reasons especially considering that 57% of national kill origin is from the dairy herd and this figure is going to increase in the coming years. <\/p>\n\n\n\n
Changes to sub-index<\/h2>\n\n\n\n
There have been three main changes to the beef sub-index within the EBI, with the inclusion of an age of slaughter trait, in-spec carcass traits and economic value updates. <\/p>\n\n\n\n
Like the new carbon sub-index, it is the first time that age of slaughter has been included in a cattle breeding objective. <\/p>\n\n\n\n
The use of sexed semen on dairy cows will result in the majority of surplus calves from the dairy herd entering the beef herd having been sired by beef bulls. <\/p>\n\n\n\n
But without more emphasis on beef traits, it will be difficult to improve the overall quality from the dairy herd – as the cow contributes up to half the beef merit of the calf.<\/p>\n\n\n\n
Beef sub-index<\/h2>\n\n\n\n
A study conducted by Teagasc compared the old sub-index to the updated sub-index on 46,000 Friesian steers slaughtered from large beef herds in 2021 and 2022.<\/p>\n\n\n\n
The study found that the old sub-index was doing a ‘fairly good job’ according to Alan Twomey from Teagasc. <\/p>\n\n\n\n
The difference between the top 20% and bottom 20% is outlined in the table below. <\/p>\n\n\n\n<\/th> | Bottom 20%<\/th> | Top 20%<\/th> | Difference<\/th><\/tr><\/thead> |
---|
Carcass weight<\/td> | 307<\/td> | 322<\/td> | 15<\/td><\/tr> |
Weight spec (280-380kg)<\/td> | 72%<\/td> | 75%<\/td> | 3%<\/td><\/tr> |
Conformation spec (\u22650=)<\/td> | 26%<\/td> | 37%<\/td> | 11%<\/td><\/tr> |
Fat spec (\u22652+ and \u22644=)<\/td> | 85%<\/td> | 85%<\/td> | 0%<\/td><\/tr> |
Age at slaughter (days)<\/td> | 771<\/td> | 768<\/td> | -4<\/td><\/tr><\/tbody><\/table>Old beef sub-index<\/figcaption><\/figure>\n\n\n\n Looking at the new sub-index, the results are outlined in the table below. <\/p>\n\n\n\n The biggest change between the two is in the age of slaughter with 20 days saved between the top 20% and bottom 20% of dairy sires. <\/p>\n\n\n\n<\/th> | Bottom 20%<\/th> | Top 20%<\/th> | Difference<\/th><\/tr><\/thead> |
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Carcass weight<\/td> | 308<\/td> | 320<\/td> | 12<\/td><\/tr> | Weight spec (280-380kg)<\/td> | 73%<\/td> | 76%<\/td> | 3%<\/td><\/tr> | Conformation spec (\u22650=)<\/td> | 25%<\/td> | 40%<\/td> | 15%<\/td><\/tr> | Fat spec (\u22652+ and \u22644=)<\/td> | 84%<\/td> | 87%<\/td> | 3%<\/td><\/tr> | Age at slaughter (days)<\/td> | 781<\/td> | 761<\/td> | -20<\/td><\/tr><\/tbody><\/table>New beef sub-index<\/figcaption><\/figure>\n\n\n\n There will be increased variation between dairy sires on beef sub-index, as there will be a \u20ac50 difference between the top and bottom 20% of bulls – compared to \u20ac29 in old index. <\/p>\n\n\n\n According to Twomey this will make it easier to select dairy bulls that are high value for beef without compromising on dairy traits. <\/p>\n\n\n\n But it will penalise bulls with poor genetic merit for beef traits, according to Twomey. <\/p>\n\n\n\n The new index will align with dairy beef index (DBI) and the commercial beef value (CBV). <\/p>\n\n\n |
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