Tue, 10 Apr 2018
UK - With the breeding season for spring block calving herds about to start, farmers choosing bulls for grazing-based systems are advised to pay attention to the new run of Spring Calving Indexes (£SCI), published last week (3 April 2018) by AHDB Dairy.
Bulls dominating the rankings are smaller than average, transmit high fat and protein percentages on to their daughters and also feature excellent daughter fertility – leading on to longer lifespans.
Leading on £SCI, and new in top position is the Jersey sire, Danish VJ Tester (SCI £510). With exceptional transmitting abilities for fat and protein percent (+0.67 per cent and +0.24 per cent), high daughter fertility (Fertility Index +12.4) and favourable somatic cell counts (SCC -11) he breeds daughters which are set up to be profitable in a spring calving system. This is enhanced by their requirement for significantly less maintenance feeding than most bulls’ daughters (Maintenance Index -62).
Also new in second position is the Jersey sire, Danish VJ Blanke Jason Janko (SCI £492). He too transmits very good components (0.55 per cent fat, 0.25 per cent protein), with good daughter lifespans (LS +0.6) and solid conformation (Type Merit +1.6).
Regular top £SCI appearances come from Danish VJ Link (SCI £490), now with 105 UK daughters included in his production index; Danish VJ Summit (SCI £476) and Danish VJ Tudvad (SCI £470) who has the best mastitis index of the top £SCI bulls at -4.
Also in the top 10 is British Friesian, Catlane Caleb (SCI £459) who stands out for his high daughter Fertility Index (+16.5)
"It’s very important for producers to remember that the £SCI is an across-breed ranking, which is designed, in particular, to help those breeders considering or using more than one breed, to make across-breed comparisons," said Fern Pearston, animal genetics manager for AHDB Dairy.
"However, it means the figures they see are very different from the same bulls’ figures on each individual breed ranking, and these should never be used to make comparisons across the breeds."