New bull for spring block calvers and stability for our autumn calving index

Spring block calving producers who are still looking for service sires this season may be encouraged to see a brand new number one bull ranked on the AHDB Dairy Spring Calving Index (£SCI).

The bull is the British Friesian, Lakemead Jingle, whose SCI of £477 gives him the edge on this across-breed ranking. Jingle transmits positive milk production, reduces cases of mastitis and has a superb daughter Fertility Index of +17.7. With a Maintenance Index of -16, his daughters are also predicted to be cheap to feed.

Former number one sire, Danish VJ Tester, has been in the running for £SCI for many index runs and now climbs back to second position from fifth place last December. This Jersey sire features excellent milk quality (0.67% fat and 0.24% protein) and good fitness and fertility (FI +12.7), while his Maintenance Index of -64 is a reflection of the small daughter he breeds which will have low feed maintenance costs. Tester’s SCI is £476.

The British Friesian, Catlane Caleb, has also been a long-standing fixture of the £SCI ranking, moving down just one position on this occasion. Another great daughter fertility improver (FI +17) he too will reduce costs of production. His SCI is £473.

Down from third to fourth place is the Holstein, Larcrest Commend, whose SCI of £472 reflects a breeding pattern of far higher production and greater maintenance costs than his contemporaries from the other breeds. However, his low cell counts (-18) and weight of fat plus protein will appeal to those looking to push up production.

Rounding off the £SCI top five is Danish Tudvad (£SCI 455), a high percentage fat improver transmitting low cell counts (-21) and good daughter fertility (+12.5).

Autumn Calving Index (£ACI)

As the spring calving season comes towards its end, producers block calving in autumn may be considering their breeding choices, or reflecting on the decisions they made last year. If that’s the case, they’ll be pleased to see little change in the Autumn Calving Index (£ACI) ranking, which sees many of the same bulls leading the way.

Number one position is retained by the Holstein, Larcrest Commend (£ACI 657), whose excellent milk and solids production (719kg milk, 35.4kg fat, 30.1kg protein, 0.10% fat, 0.11% protein) are complemented by low cell counts (SCC -18) and good daughter fertility.

Remaining in number two position is Teemar Shamrock Alphabet (£ACI 624), a transmitter of high production (794kg milk, 21.5kg fat, 22.7kg protein) and excellent daughter fertility (FI +15.7).

Moving up from fourth to third position, Hoanster Zanzibar (£ACI 617) offers excellent weight of milk (843kg), fat (33.1kg) and protein (27.1kg) combined with low cell counts (SCC -21) and great daughter fertility (+11.4).

The biggest jump in the top five comes from De-Su 12272 Apex, who moves from 11th to fourth position with an ACI of £616. He too features high weights of milk, fat and protein, outstanding cell counts (-28) and long lifespans.

Unchanged at number five is S-S-I Mogul Multiply (ACI £603), offering a good balance of production and health, including a superb daughter Fertility Index of +13.9.

“The two block calving indexes in either spring or autumn are designed for quite different management conditions,” says Marco Winters, head of animal genetics with AHDB Dairy. “They should only be used in tight block calving situations and it should be remembered that they are expressed across breeds.

“This is designed to particularly help producers who cross-breed their herds. However, it means it’s very important not to look at the components of the index and compare them with other Predicted Transmitting Abilities (PTAs) used in the calculation of £PLI and expressed on each of the individual breed scales,” he says.