Stability among the specialist dairy breeds The DairyCo sire indexes for the specialist dairy breeds show stability again this month, reflecting the significantly smaller population sizes and slower genetic turnover among the non-Holsteins.

Jerseys The leading Jersey remains Danish VJ Link, whose Profitable Lifetime Index of £494 reflects his strong production and good health, including a Somatic Cell Count Index of -19 and daughter Fertility Index of +11.1.

Sunset Canyon Daybreak graduated to the proven line-up in December 2014, but improved on all fronts this time, to move up to second position with a PLI of £454.

Danish VJ Tester drops to third position with a substantially lower volume of high-quality milk. He transmits low cell counts (SCC -21) and has a PLI of £432. British Friesians Among the British Friesians, Langley Evolution retains his lead with excellent health traits (SCC -14) and daughter Fertility Index (FI +13.1) and a PLI of £375. Catlane Chad climbs into second position, and is the breed’s leading fat and protein improver with a combined weight of 38.1kg and high components on the British Friesian base. His PLI is £366.

Catlane Caleb remains in third position with a PLI of £317 and again transmits strong components.

Ayrshire Former front-runner, Gunnarstorp has regained his number one position for the Ayrshire list, offering strong production and good health (SCC -14; FI +10.1). His PLI is £494.

Pell Pers, who was the number one Ayrshire in the December 2014 index run, dropped into second position, again transmitting strong production and good health (SCC -13; FI 6.4). His PLI is £480. Retaining his third position, R Yrite has a PLI of £464 and is the highest milk transmitter of the top five and an excellent cell count improver (SCC -22).

Other breeds From the other dairy breeds, Huray holds onto his top position for the Brown Swiss with excellent production, good daughter lifespans and fertility and a PLI of £451.

For the Montbeliarde breed, Crasat climbs to the top with high production, low cell counts and a PLI of £331.

The leading Fleckvieh is Ricki (PLI £308); new at the top of the Shorthorn list is the UK-bred Scandinavian Red, Skyhigh Oscar (PLI £354) and De Garis Bettys Bertie remains the front runner ranked on Guernsey Merit Index.

Type base adjustment “All dairy breeds have had a small downward adjustment to their type figures to reflect the genetic progress made over the last five years,” says Marco Winters, DairyCo’s head of genetics. “In addition, the Type Merit formula has been updated by DairyCo in consultation with the respective herdbooks of the Ayrshire, Brown Swiss and Jersey breeds, to better reflect the herdbooks’ breeding goals, each of which seeks to continually improve fitness.”

Comparison across breeds “As always, it’s important to remember that the £PLI and its components should not be compared directly between breeds,” adds Mr Winters. “The figures for each breed are calculated to relate to that breed average, so comparing figures across breeds would be both meaningless and potentially misleading.

“DairyCo supplies specific conversion formulae for those who want to compare one breed with another for cross-breeding purposes,” he says. “Alternatively, those on a grazing-based, spring-calving system may prefer to use the Spring Calving Index (£SCI) which ranks bulls of all dairy breeds on the same list.”