The Holstein breed achieved a new record of 700kg of combined fat and protein production (CFP) in the year ending September 2023 - up from 686kg in 2021/2022.
Highlights from National Milk Records' (NMR) annual production report also showed a milk yield increase for the breed - up to 9,409kg at 4.12% fat.
Meanwhile, the Holstein breed's average somatic cell count (SCC) dropped to 157,000 cells/ml - the lowest level in at least a decade.
The calving interval decreased by four days, down to 395 days, compared with the previous year.
Improvements from the previous year were recorded in the Jersey breed, which account for 2% of NMR recorded herds.
The breed averaged 550kg of CFP, an increase of 6kg, and 5910kg of milk, an increase of 58kg, which averaged 5.38% fat and 3.93% protein.
SCC for the Jersey breed reduced slightly compared with 2021/2022 to 185,000 cells/ml and the calving interval reduced by a day to 401 days.
The British Friesian breed, with 1.5% of total NMR recorded lactations, had a slight drop in CFP of 2kg to 481kg.
The breed also experienced a drop in average milk yield of 74kg to 6,364kg.
SCC increased by 3,000 cells/ml to 158,000 cells/ml, while calving interval dropped by four days to 387 days.
The Ayrshire breed, making up 1.2% of recorded lactations, achieved the same CFP yield as the previous 12 months at 519kg.
The breed experienced marginal drops in SCC to 155,000 cells/ml, and the calving interval, down to 399 days.
The top three Holstein herds ranked on production all achieved a CFP yield above 1,000kg.
J H Shropshire took top place, increasing its CFP by 32kg to 1,045kg and its yield by 440kg to 14,659kg.
The Shropshire-based robotically-milked herd recorded 59 completed lactations.
In second place, Marshall and Law Partners’ herd from Derbyshire had 173 completed lactations and was milked three times a day.
It recorded 1,026kg of CFP and 13,725kg of milk.
In third place is PJ and PE Ashley from Shropshire. The 106 robotically-milked cows achieved 1,002kg CFP and 13,705kg of milk.
Derbyshire-based Easom and Son remain top genetic merit Holstien herd and has increased its PLI by £24 to £365 with 334 qualifying cow lactations.
Second place is David Foot from Dorset with 699 qualifying lactations achieving a PLI of £353.