β-Lactoglobulin Phenotypes in Finnish Ayrshire and Friesian Cattle with Special Reference to Mastitis Indicators

Abstract

An unselected material consisting of composite milk samples from 1029 Ayrshire and 113 Friesian cows were analysed for the β-lactoglobulin types. The frequencies of β-Lg types were AA 8.3 %, AB 45.5% and BB 46.3 % for Ayrshire cows and 22.1 %, 45.1 % and 32.8 % for Friesian cows, respectively. The relationship between β-Lg type with milk BSA, somatic cell count, protein percentage, fat percentage and milk production were analysed. AA cows were significantly higher in daily milk yield but lower in protein percentage and fat percentage than BB cows; AB types were intermediate. The annual production was highest in AB-animals. There was a tendency for AA cows to have high somatic cell counts but low milk BSA concentrations.

β-lactoglobulins; milk BSA; somatic cell count; bovine mastitis; bovine milk; milk proteins.

Sammanfattning

Ett material av komjölkprover från 1029 Finska Ayrshire kor och 113 Friesiska kor analyserades gör att bestämma β-lactoglobulin typ. Frekvensen av β-lactoglobulin typer var AA 8.3 %, AB 45.5 % och BB 46.3 % för Ayrshire kor och 22.1 %, 45.1 % och 32.8 % för Friesiska kor. Korrelationen mellan β-lactoglobulin typ och mjölkalbumin (BSA), cellhalt, proteinhalt, fetthalt och mjölkproduktion analyserades. Den årliga mjölkproduktion en var högst hos AB kor. När mjölkens cellhalt och BSA halt analyserades hos de olika lactoglobulin typerna, künde man se en tendens att AA kor hade högre cellhalt men lägre albuminvärden an väntat.