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Casein haplotypes and their association with milk production traits in the Finnish Ayrshire cattle
Author(s) -
Velmala R,
Vilkki J,
Elo K,
MäkiTanila A
Publication year - 1995
Publication title -
animal genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0268-9146
DOI - 10.1111/j.1365-2052.1995.tb02694.x
Subject(s) - haplotype , breed , biology , casein , allele , dairy cattle , milking , zoology , genetics , locus (genetics) , gene , food science
Summary Polymorphism of casein genes was studied in half‐sib families of artificial insemination bulls of the Finnish Ayrshire dairy breed. Ten grandsires and 300 of their sons were genotyped for the following polymorphisms: α S1 ‐casein (B, C), β‐casein (A 1 , A 2 ), the microsatellite within the K‐casein gene (ms 5 , ms 4 ) and K‐casein (A, B, E). Nine different combinations of these alleles, casein haplotypes, were found. Associations between casein haplotypes and milk production traits (milk and protein yield, fat and protein percentage and milking speed) were studied with ordinary least‐squares analysis to find a direct effect of the haplotypes or an association within individual grandsire families using the granddaughter design. Estimated breeding values of sons were obtained from cow evaluation by animal model. No direct effect of the casein haplotypes on the traits was found. Within grandsire families, in one out of four families the chromosomal segment characterized by haplotype 3 (B‐A 2 ‐ms 4 ‐A) was associated with an increase in milk yield ( P <0.01) and a decrease in fat percentage ( P < 0.01) when contrasted with haplotype 8 (B‐A 1 ‐ms 4 ‐E). The results provide evidence that in the Finnish Ayrshire breed at least one quantitative trait locus affecting the genetic variation in yields traits is segregating linked to either haplotype 3 (B‐A 2 ‐ms 4 ‐A) or 8 (B‐A 1 ‐ms 4 ‐E).