Genetic polymorphism of the kappa-casein gene in Brazilian cattle.
Frequencies of kappa-casein gene alleles were determined in 1316 animals from the Brazilian Bos indicus genetic groups (Sindhi cows, Gyr sires, Gyr cows, Guzerat sires, Guzerat cows, Nellore sires, and Gyr x Holstein crossbreds) by means of polymerase chain reaction-restriction fragment length polymorphism analysis using two independent restriction nucleases (Hinf I and HaeIII). The genotyping of kappa-casein alleles (A and B) is of practical importance, since the B allele is found to correlate with commercially valuable parameters of cheese yielding efficiency. The frequencies of the B allele of kappa-casein among breeds ranged from 0.01 to 0.30. The Sindhi breed had the highest frequency for the B allele (0.30), while the frequencies of this allele in other breeds ranged from 0.01 to 0.18. A wide variation in the B allele frequency among B. indicus breeds was found suggesting that molecular selection for animals carrying the B allele could impact breeding programs for dairy production.
Azevedo
A L S
AL
Embrapa Gado de Leite, Juiz de Fora, MG, Brasil.
Nascimento
C S
CS
Steinberg
R S
RS
Carvalho
M R S
MR
Peixoto
M G C D
MG
Teodoro
R L
RL
Verneque
R S
RS
Guimarães
S E F
SE
Machado
M A
MA