title: Genetic polymorphism of the kappa-casein gene in Brazilian cattle.
abstract: 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.
authors.affiliation: Embrapa Gado de Leite, Juiz de Fora, MG, Brasil.
authors.forename: A L S
authors.initials: AL
authors.lastname: Azevedo
authors.forename: C S
authors.initials: CS
authors.lastname: Nascimento
authors.forename: R S
authors.initials: RS
authors.lastname: Steinberg
authors.forename: M R S
authors.initials: MR
authors.lastname: Carvalho
authors.forename: M G C D
authors.initials: MG
authors.lastname: Peixoto
authors.forename: R L
authors.initials: RL
authors.lastname: Teodoro
authors.forename: R S
authors.initials: RS
authors.lastname: Verneque
authors.forename: S E F
authors.initials: SE
authors.lastname: Guimarães
authors.forename: M A
authors.initials: MA
authors.lastname: Machado