Serviços Personalizados
Artigo
Indicadores
Links relacionados
- Citado por Google
- Similares em Google
Compartilhar
South African Journal of Animal Science
versão On-line ISSN 2221-4062
versão impressa ISSN 0375-1589
Resumo
CARDAK, A.D.. Effects of genetic variants in milk protein on yield and composition of milk from Holstein-Friesian and Simmentaler cows. S. Afr. j. anim. sci. [online]. 2005, vol.35, n.1, pp.41-47. ISSN 2221-4062.
Milk samples from 237 Holstein-Friesian (HF) and 177 Simmentaler cows in six herds were typed for genetic variants of αS1-, β- and κ-caseins (Cn) and β-lactoglobulin (-Lg) using ultrathin-layer polyacrylamide isoelectric focusing in the presence of carrier ampholytes (3-10 pH). The frequency distribution of genetic variants of all four milk protein systems was different in HF and Simmentaler. In addition, milk production traits of the dairy cows were compared according to the genetic variants of each milk protein fraction. Milk yield was significantly influenced by κ-Cn (genotype AA > genotype AB) and β-Lg (AB > BB > AA) in HF, while in the Simmentaler milk yield was significantly associated with ß-Cn (A2A2 > A1B > A2B > A1A2 > A1A1) and κ-Cn (AB > AA > BB). In terms of protein content αS1-Cn was significant (BC > BB) in HF, and αS1-Cn (BC > BB), ß-Cn (A1A1 > A2A2 > A1B > A1A2 > A2B), κ-Cn (AA > AB = BB) as well as ß-Lg (BB > AA > AB) were significant in Simmentaler. The effects of milk protein genetic variants on milk fat content in HF were not significant, while in Simmentaler this trait was significantly affected by αS1-Cn (BC > BB), ß-Cn (A1A1 > A1B > A2A2 > A1A2 > A2B) and ß-Lg (BB > AA > AB).
Palavras-chave : αS1-casein; ß-casein; κ-casein; ß-lactoglobulin; isoelectric focusing (IEF); polyacrylamide gel.