Prevalence of αs1-casein genotypes in American dairy goats

E. A. Maga, P. Daftari, D. Kültz, Cecilia Penedo

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15 Scopus citations


Widespread genotyping of US dairy goat breeds for casein variants has not been reported, even though the genetic data could be of use in selective breeding programs. For instance, variability in the content of protein and solids in goat milk is attributed to allelic differences in the goat αs1-casein gene. Concentrations of αs1-casein in goat milk are positively correlated with milk components and coagulation properties. The alleles A and B are designated as strong alleles, resulting in the greatest amount of αs1-casein in goat milk, whereas the E allele produces intermediate amounts and the weak allele F produces the least concentrations of αs1-casein in goat milk. Here we report on one of the first surveys of the distribution of αs1-casein genotypes in US dairy goats. The population surveyed, consisting of a total of 257 Americandairy goats representing 7 main dairy breeds, contained a greater predominance of the weaker alleles, E and F, than the strong alleles, A and B. Allele distribution was related to breed, with Toggenburg, Alpine, Saanen, and Oberhasli containing the most E and F alleles and LaMancha, Nubian, and Nigerian Dwarf the fewest. Quantification of αs1-casein production by 2-dimensional gel electrophoresis demonstrated that F/F animals had the least amount of αs1-casein protein in their milk compared with all other genotypes. The results indicate that genetic improvement of dairy goats in the United States could be achieved if an αs1-casein breeding scheme were adopted.

Original languageEnglish (US)
Pages (from-to)3464-3469
Number of pages6
JournalJournal of Animal Science
Issue number11
StatePublished - Nov 1 2009


  • α-casein
  • Genotype
  • Goat
  • Milk production

ASJC Scopus subject areas

  • Food Science
  • Animal Science and Zoology
  • Genetics


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