Abstract
Data for this study were obtained from milk collected from samples of five beef breeds and one dairy breed of cattle located at Livestock and Forage Research Center, McGregor, Texas; Beef Cattle Center and Dairy Cattle Center, Animal Science Department, Texas A&M University,; and J. D. Hudgins Ranch, Inc., Hungerford, Texas. The breeds of cattle involved were Hereford, Angus, Brahman, Charolais, Santa Gertrudis, and Holstein. On objective of this investigation was to determine electrophoretic patters of the α[subscript s1]-caseins and β-casein synthesized by these cattle. From these patterns, the types of the caseins and their distribution among the breed samples were determined. Gene frequencies were also estimated for the alleles responsible of the production of each type milk casein. It was apparent from this study that the two casein components represent polymorphic systems in the breeds studied. Two types of α[subscript s1]-casein (B and C) were detected. Quantitatively, the most striking difference between the Zebu and Western breeds was the predominance of the C-variant of α[subscript s1]-casein in the milk of Brahman cows. The Angus and Charolais were also found to have a higher frequency of the allele responsible for α[subscript s1]-casein C production than either Holstein or Herford cows. Two variants of β-casein (A and B) were also detected by electrophoresis at alkaline pH. Beta-casein A was observed most often in each group. However, a much higher frequency was found for the β-Cn[superscript B] allele in Herefords than in any of the other breed groups. ...
Caldwell, Jerry (1969). A genetic and biochemical analysis of [alpha][subscript s1]-casein and [beta]-casein in bovine species. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -778750.