Method of determining fatty acid composition of milk
A method of reducing the level of saturated fatty acids relative to the level of unsaturated fatty acids in milk. In particular, the genotyping and/or phenotyping of bovine cows on the basis of the amino acid residue located at position 67 of beta-casein produced in their milk. The invention is based on the finding that there is a correlation between the ratio of saturated to unsaturated fatty acids in milk and the beta-casein variants in milk.
1. A method of determining relative levels of saturated fatty acids and unsaturated fatty acids in bovine milk obtained from one or more cows:
(a) testing genetic material of the one or more cows for the presence of DNA encoding β-casein having a proline residue at position 67 or DNA encoding β-casein having a histidine residue at position 67;
(b) identifying whether a cow or cows (i) will likely have a lower percentage of saturated fatty acids and a higher percentage of unsaturated fatty acids based on being homozygous for DNA encoding β-casein having a proline residue at position 67 or (ii) will likely have a higher percentage of saturated fatty acids and a lower percentage of unsaturated fatty acids based on being homozygous for the DNA encoding β-casein having a histidine residue at position 67 for which genetic material was tested in (a); and
(c) obtaining milk from at least one of the one or more cows after step (b).
2. The method as claimed in claim 1 , wherein the β-casein having a proline at position 67 includes one or more of β-caseins A2, A3, D, E and F.
3. The method as claimed in claim 2 , wherein the β-casein having a proline at position 67 is β-casein A2.
4. The method as claimed in claim 1 , wherein the β-casein having a histidine at position 67 includes one or more of β-caseins A1, B, and C.
5. The method as claimed in claim 4 , wherein, the β-casein having a histidine at position 67 is β-casein A1.
6. The method as claimed in claim 1 , wherein the genetic material of the cows may be any tissue containing, or which contained, nucleated cells.
7. The method as claimed in claim 6 , wherein the genetic material is obtained from blood, hair, or milk.