Cattle Milk Protein Panel

Beta-casein (A2 Genotyping)

Genetic variants of beta-casein, a protein of cow's milk, can be classified into two groups, A1 and A2, based on the specific amino acid in position 67 of the protein. This A1 and/or A2 group designation may be of interest to breeders developing herds for human health benefits.


Kappa-casein is an important gene for protein yield and percentage in milk. Two common variants, A and B, are associated with different concentrations of kappa-casein protein in cow's milk.


Beta-lactoglobulin is the major whey protein gene. Two common variants, A and B, are associated with different concentrations of beta-lactoglobulin protein in cow's milk.

Sample Collection

Most of the cattle DNA tests offered by the VGL are carried out using cells from the roots of a hair sample (roughly 20-30 hairs).

Hair samples should be taken from the switch of the tail, the poll, or the neck.

Cattle sampling examples
Sampling from the tail switch (left); Sampling from the poll (right)

1.  Clean (use comb if possible) tail switch, poll, or neck by removing all loose hair and foreign matter.

2.  Use fingers or pliers to grasp approximately 8-10 hairs close to the skin and pull. Pull (do NOT cut) hair strands. Examine the end of hair strands for presence of root bulbs. Hair roots are necessary for DNA testing. If the majority of hair strands lack the root bulbs, discard hair and start again.

3.  Repeat until you have approximately 20-30 hairs with root follicles attached.

4.  Place the 20-30 hairs with root follicles attached in the envelope and seal with the animal’s ID written on the envelope. If hairs are long they can be taped to the submission form. Do not tape the roots

Cattle hair in envelope

hairs with roots showing

5.  Repeat steps 1-4 for each additional animal being sampled.


-  Hair should be dry.

-  If hair has excess dirt and debris, please brush out if possible before pulling hairs for sample.

-  Do not cut the hair! The roots contain the DNA for testing.

-  When sampling several animals in the same session, make sure that there are no hair strands in your hands to reduce the possibility of sample contamination. Clean hands and/or pliers if possible.

Type of Sample


Type of Panel