Marker assisted selection of bovine for improved milk composition

A method of selecting a bovine, with a genotype indicative of at least one altered milk production trait, the method comprising the steps:

• a) identifying a bovine with thymidine at polymorphic nucleotide position 658 in the growth hormone receptor (GHR) gene of SEQ ID NO:
• 2, wherein the codon including the thymidine at nucleotide position 658 of SEQ ID NO:
• 2 encodes phenylalanine at amino acid position 279 in SEQ ID NO:
• 5;
• and correlating the presence of the thymidine at position 658 of SEQ ID NO:
• 2 with at least one altered milk production trait selected from:
• i) increased milk volume;
• ii) decreased percentage of milk protein;
• and iii) decreased percentage of milk fat;
• and
• b) selecting the bovine on the basis of the identification and correlation in a).