PRL and mastitis: Twenty-six genes (ABCG2, ACLY, ACTB, ATP2B2, B4GALT1, BoLA-DRB3, BTN1A1, CCL2, CSN1S2, CSN2, DGAT1, EGF, ETS2, FEZF2, ID2, KCNK1, MFGE8, NME1, LGB, PRL, PTGS1, PTHLH, RORA, STAT5A, TLR4 and XDH) were found to be associated with mammary gland phenotypes (milk and mastitis traits) using two different study approaches, LALBA, LEP, TP53 using three different approaches, and CSN3, CSN1S1 and LTF using four different approaches.