a, BLG peptide specific to Ovis or Bovinae for DA420. b, BLG I peptide specific to Equus for DA420. c, Equus BLG I peptide for Z438. d, MS2 spectra for a Capra-specific BLG peptide for Z438. e, α-S1 casein from DA430 specific to Bovinae. f, Second α-S1 casein peptide specific to Bovidae, also from DA430. Horse, goat and cow images are reproduced from ref. 37; sheep silhouette, public domain (https://thenounproject.com/icon/12538/).