Sequence comparison of the lactoferrin of various animal species and its prospects as an animal feed additive

Lactoferrin as a feed additive is worth to be explored. However, reports on its application are contradictory, which might be associated with the genetic relatedness. Here we compare the lactoferrin nucleotide and its deduced amino acid sequence. Sequence data for lactoferrin of various animal and human were download from GenBank. The phylogenetic relatedness was inferred and the amino acid sequences were aligned to identify conserved and polymorphic sites. The protein three-dimension structures were estimated using online software. The result showed the lengths of lactoferrin, lactotransferrin or ovotransferrin are 703–711 residues. The phylogeny showed that the lactoferrins of buffalo, cow, goat, pig, camel, and horse formed one group; monkey, human, and gorilla formed a second group; and dog and cat formed a third group. Chicken ovotransferrin was an outgroup. Genetic distances between groups were 0.242–0.061, while smallest span between taxa was 0.016 (human to gorilla) and the highest was 0.612 (chicken to goat). The conserved residues spanned from the amino terminus to the carboxy terminus. There are 27 conserved cysteine residues. N-link glycosylation of the “NXS” and “NXT” motives of lactoferrin diverge between species. A species specific or group specific lactoferrin supplement should be beneficial to animal production.