RESUMEN
BACKGROUND: Lactoferrin (LTF) is an iron-binding glycoprotein found in milk and other exocrine secretion with antibacterial activity proposed as an alternative to mastitis treatment or prevention. LTF has been proposed as a candidate gene for mastitis resistance selection. The aim of this paper was to assess LTF promotor to explore variations with potential association to mastitis resistance in dairy cows from Honduras. METHODS: A resequencing of promotor and Exon I of LTF gene in extreme mastitis susceptibility cows (126 Holstein and Holstein crossbred) was performed. RESULTS: Eight polymorphisms were found in promotor region, four of them were novel variations. Two were important by frequency among extreme groups, but a polymorphism in - 421 A/T position was significantly (P = 0.0188) associated to mastitis susceptibility. CONCLUSION: Results support the key role of regulatory region of LTF gene. Some candidate genes are proposed in association with mastitis traits and implications are discussed.