Enables lactase activity and transferase activity. Involved in several processes, including response to estrogen; response to iron(II) ion; and response to lead ion. Located in brush border. Used to study diarrhea. Biomarker of colitis. Human ortholog(s) of this gene implicated in congenital lactase deficiency. Orthologous to human LCT (lactase). [provided by Alliance of Genome Resources, Apr 2022]