Enables 3-oxo-5-beta-steroid 4-dehydrogenase activity. Predicted to be involved in cellular hormone metabolic process; cholesterol catabolic process; and digestion. Predicted to act upstream of or within bile acid biosynthetic process. Predicted to be active in cytosol. Human ortholog(s) of this gene implicated in congenital bile acid synthesis defect 2. Orthologous to human AKR1D1 (aldo-keto reductase family 1 member D1). [provided by Alliance of Genome Resources, Apr 2022]