Enables 2-hydroxyacylsphingosine 1-beta-galactosyltransferase activity and UDP-galactose:glucosylceramide beta-1,4-galactosyltransferase activity. Involved in galactosylceramide biosynthetic process. Located in endoplasmic reticulum. Orthologous to human UGT8 (UDP glycosyltransferase 8). [provided by Alliance of Genome Resources, Apr 2022]