Background & aims: Gut immaturity leads to feeding difficulties in very preterm infants (<32 weeks gestation at birth). Maternal milk (MM) is the optimal diet but often absent or insufficient. We hypothesized that bovine colostrum (BC), rich in protein and bioactive components, improves enteral feeding progression, relative to preterm formula (PF), when supplemented to MM. Aim of the study is to determine whether BC supplementation to MM during the first 14 days of life shortens the time to full enteral feeding (120 mL/kg/d, TFF120). Methods: This was a multicenter, randomized, controlled trial at seven hospitals in South China without access to human donor milk and with slow feeding progression. Infants were randomly assigned to receive BC or PF when MM was insufficient. Volume of BC was restricted by recommended protein intake (4–4.5 g/kg/d). Primary outcome was TFF120. Feeding intolerance, growth, morbidities and blood parameters were recorded to assess safety. Results: A total of 350 infants were recruited. BC supplementation had no effect on TFF120 in intention-to-treat analysis [n (BC) = 171, n (PF) = 179; adjusted hazard ratio, aHR: 0.82 (95% CI: 0.64, 1.06); P = 0.13]. Body growth and morbidities did not differ, but more cases of periventricular leukomalacia were detected in the infants fed BC (5/155 vs. 0/181, P = 0.06). Blood chemistry and hematology data were similar between the intervention groups. Conclusions: BC supplementation during the first two weeks of life did not reduce TFF120 and had only marginal effects on clinical variables. Clinical effects of BC supplementation on very preterm infants in the first weeks of life may depend on feeding regimen and remaining milk diet. Trial Registration: http://www.clinicaltrials.gov: NCT03085277.