Peptides of plant and animal origin have good anti-diabetic prospects. The research objective was to use bovine colostrum peptides to reduce hyperglycemia in diabetic rats. Bovine colostrum peptides were obtained by trypsin hydrolysis of colostrum proteins with preliminary extraction of triglycerides. The study involved four groups of Wistar rats with seven animals per group. Group 1 served as control; group 2 received 300 mg/kg of trypsin hydrolysate of bovine colostrum as part of their daily diet for 30 days. Groups 3 and 4 had diabetes mellitus caused by intraperitoneal injections of 110 mg/kg of nicotinamide and 65 mg/kg of streptozotocin. Group 4 also received 300 mg/kg trypsin hydrolysate of bovine colostrum intragastrically five times a week for 30 days. Three peptides were isolated from the trypsin hydrolysate of bovine colostrum and tested for the sequence of amino acids and molecular weight. Their identification involved the Protein NCBI database, followed by 2D and 3D modeling, which revealed their chemical profile, pharmacological properties, and antioxidant activity. The diabetic rats treated with colostrum peptides had lower glucose, glycated hemoglobin, malondialdehyde, and catalase activity but a higher content of glutathione in the blood. Their leukocytes and erythrocytes also demonstrated less deviation from the standard. The antioxidant effect of colostrum protein hydrolysate depended on a peptide with the amino acid sequence of SQKKKNCPNGTRIRVPGPGP and a mass of 8.4 kDa. Colostrum peptides reduced hyperglycemia and oxidative stress in diabetic rats. The research revealed good prospects for isolating individual colostrum peptides to be tested for antidiabetic properties.