Periparturient alpha-lipoic acid supplementation improves ewe antioxidant status, colostrum quality, and lamb growth

Alpha-lipoic acid (α-LA) is a potent antioxidant with potential to enhance ruminant health and productivity, yet its effects in late-pregnant ewes are not well defined. This study evaluated α-LA supplementation (600 mg/day) from 60 days prepartum to 8 weeks postpartum on blood biochemistry, immunity, colostrum and milk composition, microbiological quality, and lamb performance in Egyptian ewes. Thirty ewes were randomly allocated to control or α-LA groups (n = 15). On day one postpartum, α-LA ewes had higher serum albumin (2.87 vs. 2.45 g/dL), globulin (2.76 vs. 2.58 g/dL), total protein (5.64 vs. 5.04 g/dL), and total antioxidant capacity (29.97 vs. 28.19 mM/L; p ≤ 0.01). Elevated immunoglobulin A persisted at 4 weeks (80.20 vs. 73.40 ng/mL; p = 0.02). Lambs from supplemented ewes showed greater IgA (135.40 vs. 89.00 ng/mL; p = 0.04), glutathione peroxidase (29.16 vs. 20.51 U/mL; p < 0.05), TAC (56.48 vs. 31.80 mM/L; p < 0.01), and higher birth (4.52 vs. 3.84 kg) and weaning weights (7.39 vs. 6.00 kg; p < 0.01). Colostrum from α-LA ewes contained more fat (16.75 vs. 7.98%), protein (8.91 vs. 6.66%), and total immunoglobulins (21.47 vs. 5.84; p < 0.01), while both colostrum and milk had reduced bacterial counts and prevalence of Staphylococcus aureus, Escherichia coli, Klebsiella spp., and Bacillus cereus. In conclusion, periparturient α-LA supplementation improved maternal immunity, antioxidant capacity, colostrum and milk quality, and lamb growth. Further research should determine optimal dosing, assess long-term impacts on milk yield, and explore its integration into mastitis control programs.