Boric acid was supplied from a commercial company (TEK-KIM, extra pure boric acid, TK.020.100.01002, Nilufer-Bursa, Turkey). The boric acid we used in the experiment was in solid form and we dissolved it thoroughly in the milk replacer (Ovilac Eurovo Milk Replacer, Societe Laitiere De Retiers À Retiers 35,240, Retiers, France) before giving it to the lambs. The boric acid levels used in the study are much lower than the LD50 levels (2660-4100 mg/kg).