Effect of Silymarin administration on plasma and milk redox status in periparturient dairy goats

The peripartum period is associaled wilh an increase in melaholic processes, and in free radicals production. The imbalance between free radìcals produclion and defence mechanisms could lead to "oxidative stress". Il was reported that dietary suppJementation of peri P art uri e n t cows with antioxidants contributes to protect from the ham1ful effects of free radicals. Retinol and ft-tocopherol, major liposo!uble antioxidanls, enhance immunity and maintain the structural nnd functional inlegrity of cclls. fn calves, milk is the mosl important source of such antìoxidants, that save food quality. Silymarin was rcported to possess antitoxic, antioxidant, and antiinflammatory properties. Twenty goals, in the dry period, were divided into two groups, according lO heahh condition, and parity (=2). Starting from seven days before calving unti! 15 days after calving, ten goals reccived l gld of silymarin, as a waler suspcnsion, by oral drench. Milk and plasma samples, collecled wcekly for 21 day s, were ana!ysed for thcir rctinol and a-tocopherol levels. Nitro-tyrosine plasma concentration \vas measured to evaluate protein oxidation by pcroxyrutrìte. Plasma titres of liposoluble antioxidants did not differ between the twogroups. Nitro-lyrosine plasma level was higher in control than in Ireated goats (P < 0.0(5). Milk level5 of reti noi ami a -tocopherol was higher in lrcatcd goats (P < 0.0 I). The results demonstrate thal Silymarin administration does noI affcct pla"ma Ievels of liposoluble antioxidants. However Silymarin seems to promote accumulalion of antioxidanls in milk, thus improving its quality. Our data al50 suggest Silymarin plays il rale in preventing plasma protein oxidation.