Attenuation of inflammatoryresponse phenomenain periparturient dairy cowsby the administrationof an omgra3 rumen protectedsupplement containingvitamin E

摘要

The aim of this research was to study theconsequences of omgra3 fatty acids (FA) administrationaround calving on inflammatoryresponse and on productive performances. Inthis period dairy cows undergo a metabolicchallenge, coming with an inflammatory-likestatus triggering the release of pro-inflammatorymediators (e.g. eicosanoids, cytokines).Eicosanoids synthesis may be modulated byaltering the ratio of their precursors (omgra3 andomgra6 FA). Ten cows received 22 g/d of rumenprotectedomgra3 FA from -21 to +21 days fromcalving (OPT), while 10 (CTR) received nosupplement. Cows were frequently monitoredfor health status, body condition score (BCS),blood (metabolic, inflammatory and FA profiles),milk yield. OPT (vs CTR) showed a similarmilk production, a numerically smallerBCS drop, lower postpartum levels of nonesterifiedfatty acids (P<0.05), β-hydroxybutyricacid (P<0.1) and creatinine (P<0.05),suggesting a milder post-calving reservesmobilization. All cows underwent an inflammatorycondition around calving, but OPTshowed a milder response, as suggested bylower levels of bilirubin (P<0.05), and by thehigher level of Liver Functionality Index(P<0.10). Plasma concentration of omgra3 FA(eicosapentaenoic and docosahexaenoicacids) increased in OPT during treatment(P<0.01 vs CTR). Since omgra3 FA are the mainreplacers of arachidonic acid in membranephospholipids, their increased levels in plasmaof OPT cows may have cut the formation ofarachidonic-derivatives (pro-inflammatorymediators), countering the beginning of theinflammation. Hence, the administration of rumen-protected omgra3 FA in transition periodseems to attenuate the effects of subclinicalinflammations and to improve the energy balance.