PRE- AND POST-PARTURITION INSULIN RESISTANCE IN GHEZEL EWES (Ovis aries)

While there are several studies on insulin resistance in ruminants, information  regarding this phenomenon in Ghezel ewes as a fat-tailed breed is rare. In the present  study, the intra-venous glucose tolerance test was performed to evaluate insulin  resistance in sheep. Five adult Ghezel ewes were selected at 4 weeks before parturition  and followed at 2 weeks before, 2 and 4 weeks, and 2, 3, and 4 months after parturition.  A blood sample was taken and dextrose 50% was administered at 500 mg/kg, 10 ml/ kg/hour. Blood samples were collected from all ewes prior to and 1, 2, 3, and 4 hours  after dextrose infusion to analyze glucose and insulin levels. The glucose and insulin  levels at Hour Four remained significantly higher than Hour Zero in pre parturition  periods. Despite presence of high concentrations of insulin, high levels of glucose were  seen in pre parturition periods which represented insulin resistance in these periods.  Finally, the highest degree of insulin resistance was observed at pre parturition periods  in Ghezel ewes and it may be concluded that protecting the ewes from insulin resistance  at pre parturition periods may manage their metabolic healthiness.