Study was carried out to assess the effect of condensed tannins (CT) containing leaf meal mixture (LMM) on feed intake, body weight changes, parasitic load, urinary excretion of purine derivatives (PD) and microbial protein synthesis (MP) in Haemonchus contortus infected sheep. Eighteen adult male sheep of similar age and body weight (25.03±1.52) were randomly divided into three groups (negative control; NC, infected control; C and treatment; T) of six each in a completely randomized block design (CRD) for a period of 90 days. Twelve H. contortusinfected sheep were allocated into C and T groups, containing 0 and 1.5% of CT, respectively. Six non-infected sheep was taken in NC group to compare their performance with C group. Concentrate intake was significantly (P<0.000) lower in T group as compared to C group, while roughage intake did not differ significantly irrespective of groups. Final body weights were comparable (P<0.063) among all three groups. Faecal egg counts (FECs) were significantly (P<0.001) higher in C group as compared to T group. MP synthesis

was calculated by estimating urinary excretion of PD through High performance liquid chromatography (HPLC). Total PD excretion, absorption of PD and Microbial nitrogen (MN) supply (g d-1) were comparatively (P<0.05) higher in T group than in the C group. It may be concluded that CT supplementation (1.5%) decreased H. contortus load in sheep by reducing FECs and has a potential benefits on protein nutrition by altering partitioning of nutrients towards higher microbial yield and absence of any depressing effect on rumen MN synthesis.