The study was carried out at Borg El-Arab station ,animal production research institute. The experiment carried out through 2008 till 2010 years. The aim of this study was to evaluate the effect of fatty calcium salts supplementation on nutrient digestibility and lactational performance of Barki goats and their crosses with Damascus. Digestion experiments was conducted using three adult Barki bucks (B) and three adult crossbred bucks (Damacus x Barik, (DxB). Thirty multiparous Barki does (B) and thirty multiparous Damascus x Barki crossbred (DxB) does every breed was divided into three groups of ten does each. The first group (Control): fed concentrate mixture and rice straw, the second group fed the same concentrate mixture with fatty calcium salts (FCS), 80 gm/ head/ day and rice straw before kidding by 6 weeks until the end of season. The third group fed concentrate mixture with fatty calcium salts 80g/ head/ day and rice straw, after kidding by 2 weeks until the end of season.
The results indicated that Feed intake (FI) was reduced by (FCS) addition. Also, the does fed FCS after kidding were significantly higher than does treated before kidding in FI. Also feeding goats on diets containing (FCS) had non significant effect on digestibility coefficients of DM, OM, CP, CF and NFE %, but there was significantly increase in the digestibility of EE as compared to the control diets. The nutritive value expressed as TDN % of the experimental diets was significantly (P< 0.01) improved as a result of addition (FCS), while, the digestible crude protein DCP % was almost comparable for the two experimental diets . Feeding does fatty calcium salts before or after parturition, insignificantly increased milk yield at days 7, 15, 30, 60, 90 and day 120 and also total milk yield .The data show no significant changes in milk composition (%) due to addition of fatty calcium salts to diets of does before or after kidding except the milk fat which significant (P<.01) increased with addition FCS . The serum total cholesterol concentrations (mg/dl) were significantly (P< 0.01) affected by addition of (FCS) to the diets before kidding (17, 19, 21 weeks) and after kidding (4, 8, 12 weeks) periods. The serum HDL and serum LDL concentrations (mg/dl) were higher for does fed diets containing (FCS) before kidding (17, 19, 21 weeks) periods and after kidding (4, 8, 12 weeks) periods. Addition of fatty calcium salts to diets of does before or after kidding significant (P<.01) increased serum concentration of aspartate aminotransferase (AST) and serum concentration of alanine aminotransferase (ALT).