Impact of using sodium or calcium salts of fatty acids as sources of energy in buffalo rations during late gestation

mammary adipose tissue and subsequent milk yield. Soapstock is produced from seeds oil refining processes as a by-product potentially harmful to the environment but can use it as dietary fat source. The aim of this study were to study impact of adding either Na-SFA or Ca-SFA as a energy source instead of corn grains in buffalo rations on rumen activities and performance of late pregnant buffalo. Thirty pregnant buffaloes expected to calve within 60-75 day were divided into three balanced groups. First group received the control ration consisted of concentrate diet (75% concentrate feed mixture with 25% yellow corn) plus berseem hay and rice straw. In the second and third rations, yellow corn was replaced with either Na-SFA or Ca-SFA. Chemical composition of Na-SFA, Ca- SFA and the experimental rations are presented. Content of AEE in Ca-SFA was lower than that of Na-SFA, while TFA's in Ca-SFA was higher. Incubation of teased rations in the rumen showed reduction in DM, OM and CP disappearances, also ED and PD with ration containing Na-SFA. Undegradable values increased with adding Na- SFA compared to adding Ca-SFA or control diet. As a result of foaming and physical coating of the fibre with added Na-SFA has been proposed as a possible theory for the sometimes observed depressed DM, OM and CP disappearances. Digestion coefficient of DM, OM, CP and WCS were decreased with feeding ration containing Na-SFA compared to that containing Ca-SFA, while no significant differences were found between ration containing Ca-SFA and control one. These results might be due to the effect of LCFA in Na-SFA, which reflects on rumen fermentation, and consequently affect fibre digestibility. Nutritive values as TDN and DCP were decreased (P < 0.05) with the ration contained Na-SFA compared to Ca-SFA. Feed intake was not affected with feed rations containing Na-SFA or Ca-SFA. Body weight was higher with feeding ration containing Ca-SFA or Na-SFA than that of the control. pH values, propionic acid and FFA's in the rumen were significantly (P < 0.05) higher when feeding ration containing Na-SFA compared to that containing Ca-SFA or control, while, significantly decreased TVFA's, acetic, Ac/Pr and NH3-N. These results might be due to release of FFA's in the rumen when feeding Na-SFA decreased both NH3-N and TVFA's. Fatty acids, especially unsaturated fatty acids, are antimicrobial and interfere with normal function of the ruminal microbes. Adding Na-SFA in the ration decreased glucose and total protein concentration in blood compared to Ca-SFA or control. Concentration of albumin, globulin and their ratio were not affected with feeding rations containing either Na-SFA or Ca-SFA. TL, triglyceride and FFA's were increased (P < 0.05) with feeding ration containing fat compare to control. (author)