This study was carried out to determine the effects of using different levels of Guar korma meal (*GK) onmilk yield and milk composition, rumen function of experimental rations fed to sheep and dairy cows. Animals were fed one of from experimental rations, control ration with 0% GK or rations with 5%, 10% and 15% GK. Animals fed rations containing guar korma showed linear decrease (P < 0.05) of total dry matter intake (DMI) with increasing ration guar korma meal level inclusion in rations. Twelve Barki male sheep were assigned randomly into 4 similar groups of 3 animals each to determine the digestibility coefficients, nitrogen balance and nutritive values of experimental rations. Results of digestibility trails showed that there were no significant differences (P< 0.05) in digestibility of DM, OM and CP for ration containing 10% GK compared to the control ration. While, there was significant (P < 0.05) decrease rations containing 5%, 15% guar korma. Similar trend recorded for the nutritive values. However, nitrogen utilization showed positive nitrogen balance with all animals fed the experimental rations. Three cannulated female Barki sheep were used to determined rumen fermentation parameters. The main results showed no significant differences among experimental groups in the values of ruminal pH and NH3-N concentrations, while the highest (P < 0.05) of TVFA'S concentrates were observed with the ration containing 10%GK and the control ration than rations containing 5%,15% guar korma. Dry matter and CP degradability showed significant (P < 0.05) increased for rations containing GK than the control ration. Eight lactating crossbred Friesian cows were used to determine milk yield and milk composition. Cows fed ration containing 5% GK showed slight improvement in milk yield in comparison with the control ration. However Milk fat (%) increased (P < 0.05) for rations containing guar meals compared with the control ration.
*GK= guar korma meal