Abstract: The effects of loadtime stress on changes in some biochemical and cellular composition of blood were evaluated in 24 matured bulls comprising 12 each of White Fulani and Sokoto Gudali breeds of cattle. The animals were stocked (3.09 m² h ¹), in a trailer pulled by Iveco Truck and transported for 42 h covering a distance of 1024 km. The animals were bled before (preload), immediately after loading (postload) and holdtime periods of 0, 6 and 12 h after transit to assess the cause effect on stress response in cattle. There was significant effect of loadtime (p<0.05) on all the variables measured in the present study. Plasma glucose concentration (7.92 mg dL ¹) at 6 h holdtime period suggests that stress was more severe at this time period. The Neutrophil:Lymphosite (N:L) ratio was however higher (p<0.05) at all time periods of holding than at preload and postload time periods indicating a prolonged effect of stress on the animals immune system at holdtime periods. Interaction between loadtime and bread was significant (p<0.05) for all measurements except plasma protein and calcium concentration. Loadtime stress increased plasma glucose and Urea N concentrations in both breeds with the magnitude of the increase being higher (p<0.05) in White Fulani cattle. However, loadtime stress decreased plasma protein and calcium concentrations in both breeds with the magnitude of the decrease being lower (p<0.05) in Sokoto Gudali cattle. The result indicate that Sokoto Gudali was less stressed and more loadtime tolerant than White Fulani cattle. Also, the higher (p<0.05) magnitude of the increase in N: L ratio due to the interaction effect of stress was sustained more in White Fulani than Sokoto Gudali cattle. The above changes in all variables measured were evidence of internal catabolism in the animal body indicating tissue dehydration and weak host defensive mechanism. As a result, fatigue and strong depression, just immediately after the transport (0 h hold time) occur and the animals could be seen lying down. Since, loadtime stress is inevitable whenever animals are transported by road, efficient management practices are necessary during the procedures of loading and unloading to reduce injuries, suffering stress and economic losses in food animals.