Many physiological organs are increasingly susceptible to stressors arising from environmental management or nutritional factors. Thus, the aim of this research was to evaluate the influence of two proposed strategies of feed restriction (FR) along with dietary supplementation of organic selenium (OS) and Iraqi protein concentrate 6×1 (IPC) on body weight (BW) and cross anatomy of selected visceral organs in broiler chickens. Totally, 420 one day-old chicks Ross 308 were used and randomly distributed into 7 treatments (60 chicks per treatment) with 3 equal replicates each. In control (T1), birds were fed ad libitum without dietary additives and birds in treatment of T2, T3 and T4 were fed quantitative FR (40%) without feed additives, with adding 0.8 mg OS and 25 g IPC per kg of diet, respectively whereas the birds in treatments of T5, T6 and T7 were fed temporal FR (12 hours/day) without feed additives, with adding 0.8 mg OS and 25 g IPC per kg diet, respectively. All birds were reared for 35 days and from 2nd till 3th week of age all birds were exposed to FR regimes with feed additives and then were freely fed without dietary additives from 4th-5th week of age in the compensatory growth phase. 3 unsexed birds closed to the average BW of experimental treatments were chosen from each replicate in treatment (no=9 per treatment) and were used for evaluation cross anatomy. The results revealed that T5, T6 and T7 maintain (p≤0.05) BW at 3th and 5 weeks. Bigger relative weight of liver (p≤0.05) was in T3 and T4 at 3th weeks with recorded reduction in abdominal fat was in T3, T4 and T6 at 6 weeks. No differences among all groups regarding to relative weights of adrenal gland, heart, pancreas, kidneys and lungs and relative length of small and large intestines and density of large intestine at 3 and 5 weeks. Generally, temporal FR followed by quantitative FR successed to maintain relative weight and lengths of each particular gastrointestinal tract (GIT) part starting from esophagus till rectum in relation to weight of BW or GIT and length of GIT depending on feed supplement. In conclusion, each treatment has its own specific mode of action to induce significant change or stability without deleterious impact on relative weights and lengths of organs especially in feed restricted diets with supplementation of OS or IPC after termination FR and compensatory growth at 3 and 5 weeks, respectively.
