Biological Evaluation of Different Di-calcium Phosphate Produced in Iran and Comparison of Their Impacts on Performance and Bone Characteristics in Male Broiler Chicks

In this study, in order to evaluate the produced domestic Di-calcium phosphate(DCP), 26 domestic DCP production factories that were active at the time of the research were visited and sampling was done randomly from the final product. After testing according to standard indices, only 7 samples of Di-calcium phosphate were in range of the national standard. To determine their biological value, 720 male Ross 308 broiler chickens were purchased and randomly divided into 8 equal groups with 6 replicates and then kept in the battery cage system for 21 days. The available phosphorus levels in all the diets used in the experimental and control groups were set at 0.48 percent. At the 10 and 21 days of age, feed consumption, weight gain and feed conversion ratio were calculated. Also At the end of 21 days of age the amount of ash, calcium and phosphorus of tibia bone was measured. At the 21 days of age, no significant difference was observed between experimental and control treatments in terms of the production indices (P>0.05) But the weight gain index at 10 days of age showed a significant difference between experimental and control treatments (P<0.05). There was no significant difference between bone ash content and test and control samples (P>0.05). But, the amounts of tibia calcium in two groups of F and G were significantly lower than those of the control group (P<0.05).Also the amounts of bone phosphorus in B, C, F and G groups were significant and lower than the control group (P<0.001). The relative biological values of the experimental samples, according to both criteria of the weight gain and the bone ash for the Di-calcium phosphates of A, B, C, D, E, F, and G samples were estimated 98.1, 103.3, 96.9, 100.2, 97.9, 94.0, and 100.2 percent, respectively.