Effect of using different levels of egg shell as calcium sources in broiler diet on growth performance, blood parameters, and bone characteristics

The study was conducted at Grdarasha field in Salahaddin University –Erbil during the period from 23 November 2021 to 5 January 2022, to determine the effect of using different calcium sources in a broiler diet on growth performance, blood parameters, bone characteristics, and immunity organs. Three hundred (300) chicks have randomly distributed into three (3) treatments following a completely randomized design (CRD). Five replications for each treatment, each replicate contains 20 birds. The dietary treatments include T1: control (0% eggshell),   T2 and T3 increasing levels of eggshell powder as a replacement to limestone at 50% and 100%, respectively. The results showed no significant (P> 0.05) differences in broiler live body weight, body weight gain (BWQ), feed intake, feed conversation ratio, and mortality % among different weeks of experiments and different treatments used. The results of blood parameters did not note any  significant variations  among different treatment groups (P > 0.05) in  TG, HDL, LDL and P, however, the significant differences (P < 0.01)was found in  the Cholesterol, VLDL, and Calcium . Bone ash mainly consists of calcium and phosphorous, and their level of them differ significantly (P < 0.01) among the different treatments. Also, the results of the effect of dietary treatments on the broilers' bone properties indicated that no significant differences in bone length (cm), diaphysis diameter (mm), Lateral wall thickness (mm), Medial wall thickness (mm), Medullary canal diameter (mm), Tibiotarsal index. However, the significance was found in bone weight and bone-breaking strength which is considered to affect bone fractures in poultry. Nevertheless, the results showed no significant differences in immunity organs, including spleen % and bursa %.