Nano Zinc Oxide Improves Growth Rate, Carcass Traits, Meat Chemical Composition, Serum and Tissue Mineral Profiles, Mineral Retention, and Intestinal Morphology in Broiler Chickens Compared to Inorganic and Organic Zinc

This study aimed to compare the impact of inorganic, organic, and nano zinc sources on growth rate, carcass traits, meat composition, mineral profiles and retention, and intestinal morphology of the broilers. A 1-day "Cobb" broiler chick (n = 192) was randomly distributed into six groups with four replicates. The groups were set up as follows: G1: G3 received a basal diet with 100 mg Zn/kg from inorganic zinc oxide, inorganic zinc sulfate monohydrate, and organic zinc methionine. Groups G4: G6 received a basal diet supplemented with nano zinc oxide at 20, 10, and 5 mg Zn/kg diet, respectively. The results revealed that the nano zinc oxide (NZnO) in G6 significantly increased the growth rate and improved carcass quantity and quality, as proved by a reduction in abdominal fat percentage. It was observed that nano zinc oxide achieved the highest crude protein and the lowest crude fat percentages in meat. The highest significant calcium (Ca), phosphorus (P), and zinc deposition in serum and breast, and thigh were observed in G5 and G6. Interestingly, a 20 mg NZnO/kg diet considerably raised Ca and P content in the tibia while having no significant difference in G2 or G3. A significant elevation in zinc (Zn) retention (%) was recorded in G6, followed by G4 and G5. The intestinal absorption surface area (ASA) in G5 and G6 showed a significant maximum value. The current study indicated that the lower levels of NZnO (10 and 5 mg/kg diet) showed promising results with no detrimental effect on health status, so it can safely be used in mineral premixes of broilers.