PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF LOCAL DOMYATI DUCKS FED DIET ENRICHED WITH ORGANIC ZINC DURING SUMMER SEASON

: Heat stress (HS) induced a big economic loss in ducks industry owing to reduce bird’s productivity. Nutritional strategy could use to attenuate the negative impacts of HS in poultry, this study purposed to decrease these impacts by organic zinc (oZn) enrichment for ducks diet at summer season on eggs production and quality, physiological and hatching parameters, subsequent growth of hatched ducklings and economic evaluation. Totally, 360 birds of Domyati ducks (300 female and 60 male), aged 25-wks were arranged at four empirical groups (each at five repeats) in a completely randomized design. The first one was considered as control and consumed the basal diet, while the 2 nd up to the 4 th empirical groups were consumed the basal diet enriched with 40 , 80 and 120 mg oZn /kg respectively, through 25-37 weeks of age under summer season. The results indicated that, ducks fed diet enriched with oZn recorded a significant (P < 0.001) increase in egg number (EN), egg weight and mass and improve feed conversion than those fed the control diet through the entire period (25-37 wks-old). Egg quality not significantly affected due to treatments except for Haugh units score. Hatchability (%) of fertile eggs was (P < 0.01) improved by oZn enrichment with 80 and 120 mg /kg diet, while total embryonic mortality was decreased in comparison with the control. Both blood hemoglobin content and lymphocytes (L, %) were elevated (P < 0.001) by oZn enrichment compared to control group, while heterophils (H, %) and H/L ratio were (P < 0.001) decreased. Serum cholesterol and liver enzymes were lowered (P < 0.001) by oZn enrichment, while HDL was (P < 0.001) elevated. Ducks fed 120 mg oZn/kg diet had a significant improvement in economic evaluation parameters than other groups. Results indicated the possibility of enriching ducks diet with 80 up to 120 mg oZn /kg could be an advantage method to attenuate the negative impacts of heat stress and improve eggs productivity, physiological performance, hatching characteristics and economic evaluation of ducks during Egyptian summer season. organic zinc.