Enhancement of tibia bone and eggshell hardness through the supplementation of bio-calcium derived from fish bone mixed with chelated trace minerals and vitamin D3 in laying duck diet

Cracked eggs cause great economic losses in duck egg production. The use of eggshell-related vitamins and minerals is one of the most suitable approaches for solving this problem. Therefore, this study aimed to evaluate the effects of dietary bio-calcium derived from fish bone mixed with chelated trace minerals and vitamin D3 (BCD) on egg performance, egg quality and the hardness of the tibia bone and the eggshell in laying ducks. A total of eighty 30-week-old Khaki Campbell laying ducks were assigned to 4 groups. Experimental birds were provided a basal diet supplemented with 0.0 (T1), 0.5 (T2), 1.0 (T3), or 2.0 (T4) g/kg BCD. Our results indicated that a negative impact on egg performance was not observed (P > 0.05) in any dietary BCD groups. The different BCD levels had no significant effects on yolk color, yolk ratio, albumen ratio, eggshell ratio or eggshell thickness. Similarly, the calcium and phosphorus contents of the eggshell and tibia bone were not influenced (P > 0.05) by the dietary BCD. Tibia bone weight and length did not differ (P > 0.05) among the 4 treatments. However, tibia bone (P = 0.006) and eggshell hardness (P = 0.025) significantly increased and correlated with increasing BCD levels. The strongest tibia bone and eggshell were found in the 2.0 g/kg BCD group when compared to the control group (P < 0.01). Thus, the study concluded that the inclusion of 2.0 g/kg BCD mixture in laying duck diets can be a potential approach to improve tibia bone and eggshell hardness, without detrimental effect on egg performance.