Effects of Supplementation of Ionized or Chelated Water-Soluble Mineral Mixture on the Live Performance, Nutrient Digestibility, Blood Profile, Egg Quality, and Excreta Microbiota of Laying Hens

Organic or Inorganic Zinc for Laying Hens? A Systematic Review and Meta-analysis of the Effects of Zinc Sources on Laying Performance, Egg Quality, and Zinc Excretion

The higher availability of zinc (Zn) from organic than inorganic sources is already established, but more assertive and cost-friendly protocols on the total replacement of inorganic with organic Zn sources for laying hens still need to be developed. Because some discrepancy in the effects of this replacement in laying hen diets is noticeable in the literature, the objective of this meta-analysis was to properly quantify the effect size of total replacing inorganic Zn with organic Zn in the diet of laying hens on their laying performance, egg quality, and Zn excretion. A total of 2340 results were retrieved from Pubmed, Scielo, Scopus, WOS, and Science Direct databases. Of these, 18 primary studies met all the eligibility criteria and were included in this meta-analysis. Overall, the replacement of inorganic Zn with organic Zn, regardless of other factors, improved (p < 0.01) egg production by 1.46%, eggshell thickness by 0.01 mm, and eggshell resistance by 0.11 kgf/cm2. Positive results of the same nutritional strategy on egg weight and Zn excretion were only observed at specific conditions, especially when organic Zn was supplemented alone in the feed, not combined with other organic minerals. Therefore, there is evidence in the literature that the total replacement of inorganic Zn with organic Zn improves egg production, eggshell thickness, and eggshell resistance. Factors such as hen age and genetics, organic Zn source, concentration of Zn in the feed, and the strategy of its supplementation have to be more carefully considered in protocols designed to address egg weight and Zn excretion by the hen.

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.