Content and uptake of minerals in the yolk of broiler embryos during incubation and effect of nutrient enrichment

Although embryo and chicken growth anddevelopment rely on mineral nutrition, information onmineral levels in the egg compartments during incubationis limited. Accordingly, we examined P, Ca, Fe, Zn,Cu, and Mn levels in the yolk of breeder eggs duringincubation and the effect of embryonic mineral (withspecific nutrients) enrichment on yolk mineral levelsand consumption. First, fertile eggs were examined onday of setting (DOS), embryonic day (E) 11, E13, E15,E17, E19, E20, and day of hatch (DOH) for the mineralcontent in the yolk (and albumen on DOS) by inductivelycoupled plasma atomic emission spectroscopy.Results showed that on DOS, the yolk is the majororigin for Mn, P, Fe, Ca, Cu, and Zn. Interestingly, P,Fe, Zn, Cu, and Mn were mostly consumed from theyolk until E17, after which their consumption was verylow. Consumption of P was constant until E17 and thendecreased until E20. Consumption of Fe, Zn, Cu, andMn was medium to mild until E11, increased betweenE11 and E17, and minimal between E17 and DOH.Enrichment treatment, where fertile eggs were dividedinto 2 groups [nonenriched (control) and enriched (withminerals, vitamins, and carbohydrates on E17 usingthe in ovo feeding method)] showed that the enrichedgroup had higher Fe, Zn, Cu, and Mn levels than thenonenriched group and exhibited higher consumptionof Fe, Zn, and Mn between E20 and DOH. Analysis ofthe shell mineral composition along incubation showedthat the shell released low amounts of P, Fe, and Mn incomparison with the yolk mineral content. Therefore,we concluded that the shell is a minor source of theseminerals. Studying the mineral resources and consumptionof embryos can lead to a better understanding ofthe mineral limitations of embryos during incubation.Additionally, because minerals are important for thedevelopment of the embryo, the higher mineral levelsand consumption observed in the enriched group mayaffect the development of critical organs, such as the skeletal system.