Mycotoxins appear to be the “Achilles’ heel” of the agriculture sector inducing enormous economic losses and representing a severe risk to the health of humans and animals. Although novel determination protocols have been developed and legislation has been implemented within Europe, the side effects of mycotoxins on the homeostatic mechanisms of the animals have not been extensively considered. Feed mycotoxin contamination and the effects on the antioxidant status of livestock (poultry, swine, and ruminants) are presented. The findings support the idea that the antioxidant systems in both monogastrics and ruminants are challenged under the detrimental effect of mycotoxins by increasing the toxic lipid peroxidation by-product malondialdehyde (MDA) and inhibiting the activity of antioxidant defense mechanisms. The degree of oxidative stress is related to the duration of contamination, co-contamination, the synergetic effects, toxin levels, animal age, species, and productive stage. Since the damaging effects of MDA and other by-products derived by lipid peroxidation as well as reactive oxygen species have been extensively studied on human health, a more integrated monitoring mechanism (which will take into account the oxidative stability) is urgently required to be implemented in animal products.

The objective of the present study was to investigate the effect of the natural flavonoid quercetin dietary supplementation on the alteration of egg metallome by applying the basic principles of elemental metabolomics. One hundred and ninety-two laying hens were allocated into 4 treatment groups: the control (C) group that was fed with a commercial basal diet and the other experimental groups that were offered the same diet further supplemented with quercetin at 200, 400 and 800 mg per kg of feed (Q2, Q4 and Q8 group, respectively) for 28 days. The diets contained the same vitamin and mineral premix, thus all birds received the same amount of elements since no differences on feed intake existed. The egg elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Se, Sr, V, Zn and was determined using inductively coupled plasma mass spectrometry (ICP-MS). Quercetin supplementation altered the elemental profile. Most notably, quercetin altered the element concentrations predominantly in egg shell and albumen. It increased the concentration of Sb while reduced that of Cr and Se in both egg shell and albumen. Moreover, it increased As, Cd in albumen and V in yolk, while compared to the control, reduced As, Cd, Cr, Cu and V and also raised Ca, Fe, Mg and Ni in egg shell. The presence of quercetin led to differentiation of the deposition of certain trace minerals in egg compartments compared to that of hens fed a basal diet, possibly indicating that tailor made eggs for specific nutritional and health requirements could be created in the future.

Dried orange pulp (Citrus sinensis) is known for its antioxidant properties. This study aimed to examine the effects of adding dried orange pulp (OP) to the layers’ diets on the concentration of selected elements in the egg. The present work was part of a bigger project aiming to investigate the effect of orange pulp in layers’ diets on the performance of birds and egg quality. There were three dietary treatments and 63 layers per treatment, with 189 layers in total. Cages were the experimental units, and seven cages were allocated per treatment (n = 7). The dietary treatments were (1) a control treatment (C) that involved a basal diet without orange pulp addition, (2) an OP treatment with the addition of 9% dried orange pulp, and (3) a hesperidin–naringin (EN) treatment with 0.767 g hesperidin and 0.002 g naringin added per kg of diet; these levels of hesperidin and naringin represent those present in dried orange pulp for the OP treatment. Birds were fed the diets for 30 days. The diets had similar energy and protein levels and contained the same vitamin and mineral premixes. The analyzed egg (yolk, albumen, shell) elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Sb, Se, Sr, V, and Zn and was determined via Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Dried orange pulp supplementation significantly altered the elemental profile. OP largely altered the element concentrations in albumen and egg yolk. Most notably, it decreased the concentrations of Co (p < 0.001), Fe (p < 0.001), Mn (p < 0.001), Ni (p = 0.046), and Se (p = 0.035) in egg yolk and those of Co (p = 0.011), Fe (p = 0.025), Cr (p = 0.049), Cu (p = 0.001), and Se (p = 0.014) in albumen. In addition, it decreased the concentrations of As (p = 0.025) and Ca (p = 0.025) in the eggshell. Principal component analysis was applied to the concentrations of the examined elements in all egg parts to explore the relationships between the elements and detect those capable of distinguishing samples, resulting in the apparent separation of yolk, albumen, and eggshell samples. Further analysis revealed that all samples were clustered into the three dietary treatments, resulting in 100% correct classification. The chelating and antioxidant capacities of flavonoids are intricate and rely on a variety of factors. OP supplementation modulated the deposition of specific elements in egg parts in comparison to those from layers fed a typical diet. Thus, this study indicated that eggs with specialized elemental profiles could be created.