Supplementation of two sources and three levels of iodine in the diet of laying hens: effects on performance, egg quality, serum and egg yolk lipids, antioxidant status, and iodine accumulation in eggs

Abstract

In total, 378 Shaver White layers were allocated into 7 treatments with 6 replicates, from 30 to 42 wk of age, to assess the effects dietary organic (ethylenediamine dihydroiodide [EDDI]) versus inorganic (calcium iodate [CIOD]) iodine in laying hens. A basal diet served as control while the remaining six diets were supplemented with either CIOD (CIOD 2 , CIOD 4 , and CIOD 8) or EDDI (EDDI 2 , EDDI 4 , and EDDI 8) to provide 2.0, 4.0, and 8.0 mg of added iodine/kg of diet, respectively. Performance and egg quality were not affected by adding 2.0 or 4.0 mg/kg of iodine to the diets. However, a progressive decline in egg performance and feed intake occurred with EDDI 8 and CIOD 8 diets. The EDDI 8 diet also increased abnormal eggs in parallel with decreasing the eggshell strength and Haugh unit and disturbing the serum and egg yolk lipids. This trend was connected with increase in triiodothyronine (T3) and thyroxine (T4), which led to oxidative stress in serum and egg contents. The iodine levels of eggshell and egg contents were increased by dietary iodine in a dose and time-dependent manner, while the effect of EDDI was higher than CIOD at all levels. To summary, supplementation of diets with 2 or 4 mg/kg of iodine as CIOD and specifically EDDI increased the iodine content of eggs without adverse effect on hen performance and egg quality traits. However, considering the time-dependent nature of this increase, a 12-wk period of supplementation might be not sufficient to achieve a specified level of iodine in the eggs. HIGHLIGHTS Diet supplementation with 2, 4, and 8 mg/kg of iodine as CIOD and EDDI increased iodine content of eggs. The highest level of iodine, especially as EDDI, diminished egg performance and egg quality connected with an increase in serum T3 and T4, which led to oxidative stress. A 12-wk period of supplementation appears to be not sufficient to achieve a specified level of iodine in the egg.

Sargassum en las dietas de gallinas Rhode Island mejora la calidad del huevo y funcionalidad por enriquecimiento con iodo

“…The concentration of iodine in this brown alga is 830-1530 µg/100 g (Rodríguez, 2018), while Teas et al (2004) reported concentrations of 39 µg/g for Sargassum spp. When diets were supplemented with mineral (calcium iodate) used 2, 4, 8 mg/kg to enrich the iodine content of the egg, the iodine content in the egg increased (0.73, 0.97, 1.56 mg/kg) as it increased in the diet (Sarlak et al, 2020); however, the concentrations obtained were lower than with algae. Although the values recorded in this study were lower than the ones reported by Rodríguez (2018), iodine is present in significant concentrations in our research, which are higher than what it has been reported for fresh whole eggs that are 9.5 -57.6 ug/100g (Fordyce, 2021).…”

Positive effects of Mulberry leaf extract on egg quality, lipid metabolism, serum biochemistry, and antioxidant indices of laying hens

“…Most plants contain anti-nutritional elements, such as tannins and phytic acids, and chemical extraction can be used to eliminate these effects on livestock and poultry and improve the palatability of feed. Previous studies have shown that the addition of natural mineral elements, such as iodine and iron, to the diet of laying hens can improve egg quality (6,7). The use of natural plant extracts for animal production has many benefits.…”