Feeding trials: Magnesium sulfate versus magnesium oxide
The study investigated how supplementing magnesium (Mg) in the form of magnesium sulfate (MgSO₄) or magnesium oxide (MgO) affects the meat quality of broiler chickens under normal and heat stress conditions. Mainly in vitro (cell culture) but also in vivo (with broilers) experiments were conducted.
Research partner
The Spanish National Research Council (Spanish: Consejo Superior de Investigaciones Científicas, CSIC) is the largest public research institution in Spain and one of the most renowned institutions in the European Research Area (ERA).
Its main objective is the development and promotion of research that contributes to scientific and technological progress. It consists of over one hundred research institutions distributed throughout Spain. This also includes its own research centre, the Estación Experimental del Zaidín (EEZ) in Granada.
Magnesium in broiler rearing
Magnesium is essential for muscle function. It plays a key role in energy metabolism and nerve transmission in muscle tissue. Adequate magnesium intake can also increase stress tolerance and improve well-being, which has a positive effect on meat quality. Poultry farmers have not yet adopted magnesium supplementation as standard practice for broiler chickens.
Although magnesium sulfate has a lower magnesium content compared to magnesium oxide, it offers a decisive advantage: it is water-soluble. This allows the magnesium from magnesium sulfate to be fully absorbed and utilized by the animal. This high bioavailability is particularly important for ensuring the effectiveness of magnesium supplementation in chicken rearing and helps to sustainably improve feed efficiency and meat quality.
Magnesium sulfate increases feed efficiency and meat quality
Supplementation with Mg had no negative impact on production parameters (feed intake, weight gain).
Compared to magnesium oxide, magnesium sulfate supplementation led to:
- better bioavailability of Mg
- higher proportion of breast meat
- better meat quality
The magnesium in our product is fully water-soluble, making it completely available to the animal. In contrast, only around 10% of the magnesium dose from magnesium oxide is available, depending on the species of animal, and most of it is excreted.
Better meat quality
After cooking, the meat from animals fed MgSO₄ had a more intense, reddish color (higher a* and chroma values) than that of the control or MgO groups. The color of the meat appeared more appealing.
MgSO₄ reduced water loss during cooking by 22% compared to the control group and improved the meat's water-holding capacity. Overall, the meat was juicier.
The texture of the meat was significantly more tender (lower shear force) when MgSO₄ was added, suggesting easier chewability and better consistency. The results suggest that MgSO₄, when used as a supplement, can improve the meat quality of broilers under heat stress.
Better bioavailability
In vitro, MgSO₄ showed significantly higher solubility and bioavailability than MgO. In vivo, feeding with MgSO₄ resulted in higher plasma Mg concentrations in the animals, indicating better absorption. Mg supplementation, especially with MgSO₄, was able to prevent the negative effects of heat stress on breast meat yield.
Published in leading journals
Our research findings have already been published in recognized journals:
Journal of Agriculture and Food Research
I. Seiquer, A. Haro, G. González-Cañas, F. M. Augusto, D. I. Jost, L. A. Rubio (2026): Effects of dietary magnesium supplementation and heat stress on meat quality in broilers. Volume 28, 2026, 102918, ISSN 2666-1543
