Growth, thyroid function, and serum macromineral levels in magnesium-deficient chicks

Area of Science:

• Animal Nutrition
• Endocrinology
• Biochemistry

Background:

• Magnesium (Mg) is essential for numerous enzymatic reactions and cellular processes.
• Thyroid hormones, thyroxine (T4) and triiodothyronine (T3), regulate metabolism and growth.
• The interplay between Mg status and thyroid function, particularly in early development, requires further elucidation.

Purpose of the Study:

• To investigate the effects of dietary magnesium deficiency on growth and thyroid hormone status in young chicks.
• To determine the critical dietary Mg levels that induce deficiency signs and physiological changes.
• To assess age-dependent alterations in thyroid hormone metabolism due to Mg deficiency.

Main Methods:

• Chicks were fed diets with varying Mg concentrations (80–315 ppm) compared to controls (578–787 ppm).
• Growth, feed intake, and serum mineral levels (Mg, Ca, K) were monitored.
• Thyroid gland weight and serum concentrations of thyroxine (T4) and triiodothyronine (T3) were analyzed at different ages.

Main Results:

• Mg deficiency signs appeared within 2–5 days at dietary levels ≤260 ppm, leading to reduced growth and feed intake.
• Serum Mg decreased, while serum Ca and K levels showed variable changes depending on deficiency severity and duration.
• Thyroid gland weight remained unchanged, but serum T3 was reduced in very young deficient chicks, and serum T4 was affected in older chicks.

Conclusions:

• Dietary magnesium deficiency significantly impacts chick growth and feed efficiency.
• Peripheral thyroid hormone metabolism is altered by Mg deficiency, with age-dependent effects on T3 and T4 levels.
• These findings highlight the critical role of adequate Mg intake for normal development and endocrine function in poultry.