Effects of Dietary Mineral Intake on Hair and Serum Mineral Contents of Horses

The objective of this study was to determine the effects of dietary mineral intake on serum and hair mineral contents of healthy horses. Twelve registered horses were used in a balanced change over design with three periods (each period, 56 days; the interval between periods, 7 days), four treatments, nine replicates per treatment, and four blocks (two genders and two age groups, <3 and >= 3 years). Two different levels (0% and 2.2% of the diet) of minerals were added to one of two different levels of daily dry matter intakes (50% and 100% of requirements) to make the dietary treatments. Mane hair and serum samples were collected at the end of each period and measured by inductively coupled plasma optical emission spectrometry method. The mineral contents of serum, except copper and strontium, were not affected by dietary treatments (P > .05). The effect of dietary treatments on hair calcium, cobalt, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, sulfur, selenium, strontium, and zinc concentrations was significant (P > .05), with higher values for mineral-supplemented diets provided at 100% of their requirements. Except for phosphorus, the effect of age on hair calcium, cobalt, copper, iron, potassium, magnesium, manganese, nickel, lead, sulfur, selenium, strontium, and zinc concentrations and calcium-to-potassium, zinc-to-copper, calcium-to-lead, and sulfur-tolead ratios were not significant (P > .05). For gender, the ratios of calcium to lead, iron to lead, and sulfur to copper in hair were higher in males than females (P <= .05). The hair showed to be a better biological indicator for mineral status in horse than the serum. (C) 2015 Elsevier Inc. All rights reserved.