Diagnosis of selenium status in grazing dairy goats on the Mexican plateau

The objective of this study was to determine the concentration of Selenium (Se) in soils, forages and the tissues of kids and does under extensive grazing conditions in two regions of the Tlaxcala state, Mexico (Carrillo Puerto and Ixtenco) in the dry and rainy season. There were no differences in the concentration of Se in soil (0.051 and 0.047ppm), pH of the soil (6.1 and 5.9), concentration of Se in the forage (0.052 and 0.075ppm) and blood serum of goats (0.02 and 0.021ppm) during the dry and rainy seasons, respectively. The Carrillo Puerto region had a significantly higher content of Se in the soil (31%), soil pH (7%), content of Se in forage (25.9%), and content of Se in blood serum of goats (16%) compared to the corresponding values obtained in Ixtenco. The mean concentration of Se in the serum of kids with clinical signs of white muscle disease, was significantly lower (36.3%) compared to the kids from the same farm that were apparently healthy. The results of this study suggest that soil, forages, and goats have a marginal Se status in both regions during the dry and rainy seasons. Further research is required to find the most appropriate method to correct the Se-deficiency in goats from these regions.