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 gra zing conditions in two regions of the Tlaxcala state, Mexico (Carrillo Puer to and Ixtenco) in the dry and rainy season. There were no differences in t he concentration of Se in soil (0.051 and 0.047 ppm), pH of the soil (6.1 a nd 5.9), concentration of Se in the forage (0.052 and 0.075 ppm) and blood serum of goats (0.02 and 0.021 ppm) during the dry and rainy seasons, respe ctively. The Carrillo Puerto region had a significantly higher content of S e in the soil (31%), soil pH (7%), content of Se in forage (25.9%), and con tent of Se in blood serum of goats (16%) compared to the corresponding valu es obtained in Ixtenco. The mean concentration of Se in the serum of kids w ith 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 resear ch is required to find the most appropriate method to correct the Se-defici ency in goats from these regions. (C) 2001 Elsevier Science B.V. All rights reserved.