COMPLEMENTING EXPECTANT EWES WITH SELENOMETHIONINE AND THE EFFECT ON DEVELOPMENT OF THEIR LAMBS

Abstract

Selenium crosses the placenta barrier effectively and can be concentrated in colostrum and milk. From the hypothesis that the use of SeMet in complementation of expectant ewes increases the concentration of blood and milk Selenium in sheep, and also the birth weight and the weight gain in lambs, a study with 14 expectant ewes was carried out, with SeMet (0.20 mg kg^-1) of Selenium)=300 mg ewe^-1 of SeMet, every 24 h for five days, and a maintenance dose every 7 days, plus the control (without SeMet). The Selenium concentration was analyzed in samples of blood serum in ewes and lambs, in commercial product with SeMet, and in wheat bran. To evaluate the weight gain and the birth weight, they were weighed every 15, 30, 45 and 60 days of age. For the Selenium concentration in the serum and weight gain in lambs, an experimental design with repeated measurements was carried out in time. For birth weight, a completely random design was used with Variance Analysis, to determine the degree of association between Selenium in blood serum of ewes and lambs, and a Pearson correlation coefficient analysis was applied. The addition of SeMet to ewes increased the serum Selenium at 25 days (P<0.05), while it decreased for this same period in lambs (P<0.05), indicating that there is no correlation between serum concentrations of Selenium in ewes and lambs at 25 days of life (-0.99604, P<0.0001). The birth weight showed a positive trend in lambs with mothers with SeMet, without statistical difference (P<0.05). The weight gain in lambs was not affected by the application of SeMet to the mother (P>0.05). The supply of SeMet to expectant sheep increased the serum concentration of the mineral at 25 days, but not the weight gain at weaning, or the birth weight; there is no correlation between the serum concentration of Selenium in ewes and weight gain in lambs.