Gewählte Publikation:
Gierus, M; Schwarz, FJ; Kirchgessner, M.
(2003):
Investigation on selenium supplementation for dairy cows in late pregnancy
ZUCHTUNGSKUNDE. 2003; 75(2): 88-100.
- Abstract:
- The Se content of locally produced feeds in Germany is low, and falls far below the requirement of 200 mug Se/kg DM (GfE, 2001) usually used for the high yielding dairy cows. The risk of insufficient Se supply seems to be higher for dry cows than for lactating ones because roughages are normally the main ingredient in the diet of dry cows. This study was conducted to investigate the influence of Se supplementation during the dry period of pregnant dairy cows on the Se status before and after parturition. The experiment was carried out with 42 dry and pregnant dairy cows, starting at day 60 before estimated calving date and lasted till 21 days after parturition Dry cows were designated to two different treatments. Cows in treatment I (T1) had no Se supplementation, only the native Se content of feeds, with mean value of 20-25 mug Se/kg DM. In treatment 2 (T2), the cows were given additional 2.4 mg Se/animal/day, as Na-selenite up to calving. Diets formulated with grass silage, corn silage and hay were fed up to 21 days before parturition. Then the cows were given additional concentrate which was adjusted accordingly after calving. From the initial values of 18 mug/l, the Se content in plasma decreased progressively during the whole dry period in T1 to the lowest level of 9 mug/l at the 7(th) day before parturition. Se content in plasma of T2 at the 21(st) day before parturition was 35 mug/l, and decreased to 23 mug/l up to 21 days after parturition. The activity of glutathione peroxidase in T2 was significantly higher after parturition, although Se supplementation was stopped with parturition. In T1, the activity did not exceed 60 U/l during the whole period, while in T2, the activity rose to 114 U/l at parturition. The Se content in colostrum were 25 and 53 mug/kg for T1 and 2, respectively. There were no significant differences in the Se content of the milk at days 7 and 21 after parturition; and the values ranged between 5 and 9 mug Se/kg. Also milk yield and composition were not affected by Se supplementation during the dry period. The present study confirms the need for Se supplementation during the dry period of pregnant dairy cows, which also affects. the Se status after parturition.
- Autor*innen der BOKU Wien:
-
Gierus Martin