Optimization Of Superovulation Scheme For Beef Cattle In Pasture

To explore the superovulation technology of Simmentals cattle under grazingcondition，five schemes （A: FSH+PG; B: FSH+PG+GnRH; C: FSH+PG+CIDR+GnRH; D: FSH+PG+CIDR+LRH-A₃; E: FSH+E₂+P₄+CIDR+PG） with domestic andimported FSH respectively was performed. Results: the number of available embryosof the five schemes were3.43±2.41,5.93±3.54,7.21±3.19,6.95±3.23and6.35±2.98respectively with the domestic FSH. The average number of available embryos inscheme of B, C, D and E were higher than scheme A （P<0.05） with domestic FSH.The average number of available embryos in scheme C was highest among schmes B,C, D and E, however there were no significant differences （P>0.05）; the number ofavailable embryos of the five schemes were4.34±2.71,6.76±3.79,7.79±4.23,7.11±3.14and6.80±3.08respectively with the imported FSH. The average number of availableembryos in scheme of B, C, D and E were higher than scheme A （P<0.05） withimported FSH. The average number of available embryos in scheme C was highestamong schmes B, C, D and E, however there were no significant differences（P>0.05）； There was no significant difference between the domestic FSH andimported FSH groups for the average number of available embryos.In conclusion:（1） The scheme C was the best among the whole five schemes,then was scheme D, E and B, and the scheme A was the worst.（2） There was nosignificant difference between the domestic FSH and imported FSH groups, however,considering the price of domestic FSH was much lower than imported FSH, so thebetter choice is domestic FSH.（3） GnRH、LRH-A₃and E₂+P₄can obviously increasethe number of available embryos.