Increased cleavage and blastocyst rate in ewes treated with XXXX somatotropin 5 days before the end of @entity1871 -based estrous synchronization.

@entity5956 @entity742 @entity1420 @entity1871 @entity9418 @entity1604 @entity291
Treatment with @entity291 somatotropin (bST) during estrous synchronization increased fertility and prolificacy in @entity742 . In the present study, a single dose of bST 5 days before the end of @entity1871 treatment improved cleavage and embryo development. Stage of estrous cycle was synchronized in ewes (n=32) with @entity1871 and superovulation was induced by use of FSH. Five days before the end of @entity1871 treatment, ewes were randomly assigned to two groups: bST group (n=16) received a depot injection of 125 mg of bST sc (Lactotropina, Elanco, M  xico) and the control group (n=16) received saline solution. Estrous was detected with rams fitted with an apron every 2 h and estrous @entity742 were mated every 8 h whilst in estrous. Embryos were recovered on Day 7 post mating, assessed microscopically and fixed in 4% @entity1604 . Cell number in blastocysts was counted after @entity5956 staining. Plasma concentrations of @entity9418 , insulin and @entity1420 were determined in eight @entity742 per group from the day of bST treatment to the day of embryo recovery. Cleavage rate, percentage of transferable embryos (transferable embryos/cleaved) and percentage of embryos reaching the blastocyst stage (blastocyst/cleaved) were compared between groups by logistic regression. @entity9418 , insulin and @entity1420 plasma concentrations were analyzed by ANOVA for repeated measurements and cell number by ANOVA. Cleavage rate was greater (P<0.01) in bST treatment group (86%) than in the control group (62%). Similarly, the proportion of embryos reaching the blastocyst stage (bST=68.7 vs control=42.5) and the number of cells per blastocyst (bST group 91.8  5.5 compared to control group 75  6) were greater (P<0.01) in the bST-treated @entity742 . Plasma concentrations of @entity9418 and insulin were greater (P<0.01) in the bST-treated group. No changes were observed in @entity1420 concentrations (P=0.5). It is concluded that bST injection 5 days before @entity1871 removal increases cleavage rate and the proportion of embryos that reach the blastocyst stage. These effects are associated with an increase in @entity9418 and insulin concentrations.
