Synchronization of estrus using progesterone injections followed by human menopausal gonadotropin in ewes.

Serial progesterone injections followed by human menopausal gonadotropin (hMG), instead of equine chorionic gonadotropin (eCG), were used to synchronize estrus in ewes. Shal ewes (n = 189) were assigned into five groups and each group was divided into two sub-groups to receive gonadotropins including eCG (300 IU; intra-muscular) or hMG (one ampoule; subcutaneously, SC). All ewes received prostaglandin (PG) F2α six days after introducing ram (day 0). Ewes received 0 (control), one, two, three or four injections of progesterone (50.00 mg; SC), 72 hr apart. The first progesterone was injected at the time of PG injection. Ewes in treatment groups received gonadotropins 48 hr after the last progesterone injection. Control group ewes received gonadotropins, at the time of PG injection. Mating was recorded after introducing fertile rams. Data were analyzed using GLM and GENMOD procedures in SAS. The incidence of estrus was less in control and ewes received a single progesterone (34.20%) compared to ewes received two (64.10%), three (81.10%) and four injections (68.40%) of progesterone. Time to estrus was earlier in control (45.70 ± 4.41 hr) than progesterone-treated groups (63.60 ± 1.79 hr). Fertility (51.30%) and fecundity (78.40%) of ewes received three progesterone injections were significantly greater than other progesterone-treated groups. There was no significant difference in reproductive indices between eCG and hMG sub-groups. In conclusion, during the non-breeding season, three injections of progesterone, three days apart, starting six days after ram exposure, in association with hMG, 48 hr after the last progesterone injection, could provide a sound reproductive performance in Shal ewes.

Production of transgenic goats expressing human coagulation factor IX in the mammary glands after nuclear transfer using transfected fetal fibroblast cells.

There are growing numbers of recombinant proteins that have been expressed in milk. Thus one can consider the placement of any gene of interest under the control of the regulatory elements of a milk protein gene in a dairy farm animal. Among the transgene introducing techniques, only nuclear transfer (NT) allows 100 % efficiency and bypasses the mosaicism associated with counterpart techniques. In this study, in an attempt to produce a transgenic goat carrying the human coagulation factor IX (hFIX) transgene, goat fetal fibroblasts were electroporated with a linearized marker-free construct in which the transgene was juxtaposed to ß-casein promoter designed to secret the recombinant protein in goat milk. Two different lines of transfected cells were used as donors for NT to enucleated oocytes. Two transgenic goats were liveborn. DNA sequencing of the corresponding transgene locus confirmed authenticity of the cloning procedure and the complementary experiments on the whey demonstrated expression of human factor IX in the milk of transgenic goats. In conclusion, our study has provided the groundwork for a prosperous and promising approach for large-scale production and therapeutic application of hFIX expressed in transgenic goats.