title: Porcine follicle-stimulating hormone treatment of gilts during an altrenogest-synchronized follicular phase: effects on follicle growth, hormone secretion, ovulation, and fertilization.
abstract: Porcine FSH (SUPER OV), containing .03% LH activity, and equine chorionic gonadotropin (eCG) were administered during an altrenogest-synchronized follicular phase to determine their effects on follicle development, estrus, ovulation, and fertilization. Treatments were made by i.m. injection starting on d 1 (24 h after the last feeding of altrenogest): 1) saline, once, n = 14; 2) eCG (1,200 to 1,500 IU) once, n = 32; 3) FSH 14 (n = 2) or 21 (n = 6) NIH-FSH-S1 units/100 kg BW, divided among six injections at 12-h intervals (FSH14/21); 4) FSH, 28 NIH-FSH-S1 units/100 kg BW, divided among six injections at 12-h intervals, n = 12; and 5) FSH, 28 NIH-FSH-S1 units/100 kg BW and 100 IU hCG, two or six injections at 12-h intervals (FSH28+hCG), n = 13. Gilts were injected with 750 IU of hCG on d 5 to ensure ovulation. Twenty-eight eCG- and FSH-injected gilts (n = 6, 8, and 11 on treatments 3, 4, and 5, respectively) were bred and laparotomized on d 7 to recover ova and record ovulation rate. The mean number of ovulations and large (6- to 10-mm) follicles, respectively, on d 7 were as follows: saline (17, .7), eCG (43, .9), FSH14/21 (15, .6), FSH28 (12, 16), and FSH28+hCG (32, 21). Plasma FSH concentrations were at least threefold higher (P < .05) in gilts treated with FSH than in gilts not treated with FSH. The percentage in estrus was higher (P < .05) for saline- and eCG-treated gilts (100 and 87%, respectively) than for FSH-treated gilts (53%). Proportion of FSH28+hCG-treated gilts with fertilized ova (27%) was lower than for other groups (79 to 100%). In summary, the 3-d high dose FSH treatment (FSH28 and FSH28+hCG) during an altrenogest-synchronized follicular phase increased the number of potentially ovulatory follicles, but this potential benefit was not realized because many follicles failed to ovulate. The co-injection of low doses of hCG (FSH28+hCG) increased the ovulation rate and estradiol secretion but reduced ova recovery and fertilization rate compared with eCG and the other FSH treatments.
authors.affiliation: Germplasm and Gamete Physiology Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705, USA.
authors.forename: H D
authors.initials: HD
authors.lastname: Guthrie
authors.forename: V G
authors.initials: VG
authors.lastname: Pursel
authors.forename: R J
authors.initials: RJ
authors.lastname: Wall
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood; D004973:Estrus Synchronization; D005260:Female; D005306:Fertilization / Q000187:drug effects* / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005498:Follicular Phase / Q000187:drug effects / Q000502:physiology; D006064:Gonadotropins, Equine / Q000008:administration & dosage / Q000494:pharmacology; D007273:Injections, Intramuscular / Q000662:veterinary; D007986:Luteinizing Hormone / Q000097:blood; D006080:Ovarian Follicle / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D010060:Ovulation / Q000187:drug effects* / Q000502:physiology; D010062:Ovulation Induction / Q000662:veterinary; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000494:pharmacology*; D012044:Regression Analysis; D013552:Swine / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D014204:Trenbolone Acetate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine; D045167:Progesterone Congeners; C023445:altrenogest; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D014204:Trenbolone Acetate