title: Ovulation induction in pre-pubertal Sahiwal-Friesian cross bred heifers by the use of clomiphene citrate and hCG.
abstract: In this study, an attempt was made to induce ovulation in crossbred pre-pubertal heifers by the use of clomiphene citrate (an anti-estrogen) and hCG. The hypothesis was that the clomiphene citrate, being anti-estrogen, would remove negative feedback effect of estrogen on the release of pituitary gonadotropins. Elevated gonadotropins would support ovarian follicular growth to a point where hCG would induce ovulation. Six pre-pubertal heifers were given clomiphene citrate orally at 300 mg/heifer for 9 days. At the same time, six control heifers were given placebo tablets. On following day, hCG was given to all heifers at a dose of 2500IU. Blood was collected before, during and after treatment and plasma was assayed for progesterone (P4) and estradiol (E2) concentrations. Five heifers (83.3%) in the experimental group had E2 concentrations above 10 pg/ml compared to one heifer (16.7%) in control group. Due to a wide variation, mean E2 concentration did not differ significantly between experimental and control heifers. The P4 assays showed that four heifers (66.7%) in the experimental group had ovulated (P4>1ng/ml plasma) compared to one heifer (16.7%) in control group, and mean P4 concentration differed (P<0.05) when concentrations were greatest in the clomiphene citrate-treated heifers. In conclusion, clomiphene citrate along with hCG can be used to induce ovulation in pre-pubertal heifers.
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Science, University of Agriculture Faisalabad, Faisalabad, Pakistan. Electronic address: Ubaid1068@yahoo.com.
authors.lastname: Ubaid-Ur-Rehman
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Science, University of Agriculture Faisalabad, Faisalabad, Pakistan.
authors.forename: Shujait
authors.initials: S
authors.lastname: Ali
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Science, University of Agriculture Faisalabad, Faisalabad, Pakistan.
authors.forename: Nazir
authors.initials: N
authors.lastname: Ahmad
authors.affiliation: Animal Science Division, Nuclear Institute for Agriculture and Biology (NIAB) Faisalabad, Faisalabad, Pakistan.
authors.forename: Shanaz Adeeb
authors.initials: SA
authors.lastname: Khanum
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Science, University of Agriculture Faisalabad, Faisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Zubair
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002417:Cattle / Q000502:physiology*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D002996:Clomiphene / Q000008:administration & dosage / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D004958:Estradiol / Q000097:blood; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage / Q000494:pharmacology; D010062:Ovulation Induction / Q000379:methods / Q000662:veterinary*; D011374:Progesterone / Q000097:blood; D012102:Reproductive Control Agents / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D012102:Reproductive Control Agents; D002996:Clomiphene; D011374:Progesterone; D004958:Estradiol
keywords: Clomiphene citrate; Cross bred; Induced ovulation; Pre-pubertal