title: Synchronization of ovulation with human chorionic gonadotropin in lactating dairy cows with ovarian cysts during heat stress.
abstract: A study was conducted during hot season to determine the effect of synchronization of ovulation with human chorionic gonadotropin (hCG) on fertility of lactating dairy cows with ovarian cysts. Non cyclic Holstein dairy cows (n = 80) were stratified by parity and diagnosed as having an ovarian cyst. The cows were further identified as follicular or luteal cysts according to the plasma progesterone (P4) concentration and the cystic image of ultrasonography. Cystic cows were randomly assigned to receive treatments (Ovsynch as the control or Ovsynch plus 3000 IU hCG). All cows were artificially inseminated at 16-18 h after the second gonadotropin releasing hormone injection. Cows supplemented with hCG had a greater number of corpus luteum (1.8 ± 0.2 and 0.8 ± 0.3; P < 0.05) and had greater P4 concentration on day 12 than those control cows (6.3 ± 0.3 and 3.9 ± 0.4 ng/ml; P < 0.05). Concentration of cortisol did not differ between groups of cystic cows. No significant differences were found in overall conception rates between the treatments; however, significantly greater conception rate (P = 0.03) was observed in cows with luteal cysts receiving Ovsynch plus hCG. This study highlights that administration of hCG following the Ovsynch-based timed artificial insemination (AI) is more effective than the control Ovsynch by which the hCG affects corpus luteum (CL) development, P4 concentration, and thus improves conception rate in dairy cows with luteal cysts.
authors: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, 40002, Thailand, chanav@kku.ac.th.
authors: Chainarong
authors: C
authors: Navanukraw
authors: Vilaivan
authors: V
authors: Khanthusaeng
authors: Aree
authors: A
authors: Kraisoon
authors: Duangkamon
authors: D
authors: Suwannarit
authors: Chaiwat
authors: C
authors: Jarassaeng
authors: Suneerat
authors: S
authors: Aiumlamai
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000503:physiopathology*; D006063:Chorionic Gonadotropin / Q000008:administration & dosage*; D003612:Dairying; D004973:Estrus Synchronization; D005260:Female; D018882:Heat Stress Disorders / Q000503:physiopathology / Q000662:veterinary*; D006358:Hot Temperature; D006801:Humans; D007315:Insemination, Artificial / Q000662:veterinary; D007774:Lactation; D010048:Ovarian Cysts / Q000503:physiopathology / Q000662:veterinary*; D010053:Ovary / Q000187:drug effects; D011247:Pregnancy
chemical_list: D006063:Chorionic Gonadotropin