Please use this identifier to cite or link to this item:
|Title:||Comparison of gonadorelin products in lactating dairy cows: Efficacy based on induction of ovulation of an accessory follicle and circulating luteinizing hormone profiles|
|Authors:||Souza, Alex H.|
Cunha, Arcelina Pacheco
Silva, Eder Pereira
Guenther, Jerry N.
Wiltbank, Milo C.
Uludağ Üniversitesi/Veteriner Fakültesi/Kadın Hastalıkları ve Doğum Anabilim Dalı.
|Citation:||Souza, A. H. vd. (2009). "Comparison of gonadorelin products in lactating dairy cows: Efficacy based on induction of ovulation of an accessory follicle and circulating luteinizing hormone profiles". Theriogenology, 72(2), 271-279.|
|Abstract:||This study evaluated whether the four gonadorelin products that are commercially available in the United States produce comparable ovulation responses in lactating cows. Dairy cows at 7 d after last gonadotropin-releasing hormone (GnRH) treatment of Ovsynch (Day 7), with a corpus luteum (CL) >= 15 mm and at least one follicle >= 10 mm, were evaluated for response to GnRH treatment. Selected cows were randomized to receive (100 mu g; im): (1) Cystorelin (n = 146): (2) Factrel (n = 132): (3) Fertagyl (n = 140); or (4) Ovacyst (n = 140). On Day 14, cows were examined for Ovulation by detection of an accessory CL. Circulating luteinizing hormone (LH) concentrations were also evaluated in some cows after treatment with 100 mu g (n = 10 per group) or 50 mu g (n = 5 per group) GnRH. Statistical analyses were performed with the procedures MIXED and GLIMMIX of the SAS program. Percentage of cows ovulating differed (P < 0.01) among groups, with that for Factrel being lower (55.3%) than that for Cystorelin (76.7%), Fertagyl (73.6%), or Ovacyst (85.0%), There was no effect of batch, parity, or follicle size on ovulation response. but increasing body condition score decreased Ovulation response. There was a much greater LH release in cows treated with 100 mu g than in those treated with 50 mu g, but there were no detectable differences among products in time to LH peak, peak LH concentration, or area under the LH curve and no treatment effects nor treatment by time interactions on circulating LH profile. Thus, ovulation response to Factrel on Day 7 of the cycle was lower than that for other commercial GnRH products, although a definitive mechanism for this difference between products was not demonstrated.|
|Appears in Collections:||Scopus|
Web of Science
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.