<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Postpartum anestrus is a physiological phenomenon in high-producing dairy cows. Static ovaries have been related as major contributors for its occurrence causing a significant reproductive problem to the dairy industry. Different treatment methods have been employed with inconsistent rate of success in initiation of cyclicity, requiring further investigations in order to achieve satisfactory results. The aim of the present study was to compare the ovarian response in cows diagnosed with static ovaries, more than 60 days postpartum using two different hormonal treatment (GnRH and eCG) methods. A total of 58 acyclic cows (no CL, follicles&lt;8mm, P4&lt;0.5ng/mL) were randomly divided into three groups: GnRH (Group 1, n=23), eCG (Group 2, n=23) and Controls (n=12), and allocated thereafter, into subgroups according to the applied doses of GnRH (100μg or 250μg); eCG (750 IU or 1000 IU) whilst control group cows were left untreated. Daily follicular growth rate and treatment respond interval were estimated based on repeated ultrasound examinations. Blood serum P4 sampling was done on d -7, d-0 (start of the experiment) and on d 7 after ovulation. Resumption of cyclic activity occurred in 55.17% (32/58) of the treated cows, 56.52% in Group 1; 60.86% in Group 2 and 41.66% in the control group. Overall, the follicular growth rate was similar between the trials group and significant with regard to the cows in the control group (p&lt;0.05). eCG or GnRH treated cows responded significantly faster 6.85±0.2 and 7.84±0.2 days, respectively, in comparison to the control group cows (17±0.7 days, p&lt;0.001). Treatment with a single dose of GnRH or eCG caused resumption of follicular growth and ovulation following luteogenesis (forming CL) without significant changes in P4 concentrations on day 7 after ovulation (p>0.05). Cows in Group 2 had significantly higher incidence of multiple ovulations than cows in Group 1 (p&lt;0.05). The eCG treatment resulted in a faster response and higher ovulation rate compared to GnRH treatment. In conclusion, both treatments have shown acceptable results in resumption of cyclicity in dairy cows with static ovaries.</p></abstract>

Postpartum anestrus is a physiological phenomenon in high-producing dairy cows. Static ovaries have been related as major contributors for its occurrence causing a significant reproductive problem to the dairy industry. Different treatment methods have been employed with inconsistent rate of success in initiation of cyclicity, requiring further investigations in order to achieve satisfactory results. The aim of the present study was to compare the ovarian response in cows diagnosed with static ovaries, more than 60 days postpartum using two different hormonal treatment (GnRH and eCG) methods. A total of 58 acyclic cows (no CL, follicles<8mm, P4<0.5ng/mL) were randomly divided into three groups: GnRH (Group 1, n=23), eCG (Group 2, n=23) and Controls (n=12), and allocated thereafter, into subgroups according to the applied doses of GnRH (100μg or 250μg); eCG (750 IU or 1000 IU) whilst control group cows were left untreated. Daily follicular growth rate and treatment respond interval were estimated based on repeated ultrasound examinations. Blood serum P4 sampling was done on d -7, d-0 (start of the experiment) and on d 7 after ovulation. Resumption of cyclic activity occurred in 55.17% (32/58) of the treated cows, 56.52% in Group 1; 60.86% in Group 2 and 41.66% in the control group. Overall, the follicular growth rate was similar between the trials group and significant with regard to the cows in the control group (p<0.05). eCG or GnRH treated cows responded significantly faster 6.85±0.2 and 7.84±0.2 days, respectively, in comparison to the control group cows (17±0.7 days, p<0.001). Treatment with a single dose of GnRH or eCG caused resumption of follicular growth and ovulation following luteogenesis (forming CL) without significant changes in P4 concentrations on day 7 after ovulation (p>0.05). Cows in Group 2 had significantly higher incidence of multiple ovulations than cows in Group 1 (p<0.05). The eCG treatment resulted in a faster response and higher ovulation rate compared to GnRH treatment. In conclusion, both treatments have shown acceptable results in resumption of cyclicity in dairy cows with static ovaries.

Two Possibile Hormonal Treatment Methods for Inducing Follicular Growth in Dairy Cows With Inactive-Static Ovaries

Ss. Cyril and Methodius University, Faculty of Veterinary Medicine - Skopje, Institute of Reproduction and Biomedicine, Skopje, R. Macedonia

Department of Reproduction, Faculty of Veterinary Medicine, Skopje, Ss. Cyril and Methodius University in Skopje Lazar Pop Trajkov 5-7, Skopje, Macedonia Phone: +389 70 258989 ; Fax. +389 2 3114619

Macedonian Veterinary Review

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Postpartum anestrus is a physiological phenomenon in high-producing dairy cows. Static ovaries have been related as major contributors for its occurrence causing a significant reproductive problem to the dairy industry. Different treatment methods have been employed with inconsistent rate of success in initiation of cyclicity, requiring further investigations in order to achieve satisfactory results. The aim of the present study was to compare the ovarian response in cows diagnosed with static ovaries, more than 60 days postpartum using two different hormonal treatment (GnRH and eCG) methods. A total of 58 acyclic cows (no CL, follicles0.05). Cows in Group 2 had significantly higher incidence of multiple ovulations than cows in Group 1 (p<0.05). The eCG treatment resulted in a faster response and higher ovulation rate compared to GnRH treatment. In conclusion, both treatments have shown acceptable results in resumption of cyclicity in dairy cows with static ovaries.

Postpartum anestrus is a physiological phenomenon in high-producing dairy cows. Static ovaries have been related as major contributors for its occurrence...

Two Possibile Hormonal Treatment Methods for Inducing Follicular Growth in Dairy Cows With Inactive-Static Ovaries

Published Online: Nov 18, 2015

Page range: 171 - 177

Received: Jun 25, 2014

DOI: https://doi.org/10.14432/j.macvetrev.2014.09.023

Keywords
true anoestrus, ovary, GnRH, eCG, dairy cow

© 2015

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Two Possibile Hormonal Treatment Methods for Inducing Follicular Growth in Dairy Cows With Inactive-Static Ovaries

Published Online: Nov 18, 2015

Page range: 171 - 177

Received: Jun 25, 2014

DOI: https://doi.org/10.14432/j.macvetrev.2014.09.023

Keywordstrue anoestrus, ovary, GnRH, eCG, dairy cow

© 2015

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
true anoestrus, ovary, GnRH, eCG, dairy cow