Veterinaria México Publicación Digital de la Facultad de Medicina Veterinaria y Zootecnia OA / 11 1 Vol. 6  No. 2  April-June  2019 Original Research http://veterinariamexico.unam.mx/ Accepted: 2019-06-18 Published: 2019-06-28 Additional information and declarations can be found on page 8 Copyright 2019 Mehmet Akkose et al. open access Distributed under Creative Commons CC-BY 4.0 Abstract Pregnancy-associated glycoproteins (PAGs) and progesterone concentrations were assessed in Holstein heifers 28 days post-insemination, following es- trus synchronization with either a double prostaglandin (PG) injection or the ovsynch protocol. Animals between 15 and 20 months of age, with a 3-3.5 BCS, were randomly assigned to three groups: Heifers in the control group (n = 70) were monitored for estrus behaviour for 21 days and inseminat- ed when detected in standing heat; Estrus of heifers in the Ovsynch group (n = 70)) was synchronized following the Ovsynch protocol, and timed ar- tificial insemination was performed 16 h after the completion of treatment; Animals in the PG group (n = 70) received two prostaglandin-F 2α injections 11 days apart, were monitored for estrus behaviour for 2-5 days following the last injection, and inseminated when in heat. Serum PAGs and progesterone concentrations were measured in pregnant heifers (control group n = 25; ovsynch group n = 22; PG group n = 21) on day 28 after artificial insem- ination (AI). Mean serum PAGs concentrations (OD: optical density) were similar between groups (control = 3.37 ± 0.148, Ovsynch = 3.21 ± 0.136, and PG = 3.34 ± 0.143; p > 0.05). However, serum progesterone concen- trations were found to be lower in the ovsynch group (4.70 ± 0.17 ng/mL) when compared to the PG (5.34 ± 0.13 ng/mL) or the control (5.37 ± 0.08 ng/mL) groups (p < 0.001). There was no correlation between serum PAGs and progesterone levels at day 28 post-insemination, or between early preg- nancy PAGs concentrations and fetal death rates. Further research, including multiple sampling time points throughout gestation, after estrus synchroni- zation protocols is warranted, to determine if there are associated temporal changes in PAGs and progesterone profiles that could impact reproductive parameters in dairy heifers. Keywords: Heifer, PAGs, Ovsynch, PGF 2α , Progesterone Pregnancy-associated glycoproteins (PAGs) and progesterone concentrations in Holstein heifers following two methods of estrus syncronization Mehmet Akkose 1,* 0000-0001-7517-4927 Cigdem Cebi Sen 2 0000-0001-6876-2069 Adnan Kirmit 3 0000-0003-2799-8416 Omer Korkmaz 4 0000-0001-5179-2181 Murat Onur Yazlik 5 0000-0002-0039-5597 Murat Gocen 6 0000-0001-7719-3304 Mushap Kuru 7 0000-0003-4409-251X Ergun Akçay 8 0000-0002-7491-5671 1 Ceylanpinar Agricultural Enterprise, General Directorate of Agricultural Enterprises, Sanliurfa, Turkey 2 Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Harran University, Eyyübiye, Sanliurfa, Turkey 3 Department of Biochemistry, Faculty of Medicine, Harran University, Osmanbey, Sanliurfa, Turkey 4 Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Harran University, Sanliurfa, Turkey 5 Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Harran University, Eyyübiye, Sanliurfa, Turkey 6 Ceylanpinar Agricultural Enterprise, General Directorate of Agricultural Enterprises, Sanliurfa, Turkey 7 Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey 8 Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Ankara University, Diskapi, Ankara, Turkey *Corresponding author: Email address: akkosem2012@gmail.com Cite this as: Akkose M, Cebi-Sen C, Kirmit A, Korkmaz O, Yazlik MO, Gocen M, Kuru M, Akçay E. Pregnancy-associated glycoproteins (PAGs) and progesterone concentrations in Holstein heifers following two methods of estrus syncronization. Veterinaria México OA. 2019;2019(2). doi: 10.22201/fmvz.24486760e.2019.2.646. DOI: http://dx.doi.org/10.22201/fmvz.24486760e.2019.2.646