Original Scientific Article
Pregnancy-specific protein B in Yankasa ewes during pregnancy and postpartum periods
Adewale Ayodeji Adeyeye*,
Yusha`u Usman Abubakar,
Olufisayo Oluwadamilare Leigh,
Iyorhembe Utim Ate,
Jashilagari Stephen,
Kabir Ayo Raheem,
Simon Azubuike Ubah

Mac Vet Rev 2021; 44 (1): i - viii


Received: 20 August 2020

Received in revised form: 02 December 2020

Accepted: 07 December 2020

Available Online First: 22 January 2021

Published on: 15 March 2021

Correspondence: Adewale Ayodeji Adeyeye, adewale.adeyeye@udusok.edu.ng


Pregnancy-specific protein B (PSPB) is produced by mono and binucleate trophoblast cells in the placenta of ruminants during pregnancy. This study was designed to determine the pattern of serum PSPB in Yankasa ewes during pregnancy and postpartum periods. Mature cycling Yankasa ewes were synchronized and divided into two groups A (n=11) and B (n=13). Group A was bred, while group B was unbred. Blood samples for PSPB assessment were collected from the ewes starting from the day of breeding until 4 weeks post-lambing. All pregnant Yankasa ewes lambed with singleton lambs after an average of 151.18 days. There was a significant (p<0.05) increase in PSPB in pregnant compared with the non-pregnant ewes in the period between 3 weeks post-breeding and 3 weeks post-lambing. Peaks were detected in the first (100.60 ng/ml), second (133.90 ng/ml), and third (114.82 ng/ml) trimesters at 5, 10 and 21 weeks of gestation, respectively, but steadily decreased within 4 weeks (2.38 ng/ml) postpartum. In conclusion, PSPB detected pregnancy in Yankasa ewes from 3 weeks post-breeding with peak levels at 5, 10 and 21 weeks post-breeding in the first, second, and third trimesters, respectively. PSPB decreased gradually after lambing until 4 weeks postpartum.

Keywords: pregnancy specific protein-B, pregnancy, postpartum, Yankasa ewes


  1. NASS (2011). National agricultural sample survey on animal census. National bureau of tatistics, Abuja, Nigeria http://nigeria.countrystat.org/documents/detail/en/c/454834/
  2. Blench, R. (1999). Traditional livestock breeds: geographical distribution and dynamics in relation to the ecology of West Africa. ODI Working paper. 122.
  3. Umaru, M.A., Adeyeye, A.A., Abubakar, A., Garba, H.S. (2009). Retrospective analysis of disease conditions among reproductive domestic ruminants in Sokoto, Nigeria. Anim Res Int. 6(1): 946-948. https://doi.org/10.4314/ari.v6i1.48100
  4. David-West, K.B. (1985). Role of government in small ruminant production. Proceedings of the national conference on small ruminants production. NAPRI, October, 6-10, (pp. 10-16), Shika, ABU, Zaria.
  5. Yakubu, A., Raji, A.O., Omeje, J.N. (2010). Genetic and phenotypic differentiation of qualitative traits in Nigerian indigenous goat and sheep populations. J Agric Biol Sci. 5(2): 58-66.
  6. Oyedipe, E.O., Pathiraja, N., Edqvist, L.E., Buvanendran, V. (1986). Onset of puberty and estrous cycle phenomena in Yankasa ewes as monitored by plasma progesterone concentrations. Anim Reprod Sci. 12(3): 195-199. https://doi.org/10.1016/0378-4320(86)90040-0
  7. Afolayan, R.A., Adeyinka, I.A., Lakpini, C.A.M. (2006). The estimation of live weight from body measurements in Yankasa sheep. Czech J Anim Sci. 51(8): 343. https://doi.org/10.17221/3948-CJAS
  8. Jainudeen, M.R., Hafez, E.S. (2000). Gestation, prenatal physiology, and parturition. In: B.Hafez, E.S.E Hafez (Eds.), Reproduction in farm animals, 7th Edition. (pp. 140-155). Wiley-Blackwell. https://doi.org/10.1002/9781119265306.ch10
  9. Noakes, D.E., Parkinson, T.J, England, G.C. (2001). Arthur’s veterinary reproduction and obstetrics. W.B. Saunders Ltd.
  10. Sousa, N.M., Beckers, J.F, Gajewski, Z. (2008). Current trends in follow-up of trophoblastic function in ruminant species. J Physiol Pharmacol. 59(Suppl. 9): 65-74.
  11. Sousa, N.M., Ayad, A., Beckers, J.F, Gajewski, Z. (2006). Pregnancy-associated glycoproteins (PAG) as pregnancy markers in the ruminants. J Physiol Pharmacol. 57(Suppl. 8): 153-171.
  12. Xie, S., Low, B.G., Nagel, R.J., Beckers, J.F., Michael Roberts, R. (1994). A novel glycoprotein of the aspartic proteinase gene family expressed in bovine placental trophectoderm. Biol Reprod. 51(6): 1145-1153. https://doi.org/10.1095/biolreprod51.6.1145 PMid:7534122
  13. Singh, S.P., Natesan, R., Sharma, N., Goel, A.K., Singh, M.K., Kharche, S.D. (2019). Pregnancyassociated glycoprotein profile in milk and its relationship with the circulating level during early pregnancy in goats. Small Rumin Res. 173, 81-87. https://doi.org/10.1016/j.smallrumres.2019.02.017
  14. Hussein, M.S., Bedier, W.E., Deghedy, A., El-Desouky, A.M., Ramoun, A.A. (2017). Serum concentration of pregnancy-associated glycoproteins (PAGs) as a predictor for embryonic/fetal losses and fetal numbers in cross-bred ewes. Life Sci J. 14(5): 106-111.
  15. Abubakar, M.I., Ahmed, A., Adeyeye, A.A., Baraya, Y.S. (2019). Comparative diagnosis of pregnancy wastage in cows at slaughter using pregnancy specific protein-B and post slaughter inspection diagnostic procedures. Anim Reprod Sci. 211: 106233. https://doi.org/10.1016/j.anireprosci.2019.106233 PMid:31785622
  16. Adeyeye, A.A., Abubakar, M.I., Ahmed, A.G. (2019). Comparative detection of pregnancy in ewes at slaughter using pregnancy specific protein-B and post slaughter examination. Glob Vet. 21(2): 48-52.
  17. Adeyeye, A.A., Ate, I.U., Lawal, A.I., Adamu, S. (2016). Changes in some pregnancy biomarkers of Yankasa ewes experimentally infected with Trypanosoma evansi. Anim Reprod Sci. 167, 109-116. https://doi.org/10.1016/j.anireprosci.2016.02.014 PMid:26936656
  18. Ranilla, M.J., Sulon, J., Carro, M.D., Mantecon, A.R., Beckers, J.F. (1994). Plasmatic profiles of pregnancy-associated glycoprotein and progesterone levels during gestation in Churra and Merino sheep. Theriogenology. 42(3): 537-545. https://doi.org/10.1016/0093-691X(94)90691-B
  19. Roberts, J.N., May, K.J., Veiga-Lopez, A. (2017). Time-dependent changes in pregnancy-associated glycoproteins and progesterone in commercial crossbred sheep. Theriogenology 89, 271-279. https://doi.org/10.1016/j.theriogenology.2016.10.029 PMid:28043363
  20. Ranilla, M.J., Sulon, J., Mantecon, A.R., Beckers, J.F., Carro, M.D. (1997). Plasma pregnancy-associated glycoprotein and progesterone concentrations in pregnant Assaf ewes carrying single and twin lambs. Small Rumin Res. 24(2): 125-131. https://doi.org/10.1016/S0921-4488(96)00922-4
  21. Shahin, M., Friedrich, M., Gauly, M., Beckers, J.F., Holtz, W. (2013). Pregnancy-associated glycoprotein (PAG) pattern and pregnancy detection in Boer goats using an ELISA with different antisera. Small Rumin Res. 113(1): 141-144. https://doi.org/10.1016/j.smallrumres.2013.01.016
  22. Sousa, N.M., Garbayo, J.M., Figueiredo, J.R., Sulon, J., Gonçalves, P.B., Beckers, J.F. (1999). Pregnancyassociated glycoprotein and progesterone profiles during pregnancy and postpartum in native goats from the north-east of Brazil. Small Rumin Res. 32(2): 137-147. https://doi.org/10.1016/S0921-4488(98)00171-0
  23. Barbato, O., Menchetti, L., Sousa, N.M., Malfatti, A., Brecchia, G., Canali, C., Beckers, J.F., Barile, V.L. (2017). Pregnancy-associated glycoproteins (PAGs) concentrations in water buffaloes (Bubalus bubalis) during gestation and the postpartum period. Theriogenology 97, 73-77. https://doi.org/10.1016/j.theriogenology.2017.04.021 PMid:28583611
  24. Echternkamp, S.E., Vonnahme, K.A., Green, J.A., Ford, S.P. (2006). Increased vascular endothelial growth factor and pregnancy-associated glycoproteins, but not insulin-like growth factor-I, in maternal blood of cows gestating twin fetuses. J Anim Sci. 84, 2057-2064. https://doi.org/10.2527/jas.2005-714 PMid:16864865
  25. Willard, J.M., White, D.R., Wesson, C.A., Stellflug, J., Sasser, R.G. (1995). Detection of fetal twins in sheep using a radioimmunoassay for pregnancy-specific protein B. J Anim Sci. 73(4): 960-966. https://doi.org/10.2527/1995.734960x PMid:7628973
  26. Ledezma-Torres, R.A., Beckers, J.F., Holtz, W. (2006). Assessment of plasma profile of pregnancy-associated glycoprotein (PAG) in sheep with a heterologous (anticaPAG55+59) RIA and its potential for diagnosing pregnancy. Theriogenology 66(4): 906-912. https://doi.org/10.1016/j.theriogenology.2006.02.031 PMid:16566995
  27. Shahin, M., Friedrich, M., Gauly, M., Holtz, W. (2014). Pregnancy‐associated glycoprotein (PAG) profile of Holstein-Friesian cows as compared to dual‐purpose and beef cows. Reprod Domest Anim. 49(4): 618-620. https://doi.org/10.1111/rda.12336 PMid:24888733
  28. El Amiri, B., Karen, A., Sulon, J., Melo, de Sousa, N., Alvarez‐Oxiley, A.V., Cognie, Y., Szenci, O., Beckers, J.F. (2007). Measurement of ovine pregnancy‐associated glycoprotein (PAG) during early pregnancy in Lacaune sheep. Reprod Domest Anim. 42(3): 257-262. https://doi.org/10.1111/j.1439-0531.2006.00761.x PMid:17506803
  29. Rovani, M.T., Cezar, A.S., Rigo, M.L., Gasperin, B.G., Nóbrega Júnior, J.E., Torres, F.D., Gonçalves, P.B., Ferreira, R. (2016). Evaluation of a bovine pregnancy-associated glycoprotein enzyme-linked immunosorbent assay kit for serological diagnosis of pregnancy in sheep. Ciênc Rural. 46(2): 362-367. https://doi.org/10.1590/0103-8478cr20150270
  30. El Amiri, B., Remy, B., Sousa, N.M., Joris, B., Ottiers, N.G., Perenyi, Z., Mboko, H.B., Beckers, J.F. (2003). Isolation and partial characterization of three pregnancy‐associated glycoproteins from the ewe placenta. Mol Reprod Dev. 64(2): 199-206. https://doi.org/10.1002/mrd.10246 PMid:12506352
  31. El Amiri, B., Remy, B., De Sousa, N.M., Beckers, J.F. (2004). Isolation and characterization of eight pregnancy-associated glycoproteins present at high levels in the ovine placenta between day 60 and day 100 of gestation. Reprod Nutr Dev. 44(3): 169-181. https://doi.org/10.1051/rnd:2004025 PMid:15460157
  32. Klisch, K., De Sousa, N.M., Beckers, J.F., Leiser, R., Pich, A. (2005). Pregnancy associated glycoprotein ‐1, ‐6, ‐7, and‐17 are major products of bovine binucleate trophoblast giant cells at midpregnancy. Mol Reprod Dev. 71(4): 453-460. https://doi.org/10.1002/mrd.20296 PMid:15822115
  33. Xie, S.C., Low, B.G., Nagel, R.J., Kramer, K.K., Anthony, R.V., Zoli, A.P., Beckers, J.F., Roberts, R.M. (1991). Identification of the major pregnancyspecific antigens of cattle and sheep as inactive members of the aspartic proteinase family. Proc Natl Acad Sci USA. 88(22): 10247-10251. https://doi.org/10.1073/pnas.88.22.10247 PMid:1946444 PMCid:PMC52905
  34. Wallace, R.M., Pohler, K.G., Smith, M.F., Green, J.A. (2015). Placental PAGs: gene origins, expression patterns, and use as markers of pregnancy. Reproduction 149(3): R115-126. https://doi.org/10.1530/REP-14-0485 PMid:25661256
  35. Haugejorden, G., Waage, S., Dahl, E., Karlberg, K., Beckers, J.F., Ropstad, E. (2006). Pregnancy associated glycoproteins (PAG) in postpartum cows, ewes, goats and their offspring. Theriogenology 66(8): 1976-1984. https://doi.org/10.1016/j.theriogenology.2006.05.016 PMid:16870244


© 2021 Adeyeye A.A. This is an open-access article published under the terms of the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 

Conflict of Interest Statement

The authors have declared that no competing interests exist

Citation Information

Macedonian Veterinary Review. Volume 44, Issue 1, Pages i-viii, e-ISSN 1857-7415, p-ISSN 1409-7621, DOI: 10.2478/macvetrev-2021-0010, 2021