Lambing rate and prolificacy in inseminated hair sheep treated with bovine somatotropin
- 253 Downloads
This study evaluated whether the administration of 50 and 100 mg bovine somatotropin (bST) at the start of estrous synchronization and at the time of artificial insemination improves lambing rate and prolificacy in hair sheep. Four hundred eighty adult hair ewes (Pelibuey, Blackbelly, Dorper, Katahdin, and their crosses) were synchronized with intravaginal sponge containing 40 mg of fluorogestone acetate. On the day of sponge insertion, ewes were assigned to three treatments: the bST-100 treatment (n = 156) received 100 mg bST at the start of synchronization (d 0) and at the time of insemination (d 14), the bST-50 treatment (n = 159) received 50 mg bST in the same schedule as the previous group, and the control (n = 165) did not receive any bST. Lambing rate and percentage of multiple births were analyzed using the GENMOD procedure of SAS. Prolificacy data were analyzed using the MIXED procedure of SAS. The IGF-1 and insulin concentrations were analyzed with ANOVA for repeated measures. The bST application did not affect the lambing rate (P = 0.06). The proportion of ewes with multiple births (P = 0.01) and prolificacy (P = 0.04) were higher in the bST-50 (54.3 % and 1.57 ± 0.1) than the bST-100 (18.2 % and 1.25 ± 0.1) and control (33.3 % and 1.28 ± 0.1) groups. The IGF-1 and insulin concentrations were higher (P < 0.05) in the bST-treated groups, but the insulin concentration was higher (P = 0.001) in the bST-100 group than in the bST-50 group. The administration of 50 or 100 mg bST at the start of synchronization and at the time of artificial insemination does not increase lambing rate. However, the dose of 50 mg increased the proportion of multiple births and prolificacy.
KeywordsArtificial insemination Sheep Somatotropin Lambing rate Prolificacy
This study was partly supported by the Fundación Produce Zacatecas A.C. (Zacatecas, México) (Project number 32-2010-0013). The authors thank participating farmers and MSD Salud Animal México for the donation of somatotropin (Boostin-S) and Dr. Eugenio Villagómez Amezcua from Centro Nacional de Investigación Disciplinaria en Microbiología—Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias for his assistance in the determination of hormone levels.
Compliance with ethical standards
Statement of animal rights
All experimental procedures were conducted according to protocols approved by the Unidad Académica de Medicina Veterinaria y Zootecnia de la Universidad Autónoma de Zacatecas Animal Care and Use Committee.
Conflict of interest
The authors declare that they have no competing interests, and this document is their original research work.
- Arroyo, J., 2011. Reproductive seasonality of sheep in Mexico. Tropical and Subtropical Agroecosystems, 14, 829–845.Google Scholar
- Betancourt-Alonso, M.A., Flores-Pérez, F.I., Rosas-Velasco, C., Pérez-Martínez, M., 2006. Role of cytokines in embryo implantation in domestic mammals. Veterinaria México, 37, 335–350.Google Scholar
- Bilby, T.R., Guzeloglu, A., Kamimura, S., Pancarci, S.M., Michel, F., Head, H.H., Thatcher, W.W., 2004. Pregnancy and bovine somatotropin in nonlactating dairy cows: I. Ovarian, conceptus, and insulin-like growth factor system responses. Journal of Animal Science, 87, 3256–3267.Google Scholar
- Bilby, T.R., Sozzi, A., Lopez, M.M., Silvestre, F.T., Ealy, A.D., Staples, C.R., Thatcher, W.W., 2006. Pregnancy, bovine somatotropin, and dietary n-3 fatty acids in lactating dairy cows: I. Ovarian, conceptus, and growth hormone-insulin-like growth factor system responses. Journal of Dairy Science, 89, 3360–3374.CrossRefPubMedGoogle Scholar
- Block, J., Rivera, M., Drost, M., Jousan, F.D., Looney, C.R., Silvestre, F.T., Paula-Lopes, F.F., Ocon, O.M., Rosson, H., Bilby, T.R., Monson, R.L., Rutledge, J.J., Hansen, P.J., 2005. Effects of bovine somatotropin and timed embryo transfer on pregnancy rates in non-lactating cattle. Veterinary Record, 156, 175–176.CrossRefPubMedGoogle Scholar
- Carrera-Chávez, J.M., Hernández-Cerón, J., López-Carlos, M.A., Lozano-Domínguez, R.R., Molinar, F., Echavarría-Cháirez, F.G., Bañuelos-Valenzuela, R., Aréchiga-Flores, C.F., 2014. Superovulatory response and embryo development in ewes treated with two dosis of bovine somatotropin. Animal Reproduction Science, 151, 105–111.Google Scholar
- Hernández-Cerón, J., Gutierrez-Aguilar, C.G., 2013. Recombinant bovine somatotropin and reproduction in cattle, sheep and goat. Agrociencia, 47, 35–45.Google Scholar
- Martínez, A.M., Gutiérrez, C.G., Domínguez, H.Y.M., Hérnandez C.J., 2011. Estrous response and pregnancy rate in seasonal anoestrous goats treated with progestogens and bovine somatropin Revista Mexicana de Ciencias Pecuarias, 2, 221–227.Google Scholar
- Matsui, M., Takahashi, Y., Hishinuma, M., Kanagawa, H., 1995. Insulin and insulin-like growth factor (IGF-I) stimulate the development of bovine embryos fertilized in vitro. Japanese Journal of Veterinary Research, 57, 1109–1111.Google Scholar
- Mendoza, M.G., Hernández, C.J., Zarco, Q.L.A., Gutiérrez, C.G., 2013. Conception rate in repeat-breeding Holstein cows treated with bovine somatotropin at the time of insemination. Revista Mexicana de Ciencias Pecuarias, 4, 177–183.Google Scholar
- Montero-Pardo, A., Hernández-Céron, J., Rojas-Maya, S., Valencia, J., Rodríguez-Cortez, A., Gutiérrez, C.G., 2011. Increased cleavage and blastocyst rate in ewes treated with bovine somatotropin 5 days before the end of progestin-based estrous synchronization. Animal Reproduction Science, 125, 69–73.CrossRefPubMedGoogle Scholar
- Ribeiro, E.S., Bruno, R.G.S., Farias, A.M., Hernández-Rivera, J.A., Gomes, G.C., Surjus, R., Becker, L.F.V., Birt, A., Ott, T.L., Branen, J.R., Sasser, R.G., Keisler, D.H., Thatcher, W.W., Bilby, T.R., Santos, J.E.P., 2014. Low doses of bovine somatotropin enhance conceptus development and fertility in lactating dairy cows. Biology of Reproduction, 90, 1–12.CrossRefGoogle Scholar
- Rodríguez, O.A., Hernández C.J., Gómez, G., 2007. Efecto de la administración de somatotropina bovina al inicio del empadre con una segunda aplicación 14 días después en la fertilidad y prolificidad en ovejas. Proceedings of the XLIII Reunión Nacional de Investigación Pecuaria, Sinaloa, México, 122.Google Scholar
- Rooke, J.A., Ainslie, A., Watt, R.G., Alink, F.M., McEvoy, T.G., Sinclair, K.D., Garnsworthy, P.C., Webb, R., 2009. Dietary carbohydrates and amino acids influence oocyte quality in dairy heifers. Reproduction, Fertililty and Development, 21, 419–427.Google Scholar
- Velázquez, R.L.E., Fregoso, A.C., López, O.R., Hernández, C.J., 2011. Estrous response and conception rate in postpartum Bostaurus-Bosindicuscows, treated with bovine somatotropinin an ovulation induction program with progestogens and eCG. Veterinaria México, 42(3), 245–251.Google Scholar