169 Superovulatory response and embryo production following administration of recombinant FSH (bscFSH-r) in dairy and beef cattle
F. Navarrete A , M. Gutiérrez-Reinoso A B , C. Aguilera A , J. Cabezas A , F. Castro A , M. Garcia-Herreros C , I. Cabezas A , O. Sánchez D and L. Rodríguez-Alvarez AA Universidad de Concepción (UdeC), Chillán, Chile
B Universidad Técnica de Cotopaxi (UTC), Latacunga, Ecuador
C Instituto Nacional de Investigação Agrária e Veterinária (INIAV), Santarem, Portugal
D Centro de Biotecnología y Biomedicina Spa (CBB), Concepción, Chile
Reproduction, Fertility and Development 34(2) 323-323 https://doi.org/10.1071/RDv34n2Ab169
Published: 7 December 2021
© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
A single-chain recombinant bovine FSH (bscFSH-r) gene sequence variant was designed using Bos taurus α and β chains linked through a flexible spacer peptide with 6 N-glycosylation sites. The objective was to evaluate bscFSH-r in superovulation (SOV) of two age classes of dairy and beef cattle. A total of 40 non-lactating cattle (BC: 3–3.5) were divided into four groups (Holstein heifers (HH; n = 10); Holstein cows (HC; n = 10); Red Angus heifers (RAH; n = 10), and Red Angus cows (RAC; n = 10)). Heifers were ∼20 months of age and received a total of 150 µg of bscFSH-r, whereas cows were ∼60 months of age and received a total of 200 µg of bscFSH-r. The SOV protocol was as follows. Day 0: intravaginal progesterone device (CIDR: 1.38 g) + 2.5 mg of oestradiol benzoate and 100 mg of progesterone (IM); Day 4: bscFSH-r once daily in decreasing doses over 4 days; Day 6: third bscFSH-r dose + 500 µg of D-cloprostenol (AM and PM); Day 7: fourth bscFSH-r dose + CIDR removal (AM). Ovarian structures (follicles and corpora lutea) were recorded by ultrasonography at the time of insemination and ova/embryo recovery 7 days later. Data were analysed by GLMM (SPSS® 25, IBM Corp.). Overall, ovarian and embryo-derived parameters were greater in cows than in heifers, irrespective of the breed (P < 0.05). Total follicles, corpora lutea, total recovered structures, and grade 1 embryos were greater in RAC (17.7 ± 6.2, 16.3 ± 6.0, 13.4 ± 4.8, and 11.0 ± 3.9, respectively) than in RAH (9.0 ± 4.5, 7.9 ± 4.0, 7.5 ± 3.8, and 6.9 ± 3.9, respectively) and HH (15.8 ± 5.1, 11.0 ± 4.6, 8.3 ± 5.3, and 5.3 ± 2.6, respectively); generally, HC (14.7 ± 3.5, 13.3 ± 2.9, 12.1 ± 2.8, and 9.6 ± 2.7, respectively) were intermediate. There were more degenerate embryos and nonovulated follicles in Holsteins than in Red Angus (P < 0.05), but there were no differences between cows and heifers. However, numbers of degenerate embryos were greater in HH than in RAH (P < 0.05). Numbers of nonovulated follicles were greater in HH than in HC, RAH, or RAC (P < 0.001). There were no differences between breeds for other ovarian or embryo-derived parameters (P > 0.05). In summary, bscFSH-r was efficacious in inducing superovulation in dairy and beef cattle; differences were observed in ovarian response and embryo production traits between breeds and ages. Although these differences may be related to age, intrinsic genetic factors may play an important role because all individuals were subjected to the same SOV protocol.
This research was partially supported by Fondef ID18I10082-ANID 21201280.
