82 Are antibiotics still truly needed in bovine embryo collection media? A preliminary study
M. Marquet A , W. Ben Hania B , C. Thorin A , L. Guilbert-Julien B , H. Quinton C , J. Pol D , P. Escouflaire D , L. Chevrier E , J. Gard F , P. Chavatte-Palmer G and L. Briand-Amirat AA Oniris, Nantes, France
B Laboratoire National de contrôle des reproducteurs, Maisons-Alfort, France
C Evolution, Sucé sur Erdre, France
D Embryovet, Haute-Goulaine, France
E IMV Technologies, L’Aigle, France
F Auburn University College of Veterinary Medicine, Auburn, AL, USA
G INRAE, Jouy en Josas, France
Reproduction, Fertility and Development 34(2) 277-278 https://doi.org/10.1071/RDv34n2Ab82
Published: 7 December 2021
© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
The OIE (World Organisation for Animal Health) and IETS recommend the addition of antibiotics to bovine embryo collection media, but the relevance of continuing to add antibiotics in this media was asked, based on the assumption that embryos will undergo 10 baths of IETS regulatory washes with antibiotics. A preliminary study was conducted in response to this question and to the pressing demands for veterinarians to decrease the use of antibiotics. The aim of this study was therefore to evaluate whether or not the removal of antibiotics from collection media leads to an additional risk compared to the standard procedure. For this purpose, 80 Prim’Holstein donors (13 months average age) were divided into two groups, a control group, batch A: n = 40; collected with Euroflush ND with antibiotics (IMV Technologies) and a second group, batch B: n = 40; collected with Euroflush without antibiotics. The rest of the procedure was identical in both batches; the embryos underwent 10 washes containing gentamicin 0.05 g L−1 and kanamycin 0.1 g L−1. The size of this study was determined considering a logistic regression model with a probability of non-infection of 0.99 for the standard procedure (with antibiotics) and of 0.95 for the batch without antibiotics, a power of 0.8, and a significance level of 0.05. To assess the impact of the removal of antibiotics on bacterial contamination, the sample from the last wash was tested for bacterial count (a batch below 100 cfu mL−1 was considered free from pathogens), and the sample from the collection medium was tested for mycoplasma. The number of viable embryos and the quality of the embryos transferred in the two groups were compared, and the success rate of embryo transfer was also evaluated. Statistical analysis were performed using R software (R Core Team, 2020) considering a significance level of 0.05. To date only 39/80 samples have been analysed. All bacterial counts were below 100 cfu mL−1, and no mycoplasma were found in the collection media of either batch (18 samples in batch A and 21 samples in batch B). Based on the preliminary results, removal of antibiotics from the collection medium does not induce additional bacterial contamination. Furthermore, no significant differences in the number of viable embryos (n = 196, P-value = 0.42, W = 208 Wilcoxon test), nor in quality and developmental stage (n = 182, P-value = 0.09, χ2 test of independence) of the 182 transferred embryos were found between the two batches. The success rate of embryo transfers was not significantly different in either batch and was 53% (P-value = 0.84 χ2 independence test; n = 44 for batch A and n = 49 for batch B). The strict hygiene of the collection teams and the 10 washing baths supplemented with antibiotics ensured the safety of the embryos. These first results are very encouraging, but further studies are necessary to bring about an evolution of in vivo bovine embryo collection practices. The health status of the embryos must be ensured in order to sustain international trade.
