Insemination timing influences reproductive performance rather than eCG (Equine Chorionic Gonadotropin) or synchronisation protocol in Murciano-Granadina does

Abstract

Counteracting goat reproduction seasonality and ensuring acceptable fertility rates are critical points of the success of selection of synchronisation protocols. The present study aims to investigate the factors that affect the performance of specific protocols to increase the probability of pregnancy results in the Murciano-Granadina breed within the official breeding program and way in which such factors interrelate. This study evaluated 11,008 artificial inseminations carried out between 2010 and 2013, using three different synchronisation protocols and eCG combinations. A categorical regression model (CATREG) was used to determine the impact of farm, doe age, birth number, kidding type, kid number, number of alive and dead born kids, synchronisation protocol, kidding month, type of semen, kidding season, eCG concentration, and their inter-actions. Results indicated that all variables, except for the number of alive and dead kids and semen type, significantly (p < 0.05) contributed to explaining the variability in pregnancy rates. Conclusively, rather than the role of eCG levels and artificial insemination (AI) protocol separately, Farm x eCG x AI Protocol interaction and the multifactorial influences on pregnancy rates should be considered when selecting does for insemination to maximise the outcomes of reproductive performance.

HIGHLIGHTS

• Farm × eCG × AI Protocol interaction and the multifactorial influences on pregnancy rates should be considered when selecting does for insemination

• Main factors to take into account would be those related to seasonality (kidding month, IA season), and also birth type

• It would be necessary adjust protocols (short term protocols has shown to have higher fertility) and eCG dosage for each farm

Keywords:

• Does
• fertility
• Murciano-Granadina breed
• synchronization protocol

Acknowledgements

The authors would like to acknowledge to the National Association of Breeders of Murciano-Granadina Goat Breed and to the Andalusian goat selection and improvement center (Fuente Vaqueros, Granada, Spain).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

The study followed the premises described in the Declaration of Helsinki. The Spanish Ministry of Economy and Competitivity through the Royal Decree-Law 53/2013 and its credited entity the Ethics Committee of Animal Experimentation from the University of Córdoba permitted the application of the protocols present in this study as cited in the fifth section of its second article, as the animals assessed were used for credited zootechnical use. This national Decree follows the European Union Directive 2010/63/UE, from the 22nd of September of 2010. Furthermore, the present study works with records rather than live animals directly, and these records were obtained after minimal handling, hence no special permission was compulsory.

Data availability statement

Data will be made available from the corresponding author F.J.N.G. upon reasonable request.

Additional information

Funding

Funding was not received for the development of the present study. The present research was carried out during the covering period of a Ramón y Cajal Post-Doctoral Contract with the reference MCIN/AEI/10.13039/501100011033 and the European Union “NextGenerationEU”/PRTR.