Developing a tool to optimize research on antioxidants for rooster semen cryopreservation

Abstract

This study aimed to develop a tool for predicting the potential impact of research studies involving the effect of antioxidants in rooster semen freezing diluent, depending on the variables that have been studied. To achieve this, a comprehensive meta-analysis of fifty-eight research documents was performed. Sixty-two traits were sorted into four major categories: study demographics, study design-related parameters, rooster semen quality-related parameters, and fertility level indicators. The quartile determination of each research document was collected from the Journal Citation Reports database. After twenty-five testing rounds, all variables that showed multicollinearity problems were discarded from further analyses (VIF < 5). HOST, pellet volume, mass motility, light hours, and sperm concentration were the most influential traits for the classification of papers in different quartiles (Wilks’ lambda: 0.797, 0.891, 0.895, 0.896, and 0.904, respectively). The research was validated as reported in the cross-validation analysis, with 93.60% of papers being correctly classified within their group. The present research assists researchers not only in the decision-making process for journals in which to publish the outcomes of their studies, but also to seek for the inclusion of parameters which attract a wider interest for the matter from scientific readers. This leads to the optimisation of resources in studies evaluating the effect of antioxidants in poultry reproduction by identifying the most scientifically relevant variables and those which in trun will lead toa greater impact on research publications.

HIGHLIGHTS

• Using the discriminant canonical analysis, the scientific community can know which variables to take into account to achieve a greater impact in the cryopreservation studies of rooster sperm.

• The study of membrane functionality (HOST) could be a surrogate for in vivo fertility assessment as it predicts the survival rate of spermatozoa in the female reproductive tract.

• Pellet volume, mass motility, light hours for sperm-donor animals, and semen concentration have a higher discriminatory capacity for studies in different quartiles of the JCR database.

Keywords:

• Antioxidant effect
• research documents
• preservation of genetic material
• spermatozoa
• rooster

Acknowledgements

This work would not have been possible if it had not been for the assistance of the Provincial Agricultural Centre of the Cordoba Provincial Council and the PAIDI AGR 218 research group.

Ethicial Approval

The present study is out of the scope of evaluation of the Ethics review board of the University of Córdoba, as it does not fall under the legislation for the protection of animals used for scientific purposes. In these regards, the national Royal Decree Law 113/2013, of February 1, which establishes the basic rules applicable to the protection of animals used in experimentation and other scientific purposes, including teaching (Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes) states that it shall apply until the animals referred to in the first section have been sacrificed, relocated or reintegrated into a suitable habitat or zootechnical system. Hence, contextually, the reasons for this exemption are that this study involves practices that are unlikely to cause pain, suffering, distress or lasting harm equivalent to or greater than that caused by the introduction of a needle in accordance with good veterinary practice, that practices were carried out for recognized zootechnical purposes and that animals were not sacrificed because the data was collected during the application of regular zootechnical procedures at the farms where the animals are housed.

Disclosure statement

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

Data availability statement

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.

Additional information

Funding

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.