Two decades of sperm sex-sorting in animals: A comprehensive systematic review and meta-analysis of techniques, effectiveness, and global research trends (2005

Vet World Vol.18 December-2025 Article - 25

Research Article

Veterinary World, 18(12): 4009-4024

https://doi.org/10.14202/vetworld.2025.4009-4024

Two decades of sperm sex-sorting in animals: A comprehensive systematic review and meta-analysis of techniques, effectiveness, and global research trends (2005–2025)

Thatawat Yodrug¹

, Orachun Hayakijkosol²

, and Tuempong Wongtawan^1,3

1. Animal Innovation Research Group, Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat 80160, Thailand.

2. College of Science and Engineering, Academy Division, James Cook University, Queensland, Australia.

3. Centre for One Health, Walailak University, Nakhon Si Thammarat 80160, Thailand.

Background and Aim: Sperm sex-sorting technologies are crucial tools for enhancing reproductive management, production efficiency, sustainability, and animal welfare. Although widely used across various species, the effectiveness of these technologies, particularly between flow cytometry and emerging alternative methods, remains inconsistently reported. This systematic review and meta-analysis examined research published worldwide over the past 20 years to compare the performance of different sperm sex-sorting techniques, evaluate pregnancy outcomes and offspring sex ratios, and identify research trends, limitations, and knowledge gaps.

Materials and Methods: A thorough search of PubMed, Scopus, and Google Scholar identified studies published from 2005 to 2025. Ninety-one studies met the criteria for systematic review, and 22 were included in the quantitative synthesis. Data extraction included species, sex-sorting method, experimental design, sperm quality parameters, pregnancy outcomes, and female-offspring proportions. Random-effects proportional meta-analyses were conducted for pregnancy rate and sex-ratio outcomes. Heterogeneity was assessed using I², Tau², and H², while publication bias was evaluated with funnel plots and Egger’s/Begg’s tests.

Results: Flow cytometry was the most widely used method (64 studies), especially in North America, while research in Asia focused more on alternative techniques such as antibody-based sorting, centrifugation, modified buffers, magnetic beads, and microfluidics. Meta-analysis of in vivo studies showed an overall pregnancy rate of 46.47% for flow cytometry, with significant differences among cattle, buffalo, and deer. Centrifugation-based methods had a higher pooled pregnancy rate of 66.49%, though this was based on only three studies. The overall proportion of female offspring after flow-sorting across all species was 81.72%, with cattle reaching 84.40%. Significant heterogeneity was present (I² > 73%), but no publication bias was found.

Conclusion: Flow cytometry remains the global gold standard for sperm sex-sorting, offering high accuracy, but it is limited by cost, technical requirements, and reduced accessibility in developing regions. Growing research activity in Asia highlights increasing interest in alternative, low-cost methods; however, in vivo validation remains limited. Future efforts should focus on large-scale field trials, standardized protocols, comparative studies with unsorted semen, and expanded research across species, including wildlife, to improve practical applicability, sustainability, and One Health benefits.

Keywords: assisted reproduction, centrifugation, flow cytometry, livestock production, magnetic beads, microfluidics, offspring sex-ratio, One Health, pregnancy rate, sperm sex-sorting.

How to cite this article: Yodrug T, Hayakijkosol O, and Wongtawan T (2025) Two decades of sperm sex-sorting in animals: A comprehensive systematic review and meta-analysis of techniques, effectiveness, and global research trends (2005–2025), Veterinary World, 19(1): 4009–4024.

Received: 12-08-2025 Accepted: 21-11-2025 Published online: 23-12-2025

Corresponding author: Tuempong Wongtawan E-mail: tuempong.wo@mail.wu.ac.th

DOI: 10.14202/vetworld.2025.4009-4024

Copyright: Yodrug, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.