Removal of bacteria from stallion semen by colloid centrifugation

J. M. Morrell, C. Klein, N. Lundeheim, E. Erol, M. H.T. Troedsson

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


Bacteria (environmental contaminants and occasionally potential pathogens) are found in most stallion ejaculates and may negatively affect sperm quality during storage. Since the use of antibiotics can lead to the development of resistance, an alternative means of microbial control is desirable. The removal of bacteria from stallion semen using Single Layer Centrifugation through Androcoll-E was investigated. Known doses of cultured bacteria were added to freshly collected ejaculates (15mL aliquots) before processing by Single Layer Centrifugation. The resulting sperm pellets and controls (not processed by Single Layer Centrifugation) were cultured and the bacteria identified. In experiment 1, doses of E. coli from 2×102 to 2×107 colony forming units were added to aliquots of semen. In experiment 2, Taylorella equigenitalis or a mix of E. coli, Klebsiella pneumoniae and Streptococcus equi subsp. zooepidemicus (approximately 7×106, 5×106, and 6×106cfu, respectively) were added to 15mL aliquots of semen. In experiment 1, more than 90% of the bacteria were removed where loading doses were >×104cfu/mL. In experiment 2, varying proportions of different bacteria were removed, ranging from 68% for naturally occurring Corynebacterium spp. to >97% for added cultured E. coli. Thus, Single Layer Centrifugation can separate spermatozoa from many, but not all bacteria in stallion ejaculates and could be a useful alternative to adding antibiotics to semen extenders to control bacterial contamination. However, further research is needed to determine the effect of small numbers of bacteria on sperm quality.

Original languageEnglish
Pages (from-to)47-53
Number of pages7
JournalAnimal Reproduction Science
Issue number1-2
StatePublished - Feb 2014

Bibliographical note

Funding Information:
We thank the farm personnel, Department of Veterinary Science for the management of the stallions and for facilitating semen collection. The study was financed by a travel fellowship from the Swedish Research Council for the environment, agricultural sciences and spatial planning (FORMAS) and by the Albert and Lorraine Clay Fellowship Endowment Fund . The funding bodies played no part in the study design, in the collection, analysis and interpretation of data, in the writing of the report, or in the decision to submit the article for publication

Copyright 2014 Elsevier B.V., All rights reserved.


  • Androcoll-E
  • Contaminating bacteria
  • Pathogens
  • SLC

ASJC Scopus subject areas

  • Food Animals
  • Animal Science and Zoology
  • Endocrinology


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