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Research article - Peer-reviewed, 2004

Sperm morphology in Estonian and Tori breed stallions

Kavak A, Lundeheim N, Aidnik M, Einarsson S


The standard procedure for assessing the breeding potential of a stallion includes the parameter total number of spermatozoa classified as morphologically normal. This study investigated sperm morphology of fresh semen in randomly chosen Estonian (E, n=8) and Tori (T, n=7) breed stallions with proven fertility. Two ejaculates were examined from each stallion. An aliquot from each ejaculate was fixed in 1 mL formol-saline immediately after collection and examined with phase-contrast microscope at a magnification 1000x for all types of morphological abnormalities. Furthermore smears were prepared and stained according to Williams (carbolfuchsin-eosin) for a more detailed examination of the sperm heads with light microscope at a magnification 1000x. Analysis of variance was applied to the data, and results are presented as LSmeans (+/-SE). One T stallion that had a disturbance in the spermatogenesis and one 22-year-old E stallion were not included in the analyses. The T stallions had on average 57.5+/-4.1% and the E-stallions 74.4+/-3.8% morphologically normal spermatozoa (p=0.012). In 4 of 7 T stallions and 7 of 8 E stallions both ejaculates had >50% morphologically normal spermatozoa. There was a significant difference between breeds in mean percentage of proximal droplets (17.3+/-2.7% and 2.9+/-2.5% for T and E stallions, respectively; p=0.003)


Sperm morphology; stallion

Published in

Acta Veterinaria Scandinavica
2004, volume: 45, number: 1-2, pages: 11-18

Authors' information

Swedish University of Agricultural Sciences, Department of Animal Breeding and Genetics
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Kavak, Ants
Aidnik, Madis

UKÄ Subject classification

Veterinary Science
Animal and Dairy Science

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