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On-line version ISSN 1678-4596
FERNANDES, Carlos Eurico and PIMENTEL, Cláudio Alves. Acrossomal abnormalities and fertility in a stallion: a case report. Cienc. Rural [online]. 1997, vol.27, n.2, pp. 345-349. ISSN 1678-4596. http://dx.doi.org/10.1590/S0103-84781997000200031.
It is described certain qualitative seminal characteristics and the fertility of a Thoroughbred stallion, during five consecutive breeding seasons (1990 a 1994). High percentages (13.6 a 39%) of abnormal acrossomes were observed in the ejaculates (N° = 15), being the majority of the "Knobbed Acrosome Defect" type (dark staining area or eccentric thickening at the apex of affected spermatozoa). The pregnancy rate (P) varied between 25 e 90% and the per cycle pregnancy (P/C) between 20 e 59%. Regression analysis showed that P/C was significantly (p<0.05) related to the percentage of abnormal acrossomes (R2=0.87). Other seminal characteristics considered in this report were not associated (P>0.05) to fertility indexes. The conclusion is that the acrossomal defect, in the present case, could be attributed to arrested spermiogenesis. Such abnormality significantly affected stallion fertility.
Keywords : stallion; acrossome; semen; fertility.