[Morphology of live and dead spermatozoa of stallions (author’s transl)].

The research study analyzed 539 stallion ejaculates to determine the morphology and vitality of the sperm, finding that approximately 60% of the sperm were normal and 75% were alive, with a slight increase in abnormality as the animals aged.

Study Overview

• The study involved the examination of 539 ejaculates from stallions of various breeds to understand the vitality (live/dead) and morphological (normal/abnormal) state of the sperm in the ejaculates. The focus was on how these states change with the age of the stallions.

Findings

• About 60% of the sperm were found to be morphologically normal, of which 13% were dead.
• Overall, 75% of the sperm were alive. However, 32% of these live sperm were noticeably abnormal, with 22% of this abnormality rate attributable to the live sperm and 10% to the dead sperm.
• Sperm with separated heads (both normal and abnormal) were significantly more common among dead sperm as opposed to live sperm.
• Protoplasmic droplets, which were mainly present in live sperm, were found at the neck and at the end of the middle piece of the sperm.

Age-related Changes

• With age, the total proportion of abnormal sperm only showed a minimal increase.
• This increase in abnormality is generally due to an increase in the number of dead, abnormal sperm, as live sperm showed a reduction in abnormal forms.
• With age, the proportions of abnormal and separated heads reduced in live sperm, while dead sperm showed a marked increase in separated heads.

Second Ejaculates

• In the case of second ejaculates, the total number of abnormal sperm reduced by an average of 4%, but there was an increase of 8% in abnormalities among live (unstained) sperm.