Evidence map›Paper›PMID 40028825›Full record

ArticleReproduction in domestic animals = Zuchthygiene2025

The Percentage of Normal Sperm Declines in Consecutively Collected Ejaculates of Ram Semen.

Katherine R Seymour, Jessica P Rickard, Simon P de Graaf

Abstract read
In one paragraph

Article in Reproduction in domestic animals = Zuchthygiene, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Katherine R SeymourSchool of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia.ORCID https://orcid.org/0009-0000-8010-6750
Jessica P RickardSchool of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia.
Simon P de GraafSchool of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Sperm morphology is an important marker of fertility in livestock. Since poor sperm morphology can disqualify a sire from being sold or used for breeding, it is crucial to understand the factors that influence changes in sperm morphology over time. It is often hypothesised that little variation exists in sperm morphology from ejaculate to ejaculate so long as factors such as nutrition, season, health, and thermal status remain the same. This study aimed to test this hypothesis by investigating the morphology of sperm collected from rams (Ovine aries) (n = 3) twice daily, three times per week, over an 8-week period. Sperm morphology was evaluated using an eight-category classification system. Results revealed that each ram exhibited high levels of variability, with only 10.4% of ejaculates within ±5% of their own mean percentage normal sperm (PNS). The percentage of normal sperm over the 8-week period was significantly influenced by intra-week variation, although no consistent trend was observed across the full duration of the study. Within each day, a significant decline in the percentage of normal sperm was observed when a second ejaculate was collected consecutively. This decline was primarily attributed to an increase in cytoplasmic droplets and midpiece abnormalities. These findings suggest that rams subjected to regular semen collection in a controlled environment are likely to exhibit considerable variation in the percentage of normal sperm from ejaculate to ejaculate. For artificial breeding centres and veterinarians, repeated semen collection on the same day may reduce the proportion of normal sperm. As such, assessment of each separate ejaculate for sperm morphology is recommended before pooling for processing or insemination.

Indexed as

Semen AnalysisSheep, DomesticSpermatozoaAnimalsMaleSemenSheepadvanced semen assessmentfertilitylivestockramsperm morphology

Identifiers

PMID40028825
PMCPMC11874250

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.