Testicular measurements and reproductive characteristics in stallions.
Abstract: Factors affecting testicular measurements in situ and the relationships among the measurements and various reproductive characteristics were studied using data from 48 stallions. Mean values during the breeding season are provided for scrotal width, widths and lengths of individual testes, combined weight of testicular parenchyma, daily sperm production and daily sperm output. Testicular measurements were highly repeatable from day to day and for repeated measurements on a given day; technician provided the largest source of variation in the measurements of a given stallion. Age significantly affected all testicular measurements; testicular size for 2- to 3-year-old stallions did not differ (P greater than 0.05) from that for 4- to 6-year-olds, but was smaller (P less than 0.05) than testicular size of stallions greater than or equal to 7 years old. Scrotal width was correlated (P less than 0.01) with daily sperm production (r = 0.75) and daily sperm output (r = 0.55) and was generally the most repeatable measurement.
Publication Date: 1979-01-01 PubMed ID: 289781
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- Journal Article
Summary
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This study investigates the various elements that influence testicular measurements in stallions, analysing the link between these measurements and diverse reproductive features.
Study Overview
- The research involved studying data collected from 48 stallions to identify factors that affected testicular measurements in situ (in their natural position).
- The aim was also to understand the correlation between these measurements and various reproductive characteristics of the stallions.
- The study provided mean values for several parameters during the breeding season, such as scrotal width, widths and lengths of testes, combined weight of testicular parenchyma (the functional tissue in the testes), daily sperm production, and daily sperm output.
Key Findings
- The researchers found out that testicular measurements were consistent from day-to-day and even with repeated measurements taken on the same day.
- It was observed that the largest source of variation in the measurements for a given stallion was the technician performing the measurement.
- The study revealed the significant influence of the stallion’s age on all testicular measurements. Stallions between the ages of 2 and 3, and those between 4 and 6 had similar testicular sizes. However, the testicular size of stallions aged 7 or above was significantly larger.
- The study found that scrotal width was significantly correlated with daily sperm production and output, with correlation coefficients of 0.75 and 0.55, respectively. This measurement was also found to be the most repeatable, meaning it showed the least variation across different measurement points.
Implications of the Study
- This study provides crucial information for understanding the reproductive characteristics of stallions.
- By identifying the factors influencing testicular measurements, it could help in developing better management practices in horse breeding.
- Understanding the relation between reproductive characteristics and testicular measurements might eventually lead to more predictable breeding outcomes.
Cite This Article
APA
Thompson DL, Pickett BW, Squires EL, Amann RP.
(1979).
Testicular measurements and reproductive characteristics in stallions.
J Reprod Fertil Suppl(27), 13-17.
Publication
Researcher Affiliations
MeSH Terms
- Aging
- Animals
- Functional Laterality
- Horses / anatomy & histology
- Horses / physiology
- Male
- Reproduction
- Sperm Count
- Spermatogenesis
- Testis / anatomy & histology
Citations
This article has been cited 7 times.- Martins-Bessa A, Quaresma M, Leiva B, Calado A, Navas González FJ. Bayesian Linear Regression Modelling for Sperm Quality Parameters Using Age, Body Weight, Testicular Morphometry, and Combined Biometric Indices in Donkeys. Animals (Basel) 2021 Jan 13;11(1).
- Toishi Y, Tsunoda N, Nagata SI, Kirisawa R, Nagaoka K, Watanabe G, Yanagawa Y, Katagiri S, Taya K. Evaluation of the chemiluminescent enzyme immunoassay system for the measurement of testosterone in the serum and whole blood of stallions. J Reprod Dev 2018 Feb 27;64(1):41-47.
- Abraham MC, Puhakka J, Ruete A, Al-Essawe EM, de Verdier K, Morrell JM, Båge R. Testicular length as an indicator of the onset of sperm production in alpacas under Swedish conditions. Acta Vet Scand 2016 Feb 2;58:10.
- Fayrer-Hosken R, Stanley A, Hill N, Heusner G, Christian M, De La Fuente R, Baumann C, Jones L. Effect of feeding fescue seed containing ergot alkaloid toxins on stallion spermatogenesis and sperm cells. Reprod Domest Anim 2012 Dec;47(6):1017-26.
- Koskinen E, Andersson M, Katila T. Effect of 19-norandrostenololylaurate on testicular growth in colts. Acta Vet Scand 1997;38(1):51-7.
- Pitnick S, Markow TA. Large-male advantages associated with costs of sperm production in Drosophila hydei, a species with giant sperm. Proc Natl Acad Sci U S A 1994 Sep 27;91(20):9277-81.
- Folgmann MS, Stock KF, Feige K, Delling U. Clinical findings of candidate stallions presented for licensing at all German Warmblood horse-breeding associations in 2018-2020. Equine Vet J 2025 Nov;57(6):1584-1591.
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