Echographic and thermographic examination of bull testis

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Echographic and thermographic examination of bull
testis

• György Gábor, DVM, Ph.D senior scientist
• Res. Inst. For Animal Breeding and Nutr.
• HERCEGHALOM, HUNGARY

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Introduction

• The aim of these examinations
• to determine if ultrasonic echotexture and
  endocrine status is associated with semen
  production of bulls
• to determine the change in scrotal surface
  temperature (SST) after GnRH treatment
• to select those young bulls which are certainly
  not useful for the AI before the semen examination

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Material and Methods

• Experimental animals
• H-F AI bulls 6-79 months of age in several
  examinations between 1994 and 1997
• Morphological examinations
• scrotal circumference (SC) Coulter scrotal tape
• scrotal width (SCW) and and length (SCL)
• 1. digitalization of the video image capture
  card
• 2. evaluation of the video image Testigabsas
  software

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Coulter Scrotal Tape
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Evaluation of the video image (Testigabsas
software)
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Examination of echotexture 1.

• The ultrasonic examination of the testes was done
  with a B-mode scanner (Pie Medical, Model 450)
  with a 7.5 MHz linear-array transducer. Gain was
  held constant for all examinations.
• The transducer was aligned at the center of each
  testis and perpendicular to the vertical axis. A
  custom, electromechanical device for holding the
  probe was used to assure that the same pressure
  was applied by the probe against tissues upon
  which liberal amounts of ultrasound coupling gel
  had been applied.
• At approximately 0.76 kg/cm2 pressure, an
  indicator lamp lighted as a spring-loaded switch
  was compressed. At that instance the
  ultrasound-image was frozen on the scanner
  console and the image was captured and stored.

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The custom electromechanical device
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Examination of echotexture 2.(Testigabsas
software)

• Image analysis was used for the evaluation of
  ultrasonic images. The ultrasonic images of left
  and right testes are aligned and recorded on the
  left panel. After making a distance-calibration
  an examination area (box) was created (6.5 x 1.0
  cm, area 6.5 cm2). The box was moved to the
  surface of the testicular tissue just under the
  scrotal skin and fat (white area). The average
  gray level (termed echotexture) and a histogram
  of the different gray levels (right panel) of the
  examined area were presented immediately. The
  bar below the histogram is of gray levels with
  zero on the left (dark) and 64 on the right
  (light). All of the nominal values were saved
  into a data file.

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Examination of the scrotal surface temperature
(SST)

• An im injection of 100 µg GnRH was administered.
  The SST was measured before and 45 min. after
  treatment. An AGEMA 880 LWB infrared
  thermography camera was used.
• Thermograms were stored on a computer, and
  subsequently analyzed with Irwin2 image analysis
  software. The SST at the top of the scrotum
  (SSTTOP) and the SST at the bottom of scrotum
  (SSTBOT) were measured, using a line one pixel
  high and the width of the scrotum.

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Semen collection and evaluation

• Collection by artificial vagina, twice a week.
• Evaluation
• the total number of spermatozoa per ejaculate
  (TNS), the percentage of the live and motile
  spermatozoa
• by
• HTM motility analyzer
• or
• visual analysis

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Endocrine measures

• Serum testosterone concentration
• Blood samples were collected just before and 90
  min after GnRH treatment. Samples were
  centrifuged and plasma frozen pending
  determination of plasma testosterone
  concentration by 3H radioimmunoassay. The
  sensitivity of the assay was 0.3 nmol and the
  intra- and inter-assay coefficients of variation
  were 7.1 and 11.7, respectively.

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RESULTS

• Morphological examinations
• - SC is a highly repeatable measure
• r0.75-0.95 Plt0.0001
• - examination of the video image has a
• lower repeatability
• SCL r0.25-0.54
• SCW r0.42-0.88
• CONCLUSION using of SC is recommended

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Testicular echotexture 1

• Relatively high repeatability in both, young and
  older bulls
• r0.53-0.86 Plt0.01-0.001
• Good correlation with the total number of
  spermatozoa per ejaculate in young bulls
• r between -0.29 and -0.70
• P between 0.001 and 0.11

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Testicular echotexture 2
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Testicular echotexture 3

• A lower echotexture suggests a greater
  seminiferous tubule lumenal space and fluid
  content within the examined area of the
  testicular parenchyma. Older bulls expected to
  have greater seminiferous tubule activity, have a
  lower echotexture. Amount of blood content could
  also play a role.
• CONCLUSION
• Echotexture probably useful on practical level
  to predict semen production in young (12-36
  months) bulls. The highly significant negative
  correlation between echotexture and TSN supports
  this concept. However in older bulls (60-79
  months), there was no correlation with TSN and
  echotexture.

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Change of SST after GnRH challenge 1

• Thermal (SST, oC) data of 20 older bulls
  measured with 30 days interval
• Ambient 10 oC 20 oC 26 oC
• Correlation
• 1 2 3 1-2 2-3
  1-3
• TOP 1 33.7 .1 34.8 .2 36.4 .1 .28
  .49b .21
• TOP 2 35.1 .1 35.1 .2 36.3 .2 .39
  .59b .35
• TOP D 1.44 .1 .40 .1 -.10 .2
  -.09 .49b .08
• BOT 1 30.4 .2 30.8 .2 33.1 .2
  .31 .56b .35
• BOT 2 32.2 .2 31.5 .2 33.4 .2
  .44a .67c .29
• BOT D 1.80 .2 .70 .2 .30 .2
  .30 .43a .38
• GRAD 1 3.3 .2 3.9 .3 3.3 .3
  .38 .56b .32
• GRAD 2 2.9 .2 3.6 .2 2.9 .2
  .43a .66b .40
• GRAD D -.37 .1 -.3 .2 -.36 .2
  .42a .53b .29

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Change of SST after GnRH challenge 2
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Change of SST after GnRH challenge 3

• SST increased following GnRH treatment.
• SST measurements (after GnRH treatment) in young
  bulls were of some value in predicting the number
  of spermatozoa that could be collected.
• However the ambient temperature has a greater
  effect on basal (pre-treatment) SST than SST
  following GnRH. These results support the
  combination of infrared thermography of SST and
  the GnRH challenge in order to decrease the
  effect of the ambient temperature.

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The original aims were

• to determine if ultrasonic echotexture and
  endocrine status are associated with semen
  production of bulls
• to determine the change in scrotal surface
  temperature (SST) after GnRH treatment
• to select those young bulls which are certainly
  not useful for the AI before the semen examination

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Replies 1

• Yes, in young bulls echotexture can be further
  optimized to improve the predictability of number
  of spermatozoa collected.
• Yes, significant regression equations were
  derived for the total number of spermatozoa in
  older bulls plasma testosterone concentrations
  were the significant independent variables
• Experiment 1 Y 5.72 0.076 Testosterone D
• Experiment 2 Y 10.37 - 0.201 Initial
  Testosterone
• Experiment 3 Y 11.30 - 0.094 GnRH induced T.

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Replies 1(cont.)
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Replies 2

• SST increased following GnRH treatment both in
  young and older bull groups.
• SST measurements (after GnRH treatment) were of
  some value in predicting the number of
  spermatozoa that could be collected.
• BUT The ambient temperature has a great effect
  on SST. Combination of infrared thermography of
  SST and the GnRH challenge could help to decrease
  the effect of the ambient temperature.

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Final conclusions

• SC, ET, and SST represent the scrotal and
  testicular characteristics referring to semen and
  endocrine measures
• An andrological data base for males (bulls) may
  help to find those markers which are the most
  typical for the selection of those young bulls
  before the semen examination which are certainly
  not useful for the AI.

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The future.

• New devices or improvement of the old ones?

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Electronic tonometer
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A custom thermograph
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My right hand with the Computherm 1000