New technologies for testicular
and semen assessment
György Gábor
Research Institute For Animal Breeding and Nutrition
HERCEGHALOM, HUNGARY
Introduction
The aim of the examinations is:
• to determine if ultrasonic echotexture is associated with
semen production of bulls and boars
• to select those young bulls which are certainly not useful for
the AI before the semen examination
• check semen quality by an objective instrument method (dog,
bull, boar, ram)
• develop a bull andrological data base
Material and Methods
• Examined animals:
•
•
•
H-F AI bulls 6-18 months of age in several examinations between 1998
and 2000
breeding boars (different breeds) 10-60 months of age between 19982000
breeding male dogs (different breeds) 14-86 months of age between
1999-2000
• Morphological examinations:
•
scrotal circumference (SC): Coulter scrotal tape (bulls)
•
scrotal form: digital camera (bulls, boars; storing format: jpg)
•
testicular consistency (Consitest electronic tonometer; bull, boar)
Coulter Scrotal Tape
Scrotal forms (bulls)
Scrotal forms (boars)
Examination of the testicular
echotexture (bull, boar, dog)
• The ultrasonic examination of the testes was done with a Bmode scanner (Pie Medical, Model 100 LC VET) with an 8
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 (except with dogs).
• At approximately 0.8 kg/cm2 pressure a spring-loaded
switch was compressed. At that instance, the ultrasound
image was frozen on the scanner and the image was stored.
Examination of the ET by the help of an
electronic (auto image freezing function)
transducer’s holder
Consitest electronic tonometer
(bull, boar)
• The spring loaded measuring heads use
1500 grams of pressure at all times.
Because of the difference in dimension
of the two heads (1:3), the penetration to
the observed tissue will be different.
The transmission changes from a linear
movement to a circular movement. A
rotating code disk interrupts the infrared
light, which counts the impulses for the
microprocessor, which then summarizes
the results and presents it on the display.
Evaluation of the echotexture
(ET) by Scanner 100
left testis
right testis
• The ultrasonic images of left and right testicles are recorded on
disk. The average gray level were characterized on a 256 gray
scale: 0 (dark) and 255 (light).
TesTracto software (developed for the
data base) was used for the evaluation of
the ultrasonic ET
New New development of the software:
distribution evaluation of the gray levels
Ultrasonic examination of the
prostate in dogs
Diameter:>5.5 cm
Echodenz spot
Echo poor area
Semen samples and evaluation
• Samples:
• fresh: boar
• frozen: bull, dog
• Evaluation:
• the total number of spermatozoa per ejaculate (TNS),
the percentage of the live and motile spermatozoa by
CASPAR software (Makler chamber was used to keep
the 10 mm depth)
Using CASPAR for the semen evaluation
Statistical analysis
• Mean values and Person correlation
coefficients
• true positive and negative diagnosis
• false positive and negative diagnosis
• positive prediction value
Results
1. Morphological and semen (CASA) data
BULL (n=25) BOAR (n=14)
Age (mo)
14.0 ± 2.7
12.3 ± 4.7
SC (cm)
32.9 ± 4.1
-
TM (mm)
4.9 ± 1.2
7.2 ± 1.4
ET (0-255)
44.7 ± 18.0
56.3 ± 6.0
Live %
71.0 ± 10.8
79.0 ± 10.2
Linear %
68.0 ± 8.6
47.3 ± 11.6
Speed (mm/s)
96.9 ± 10.9
50.7 ± 7.8
-
6.1 ± 1.0
Scrotal skin
(mm)
2. Correlation coefficients and probabilities
BULL
BOAR
Age vs. ET
-0.12 (NS)*
-0.81 (P<0.001)
Age vs. SC
0.87 (P<0.001)
-
Age vs. Live %
0.45 (P=0.02)
0.30 (NS)
SC vs. Live %
0.49 (P=0.01)
-
ET vs. Live %
-0.46 (P=0.02)
-0.37 (NS)
ET vs. Scrotal skin
-
-0.81 (P<0.001)
TM vs. Scrotal skin
-
0.37 (NS)
-0.23**(NS)
0.40 (NS)
TM vs. Live %
Usually around -0.50, significant
** Usually it’s a positive, significant correlation
*
3. Correlation coefficients and probabilities for H-F bulls
with visually examined semen data (n=88)
SC
AGE 0.6453
0.0000
SC
1.0000
0.0000
ET
0.2772
0.0093
TM
0.5287
0.0000
SV
0.3719
0.0004
SD
0.0519
0.6333
TSN 0.3390
0.0013
LIVE 0.4051
0.0001
ET
TM
SV
-0.3921 0.3558 0.5574
0.0003 0.0007 0.0000
0.2772 0.5287 0.3719
0.0093 0.0000 0.0004
1.0000 0.7014 -0.0895
0.0000 0.0000 0.4098
0.7014 1.0000 0.1312
0.0000 0.0000 0.2257
-0.0895 0.1312 1.0000
0.4098 0.2257 0.0000
-0.0407 -0.1184 0.2466
0.7084 0.2748 0.0213
-0.0865 0.0450 0.8822
0.4259 0.6787 0.0000
-0.0666 0.0485 0.5059
0.5398 0.6555 0.0000
SD
TSN
LIVE
-0.1767 0.3887 0.3557
0.1016 0.0002 0.0007
0.0519 0.3390 0.4051
0.6333 0.0013 0.0001
-0.0407 -0.0865 -0.0666
0.7084 0.4259 0.5398
-0.1184 0.0450 0.0485
0.2748 0.6787 0.6555
0.2466 0.8822 0.5059
0.0213 0.0000 0.0000
1.0000 0.5136 0.1965
0.0000 0.0000 0.0681
0.5136 1.0000 0.5325
0.0000 0.0000 0.0000
0.1965 0.5325 1.0000
0.0681 0.0000 0.0000
4. Categories of diagnosis (just for bulls)
* Based on SC, ET and TM. Examination of the
bulls was performed at least 2 months prior to the
semen production.
* Semen was measured for at least 2 months after
the beginning of the semen production: SV, SD,
TSN
• NP - No predicted semen production problem
• PP - Possible predicted semen production problem
• NUAI - Prediction: not useful as a breeding bull
5. Prediction results in 1998
NP
PP
UAI
Number of DG
49
41
4
Correct DG
47
22
4
Incorrect DG
2
19
0
Sensitivity
0.71
Specificity
0.94
Positive prediction
value
Negative
prediction value
0.61
0.96
6. Prediction results in 1999
NP
PP
UAI
Number of DG
42
52
3
Correct DG
39
35
3
Incorrect DG
3
17
0
Sensitivity
0.69
Specificity
0.93
Positive prediction
value
Negative
prediction value
0.69
0.93
Possible reasons of the incorrect predictions
Calcification. Dg.: PP
normal semen production
6 months later
Small SC (20 cm at 8 months of age
normal SC size (32 cm) and semen
production4 months later
Possible reasons of the rejection
Cryptorchidism
Left testis: orchitis
right testis: fibrosis
Results of the dog semen freezing
Examined dog
Semen collection
Oligospermia
Aspermia
Freezing
Good quality of thawed semen
17
14
3
2
11
8
Conclusions
• The morphological parameters (SC and ET,
possibly TM) of testis and scrotum reflect
semen measurement.
• Andrological data bases for males help define
the “gold standards” of these markers at
different age levels prior to semen production
and assist in identifying young bulls which are
not useful to the AI industry.