Transcript EARLY PREGNANCY DETECTION DAIRY

USE OF PREGNANCY SPECIFIC PROTEIN B
TEST FOR PREGNANCY DIAGNOSIS AND
ASSESMENT OF BULL FERTILITY
G. Gábor, F. Tóth, N. Solymosi
C ha ng e o f pa rturitio n inte rv a l in c o ntro lle d he rds
in H ung a ry be twe e n 1 9 7 0 - 2 0 0 2
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d
PSPB is a novel protein that was first reported by
scientists at the University of Idaho. PSPB is located in
the giant binucleate cells of the trophoblastic ectoderm
of the placenta and this indicated that it was either
synthesized or sequestered by those cells.
Caruncle
Cotyledon
Migration of these cells result the appearance of
PSPB in the maternal circulation.
Bi-Nucleated
Cells
Placenta
Uterus
PSPB in
Circulation
PSPB ng/mL
•PSPB is detectable in serum from 24 to 282
(parturition) days of gestation and can be
applied reliably in dairy cow herds at 28 to
30 days after breading.
Parturition
Days post breeding
• The PSPB was found in sera of some primiparous
cows as early as 15 days following conception and
in sera of most cows at 24 days following
conception.
• Complete clearence of the protein from blood may
not occur until 80 to 100 days after parturition. For
this reason testing of blood for a new pregnancy
following parturition may give false positive tests.
• An ELISA test (BioPryn™ by BioTracking LLC)
has been developed for the examination of the
PSPB in cattle 30 days after AI (at least 90 days
after the previous parturition).
Biopryn ELISA test – color reaction
Biopryn ELISA test – stop color reaction
OBJECTIVES
Decreasing of the parturition interval and checking bull fertility are both important
issues in dairies. Measuring of Pregnancy Specific Protein B (early
pregnancy detection) appears to be a useful tool assess the true fertility of
breeding bulls.
The objectives were:
•
to verify the BioPRYN™ test is adapted method for pregnancy
detection in cattle.
•
to determine the sensitivity of the BioPRYN™ test and compare with
the sensitivity of the ultrasonic examination.
•
to define the practicability of PSPB test in Hungarian field and in
monitored circumstances.
•
to exam the reliability of PSPB test for the bull fertility.
•
checking the prediction value of PSPB test for the embryonic loss.
METHODS
Experiment 1
No. of cows
69
No. of farms
1
• The cows were examined by rectal ultrasonography
between 29 and 55 days after AI. Blood samples were
taken at the same time and were assayed for PSPB
with BioPRYN™ when all the samples has been
collected.
Experiment 2
No. of cows
336
No. of farms
1
• In Experiment 3, blood samples were assayed
with BioPRYN™ for early pregnancy detection
(30-36 days after AI) in 306 Holstein-Friesian and
30 Hungarian Fleckvieh cows. Confirmation was
done by rectal ultrasonography one day after the
blood collection.
Ultrasonic appearance of the bovine fetus at
different stages of the pregnancy
Experiment 3
No. of cows
1742
No. of farms
23
• AI’s were carried out in 23 dairies and blood was
drawn from 30 to 36 days after AI and assayed for
early pregnancy by BioPRYN™. To confirm the
pregnancy diagnosis, rectal palpation was done on
the farms at 60 days after AI.
Experiment 4
No. of bulls
8
No. of AI: 816
No. of farms
3
Semen was collected from the 8 bulls and (61-139
inseminations per bull) AI’s were carried out in 3 dairies.
Blood was drawn from 30 to 36 days after AI and assayed
for early pregnancy by BioPRYN™. To confirm the
pregnancy diagnosis, rectal palpation was done on the
farms at 60 days after AI.
RECENT EXPERIMENTS
• Routinely collected blood sample from 3 farms for
almost 1 year, and checking pregnancy status by
PSPB test 30-36 days after AI. Open cows and cows
with low OD of PSPB (range: ±10 % of cutoff)
were assayed for serum P4.
• Confirmation of the pregnancy was done by rectal
palpation and the most important reproduction,
production and breeding information were also
collected in a data base.
RESULTS
Distribution of Optical Density (OD)
0.6
0.5
0.4
OD
0.3
Series1
0.2
cutoff
0.1
71
66
61
56
51
46
41
36
31
26
21
16
11
6
1
0
Experiment 1
100 % agreement was found between the serum PSPB and
ultrasonic examinations
OD values
Mean
Minimum
Maximum
Days After AI
open
pregnant open
pregnant open
pregnant
29 - 35
0.22
n= 20
0.91 0.17
n= 19
0.626 0.31
1.41
36 - 55
0.20
n= 17
0.92 0.16
n= 13
0.704 0.26
1.17
Total
0.21
n= 37
0.92 0.16
n= 32
0.63 0.31
1.41
Cutoff:
0.33
Experiment 2
Number of AI
Correct positive diagnosis
Correct negative diagnosis
Fals positive diagnosis
Fals negative diagnosis
Sensitivity
Specificity
Positive predicted value
Negative predicted value
336
152
164
20
0
100
89.1
88.4
100
Correct diagnosis: result of PSPB test corresponds with the result of ultrasonic examination. False diagnosis:
result of PSPB test differs from the result of ultrasonic examination. Sensitivity: 100*correct positive
diagnosis/correct positive diagnosis+false negative diagnosis. Specificity: 100*correct negative
diagnosis/correct negative diagnosis+false positive diagnosis. Positive predicted value: 100*correct positive
diagnosis/correct positive diagnosis+false positive diagnosis. Negative predicted value: 100*correct negative
diagnosis/correct negative diagnosis+false negative diagnosis.
Experiment 3
Number of AI
Correct positive diagnosis
Correct negative diagnosis
False positive diagnosis
False negative diagnosis
Sensitivity
Specificity
Positive predicted value
Negative predicted value
1742
772
638
292
40
95.1
68.6
72.6
94.1
Experiment 4
Bull
Pregnant
Open
Total
Emb. loss %
Z
85
9
94
9.6
G
73
10
83
12.0
S
111
18
129
14.0
F
119
20
139
14.4
W
99
18
117
15.4
T
61
12
73
16.4
V
50
11
61
18.0
R
97
23
120
19.2
TOTAL:
695
121
816
14.8
Mean
Prediction of the embryonic loss by
Biopryn and serum P4 (I. total loss)
Number of pregnancies
2081
Predicted embryonic loss
206
True embryonic loss
101
49.03%
Non predicted loss
239
12.75%
Total embryonic loss
340
16.33%
Prediction of the embryonic loss by
Biopryn and serum P4
(II. Based on serum P4 level)
Serum P4 level groups
True
embryonic
loss
False
embryonic
loss
High P4 serum level (>4
ng/ml)
27
50
Medium P4 serum level (2-4
ng/ml)
41
42
Low P4 serum level (<2
ng/ml)
33
13
Prediction of the embryonic loss by
Biopryn and serum P4
(III. based on milk production)
Group
(kg
milk)
Age
(year)
Day
after
calving
No.
cows
No.
calving
Milk
(kg)
Embr.
loss%
0-20
232
2.4
15.5
4.3
211.8
12.93
20-30
735
2.1
25.4
3.8
157.5
14.69
30-40
853
2.3
34.2
3.9
125.5
17.47
40-50
248
2.7
44.1
4.3
100.8
20.56
Prediction of the embryonic loss by
Biopryn and serum P4
(IV. Based on loss of AI bull groups)
Category (loss of AI bulls)
No.
bulls Pregnancies Pregnant Open
0-10 % (mean: 2.9 %)
6
172
167
5
10-20 % (mean: 14.7 %)
15
712
607
105
>20 % (23.3 %)
11
545
418
127
Total
32
1429
1192
237
Prediction of the embryonic loss by Biopryn and
serum P4 (V. based on the loss of offspring)
Group (loss%) father bulls
0-10 %
10-20 %
> 20 %
Total
Bulls
27
27
31
85
Examined
374
497
509
1380
Pregnant cows
13.1
15.7
12.7
Open cows
0.8
2.7
4.3
Non predicted loss
0.4
1.8
3.0
Predicted loss
1.1
1.8
2.1
True loss
0.4
0.9
1.3
Parturition /cow
1.9
2.2
2.4
AI /cow
2.7
2.5
2.7
Day after calving
148.5
135.7
142.5
Milk kg/cow
28.9
30.8
31.2
Age (year)
3.5
3.9
4.1
Embryonic loss %
4.1
14.2
26.5
The two highly controlled experiments (1 and
3) show that BioPRYN™ was an excellent
test for pregnancy detection, that’s why
BioPRYN™ test for PSPB is a practical and
safe system for pregnancy detection in
cattle.
• It looks also useful to check the real bull
fertility.
• It may have a role (combining with the
control of the serum P4 level) in prediction
of the embryonic loss as well.