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Detection of the embryonic loss in dairy cattle
by ELISA tests György Gábor1 - Fruzsina Tóth1
László Ózsvári2 Garth Sasser3 1Research
Institute for Animal Breeding and Nutrition,
Herceghalom, Hungary, 2Faculty of Veterinary
Sciences, SZIE, Budapest, Hungary, 3Biotracking
LLC, Moscow, ID, US
Introduction Improvement of reproductive
management in the dairy industry is essential.
The continuous elevation of milk production is
associated with a simultaneous dramatic decrease
of reproductive performance. Delayed post-partum
interval, poor heat expression, inefficient
detection of estrus and fertilization failure are
probably the major causes of the reproductive
wastage but early embryonic death is recognized
as the major cause of reproductive wastage in
cattle. The most common methods for early
pregnancy check /rectal palpation (35-42 days
PI), B-mode ultrasonography (25-30 days PI) and
examination of pregnancy specific proteins (PSPB,
PAG, 29-30 days PI)/ are used for the decreasing
of the calving interval in cattle. BioPrynTM
(BioTracking LLC, Moscow, ID, US), an ELISA test
has been developed and is distributed for the
detection of PSPB in the circulation of pregnant
cows. Pregnancy detection by BioPrynTM is already
routinely used in the authors laboratory.
Objectives The objective of this study was to
develop a method for the recognition of embryonic
loss (EL) at the time early pregnancy detection
(approximately 30-36 days post insemination) by
serum PSPB and serum P4 assays.
Material and Methods Blood samples were assayed
for the determination of the serum PSPB and P4
concentrations months at three Hungarian large
scale dairy farms 30 to 36 days post
insemination. BioPryn was used for the early
pregnancy detection (EPD) and retention of
pregnancy was determined by rectal palpation (RP)
on Day 60 (day of AI0). After the early
pregnancy diagnosis, open cows were immediately
injected with either PGF2a (presence of the
corpus luteum, CL) or were put into an Ovsynch
regimen (non-cycling cows). Lower than expected
optical density (OD) values for BioPRYN (10 of
cutoff OD) and the serum concentration of
progesterone were used for prediction of
embryonic loss. If the OD value of a sample
(PSPB) was 10 to the cutoff OD for
determining pregnancy, the same sample was
checked by a progesterone (P4) ELISA test
(QuantiCheck, Veterinorg Ltd., Budapest,
Hungary). According to serum P4 concentration,
cows were assigned to 3 categories high (gt4
ng/ml maintenance of pregnancy), medium (2-4
ng/ml possible EL) and low (lt2 ng/ml EL) serum
progesterone (see Figure 1). Real embryonic
losses were determined at the time of rectal
palpation (EPD RP).
Figure 1 The prediction process for embryonic
loss and for the treatment methods of open cows
and cows returning in estrus
Results Pregnancies (n1575) were detected from
3833 blood samples between 30-36 days post AI and
13.5 of the pregnancy samples were tested by
the P4 assay. A total of 269 ELs were detected
(17.1 ) after palpation on Day 60 and 50.9 of
them were predicted by ELISA at 30 to 36 days
after AI. The rate of EL among the progesterone
categories were 83.8 (low), 64.9 (medium) and
37.5 (high) respectively.
Farm No. of pregnant cows No. of real EL's EL No. of non predicted EL (NEL) NEL No. of predicted EL (PEL) PEL
1 634 115 18,1 51 44,3 64 55,7
2 591 117 19,8 65 55,6 52 44,4
3 350 37 10,6 16 43,2 21 56,8
Total 1575 269 17,1 132 49,1 137 50,9
Table 1 Number of predicted and non predicted
embryonic loss by Biopryn
Serum progesterone Level Serum progesterone Level Serum progesterone Level Serum progesterone Level Serum progesterone Level Serum progesterone Level
Low Low Medium Medium High High
Farm Predicted EL True EL Predicted EL True EL Predicted EL True EL
1 33 27 39 29 17 8
2 19 19 34 27 14 6
3 16 11 24 7 17 4
Total 68 57 97 63 48 18
Prediction 83,8   64,9   37,5  
Table 2 Efficiency of the EL prediction based on
the serum P4 concentration

• Discussion
• It was found that the BioPRYN, with OD an
  indicator of PSPB level, and serum P4
  concentration could identify EL. Lower PSPB serum
  level significantly refers for LEL (p lt 0.0001).
  Most of the cows with low serum PSPB level and
  have lt 2 ng/ml serum P4 concentration lost the
  embryo between the first and second pregnancy
  check (p lt 0.0001). The most effective prediction
  rate was found in low P4 category ( 90 ) while
  prediction rate in the medium and high P4
  category varied among the farms.

Conclusion It can be concluded that BioPryn was
useful for prediction of part of EL in dairy cows
and that P4 concentration in these was related to
rate of EL.
email h12617gab_at_helka.iif.hu