1. Causes of Embryonic mortality

2. Highly complicated process
Embryo, uterus, cow
No single factor that can be manipulated

3. What is embryonic mortality
infertility
Stages of differentiation
It refers to losses which occurs in period between fertilisation and completion of stage of differentiation
EEM and LEM
It is regarded as 1 of major causes of reproductive failure
There is reduced pregnancy rates, slower genetic improvement, infertility, substantial losses to dairy producers.

4. The oocyte quality
The oocyte or unfertilized egg develops within the follicle.
It is quite common for lactating dairy cows to ovulate poor quality oocytes, and one reason may be follicles that persist contain poor quality oocytes.
These inferior oocytes lead to inferior quality embryos which are more apt to be lost.

5. Uterine Environment
Uterine environment also contributes to embryonic loss.
Examines of uterine fluid/discharge
Intrauterine infections
Endometritis
Pyometra
Repeat breeders
Previous history

6. Blood progesterone level
Must be maintained to support pregnancy.
the industry’s efforts to maximize feed intake and boost milk production.
When feed intake increases, more blood passes through the liver which breaks down the progesterone and estrogen.
This decrease in progesterone levels is thought to lead to more embryonic loss
Life span of CL

7. Asynchrony
Maternal recognition occurs at days of pregnancy
The embryo secretes bovine trophoblast protein (BTP)which alters the production of prostaglandin and prevents the luteolysis.

8. Reproductive diseases
There are also many disease processes that can cause EED. BVD- BVDV Mastitis- E.coli Trichomoniasis- T. foetus –pyometra, endometritis, mummified foetus Vibriosis- Campylobacter foetus-poor conception rate, calving interval long Leptospirosis-Leptospira, decrease of immunity

9. Chromosomal abnormalities/genetic factors
10% embryos have chromosomal abnormalities.
Some time a lethal genes expressed which causes death of embryo within 5 days of pregnancy.
Aneuploidy- abnormal no. of chromosomes

10. Environmental factors
Age- Heifer have high conception rate
Climate/Heat stress
Nutrition
Effect of toxic plants- Lupine, Tobacco tree
These can also effect the spermatogenesis in bulls and oogenesis.
Can cause abortion, skeletal muscles abnormalities

11. Energy ration
Excess level of dietary Protein diet could alter hormone secretion such as progesterone
Could increase the blood urea concentration
Deamination
These changes could be toxic to developing embryo.

13. How to reduce embryonic mortality losses
Adaption of better animal husbandry conditions
Management
Nutrition
Stress
Animal Health
Vaccination schedule
Treatment with HCG