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Repeat Breeding
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If
an animal does not conceive for three inseminations then it is
called as repeat breeder. This repetition of estrous cycle and
repeat breeding has various factors
From
Female Side
If
we take female side there are so many problems which make it to
repeat. Some are anatomical defects which make the animal not to
conceive e.g. segmental aplasia of reproductive tract.
Anatomical Problems:
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White heifer disease: some part or reproductive tract is missing
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Sometimes there is blockage of fallopian tube
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Persistence of hymen (at junction of vagina in shape of sheath).
Either it is in form of band or sheath and normally breaks when
puberty comes. It can be problem but not of repeat breeding but
of dystocia.
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Sometimes there is double cervix. In this case chances of
conception in case of natural mating but not in case of AI
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Missing of uterinal gland: The glands produce mucous and
uterine milk which is source of energy for embryo but if these
glands are missing then pregnancy will not occur.
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Complete absence of one horn
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Ovarobursal growth which is occluding the fallopian lumen
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Cystic growth in mesosalpinx, compress the fallopian tube and
animal will repeat.
Infectious Causes of Repeat Breeding:
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Some specific and non specific causes e.g. vibriosis,
trypanosomiasis, streptococcus, pseudomonas, fungal infections.
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Mostly these infections are checked by freezing of semen. It
contains pus in it and diagnosis of these diseases become easy.
These infections mostly result in endometritis if not treated
then metritis and pyometra. Vibriosis and trypanosomiasis result
in early embryonic mortality.
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In endometritis uterine wall becomes thick and if animal in heat
there is increased tonicity and mucous is more watery, it is not
stingy.
Delayed Ovulation:
If
there is delayed ovulation. The normal ovulation time 10-15 hours
after the end of estrous. But some animals ovulate late and you have
inseminated it after estrous then sperms will die and do not
fertilize LH is not secreted in delayed ovulation.
Anovulated Follicles:
Animal come in heat but no ovulation occurred and the estrus will be irregular
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Cystic Ovarian Degeneration:
It
may be follicular cyst or luteal cyst. Granulose cells change into
luteal cells, there is production of progesterone and animal will
not come into heat.
Polycystic Ovaries:
Many
follicles which changed in cyst.
Hormonal Problems:
Problems From Male Side
Many problems which lead to repeat breeding
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Male carrier of venereal disease e.g. vibriosisi, compylobacteresis brucella etc. if natural mating or semen from
infected bull
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Morphological effect in male e.g. blockage of epidydimus and
mostly in natural mating.
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Sometime cryptochid testes or testicular degeneration in which
no sperms or oligospermia.
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If no. of abnormal sperms are more (semen quality is very low)
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Sometime acrosomal defects, head defects
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If vas deferens not properly functioning
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If the bull is excessively used (service a lot of females in a
day). Then there is depletion of sperms.
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Segmental aplasia of spermatic duct: sperm normally produce but
can not pass as no ejaculation. A spermatocoele will be formed
at blockage site.
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Due to blockage of vas deference
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Inflammation of accessory sex glands: prostitis, seminal
vesiculitis. Chemical composition of seminal plasma change there
will be death of sperms and repeat breeding.
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Fibrosis of accessory sex glands
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Non availability of the bull
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Poor quality semen, infected semen
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Chromosomal defects in sperms
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Immunodepression or immunogenic semen auto immune infertility
Problems from Veterinarian or Technician Side
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The part played by veterinarian or technician
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Lack of know how. The doctor or technician is not well trained
or well experienced. He is unable to properly diagnose stage of
estrous and time of ovulation and time of insemination.
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He is untrained to detect the reproductive problem e.g. delayed
ovulation, endometritis, cystic ovaries or morphological
abnormality
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He is professionally dishonest
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He is professionally inexperienced about handling of semen i.e.
storage of semen, picking of dose, loading of gun.
Part of Owner
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Owner is not properly vigilant about the animals
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Even vigilant owners sometime missed the estrous due to silent
nature of estrous
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He is unable to arrange natural mating or AI
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Even if he is able to arrange it is too late or too early
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The doctor or technician says it is infection it will not
conceive even then owner says to inseminate.
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Copyrights © Dr. M Jassar
Aftab, All Rights Reserved |
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