VGO 511: Veterinary Andrology and Reproductive Techniques (1+1)

IMPOTENTIA GENERANDI ASSOCIATED WITH NORMAL SEMEN PRODUCTION

• Bulls infected with brucellosis, vibriosis, trichomoniasis, IBR-IPV virus, mycoplasma may produce normal semen but service by these bulls causes failure of fertilization, early embryonic death and repeat breeding in females.
• Active brucellosis in a herd of cattle is associated with symptoms of infertility.
• Intrauterine insemination of brucella infected semen usually results in infertility.
• Abnormal acrosomes eg. knobbed spermatozoa related to the defective spermatogenesis involving gogli apparatus is the cause of infertility in bulls, boars and dogs.
• Some strains used for preparing the spermatozoa for morphological examination do not reveal this defect.
• But Nigrosin-Eosin, India ink or Giemsa show a refractive unstained or lightly stained area in the anterior pole or acrosome of the head of the spermatozoa.
• The defective acrosome causes the sperm cell incapable of penetrating and fertilizing the ovum.

The acrosomal defects in spermiogenesis is due to an autosomal recessive sex linked defect in Friesian bulls.

• Cytogenetic studies of sperms indicated that gene or chromosomal defects may occur at the time of meiosis and result in infertility.
• Further many infertile bulls had lower DNA content of the spermatozoan nucleus than fertile bulls.

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