Introduction

INTRODUCION

  • Semen evaluation alone should not be interpreted as the sole indicator of the fertility of the bull.
  • Suitability of semen for artificial insemination depends on semen characteristics.
  • Evaluation of semen provides information on the complex of sexual functions and therefore must not be neglected.
  • It has not been possible so far to evaluate semen on the basis of a single trait.
  • The results of these tests are essential to judge the efficiency of semen prior to use. As soon as the semen sample is received, it is kept in the laboratory at 34oC till examination is over.
  • The evaluation of semen involves handling of living cells and therefore care should be taken to avoid creation of artifacts and damage to the cells between collection and completion of tests.
  • There are standard tests carried out for the evaluation of semen quality in artificial insemination techniques and the bulls are rated accordingly.
  • The semen is the normal discharge of the male at time of mating. It is a suspension of spermatozoa in a fluid medium called seminal plasma.
  • Spermatozoa originates from the testes, primary sex glands and stored in the epididymis constitute 10% of the total volume, while the seminal plasma is a mixture of secretions from seminal vesicles, cowper’s gland, prostate gland, ampullae and epididymis.
  • Secretions of seminal vesicles form nearly 55% of the total volume of the bull semen. Seminal plasma with all its favorable biochemical composition nourishes the sperm cells at the time of ejaculation.
  • It takes about 60 days before spermatozoa appear in the ejaculated semen.
  • The factors that affect the characteristics of semen include breed, frequency of collection, age of the bull, condition of the bull, season, degree of sexual excitement prior to collection and skill of the operator.
  • The changes in the spermatozoa are due to aging, cold shock, dilution and preservation.
  • Generally life of the spermatozoa is limited by source of energy it contains.
  • The semen examination is of great diagnostic value in determining the cause, severity and degree of pathological conditions of the testes and other genital organs.
  • The quality of the semen can be useful in assessing the fertility of a male animal.
  • The quality of the semen will vary only in narrow limits between different ejaculates of a bull.
  • During adverse conditions the semen quality will be affected at a very faster rate but the recovery takes a longer time.
  • The semen is a highly fragile material. The semen quality should be assessed immediately after collection.
  • Once the sample is received inside the laboratory it should be kept in a water bath of 370C and evaluation should be started.
  • There are several parameters are available to assess the semen quality.
  • The good quality semen will have better fertility but the poor quality semen will have poor fertility.
  • There are combination of tests are used to assess the semen quality.
  • There is no any single test available to certify a semen sample.
Last modified: Monday, 11 June 2012, 12:01 PM