Evaluation of seminal characteristics of Zebu bulls to utilization in artificial insemination

Abstract

The semen picture of 13 zebu bulls, used as donors in an Artificial Insemination Center, was studied weekly during nine weeks. Average seminal characteristics were as follows: volume ranged from 7.89 to 13.44 ml progressive motility from 48 .6 3 to 73.89%, spermatic concentration from 712.000 to 1.774.000 spermatozoa / mm3. Spermatic pathology percentage observed with DIC and phase contrast microscopy, varied, respectively to total, major and minor defects, from 11.83 to 45.87%; from 3.50 to 35.50% and from 1.72 to 14.90% and from 7.56 to 42.3 4% from 2.83 to 31.02% and from 1.72 to 11.32%. Results based on a single examination of semen did not offer sufficient information because many samples with a high percentage of abnormal spermatozoa exhibited normal motility. The DIC microscopy was appreciably superior that of phase contrast for observation of spermatic defects.