An in-vitro criterion for comparative assessment of fertility characteristics of bull semen in Kenya

The goal of a contemporary dairy farmer is to maximise the efficiency of milk production. Reproductive efficiency of the cow and bull fertility is major component of efficient production. General macro- and micro semen characteristics such as volume, motility and concentration have been majorly used to assess bull fertility in Kenya. Confounding reports as to the correlation between these parameters and bull fertility in Kenya may be due to their subjectivity and variability. Therefore, the need to develop objective and consistent analysis methods was considered necessary for the present study. Room temperature and deep frozen semen samples from six bulls at the Central Artificial Insemination Station in Kenya were used. The volume, motility, concentration, morphology, cleavage, Blastocyst and non- return rates of all the bulls were assessed. Correlation analysis was done between the various parameters. Significant differences (P≤0.05) were observed between breeds as well as between individual bulls within the same breed. There was a positive correlation observed between cleavage and blastocyst formation rates with semen motility and a negative correlation with concentration. Correlation was also observed between percentage of morphological abnormalities and cleavage and blastocyst rate. The results suggest that no single parameter can be used on its own to objectively predict bull fertility. Therefore multiple characteristics should be assessed in order to try to predict fertility. In addition, motility, concentration, cleavage and blastocyst formation rates can be used to assess bull fertility according to this study. - See more at: http://www.pearlresearchjournals.org/journals/jasft/archive/2016/July/Abstract/Mutembei%20et%20al.html#sthash.fX6DelPb.dpuf