Comparative study for different treatments to improve the sexual efficiency of bulls in the department of artificial insemination _Abu Ghraib

Abstract

This study was aimed to improve the sexual ability of low fertile bulls.It was done between 1st May 2009 and 30th April 2010. The study was carried on four Holstein bulls aged between 5 to 5.5 years. All of these bulls were suffering from impotency (have no ability to mount or ejaculate). These bulls were treated with different unhormonal methods in order to stimulate their desire to mount and ejaculate. Then they were treated with different hormonal methods including GnRH, FSH, and LH, to improve their sexual ability. Blood samples were collected from every trial of semen collection and within different methods of treatment for estimation of testosterone and prolactin levels. Result showed that unhormonal treatment to stimulate the sexual desire of bulls to mount the teaser or obtain semen by electro ejaculators were useless, but the result of different hormonal treatment showed the response of the first bull after four days following the first dose of LH hormone and a clear continuous improvement after the other treatment with GnRH and FSH. The second bull was responded after 5 days from GnRH injection and has the ability to mount and ejaculate. The improvement continues with the FSH hormonal treatment. The third and fourth bulls did not respond even after the end of the experiment. This study recorded that testosterone and prolactin level were varied after the hormonal treatment especially after the second dose of LH hormone then FSH and GnRH in comparison with the first dose of LH or before commencement of treatment. Also the study showed the increased level of prolactin hormone after the GnRH and FSH hormonal treatment, in comparison with its level before the hormonal treatment and after the first and second dose of LH hormone. The significant effect p < 0.05 of the hormonal treatment on the ejaculate volume, sexual reaction time, individual movement and mass activity was noticed especially after FSH hormone treatment.The frozen semen from the first and second bulls was used after the end of hormonal treatment. The two bulls showed improvement of the sexual ability to mount and rapid ejaculation of semen. Following insemination of six cows from the first bull pregnancy was diagnosed in five cows after sixty days. The ratio of pregnancy is 83.3%. Cows inseminated with the semen of the second bull led to pregnancy in one however a failure in the other resulting in a ratio of pregnancy at 50%. We concluded that the ability of using the hormonal treatment to improve the sexual efficiency of bulls