Effects of Oral Administration of Clomiphene Citrate and Frequency of Ejaculation on Ejaculate Characteristics of Chickens

摘要

The effects of clomiphene citrate (CC) and ejaculation frequency on semen characteristics of chickens were evaluated using 36 Black Nera cocks aged 24-28 weeks, and weighting 1.96kg to 2.39kg in a 4 x 3 factorial experiment, with clomiphene citrate dose at four levels (0mg, 5mg, 10mg and 15mg/kg body weight) and ejaculation frequency at three levels (once a week, twice weekly and thrice weekly) as factors. Ejaculate volume and colour, sperm motility, sperm concentration and total sperm per ejaculate generally increased progressively with increase in CC administration, with the 15mg CC group being significantly (P0.05) effect on semen pH and morphologically abnormal sperm. Percent sperm motility increased significantly (P0.05) by frequency of ejaculation. Ejaculation frequency, at each level of CC application, had no significant (P>0.05) effect on semen volume, semen colour score, sperm motility and total sperm per ejaculate. However, 15mg CC in combination with three ejaculations per week resulted in the highest numerical values of these characteristics, and in the lowest proportion of morphologically abnormal sperm. It was concluded that oral administration of 15mg CC kg-1 body weight alone or in combination with frequent ejaculations significantly improved semen output, sperm motility and % live sperm, and reduced the proportion of morphologically abnormal sperm in the cocks. Keywords: chickens, clomiphene citrate, cocks, ejaculate, ejaculation frequency, semen