PHYSICAL SEMEN CHARACTERISTICS OF CALIFORNIA RABBIT BUCKS ADMINISTRATED WITH DIFFERENT CHROMIUM LEVELS

The experimental work was carried out in the Rabbit Production Farm, Agricultural Researches and Experiments Station, Faculty of Agriculture, MansouraUniversity, during the period from February to Augusts  2006. A total of 12 sexually mature California bucks having 6-8  months of age and 3.0-3.5 kg live body weight) was used in this study. Bucks were healthy, free of diseases and external parasites. The experimental bucks were divided into three groups (4 males in each group) according to treatment. Bucks in the 1st Group served as control. However, group 2 and 3 were given chromium picolinate (9 and 18 μg/kg body weight) respectively. The bucks were given the dose orally every day as a suspend buck. To determine mass motility, progressive motility, Sperm cell concentration,  Percentage of dead spermatozoa, percentage of abnormal spermatozoa was recorded. Results show that ejaculate volume of rabbit bucks significantly (P<0.05) decreased in both treated groups as compared to control group. This reduction was higher with low than high Cr dose, being about 12.5 and 8.6%, respectively. The obtained results revealed a negative effect of Cr treatment on ejaculate volume of rabbit bucks. Mass motility or percentage of progressive motility was significantly (P<0.05), being positive for the low level (9 µg/kg) and negative for the high level (18 µg/kg) of Cr. Level of 9 µg/kg significantly (P<0.05) increased score of mass motility by about 24% and progressive motility by about 34%, however, level of 18 µg/kg significantly (P<0.05) decreased score of mass motility by about 16% and progressive motility by about 22% as compared to controls. Dead sperm percentage was significant (P<0.05), being lower by about 17% for the low level (9 µg/kg) and higher by about 4% for the high level as compared to the control group (18 µg/kg) of Cr. Percentage of sperm abnormality was affected significantly (P<0.05) by the low Cr level, but was not affected by the high level of Cr. Sperm abnormality percentage significantly (P<0.05) reduced by about 48% as compared to the control group. Sperm cell concentration (x10⁶/ml) significantly(P<0.05) increased by about 37% in low Cr group, but was not affected by the high level of Cr. However, total sperm output (x10⁶/ejaculate) significantly (P<0.05) increased by about 16.5% in low Cr group and reduced by about 10% in high Cr group as compared to the control group.