Thesis (M.Sc.)--Chulalongkorn University, 2007

To evaluate the effect of organic Se on Se level in plasma, sperm morphology, and sperm motility of dogs, and to determine the suitable amount of organic Se supplement which can enhance sperm motility and morphology. Nine healthy male beagle dogs age between 4.5-5 years, have average weight between 10-13 kg. An experimental design was a complete randomized design (CRD). Seven days before the experiment, semen was collected and was examined microscopically to determine the semen quality. The examined parameters were membrane integrity (Hypo-osmotic swelling test) and sperm motility. Then statistical data (percentage) would be calculated and used to pick up nine samples from the entire dogs. The selected samples would be categorized into three groups with three dogs each. This would decrease the variations between the treatment groups. Group 1 was the control group (non supplemented Se), group 2 and 3 were supplemented with organic Se at 1 and 3 ppm, respectively. The dogs received a basal diet that was found to contain Se at 0.03 ppm for 2 weeks. After that, the dogs were fed a basal diet and supplement with various amounts of organic Se for 16 weeks. Supplementation of organic Se at 1 and 3 ppm had no affect on body weight, color of semen, pH, creatinine, glutamate pyruvate transaminase (GPT), free 3,3',5-triiodothyronine (FT3) and free thyroxine (FT4) in serum. But at week 12th, all three groups had total 3,3',5 triiodothyronine (TT3) in serum greater (P