the influence of different sources of oral selenium supplementation on the total antioxidant capacity (TAC), glutathione peroxidase (GPx) activity, and lipid peroxidation of semen in aged broiler breeder roosters

Supplementation of elements such as selenium into a diet is one of the ways to improve fertility. The effects of selenium supplementation vary and are strongly influenced by the source and amount of dietary selenium. Therefore, the present study was conducted to investigate the influence of different sources of oral selenium supplementation on the total antioxidant capacity (TAC), glutathione peroxidase (GPx) activity, and lipid peroxidation of semen in aged broiler breeder roosters.

This research was carried out using 120 broilers aged 45 weeks in a completely randomized design with 10 treatments and 4 replicates and 3 birds in each replicate. The experimental treatments included: the control diet based on standard nutrition requirements of roosters, and adding the following sources of selenium to the basic diet at levels of 0.0, 0.15, 0.30, and 0.45 mg/kg, including sodium selenite, organic selenium, and selenium nano-bio-chelate. After two weeks of feeding with the basal diet, the roosters received the experimental treatments for 40 days from the beginning of the age of 47 weeks. Semen was collected by abdominal massage from roosters every 10 days once and then the total antioxidant capacity, glutathione peroxidase activity, semen lipid peroxidation, and plasma testosterone concentration were measured at the beginning and end of the experiment. Data analysis was done using the GLM procedure of SAS 9.4 software (2012).

It was observed that higher levels of selenium (0.30 and 0.45 mg/kg) improved TAC, GPx activity, and decreased lipid peroxidation compared to the control group.  Also, the level of 0.30 mg/kg selenium from Celemax and BondaSel sources led to the highest level of glutathione peroxidase activity compared to other treatments (P≤0.05). The highest amount of lipid peroxidation was observed in the control and 0.15 mg/kg of sodium selenite groups. The highest level of total antioxidant capacity and the highest glutathione peroxidase enzyme activity was observed on day 20 of the experiment in the group receiving 0.30 mg/kg Celemax and on day 10 of the experiment in the 0.30 mg/kg sodium selenite groups respectively. The lowest amount of lipid peroxidation on day 20 of the experiment was related to the 0.30 mg/kg BendaSel group. Testosterone concentration in the 0.30 mg/kg Celemax group was significantly higher than the control and 0.15 mg/kg Celemax groups, but no differences were observed among other treatments.

The results showed diet supplementation of 0.30 mg/kg of selenium from organic sources (Celemax and BondaSel) to the diet improves the reproductive performance of aged roosters.