Metabolic and immune response of young turkeys originating from parent flocks fed diets with inorganic or organic selenium.

The aim of this study was to verify the hypothesis that the health and growth of turkey poults may be improved by supplementing diets fed to parent flocks with available selenium. Experimental poults originated from parent flocks fed with diets containing 0.3 mg/kg inorganic selenium (control group Se(M)) and organic selenium (experimental group Se(O)). Egg yolk selenium content was comparable in both flocks (0.72 and 0.70 mg/kg d.m., respectively). Eggs from the Se(O) flock had a significantly lower content of thiobarbituric acid reactive substances - TBARS (31.13 vs. 53.10 nmol/g, p > 0.001). Se(O) group poults were characterized by higher activity of glutathione peroxidase (7.54 vs. 5.92 U/mL, P = 0.001) and superoxide dismutase (89.30 vs. 79.23 U/mL, P = 0.026). The thigh muscles of Se(O) group birds had significantly higher selenium concentrations (0.74 vs. 0.57, p = 0.045) and a significantly lower TBARS content (38.42 vs. 65.01, p = 0.001). No differences were found between the groups with respect to the content of total protein, albumins and uric acid, and the activites of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (DLH) in day-old poults. On day 28, groups Se(O) and Se(M) differed in the activity of ALT (20.50 vs. 26.33, p = 0.05) and SOD (87.29 vs. 100.02 U/mL, p = 0.035). There were no differences between the groups regarding the percentages of T lymphocyte subpopulations CD4+, CD8+, CD4+CD8+ and B lymphocyte subpopulations (IgM+) at 1 and 28 days of age. Over the experimental period, mortality rates were similar in both groups (7.32 and 8.87%), and so were the final body weights of birds (1108 vs. 1135 g). The results of the study show that the dietary supplementation of organic selenium in turkey parent flocks reduces the rate of oxidation processes in the egg and in the tissues of newly-hatched poults, yet it has no effect on the analyzed parameters of cell-mediated immunity and the growth performance of birds during the first five weeks of their life.

Effect of organic and inorganic forms of selenium in diets on turkey semen quality.

The effects of Se supplementation and its organic or inorganic form on semen quantitative parameters (ejaculate volume, sperm concentration, and total number of sperm) and biochemical parameters of seminal plasma (protein concentration, acid phosphatase activity, superoxide dismutase activity, and total antioxidant capacity) were investigated over a 25-wk reproductive season. Additionally, DNA fragmentation and motility characteristics of turkey spermatozoa were measured. The parameters of turkey semen in relation to yellow semen syndrome were also determined. Twenty-four males (Big 6) were divided into 3 experimental groups differing in form of Se supplementation (no Se supplementation, 0.3 mg/kg of inorganic Se from sodium selenite and 0.3 mg/kg of organic Se from Sel-Plex, Alltech Inc., Nicholasville, KY). Dietary Se supplementation enhanced the sperm concentration and total number of sperm and did not influence the antioxidative properties of turkey seminal plasma and most biochemical parameters. Only seminal plasma acid phosphatase activity was increased in turkeys fed inorganic Se. The main sperm DNA fragmentation parameters were not affected by dietary Se. The highest percentage of motile spermatozoa (85%) was recorded for the semen of turkeys fed organic Se. Values of the biochemical parameters (acid phosphatase, superoxide dismutase, total antioxidant capacity) of seminal plasma increased during the reproductive season. Yellow semen was characterized by increased biochemical parameters and decreased spermatozoa motility characteristics. However, the percentage of motile spermatozoa did not differ between white and yellow semen. Organic Se seemed to be the preferred form of diet supplementation in comparison with inorganic Se. Biochemical parameters of semen and spermatozoa motility parameters appear to be useful for evaluating the effect of age on semen quality. Monitoring the DNA fragmentation of spermatozoa at the end of the reproductive season could be a useful tool for monitoring turkey semen quality. Increased superoxide dismutase activity can be used as an indicator of yellow semen. A decline in the quality of yellow semen can be related to a decrease in the spermatozoa motility parameters of turkeys.