Effects of Selenium and Methionine Supplementation of Breeder Hen Diets on Selenium Concentration and Oxidative Stability of Lipids in the Thigh Muscles of Progeny

Effect of Dietary Modulation of Selenium Form and Level on Performance, Tissue Retention, Quality of Frozen Stored Meat and Gene Expression of Antioxidant Status in Ross Broiler Chickens

Simple Summary

Although the importance of usage of selenium as essential trace element in poultry production has been proven, the best source and level has not been fully addressed yet. Three different dietary selenium forms with three different levels were chosen to be added in broiler diet. Met-Se or nano-Se up to 0.6 mg/kg increased their performance and was more efficiently retained in the body than SeS. Frozen stored meat quality was improved in a dose-dependent manner especially with both Met-Se and nano-Se. Nano-Se was more potent than Met-Se, which in turn was more potent than inorganic Se against oxidative stress, which improved the quality of meat under frozen conditions.

Abstract

This study compares between different selenium forms (sodium selenite; SeS, selenomethionine; Met-Se or nano-Se) and levels on growth performance, Se retention, antioxidative potential of fresh and frozen meat, and genes related to oxidative stress in Ross broilers. Birds (n = 450) were randomly divided into nine experimental groups with five replicates in each and were fed diets supplemented with 0.3, 0.45, and 0.6 mg Se/kg as (SeS, Met-Se), or nano-Se. For overall growth performance, dietary inclusion of Met-Se or nano-Se significantly increased (p < 0.05) body weight gain and improved the feed conversion ratio of Ross broiler chicks at the level of 0.45 and 0.6 mg/kg when compared with the group fed the same level of SeS. Se sources and levels significantly affected (p < 0.05) its concentrations in breast muscle, liver, and serum. Moreover, Se retention in muscle was higher (p < 0.05) after feeding of broiler chicks on a diet supplemented with Met-Se or nano-Se compared to the SeS group, especially at 0.6 mg/kg. Additionally, higher dietary levels from Met-Se or nano-Se significantly reduced oxidative changes in breast and thigh meat in the fresh state and after a four-week storage period and increased muscular pH after 24 h of slaughter. Also, broiler’s meat in the Met-Se and nano-Se groups showed cooking loss and lower drip compared to the SeS group (p < 0.05). In the liver, the mRNA expression levels of glutathione peroxidase, superoxide dismutase, and catalase were elevated by increasing dietary Se levels from Met-Se and nano-Se groups up to 0.6 mg/kg when compared with SeS. Therefore, dietary supplementation with 0.6 mg/kg Met-Se and nano-Se improved growth performance and were more efficiently retained than with SeS. Both sources of selenium (Met-Se and nano-Se) downregulated the oxidation processes of meat during the first four weeks of frozen storage, especially in thigh meat, compared with an inorganic source. Finally, dietary supplementation of Met-Se and nano-Se produced acceptable Se levels in chicken meat offered for consumers.

Safety Assessment and Comparison of Sodium Selenite and Bioselenium Obtained from Yeast in Mice

Detailed safety assessment of sodium selenite and bioselenium (bio-Se) was conducted and the results were compared and discussed for the purpose of assessing safety of bio-Se for use in food applications. In this work, acute toxicity studies, micronucleus test, and sperm aberration study in mice, 30-day feeding test of mice, were conducted to evaluate the toxicity of bio-Se obtained from yeast with different fermentation time (transformative time: one month, three months, and six months), and the results were compared with that of inorganic Se (sodium selenite). LD₅₀ of sodium selenite was calculated to be 21.17 mg/kg. LD₅₀ of bio-Se obtained from yeast with different fermentation time was calculated to be 740.2 mg/kg, 915.3 mg/kg, and 1179.0 mg/kg, respectively. In the genotoxicity test, bio-Se did not show cytotoxicity and genotoxicity of mice while sodium selenite at all dose groups was significantly different from the negative group. In the 30-day subchronic oral toxicity study, sodium selenite may slow down the growth of the mice and lead to organic damage to some extent. Bio-Se had facilitated effect towards the body weight of the mice and had no significant effect on the shape and function of the important organs of the mice.

Selenium significantly inhibits adipocyte hypertrophy and abdominal fat accumulation in OLETF rats via induction of fatty acid β-oxidation

A combination of selenium (Se) with other trace element is associated with partially modulate fatty acid distribution as well as reduction of the body weight and feed efficiency. To investigate whether or not Se treatment has an impact on lipid metabolism, we examined the levels of lipid metabolism-related factors, including abdominal fat, adiponectin, cholesterol, very long chain dehydrogenase (VLCAD), and medium chain acyl-CoA dehydrogenase (MCAD) in 20-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats following sodium selenite treatment for 2 weeks. Herein, we observed that (a) Se treatment induced insulin-like effects by lowering the serum glucose level in rats; (b) Se-treated rats showed significance values decreases in abdominal fat mass, adipocyte size, and adiponectin, which are associated with lipid metabolism; (c) Se treatment led to reduced levels of cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol; (d) fat tissue in Se-treated rats displayed significantly lower expression of adipocyte marker genes along with increased expression of VLCAD and MCAD; and (e) fatty liver formation and β-oxidation gene expression were both significantly reduced in liver tissue of Se-treated rats. Therefore, our results suggest that Se may induce inhibition of adipocyte hypertrophy and abdominal fat accumulation along with suppression of fatty liver formation by the differential regulation of the gene expression for fatty acid β-oxidation in the OLETF model.

Supranutritional selenium level affects fatty acid composition and oxidative stability of chicken breast muscle tissue

A total of 128 broilers were used to investigate the effect of selenium (Se) on fatty acid (FA) composition and oxidative stability of lipids in the breast muscle tissue. There were 4 replicates of 4 dietary treatments: T1 (basal diet with no added Se), T2 (T1 with 0.15 mg Se added per kg diet), T3 (T1 with 0.3 mg Se added per kg diet) and T4 (T1 with 3.0 mg Se added per kg diet). A yeast source was used for added Se. Breast muscle tissue was collected from two chickens per replicate pen for the determination of Se concentration by ICP-MS, FA profile by GC and lipid oxidation using thiobarbituric acid reactive substances method. Addition of supranutritional Se levels to chicken diets leads to the production of Se-enriched meat. Consumption of 100 g of breast meat from chickens fed diets supplemented with 0.15, 0.3 and 3 mg Se per kg of diet can provide 26, 41 and 220 μg of Se, respectively. Long-chain polyunsaturated fatty acids namely C20:3n-6, C20:4n-6, C20:5n-3, C22:5n-3 and C22:6n-3 increased linearly (p = 0.047, p < 0.001, p = 0.023, p = 0.003 and p = 0.002, respectively) as the Se inclusion levels in the diets increased. At slaughter, a linear decrease in lipid oxidation (p = 0.019) was observed with Se addition, possibly attributed to the antioxidant properties of Se. Addition of supranutritional Se to chicken diets, at levels well below those causing toxicity, leads to production of Se-enriched meat, protection of health-promoting long-chain FA like C20:5n-3 and C22:6n-3 and protection of meat quality from oxidation at day 1 after slaughter.

Methionine and selenium yeast supplementation of the maternal diets affects antioxidant activity of breeding eggs

Four hundred fifty 52-wk-old Langshan layer hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates in each treatment. Birds were fed corn-soybean diets (0.13 mg of Se/kg) supplemented with 0, 0.30, and 0.60 mg/kg of Se from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. Increasing Se yeast supplementation significantly increased Se concentration in the egg yolk (P < 0.01) and the Se concentration of the 3.2 g of Met/kg treatment was higher than those of the 4.0 and 5.4 g of Met/kg treatments. Adding 0.3 mg of Se/kg to the diet significantly increased glutathione peroxidase (GSH-Px) activity in the egg yolk compared with 0 and 0.6 mg of Se/kg (P < 0.01) and increasing Se yeast supplementation significantly increased the GSH-Px activity in the egg albumen (P < 0.01). Increasing Met supplementation significantly decreased the GSH-Px activity in both the yolk and the albumen of the eggs (P < 0.01). Methionine supplemented at 3.2 and 4.0 g/kg significantly increased glutathione concentration in the egg yolk compared with 5.4 g of Met/kg (P < 0.01) and increasing Met supplementation increased the glutathione concentration in the egg albumen. Increasing Met supplementation significantly decreased malondialdehyde concentration in the egg yolk (P < 0.01) and Se supplemented at 0 and 0.6 mg/kg increased the malondialdehyde concentrations in the egg yolk compared with 0.3 mg of Se/kg (P < 0.01). Methionine supplemented at 4.0 and 5.4 g/kg significantly decreased carbonyl concentration compared with 3.2 g of Met/kg. The conclusion was drawn that Se yeast and Met supplementation of the maternal diets could enhance antioxidant activity of breeding eggs.