Different dietary sources of selenium alter meat quality, shelf life, selenium deposition, and antioxidant status in Hu lambs

Different artificial feeding strategies shape the diverse gut microbial communities and functions with the potential risk of pathogen transmission to captive Asian small-clawed otters (Aonyx cinereus)

Captive otters raised in zoos are fed different artificial diets, which may shape gut microbiota. The objective is to evaluate the impacts of two different artificial diets on microbial communities and function capabilities and short-chain fatty acid (SCFA) profiles in healthy otters' feces. A total of 16 Asian small-clawed otters in two groups (n = 8) were selected. Group A otters were fed raw loaches supplemented with commercial cat food (LSCF) diet, and group B otters were fed raw crucian diet. The communities and functional capabilities of microbiota in feces were assessed with metagenomic sequencing. Captive otters fed two kinds of diets possessed different gut microbial communities and functional capabilities. Various pathogenic bacteria, like Escherichia coli and Clostridium perfringens, were enriched in the samples from the two groups, respectively. Most of the differential pathways of nutrient metabolism were significantly enriched in group A, and the distributions of carbohydrate enzymes in the two groups significantly differed from each other. Multiple resistance genes markedly accumulated in fecal samples of the group A otters with LSCF diet. Higher concentrations of SCFAs were also observed in group A otters. Two feeding strategies were both likely to facilitate the colonization and expansion of various pathogenic bacteria and the accumulation of resistance genes in the intestines of captive otters, suggesting that risk of pathogen transmission existed in the current feeding process. Commercial cat food could supplement various nutrients and provide a substrate for the production of SCFAs, which might be beneficial for the otters' intestinal fermentation and metabolism.

IMPORTANCE

Captive otters fed with different diets possessed distinct gut microbial communities and functions, with the enrichment of several pathogens and multiple resistance genes in their gut microbiota. The current artificial feeding strategies had the possibility to accelerate the colonization and proliferation of various pathogenic bacteria in the intestines of otters and the spread of resistance genes, increasing the risk of diseases. In addition, supplementation with commercial cat food had benefits for otters' intestinal fermentation and the metabolism of gut microbiota.

Prevotella copri Improves Selenium Deposition and Meat Quality in the longissimus dorsi Muscle of Fattening Pigs

Selenium is among the important trace elements that influence the quality of meat. Although it has been established that the gut microbiota is closely associated with selenium metabolism, it has yet to be determined whether these microbes influence the accumulation of selenium in muscles. To identify gut microbiota that potentially influence the deposition of selenium in muscles, we compared the colonic microbial composition of pigs characterized by high and low contents of selenium in the longissimus dorsi muscle and accordingly detected a higher abundance of the bacterium Prevotella copri (P. copri) in pigs with a higher muscle selenium content. To verify the effect of P. copri, 16 pigs weighing approximately 61 kg were fed either a basal diet or a basal diet supplemented with P. copri (1.0 × 1010 CFU/kg feed) for 45 days. The results revealed significant increases in the contents of selenium and selenoprotein in the serum and longissimus dorsi muscle of fattening pigs fed the P. copri-supplemented diet. Moreover, supplementing the feed of pigs with P. copri was observed to promote significant improvement in the antioxidant capacity and quality of meat, including drip loss, pH, and meat color. In conclusion, our findings in this study indicate that P. copri has potential utility as a dietary supplement for improving the selenium status and meat quality in fattening pigs.

Preliminary genetic parameter estimates of meat quality traits in Hu sheep

Because substantial numbers of Chinese consumers are prepared to pay for tender and quality lamb, meat quality traits are becoming more relevant for breeding programs for Chinese sheep breeds. The current study estimated heritabilities and genetic correlations for 13 meat quality traits recorded on lamb loins from Hu sheep. Heritability estimates ranged from 0.04 ± 0.06 for meat redness at 45 min to 0.57 ± 0.10 for drip loss, with most of the meat quality traits having moderate heritabilities. Positive genetic correlations were observed among meat color traits. Intramuscular fat (IMF) was genetically correlated with most meat quality traits, indicating that increasing IMF can favor meat pH, color, and tenderness, but would lead to increased cooking loss. Direct selection to increase IMF of loins is recommended to be included in breeding programs for Hu sheep, as it was more efficient than indirect selection on the other meat quality traits. The genetic parameters presented in this preliminary study provide valuable genetic information needed to design a breeding program aimed at improving the quality of lamb meat from Hu sheep.

Effects of replacing Na selenite in laying hen feed with selenized glucose on production performance, egg quality, egg selenium content, microbial population, immunological response, antioxidant enzymes, and fatty acid composition

This study aimed to explore the effects of selenized glucose (SeGlu) and Na selenite supplementation on various aspects of laying hens such as production performance, egg quality, egg Se concentration, microbial population, antioxidant enzymes activity, immunological response, and yolk fatty acid profile. Using a 2 × 2 factorial design, 168 laying hens at 27-wk of age were randomly divided into 4 treatment groups with 7 replications. Se source (Na selenite and SeGlu) and Se level (0.3 and 0.6 mg/kg) were used as treatments. When 0.3 mg SeGlu/kg was compared to 0.3 mg Na selenite/kg, the interaction findings revealed that 0.3 mg SeGlu/kg increased egg production percent and shell ash (P < 0.05). When compared to 0.3 mg Na selenite/kg, dietary supplementation with 0.3 and 0.6 mg SeGlu/kg resulted in an increase in albumen height, Haugh unit, and yolk color of fresh eggs (P < 0.05). SeGlu enhanced albumen height, Haugh unit, shell thickness (P < 0.01), albumen index, yolk share, specific gravity, shell ash (P < 0.05) of fresh eggs and shell thickness (P < 0.05) of stored eggs as compared to Na selenite. The interaction showed that 0.6 mg SeGlu/kg enhanced yolk Se concentration while decreasing malondialdehyde levels in fresh egg yolk (P < 0.05). SeGlu enhanced Se concentration in albumen and glutathione peroxidase activity in plasma (P < 0.05) as compared to Na selenite. 0.6 mg Se/kg increased lactic acid bacteria, antibody response to sheep red blood cells, and lowered ∑n-6 PUFA/ ∑n-3 PUFA ratio (P < 0.05). As a result, adding SeGlu to the feed of laying hens enhanced egg production, egg quality, egg Se concentration, fresh yolk lipid oxidation, and glutathione peroxidase enzyme activity.

Improving Shelf Life and Content of Unsaturated Fatty Acids in Meat of Lambs Fed a Diet Supplemented with Grape Dregs

This study was conducted to evaluate the potential effects of dietary grape residue levels on the slaughter indicators, meat quality, meat shelf-life, unsaturated fatty acid content, and expression of fatty acid deposition genes in the muscle of lambs. Sixty 30-month-old male Dorper and Small-Tailed Han F1 hybrid lambs were assigned to a single factor complete randomized trial design and fed with four different diets including 0%, 8%, 16%, and 24% grape dregs, respectively. The findings regarding meat production efficacy in the lambs revealed substantial differences. The control group showed notably lower dressing percentage, carcass weight, net meat weight, meat percentage concerning carcass, meat-to-bone ratio, relative visceral and kidney fat mass, and rib eye area compared to the other groups (p < 0.05). Additionally, the meat shearing force of lambs fed a diet with 16% grape pomace (GP) was significantly higher than that of the 24% GP group (p < 0.05), while the 24 h meat color parameter a* value of the control group was notably higher than that of the 8% GP group (p < 0.05). In addition, compared to the control group, lambs fed with a diet containing 16% GP had higher levels of oleic acid (C18:1n-9c), linoleic acid (C18:2n-6c), behenic acid (C22:0), tricosanoic acid (C23:0), lignoceric acid (C24:0), and conjugated linoleic acid (CLA), at a ratio of ∑CLA/TFA, ∑n-6, ∑MUFA, and ∑PUFA in the longissimus dorsi muscle (p < 0.05), but the reverse case was applicable for Total Volatile Basic Nitrogen (TVB-N) content (p < 0.05). GP supplementation did not substantially affect the expression of stearoyl-CoA desaturase (SCD), peroxisome proliferator activated receptor alpha (PPARα), and peroxisome proliferator-activated receptor gamma (PPARγ) genes (p > 0.05). The findings indicated that incorporating grape dregs in the diets of fattening lambs leads to notable enhancements in meat production and the antioxidant capacity of lamb meat, and effectively extends the shelf life of the meat.

The importance of selenium in food enrichment processes. A comprehensive review

Selenium is an essential element that determines the proper life functions of human and animal organisms. The content of selenium in food varies depending on the region and soil conditions. Therefore, the main source is a properly selected diet. However, in many countries, there are shortages of this element in the soil and local food. Too low an amount of this element in food can lead to many adverse changes in the body. The consequence of this may also be the occurrence of numerous potentially life-threatening diseases. Therefore, it is very important to properly introduce methods that condition the supplementation of the appropriate chemical form of this element, especially in areas with deficient selenium content. This review aims to summarize the published literature on the characterization of different types of selenium-enriched foods. At the same time, legal regulations and prospects for the future related to the production of food enriched with this element are presented. It should be noted that there are limitations and concerns with the production of such food due to the narrow safety range between the necessary and the toxic dose of this element. Therefore, selenium has been treated with special care for a very long time. For this reason, the presented mechanisms of production processes related to increasing the scale of selenium supplementation should be constantly monitored. Appropriate monitoring and development of the technological process for the production of selenium-enriched food is very important. Such food should ensure consumer safety and repeatability of the obtained product. Understanding the mechanisms and possibilities of selenium accumulation by plants and animals is one of the most important directions in the development of modern bromatology and the science of supplementation. This is particularly important in the case of rational nutrition and supplementing the human diet with an essential element such as selenium. Food technology is facing these challenges today.

Effects of organic and inorganic selenium on selenium bioavailability, growth performance, antioxidant status and meat quality of a local beef cattle in China

Selenium (Se) is an essential nutrient with multiple health benefits to humans and animals. Cattle generally require dietary Se supplementation to meet their daily requirements. The two main forms of dietary Se in cattle are organic Se and inorganic Se. Data comparing the health and productivity effects of organic Se and inorganic Se on cattle are still insufficient, and it is necessary to conduct more research to evaluate the bioavailability, nutritional value, deposition, and body functions of Se sources in different breeds and physiological stages of cattle raised in areas with different Se levels. The objectives of this study were to determine the effects of organic and inorganic sources of Se on plasma biochemical indices, Se bioavailability, deposition in body tissues and organs, growth performance, antioxidant capacity and meat quality of beef cattle raised in Se-deficient areas. Fifteen Chinese Xiangzhong Black beef cattle with an average weight of 254.5 ± 8.85 kg were assigned to three dietary groups. The three groups were fed the same basal ration and supplemented with either an inorganic [sodium selenite (SS)] or organic [selenomethionine (SM) or Se-enriched yeast (SY)] source of Se (0.1 mg/kg dry matter) for 60 days. At the end of the experiment, three cattle from each group were randomly selected and slaughtered, and samples were collected from tissues and organs for analysis. The results revealed that growth performance, slaughter performance, Se content of tissues and organs, meat quality characteristics including chemical composition, pH_45min, pH_24h, drip loss, and cooking losses did not differ (p > 0.05) due to supplementation of the different organic and inorganic sources of Se. SM and SY were more effective in increasing (p < 0.05) immunoglobulin M (IgM) concentrations in the blood and reducing (p < 0.05) malondialdehyde (MDA) content in the longissimus dorsi than SS. In conclusion, organic Se is more effective than inorganic Se in improving the immune and antioxidant capacity of Chinese Xiangzhong Black beef cattle.