Influence of dietary selenium and vitamin E on quality of veal

Use of sustainable packaging materials for fresh beef vacuum packaging application and product assessment using physicochemical means

Packaging material should guarantee the longest possible shelf life of food and help to maintain its quality. The aim of the study was to assess the physicochemical changes taking place during 28-day ageing of beef steaks packed in two types of multilayer films containing biodegradable polymers - polylactic acid (NAT/PLA) and Mater-Bi® (NAT/MBI). The control group consisted of steaks packed in synthetic polyamide/polyethylene (PA/PE) film. The samples stored in NAT/PLA had significantly lower purge loss than the control samples and the lowest expressible water amount after 14 and 21 days. Following blooming, the most favourable colour was shown in steaks stored in NAT/MBI, with the highest values for the L*, a* and C* parameters and the R630/580 ratio, a high proportion of oxymyoglobin, and the lowest share of metmyoglobin. All steaks, regardless of the type of packaging material, had acceptable tenderness and were stable in terms of lipid oxidation.

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.

The Importance of Dietary Antioxidants on Oxidative Stress, Meat and Milk Production, and Their Preservative Aspects in Farm Animals: Antioxidant Action, Animal Health, and Product Quality-Invited Review

The biological effects of oxidative stress and associated free radicals on farm animal performance, productivity, and product quality may be managed via dietary interventions-specifically, the provision of feeds, supplements, and forages rich in antioxidants. To optimize this approach, it is important first to understand the development of free radicals and their contributions to oxidative stress in tissue systems of farm animals or the human body. The interactions between prooxidants and antioxidants will impact redox homeostasis and, therefore, the well-being of farm animals. The impact of free radical formation on the oxidation of lipids, proteins, DNA, and biologically important macromolecules will likewise impact animal performance, meat and milk quality, nutritional value, and longevity. Dietary antioxidants, endogenous antioxidants, and metal-binding proteins contribute to the 'antioxidant defenses' that control free radical formation within the biological systems. Different bioactive compounds of varying antioxidant potential and bio-accessibility may be sourced from tailored feeding systems. Informed and successful provision of dietary antioxidants can help alleviate oxidative stress. However, knowledge pertaining to farm animals, their unique biological systems, and the applications of novel feeds, specialized forages, bioactive compounds, etc., must be established. This review summarized current research to direct future studies towards more effective controls for free radical formation/oxidative stress in farm animals so that productivity and quality of meat and milk can be optimized.

Effects of Selenium Supplementation on Rumen Microbiota, Rumen Fermentation, and Apparent Nutrient Digestibility of Ruminant Animals: A Review

Enzymes excreted by rumen microbiome facilitate the conversion of ingested plant materials into major nutrients (e.g., volatile fatty acids (VFA) and microbial proteins) required for animal growth. Diet, animal age, and health affect the structure of the rumen microbial community. Pathogenic organisms in the rumen negatively affect fermentation processes in favor of energy loss and animal deprivation of nutrients in ingested feed. Drawing from the ban on antibiotic use during the last decade, the livestock industry has been focused on increasing rumen microbial nutrient supply to ruminants through the use of natural supplements that are capable of promoting the activity of beneficial rumen microflora. Selenium (Se) is a trace mineral commonly used as a supplement to regulate animal metabolism. However, a clear understanding of its effects on rumen microbial composition and rumen fermentation is not available. This review summarized the available literature for the effects of Se on specific rumen microorganisms along with consequences for rumen fermentation and digestibility. Some positive effects on total VFA, the molar proportion of propionate, acetate to propionate ratio, ruminal NH3-N, pH, enzymatic activity, ruminal microbiome composition, and digestibility were recorded. Because Se nanoparticles (SeNPs) were more effective than other forms of Se, more studies are needed to compare the effectiveness of synthetic SeNPs and lactic acid bacteria enriched with sodium selenite as a biological source of SeNPs and probiotics. Future studies also need to evaluate the effect of dietary Se on methane emissions.

Effect of supplementing hydroxy selenomethionine on meat quality of yellow feather broiler

This study was conducted to evaluate the effect of supplementing hydroxy selenomethionine (OH-SeMet) on performance, selenium (Se) deposition in the breast muscle, quality and oxidative stability, and expression of selenoprotein encoding genes of breast meat of the native slow-growing yellow-feathered broiler birds. A total of 375 one-day-old local yellow male birds were randomly assigned into 5 dietary treatments, supplemented with Se 0.0, 0.2, 0.4, 0.6, and 0.8 mg/kg in the form of OH-SeMet. Each treatment consisted of 5 replicates and each replicate had 15 birds, the birds were fed on basal diet containing corn and soybean meal, and the experiment lasted for 63 d. The results showed that dietary Se supplementation linearly increased (P < 0.001) Se contents in both serum and muscle, no significant changes (P > 0.05) were observed on growth performance, yield of breast, meat color, and intramuscular fat deposition of the breast muscle. Dietary Se addition improved water-holding capacity, the pH_24h value, and tenderness of breast muscle, evidenced by a linear decreases of shear force (P < 0.05), accompanied by lower thiobarbituric acid reactive substances and higher glutathione reductase activity. The mRNA abundance of selenoprotein encoding genes also responded to dietary Se levels. It is concluded that, dietary supplementation with OH-SeMet improved muscular Se deposition and meat quality of the native yellow birds, with enhanced antioxidant capability and regulation in selenogenome.

The Effect of Different Sources of Selenium Supplementation on the Meat Quality Traits of Young Charolaise Bulls during the Finishing Phase

The aim of the study was to compare the effects of sodium selenite (SS), selenium yeast (SY), and hydroxy-selenomethionine (OH-SeMet) on the meat quality and selenium (Se) deposition of finishing beef cattle. Sixty-three bulls were distributed over 3 treatments and fed SS, SY, or OH-SeMet at 0.2 mg kg⁻¹ dry matter (DM) for 60 d. None of the Se sources affected the growth performance or carcass characteristics. OH-SeMet showed a higher Se transfer to the meat than SS or SY (p < 0.01). SY and OH-SeMet reduced the shear force of the meat (p < 0.0001), improved pH (p < 0.001), and reduced the drip losses (p < 0.001) and the lipid oxidation of the meat (p < 0.001). During 8 d of storage, OH-SeMet showed higher levels of meat lightness (L*) and yellowness (b*) than SS (p < 0.001), while the SY meat showed a higher L* than SS, albeit only on d 6. OH-SeMet improved b*, compared to SS, and also compared to SY on days 4, 7, and 8 (p < 0.001). Supplementing beef with SY and OH-SeMet improved several meat quality parameters. OH-SeMet appears to be the most effective strategy to improve the Se content and color stability of beef cattle meat.

Quality, nutrient and sensory characteristics of aged meat from lambs supplemented with selenomethionine

Selenium (Se) as a co-factor of antioxidant enzymes is metabolically essential for animals. Its presence in muscle can improve the oxidative stability of meat and is a desirable nutrient for consumers. A novel approach to Se supplementation for meat-producing livestock was demonstrated in a 95-day study of young lambs. DL-selenomethionine (SeMet) was administered by subcutaneous injection at day 0 (3-4 weeks of age) and again at day 54. A Control group (n = 9) received carrier only, whilst Medium and High groups (n = 10) received graded levels of Se. Physicochemical attributes of meat quality and sensory characteristics were measured at 1, 3, 14 and 42 days of ageing (vacuum packaged at -1.5 °C), followed by instrumental colour measurements after 7 days of simulated retail display. There were no significant interactions between SeMet treatment and ageing. Muscle pH, drip and cooking losses, initial display colour and sensory evaluations by trained and consumer panels were unaffected by treatment. Smaller changes in colour during display were observed for the Medium group compared to Control (P < 0.05). The shorter range of ageing times improved meat tenderness however extended ageing decreased colour stability. SeMet markedly increased Se concentrations in muscle, blood, kidney and liver (P < 0.05), resulting in Se enriched meat without appreciable changes in meat quality.

Effects of Dietary Supplementation with Selenium and Vitamin E on Growth Performance, Nutrient Apparent Digestibility and Blood Parameters in Female Sika Deer (Cervus nippon)

To evaluate the effects of selenium (Se) and vitamin E (Vit E) on female sika deer. This study was conducted using a 3 × 2 + 1 factorial experiment. Depending on treatment design, the deer were fed with the basal diet supplemented with 0.2, 0.3, and 0.4 mg of selenium as well as 100 and 200 IU of vitamin E per kg of dry matter (DM). Accordingly, six groups named G1 to G6 are involved in this study. In addition, group G0 was available in the study, in which the deer were fed with only basal diet. The results show that the final body weight (BW), average daily gain (ADG), and apparent digestibility of crude protein, ether extract, and neutral detergent fiber of the deer in G1 to G6 increased as the selenium level increased from 0.2 to 0.3 mg per kg of DM (P < 0.05). Higher IgG content of the deer was observed with the intake of selenium and vitamin E (P < 0.05). The total content of protein of the deer in G3 was higher than that in G0 (P < 0.05), and the activity of glutathione peroxidase increased following the increase in the supplementation levels of selenium and vitamin E (P < 0.05). Furthermore, selenium had significant effects on the concentration of T4 and T3 (P < 0.05). The optimum levels of selenium and vitamin E for 1-year-old female sika deer were 0.3 mg and 100 IU per kg of dietary DM, respectively.

Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review

Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Se intake in humans is often low and very seldom excessive, and its bioavailability depends also on its chemical form, with organic Se as the most available after ingestion. The main dietary source of Se for humans is represented by plants, since many species are able to metabolize and accumulate organic Se in edible parts to be consumed directly (leaves, flowers, fruits, seeds, and sprouts) or after processing (oil, wine, etc.). Countless studies have recently investigated the Se biofortification of plants to produce Se-enriched foods and elicit the production of secondary metabolites, which may benefit human health when incorporated into the diet. Moreover, feeding animals Se-rich diets may provide Se-enriched meat. This work reviews the most recent literature on the nutraceutical profile of Se-enriched foods from plant and animal sources.

Potential effect of the microbial fermented feed utilization on physicochemical traits, antioxidant enzyme and trace mineral analysis in rabbit meat

The study investigated the potential effect of the microbial fermented feed utilization on physicochemical traits, antioxidant enzyme and trace mineral analysis in rabbit meat. A total of 72 six-week-old male rabbits were weighed and randomly divided into four groups (1) (SRKC) control; (2) (SRKP) Lactobacillus plantarum 1 × 10⁶  cfu/g fresh weight (FW); (3) (SRKG) Pediococcus acidilactici 1 × 10⁶ cfu/g FW and (4) (SRKPG) P. acidilactici + L. plantarum 1 × 10⁶ cfu/g FW. Performance characteristic, weekly body weight, was positively (p < .05) enhanced, while daily feed intake (DFI) and feed convention ratio (FCR) were not influenced in treatments group as compared to untreated. The water, protein, water holding capacity (WHC) and dry matter (DM) concentration were positively (p < .05) influenced, while ash, pH, lightness, redness and yellowness were not influenced in treated group as compared to untreated. The concentration of glutathione peroxidase (Gpx), superoxide dismutase (SOD) and aspartate aminotransferase (AST) was positively (p < .05) influenced in treatments group as compared to control. Regarding trace minerals, copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) were positively (p > .05) reduced in treated group as compared to untreated. It is concluded that the addition of lactic acid bacteria (L. plantarum and P. acidilactici) in Hybrid pennisetum silage had a constructive influence on rabbit health performance and meat biochemistry.

Performance, carcass characteristics and meat quality of Nellore cattle supplemented with supranutritional doses of sodium selenite or selenium-enriched yeast

The enrichment of meat with selenium is important to improve the intake of selenium by humans. The effects of supranutritional doses of sodium selenite or selenium-enriched yeast on performance, carcass characteristics and meat quality were evaluated using 63 Nellore cattle in a completely randomized design with two sources (sodium selenite and selenium-enriched yeast), three levels (0.3, 0.9 and 2.7 mg Se/kg DM) and control treatment (without addition of selenium). Final body weight (BW), average daily gain, dry matter intake and gain to feed ratio (G : F) at the end of 84 days of supplementation were not influenced by treatments (P>0.05). Values of pH, ribeye area, back fat thickness and marbling score were also not influenced by treatments ( P>0.05). Dressing percentage was greater (P=0.02) in Nellore cattle supplemented with organic Se (58.70%) compared to animals supplemented with inorganic Se (57.94%). Hot carcass weight increased ( P=0.05) with the increasing of Se levels in the diet. Colour, shear force (SF), cooking and drip loss remained unchanged ( P>0.05); however thiobarbituric acid reactive substances was 15.51% higher with inorganic Se compared with organic Se. The selenium concentration in the meat of animals receiving organic selenium was higher ( P<0.001) than that of animals receiving sodium selenite, at all levels (0.3; 0.9 and 2.7 mg/kg DM). The meat of animals receiving 2.7 mg of organic Se/kg of DM presented concentration of 372.7 μg Se/kg in the L.dorsi muscle, and the intake of 150 g of this meat by humans provides approximately 100% of the recommended Se intake (55 μg Se/day for adults). Therefore, the use of supranutritional doses of 2.7 mg Se/kg of DM, regardless of source, is a way of naturally producing selenium-enriched meat without compromising performance, carcass characteristics and quality of Nellore bovine meat.

Effects of Selenium- and Chromium-Enriched Diets on Growth Performance, Lipid Profile, and Mineral Concentration in Different Tissues of Growing Rabbits

The aim of this study was to investigate the effect of dietary supplementation with different sources of selenium and/or organic chromium on the growth performance, digestibility, lipid profile, and mineral content of hair, liver, and fore and hind limb of growing rabbits. A total of 150 weanling New Zealand White (NZW) male rabbits were randomly allotted to six dietary treatment groups: (1) basal diet (control group), (2) basal diet + 0.6 mg sodium selenite/kg diet, (3) basal diet + 0.6 mg selenium yeast/kg diet, (4) basal diet + 0.3 mg sodium selenite/kg diet + 0.3 mg selenium yeast/kg diet, (5) basal diet + 0.6 mg chromium yeast/kg diet + 0.6 mg selenium yeast/kg diet, (6) basal diet + 0.6 mg chromium yeast/kg diet. Only the combination between inorganic and organic selenium led to significant improvement in body weight, body weight gain, and feed conversion ratio. Carcass traits were not different in all groups. Selenium (Se) and chromium (Cr) were deposited in the tissues of rabbits fed diets supplemented with Se and Cr, respectively. Blood serum in both of selenium- and chromium-supplemented groups showed declined total cholesterol, triglycerides, and low-density lipoprotein (LDL). Group supplemented with organic chromium showed higher high-density lipoprotein (HDL) than the other groups. It could be concluded that using a mixture of inorganic and organic Se has a positive effect on the growth performance of growing rabbits. Both Se and Cr have hypocholesterolemic effect. Both of Se and Cr can be deposited in the meat and other tissues of rabbits and that improves meat quality which positively reflects on human acceptance. The combination between inorganic (0.3 mg sodium selenite/kg diet) and organic selenium (0.6 mg selenium yeast/kg diet) improved growth performance traits of growing rabbits.

Impacts of selenium and vitamin E supplementation on mRNA of heat shock proteins, selenoproteins and antioxidants in broilers exposed to high temperature

The study was carried out to investigate the effect of dietary selenium (Se) and vitamin E (VE) supplementation on mRNA level of heat shock proteins, selenoproteins, and antioxidant enzyme activities in the breast meat of broilers under summer heat stress conditions. A total of 200 male broilers (Ross 308) of 1 day age were randomly separated into 4 groups in a complete randomized design and were given a basal diet (Control, 0.08 mg Se/kg diet) or basal diet supplemented with VE (250 mg/kg VE), sodium selenite (0.2 mg/kg Se), or Se + VE (0.2 mg/kg Se + 250 mg/kg VE) to investigate the expression of key antioxidant and heat shock protein (HSP) genes under high temperature stress. Dietary Se, VE and Se + VE significantly enhanced the activities and mRNA levels of catalase as well as superoxide dismutase (SOD) but decreased the mRNA levels of HSP70 and HSP90. Se alone or combined with VE increased the concentration of selenoprotein P and selenoproteins mRNA level and decreased the expression of HSP60. In addition, Se and Se + VE significantly enhanced the glutathione peroxidase (GPx) activity and the expression of GPx1 and GPx4 in breast muscle tissues. It is noteworthy that all the treatments significantly decreased malondialdehyde (MDA) level in the breast meat. Overall results showed that Se in combination with VE has maximal effects to mitigate heat stress. Based on given results it can be recommended that Se + VE are a suitable dietary supplement for broilers to ameliorate the negative effects of summer heat stress conditions.

Impact of vitamin E and selenium on antioxidant capacity and lipid oxidation of cheddar cheese in accelerated ripening

Background

Ripening of cheddar cheese is a time taking process, duration of the ripening may be as long as one year. Long ripening time is a big hindrance in the popularity of cheese in developing countries. Further, energy resources in these countries are either insufficient or very expensive. Therefore, those methods of cheese ripening should be discovered which can significantly reduce the ripening time without compromising the quality characteristics of cheddar cheese. In accelerated ripening, cheese is usually ripened at higher temperature than traditional ripening temperatures. Ripening of cheddar cheese at high temperature with the addition of vitamin E and selenium is not previously studied. This investigation aimed to study the antioxidant activity of selenium and vitamin E in accelerated ripening using cheddar cheese as an oxidation substrate.

Methods

The ripening of cheddar cheese was performed at 18 °C and to prevent lipid oxidation, vitamin E and selenium were used alone and in combination. The treatments were as: cheddar cheese without any addition of vitamin E and selenium (T1), cheddar cheese added with 100 mg/kg vitamin E (T₂), 200 mg/kg vitamin E (T₃), 800 μg/kg selenium (T₄), 1200 μg/kg selenium (T₅), vitamin E 100 mg/kg + 800 μg/kg selenium (T₆) and vitamin E 200 mg/kg + 1200 μg/kg selenium (T₇). Traditional cheddar cheese ripne ripened at 4-6 °C for 9 months was used as positive control. Cheese samples were ripened at 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 6 and 12 weeks of storage. All these treatments were compared with a cheddar cheese without vitamin E, selenium and ripened at 4 °C or 12 weeks. Vacuum packaged cheddar cheese was ripened 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 4 and 8 weeks of storage period.

Results

Addition of Vitamin E and selenium did not have any effect on moisture, fat and protein content of cheddar cheese. After 6 weeks of ripening, total antioxidant capacity of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese were 29.61%, 44.7%, 53.6%, 42.5%, 41.4%, 64.1%, 85.1% and 25.4%. After 6 weeks of ripening, reducing power of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and SC cheese were 14.7%, 18.1%, 26.3%, 19.2%, 25.3%, 33.4%, 40.3% and 11.6%. After 6 weeks of ripening, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of T₆ and T₇ were 54.2% and 66.9%. While, DPPH free radical scavenging activity of T₁ and standard cheese after 6 weeks of ripening were, 19.1 and 18.5%, respectively. Free fatty acids of vitamin E and selenium supplemented, non-supplemented and standard cheese were not significantly influenced from each other in 0, 6 and 12 weeks old cheddar cheese. Peroxide values of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese after 6 weeks of accelerated ripening were 1.19, 1.05, 0.88, 1.25, 0.29, 0.25, 0.24 and 0.28 (MeqO₂/kg). After 6 weeks of ripening, anisidine value of T₆ and T₇ were 6.55 and 6.14. Conjugated dienes of T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese, after 6 weeks of accelerated ripening were 0.61, 0.55, 0.42, 0.77, 0.65, 0.17, 0.15 and 0.19. After 6 weeks of accelerated ripening, concentrations unsaturated fatty acids in T₁, T₂, T₃, T₄, T₅, T₆, T₇ and standard cheese decreased by18.19%, 17.45%, 16.82%, 16.19%, 12.71%, 8.48%, 6.92% and 14.71%. After 12 weeks of accelerated ripening, concentration of unsaturated fatty acids in T₁, T₂, T₃, T₄, T₅, T₆ and T₇ and standard cheese decreased by 26.2%, 21.2%, 18.7%, 14.2%, 10.4%, 4.84%, 1.03% and 6.78%. Cheddar cheese samples added with vitamin E, selenium and their combinations produced more organic acids during the ripening period of 12 weeks. After 6 and 12 weeks of ripening, flavor score of T₆ and T₇ was better than standard ripened cheddar cheese.

Conclusions

After 6 weeks of accelerated ripening, sensory characteristics of T₆ and T₇ were similar to cheddar cheese that was ripened at 4 °C for 9 months. Ripening time of cheddar cheese may be reduced to 6 weeks by elevated temperature (18 °C) using vitamin E and selenium as antioxidants at T₆ and T₇ levels.

Protein profile and physicochemical characteristics of meat of lambs fed diets supplemented with rapeseed oil, fish oil, carnosic acid, and different chemical forms of selenium

Abstract. The objective of this study was to evaluate the physicochemical characteristics of the longissimus muscle of lambs fed a control diet containing 3 % rapeseed oil (RO) (group I); an experimental diet with 2 % RO and 1 % fish oil (FO) (group II); or experimental diets with coupled addition of 2 % RO, 1 % FO, and 0.1 % carnosic acid (CA) (group III) without/with 0.35 ppm Se as selenized yeast (SeY) (group IV) or selenate (SeVI as sodium selenate, Na2SeO4) (group V). The results showed that dietary FO or SeVI affected the ultimate pH and meat color in comparison to lambs fed the control diet. The differences noted between diets in the case of muscle tissue were as follows: myosin HC (heavy chain) and LC1 (light chain), 150 kDa, α-actinin, 60 kDa, and TnT (troponin T), 30 kDa protein. The addition of FO to lamb diets resulted in a lower content of 30 kDa proteins, which are indicators of proteolysis. Considering the protein profile of drip loss, results showed effects of dietary administration of FO, CA, and Se (as SeY and SeVI) on the abundance of the following sarcoplasmic proteins: AMPDA (AMP deaminase), PGM (phosphoglucomutase), PK/PGI (pyruvate kinase/phosphoglucose isomerase), CK/PGAK (creatine kinase/phosphoglycerate kinase), ALD (aldolase), LDH (lactate dehydrogenase), PGAM (phosphoglycerate mutase), and TPI (triosephosphate isomerase). The lower content of TPI (in group II with comparison to groups III–V) and PGAM (in group II with comparison to group I and III) could be due to a higher ultimate pH in the group with FO addition, whereas lower contents of CK/PGAK, ALD, and LDH were attributed to Se addition. In comparison to the control diet, all experimental diets without SeVI decreased the content of the sum of all assayed amino acids ( ∑ AAs), indispensable amino acids ( ∑ IAAs), and dispensable amino acids ( ∑ DAAs) in the muscle. The highest ratios of  ∑ IAAs to  ∑ DAAs and  ∑ IAAs to  ∑ AAs were found in the muscle of lambs fed the diet containing RO, FO, and CA. The FO-supplemented diet with CA and SeVI increased the abundance of methionine in the muscle in comparison to the control diet and the FO-supplemented diet without/with CA.

A role for Sel-Plex™, a source of organic selenium in selenised yeast cell wall protein, as a factor that influences meat stability

Selenium is an important mineral required in the antioxidant system in animals, which is involved with oxidative stability in tissues, particularly membranes, and is involved in various aspects of meat quality and stability on the shelf, due to its protective properties on lipids, preventing rancidity. Se can be supplied in an inorganic or chemically organic form, and it is well known that the latter has beneficial properties and improved functionality in physiological systems compared to the former. Research has shown that organic Se is associated with increased tenderness and the prevention of certain problems in pale exudative meat, discolouration and off-flavours and odours in meat, although this depends on other components of the antioxidant system, such as vitamin E, being present as well. The change in prominence of glutathione peroxidase forms in their interaction with vitamin E in cell membranes is also noted. The following review (the third in a series) details the research that has been conducted into the role of Se in meat stability and related factors, with specific focus on organic forms of Se, namely the commercial product Sel-Plex™ (Alltech Inc, Nicholasville, KY, USA), which is derived from yeast and in which selenium replaces sulphur in methionine forming selenomethionine in yeast protein.

Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves

The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( < 0.05) in the HEAD/HEART group (45.08 ± 0.72) than the CONTROL group (47.10 ± 0.72). There were no differences ( > 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( < 0.05) than that from the HEAD/HEART group (6,656.4 ± 143.5 g). Overall, the data indicated no difference between the CONTROL and HEAD/HEART groups with regard to animal welfare because the initial stun was effective in all calves. However, longissimus thoracis L* and blood yield were negatively impacted by the HEAD/HEART method. The data in this study suggest that secondary induction of cardiac arrest is not necessary with effective nonpenetrating captive bolt stunning in veal calves.

Sel-Plex™, a source of organic selenium in selenised yeast protein, as a factor that influences meat quality

The storage and cooking quality of meat is dictated by the ability of muscle cells to effectively hold water. If this ability is diminished, then presentation at time of purchase is poorer, as the packaging fills with watery exudates (termed ‘drip loss’), which is detrimental to sales. In addition, these losses affect cooking and eating sensory qualities. It is known that antioxidants play a major role in ensuring robustness of the cell membrane in muscle, and within this, selenium (Se) plays a major part, being an essential component within an antioxidant enzyme system and its interaction with vitamin E within membranes. The following review examines the body of evidence for Se as an antioxidant to preserve water holding capacity, especially with reference to using a chemically organic form of the mineral which is akin to those forms found in natural feed materials.

Effects of dietary supplementation of selenium and iodine on growth performance, carcass characteristics and histology of thyroid gland in goats

This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty-four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat.

Meat composition and quality of young growing Belgian Blue bulls offered a fattening diet with selenium enriched cereals

Mehdi, Y., Clinquart, A., Hornick, J.-L., Cabaraux, J.-F., Istasse, L. and Dufrasne, I. 2015. Meat composition and quality of young growing Belgian Blue bulls offered a fattening diet with selenium enriched cereals. Can. J. Anim. Sci. 95: 465–473. The objective of this study was to evaluate the effects of selenium (Se) enrichment of cereals on the performance of Belgian Blue bulls, meat quality and chemical composition. Twenty-three bulls were used in the present study. Twelve bulls were offered a control diet containing Se at a basal concentration of 58 µg kg−1 of dry matter (DM) and the other 11 bulls were given a diet containing 173 µg kg−1 DM of Se by means of Se-enriched spelt and barley. The Se enrichment of the diet did not affect the growth performance, the slaughter data or meat quality (P > 0.05). There were no effects of Se on tenderness, oxidative rancidity and water losses. However, there were some effects of Se enrichment on the meat chemical composition. The ether extract was decreased from 2.1 to 1.7% DM (P<0.05). There was also significant Se enrichment (P<0.001) in the longissimus thoracis muscle (177 vs. 477 ng g−1 DM) and organs: liver (474 vs. 1126 ng g−1 DM) and kidney (4956 vs. 5655 ng g−1 DM), Under such conditions, the human consumption of a piece of such meat or liver can provide a large part of the recommended daily Se intake, estimated between 30 and 57%.

Effects of housing systems and the diet supplements on the slaughter value and concentration of mineral elements in the loin muscle of lambs

The objective of this study was to investigate the effect of maintenance system as well as the effect of Se, Zn, and vitamin E supplementation of ram-lambs on the slaughter value and concentration of mineral elements in the loin muscle of lambs. The experiment was conducted on 72 Polish Merino ram-lambs divided into three groups: group C, indoor with no supplement, 19 lambs; S, indoor with supplement, 23 lambs; G, outdoor with no supplement, 30 lambs. From birth all the lambs were maintained indoor with their dams and then weaned at the age of 8 weeks. The rams from group C and S were placed in individual straw-bedded pens and fattened individually with concentrate mixture offered ad libitum until the age of 16 weeks. The lambs from group G were grazed every day from May to July (2 months). During the fattening period each lamb from the supplemented group S was administered per os 1 mL 0.1% Na₂SeO₄ (Se, 0.42 mg), 3 mL 10% ZnSO₄ (Zn, 68 mg), and 1 mL premix protect vitamin E (0.1 g α-tocopherol, 5 mg lysine, 5 mg methionine) daily. A comparison of half carcasses across the groups has shown no difference between the control group and the one with supplements, while the weight of half carcasses in the grazing group was smaller in comparison with groups C and S (p<0.001). The meat content in the pelvic limb showed no differences across all groups under study. The pelvic limb of grazing lambs contained less fat compared to the control and supplemented groups (p<0.001). The concentrations of Se and Zn in the blood plasma of ram-lambs from the supplemented group were significantly higher than for the control and grazing lambs. Inorganic Se and Zn supplementation with vitamin E to the diet of lambs increased Se and Zn levels in loin muscle (p<0.001) to 0.46 μg/g and 32.9 μg/g in fresh tissue, respectively.

Fatty Acid Profiles of Supraspinatus, Longissimus lumborum and Semitendinosus Muscles and Serum in Kacang Goats Supplemented with Inorganic Selenium and Iodine

Fat and fatty acids in muscle and adipose tissues are among the major factors influencing meat quality particularly nutritional value and palatability. The present study was carried out to examine the effects of supplementing inorganic selenium (Se), iodine (I) and a combination of both on fatty acid compositions in serum, and supraspinatus (SS), longissimus lumborum (LL), and semitendinosus (ST) muscles in goats. Twenty-four, 7 to 8 months old, Kacang male goats with a mean live weight of 22.00±1.17 kg were individually and randomly assigned into four groups of six animals each for 100 d of feeding prior to slaughter. The animals were offered the same concentrate (basal) diet as 1% of body weight with ad libitum amount of fresh guinea grass. The four groups were as follows: T1 (control) - basal diet without supplementation; T2 - basal diet with 0.6 mg Se/kg DM; T3 - basal diet with 0.6 mg I/kg DM; T4 - basal diet with combination of 0.6 mg Se/kg DM and 0.6 mg I/kg DM. The major fatty acids (FAs) detected in the serum were palmitic (C16:0), stearic (C18:0), oleic (C18:1n9) and linoleic (C18:2n-6), while the major FAs in the selected muscles were C16:0, C18:0 and C18:1n9 acids. The main polyunsaturated fatty acids (PUFA) detected in muscles and serum were (CI8:2n-6), linolenic acid (C18:3n-3), and arachidonic acid (C20:4n-6). No significant differences (p>0.05) were observed in the concentration of total saturated fatty acids (SFA) among the four groups. PUFA concentrations in the goats supplemented with Se (T2) were significantly higher (p<0.05) than the goats of the control group (T1). The PUFA: SFA ratio was significantly higher in the animals supplemented with dietary Se (T2) than those of control ones (T1). It is concluded that dietary supplementation of inorganic Se increased the unsaturated fatty acids in muscle. The supplementation of iodine with or without Se had negligible effects on muscle fatty acid content of Kacang crossbred male goats.

Effects of the Programmed Nutrition Beef Program on meat quality characteristics

The objective of this study was to examine the effects of alternative finishing strategies on beef steak color and cooked meat characteristics. Beef steers (n = 64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement and initial body weight serving as the blocking factor. Factor 1 consisted of dietary treatment with cattle either being fed a conventional feedlot diet (CON) or a diet that included Programmed Nutrition Beef Program supplements. Cattle in the Programmed Nutrition (PN) treatments were fed in two-stages: 1) the basal diet with Programmed Nutrition Beef Receiver from d 1 to 20 and the basal diet with Programmed Nutrition Beef Finisher from d 21 to harvest. Factor 2 consisted of the inclusion (EGP+) or absence (EGP-) of an exogenous growth promoting program. Steers in the EGP+ treatments were implanted initially with Component E-S, reimplanted with Component TE-IS, and fed 400 mg · d(-1) · steer(-1) of ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175 of feeding and 1 strip loin was removed from 2 carcasses selected at random from each pen for transport to Kansas State University. After 14 d of aging, loins were fabricated into 2.54-cm thick steaks for objective and trained sensory panel measurement of cooked meat characteristics and objective color measurements during 7 d retail display. There were no interactions (P > 0.10) between feeding strategy and exogenous growth promotants for all objective measures of color and cooked meat characteristics. Throughout the display period, PN steaks were darker (P = 0.02) than CON steaks, but surface percentages of oxymyoglobin and metmyoglobin and metmyoglobin reducing ability were unaffected by feeding strategy (P > 0.10). Loins and steaks from PN cattle possessed decreased moisture loss during aging and cooking (P < 0.01). Trained sensory panel evaluation of cooked meat revealed a dietary program × growth promotant interaction for myofibrillar tenderness, connective tissue amount, and overall tenderness (P = 0.01). Compared to the CON/EGP- and PN/EGP- treatments, steaks from the CON/EGP+ and PN/EGP+ treatments were evaluated by panelists as being less myofibrillar and overall tender (P < 0.05). The alternative feeding strategies presented in this study can favorably impact water-holding capacity without negatively compromising retail display discoloration.

Dietary walnut oil modulates liver steatosis in the obese Zucker rat

Purpose

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. We aimed to clarify the impact of dietary walnut oil versus animal fat on hepatic steatosis, representing the initial step of multistage pathogenesis of NAFLD, in Zucker obese rats.

Methods

Zucker lean ad libitum (a.l.), Zucker obese a.l. or Zucker obese pair fed (p.f.) to the lean received isocaloric diets containing 8 % walnut oil (W8), W14 or 14 % lard (L14) (n = 10/group). Body weight, clinical serology, liver weight, lipid content and fatty acid composition and hepatic lipid metabolism-related transcripts were evaluated.

Results

Compared to lean, Zucker obese a.l. and p.f. showed hepatic triacylglyceride (TAG) accumulation. In Zucker obese p.f., W14 compared to W8 and L14 reduced liver lipids, TAG as well as hepatic omega-6 (n-6)/n-3 ratio and SCD activity index [(C18:0 + C18:1)/C18:0 ratio] paralleled by decreased lipoprotein lipase mRNA in obese p.f. and elevated microsomal triglyceride transfer protein mRNA in lean and obese. Further, W14 elevated the fasting blood TAG and reduced cholesterol levels in obese.

Conclusions

In our model, consumption of W14 inhibited hepatic lipid accumulation along with modulated hepatic gene expression implicated in hepatic fatty acid influx or lipoprotein assembly. These results provide first indication that dietary lipids from walnut oil are modulators of hepatic steatosis as the initial step of progressive NAFLD pathogenesis.

Effects of dietary selenium supplementation on tissue selenium distribution and glutathione peroxidase activity in Chinese Ring necked Pheasants

The objective of this study was to determine the concentration of total selenium (Se) and the proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the postmortem tissues of female pheasants (Phasianus Colchicus Torquator) offered diets that contained graded additions of selenised-enriched yeast (SY) or a single comparative dose of sodium selenite (SS). Thiobarbituric acid reactive substances (TBARS) and tissue glutathione peroxidase (GSH-Px) activity of breast (Pectoralis Major) were assessed at 0 and 5 days postmortem. A total of 216 female pheasant chicks were enrolled into the study. Twenty-four birds were euthanased at the start of the study, and samples of blood, breast muscle, leg muscle (M. Peroneus Longus and M. Gastrocnemius), heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments (n = 48 birds/treatment) that either differed in Se source (SY v. SS) or dose (control (0.17 mg total Se/kg), SY-L and SS-L (0.3 mg/kg total Se as SY and SS, respectively) and SY-H (0.45 mg total Se/kg)). Following 42 and 91 days of treatment, 24 birds per treatment were euthanased, and samples of blood, breast muscle, leg muscle, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and TBARS were determined in breast tissue at the end of the study. There were increases in both blood and tissues to the graded addition of SY to the diet (P < 0.001), but the same responses were not apparent with the blood and tissues of selenite-supplemented birds receiving a comparable dose (SY-L v. SS-L). Although there were differences between tissue types in the distribution of SeMet and SeCys, there were few differences between treatments. There were effects of treatment on erythrocyte GSH-Px activity (P = 0.012) with values being higher in treatments SY-H and SS-L when compared with the negative control and treatment SY-L. There were no effects of treatment on tissue GSH-Px activity, which is reflected in the overall lack of any treatment effects on TBARS.

Effects of dietary sodium selenite and selenium yeast on antioxidant enzyme activities and oxidative stability of chicken breast meat

The effects of sodium selenite (SS) and selenium yeast (SY) alone and in combination (MS) on the selenium (Se) content, antioxidant enzyme activities (AEA), total antioxidant capacity (TAC), and oxidative stability of chicken breast meat were investigated. The results showed that the highest (p < 0.05) glutathione peroxidase (GSH-Px) activity was found in the SS-supplemented chicken breast meat; however, SY and MS treatments significantly increased (p < 0.05) the Se content and the activities of catalase (CAT), total superoxide dismutase (T-SOD), and TAC, but decreased (p < 0.05) the malondialdehyde (MDA) content at 42 days of age. Twelve days of storage at 4 °C decreased (p < 0.05) the activity of the GSH-Px, but CAT, T-SOD, and TAC remained stable. SY decreased the lipid oxidation more effectively in chicken breast meat. It was concluded that SY and MS are more effective than SS in increasing the AEA, TAC, and oxidative stability of chicken breast meat.

Reducing lipid peroxidation for improving colour stability of beef and lamb: on-farm considerations

Meat colour and lipid stability are important sensory properties. Myoglobin oxidation is correlated with lipid oxidation, and one can exacerbate the occurrence of the other. Approaches to reduce both oxidative processes could focus on minimising oxidising agents in meat. In on-farm practices, dietary supplementation of antioxidants is a useful approach for improving lipid stability and then meat colour stability, and further improvement could be a combination of using hydrophobic and hydrophilic antioxidants. Genetic variations in the endogenous antioxidant systems could be identified for the development of a breeding strategy to bring a long-term benefit to the meat industry. To have a better understanding of oxidative stress and oxidation of long chain unsaturated fatty acids in live animals, the isoprostanes could be measured as an effective marker in vivo.

Effects of excessive selenium supplementation to diet contaminated with deoxynivalenol on blood phagocytic activity and antioxidative status of broilers

This study examined the effects of excessive dietary supplementation with organic selenium on phagocytic activity and antioxidative status of chickens for fattening fed diet contaminated with deoxynivalenol (DON). Sixty chickens of Ross 308 hybrids were at day of hatching divided into four groups with 15 birds in each. The background DON dietary levels in both negative and positive control groups were 0.2 mg/kg. The complete feed for positive control group was supplemented with Se dose 1 mg/kg in the form of Se-yeast. Group 3 was fed diet with DON level 3 mg/kg while diet for group 4 combined DON level 3 mg/kg with a excessive supplement of Se-yeast (Se dose 1 mg/kg). After 6 weeks of dietary intake, six randomly-chosen chickens from each group were sampled. Feeding of contaminated diet resulted in significantly reduced blood phagocytic activity (19.5 ± 1.1% in the negative control vs. 12.8 ± 0.8% in the DON-treated group, p < 0.05). Se-yeast supplemented to the DON contaminated diet prevented suppression of phagocytic activity. Dietary intake of DON at levels 3 mg/kg did not influence the plasma α-tocopherol level while excessive dietary Se dose reduced it in both Se supplemented groups. Neither the birds of DON-treated group nor the birds from group 4 with DON and Se-yeast showed any response in plasma γ-glutamyltransferase (GGT) activity. Subtoxic dietary level of DON significantly increased the activity of glutathione peroxidase (GPx) in the duodenal mucosa, while additional Se supplementation prevented such a response to mycotoxin. On the other hand, both Se supplemented groups showed significantly elevated GPx activities in blood, liver and kidney, (p < 0.05). The results suggest a potential ability of excessive supplementation of organic selenium to prevent the blood phagocytic activity suppression and changes in GPx activity in duodenal tissue induced in broilers by subtoxic dietary levels of DON.

Enhanced water-holding capacity of meat was associated with increased Sepw1 gene expression in pigs fed selenium-enriched yeast

To study the effect of selenium-enriched yeast (SeY) level on selenoprotein genes expression and the relation between gene expression and antioxidant status and meat quality, 30 selenium (Se)-depleted pigs (7-week old, 10.30±0.68 kg) were randomly divided into 3 groups and fed a basal diet plus 0, 0.3 and 3.0 mg Se/kg as SeY for 8 weeks. Results showed that dietary SeY supplementation improved the antioxidant status in muscle. The increased levels of SeY decreased (P<0.05) the drip loss and the concentration of thiobarbituric acid reactive substances in the muscle and meat. However, increased dietary SeY intake quadratically increased (P<0.01) the mRNA level of Sepw1 gene among the 12 selenoprotein genes examined in muscle. Statistical analysis showed drip loss was negatively correlated with the mRNA level of Sepw1 gene. These suggested that the enhanced water-holding capacity of meat was associated with the increased expression of Sepw1 gene.

Selenium distribution in camel blood and organs after different level of dietary selenium supplementation

Eight young female camels shared in four groups of two 2 years received a basal diet enriched respectively with 0, 2, 4, and 8 mg selenium under sodium selenite form for 64 days. Feed intake was assessed daily; blood samples were taken on weekly basis. One camel from each group was killed at the end of the experiment. Se concentration in serum was increased significantly in the supplemented groups with an average of 176.3 +/- 18.0 ng/mL in the control group, 382.7 +/- 107.6 in the group receiving 2 mg Se, 519.8 +/- 168.4 in the group receiving 4 mg Se, and 533.4 +/- 158.6 in the group receiving 8 mg Se daily. For glutathione peroxidase (GSH-Px) activity, the control group (51.0 IU/g Hb) and the group receiving 2 mg (50.5 IU/g Hb) were significantly different than groups receiving 4 and 8 mg (respectively, 65.9 and 76.1 IU/g Hb). No significant variation occurred for vitamin E (mean, 0.56 +/- 0.23 ng/mL). Significant correlation between serum Se and GSH-Px was reported. Kidney was the richest organ in selenium followed by lung, spleen, and liver, but the increase in supplemented groups was more marked in liver and kidney. The hair seemed to be the best indicator of selenium intake in camel.

Antibacterial action of selenium-enriched probiotics against pathogenic Escherichia coli

The purpose of this study was to evaluate the inhibitory activity of selenium-enriched probiotics against pathogenic Escherichia coli (E. coli) in vitro and in vivo. Escherichia coli was co-cultured in vitro with each probiotic strain individually, and a mixture of the four strains and its population was counted at various time points. We also collected a cell-free culture supernatant (CFCS) of each probiotic strain and the four-strain mix to examine their antibacterial activity, using the cylinder plate method. Results demonstrated that co-culture with probiotics significantly reduced the number of E. coli. The different sizes of the inhibition zones made by each CFCS proved that E. coli was inhibited by the metabolites of the probiotics. In vivo, Kunming mice were allocated to different groups supplemented with selenium-enriched and other probiotics. After 28 days, the mice were inoculated with pathogenic E. coli so that we could compare mortality rates and inspect other indexes of each treatment. The mortality of the group with selenium-enriched probiotics was the lowest. In addition, the organic antioxidant status improved, immunity was fortified, and the internal environment of the intestinal tract was enhanced with selenium-enriched probiotic supplementation. In conclusion, selenium-enriched probiotics can strongly antagonize pathogenic E. coli in vitro and in vivo.

Effects of selenium source and level of supplementation on the performance and meat quality of lambs

Objective of this study was to evaluate the performance, the quality and oxidative stability of meat, the total Se and specific selenoamino-acids content of muscle of lambs that were fed diets supplemented from different Se sources and at different levels. Forty-eight Apennine lambs 30day old (12.78±0.94kg) received, during a 63day period, a total mixed ration (TMR) which was either Se unsupplemented (Control group - background only- 0.13mg/kg Se) or supplemented with Na selenite (0.30mg/kg Se as sodium selenite) or selenium enriched yeast (0.30mg/kg and 0.45mg/kg Se as Se-yeast). Growth performance, feed to gain ratio, carcass and meat quality (pH, drip and cooking losses, colour, GSH-Px activity and chemical analysis) did not show any difference between the treatments. Meat colour and oxidative stability during 9 days of refrigerated storage were unaffected by dietary supplementation, suggesting that, at the levels of Se used in this experiment, dietary Se, even from an organic source, had limited potential for reducing lipid oxidation. Selenium supplementation raised the Se content in muscle (P<0.001) with the greatest increase when Se-yeast was fed. Although selenite increased total Se, it did not influence total or specific selenoamino-acids in this tissue. On the contrary, Se-yeast supplementation led to an increase in muscle Se-methionine content. We conclude that Se supplementation can increase significantly muscle Se levels and produce, particularly when Se-yeast is fed, a source of Se enriched meat as Se-methionine.

Effect of different selenium supplementation levels on selenium status in camel

Twelve female camels divided into three groups received, after a 2-week adaptation period, an oral Se supplementation (0, 2, and 4 mg, respectively) under sodium selenite form for 3 months. Feed intake was assessed daily, blood samples and body weight were taken on a weekly basis, and feces and urine samples were collected every 2 weeks up to 1 month after the end of the supplementation period. The Se concentration in serum was increased significantly in supplemented groups. The maximum level was observed in the period of supplementation in the camel receiving 4 mg (492.5 ng/mL), which was fourfold higher than the value at the beginning of the trial (126 to 138.5 ng/mL according to the groups). The selenium concentration increased significantly in urine and feces but to a lesser extent. A similar trend was observed with glutathione-peroxidase (GSH-Px) values varying between 8.4 and 96.5 IU/g Hb. However, no difference occurred between the two groups receiving 2 or 4 mg Se at the supplementation period. Vitamin E (mean 1.13 +/- 0.61 microg/mL with range 0.27-3.09) did not change significantly. Significant correlations were reported between serum Se, GSH-Px, fecal, and urinary excretion or concentration.