Effects of supplemental levels of hesperetin and naringenin on egg quality, serum traits and antioxidant activity of laying hens

Hesperetin and naringenin phytochemicals are naturally occurring flavanoids in citrus fruits. The purpose of this study was to evaluate the effects of supplementing different levels of extracted hesperetin and naringenin on egg quality, serum traits and antioxidant activity in laying hens. Two experiments were conducted, each for 10 weeks, in a completely randomized experiment design. Each had 100 Leghorn laying hens (26 weeks old) randomly assigned into five groups (n = 20) based on dietary categories of hesperetin 0, 0.5, 1, 2, 4 g/kg and naringenin 0, 0.5, 1, 2, 4 g/kg. Experimental results indicated that there was increased (P<0.05) egg production in the 1 g/kg naringenin-supplemented group, but lower (P<0.05) egg production in the hesperetin- and naringenin-supplemented groups given 4 g/kg. Cholesterol content (per gram yolk) and total cholesterol content (per egg) were lower (P<0.05) in the hesperetin- and naringenin-supplemented groups as compared to the control group, and the 2 g/kg hesperetin- and naringenin-supplemented groups showed the most significant difference. Both serum cholesterol and triglyceride concentrations were lower (P<0.05) in the 2 g/kg hesperetin- and naringenin-supplemented groups. The SOD and catalase activities, scavenging O₂⁻ and iron-chelating abilities were higher (P<0.05) in the 2 g/kg hesperetin- and naringenin-supplemented groups, and the trolox equivalent antioxidant capacity was higher (P<0.05) in the 2 g/kg naringenin-supplemented group. The results confirmed that both hesperetin and naringenin could lower serum and egg yolk cholesterol levels, and improve the antioxidant activities, however the measured variables generally showed significant quadratic responses to increasing amounts of the compounds. The recommended supplementation level of hesperetin and naringenin is 2 g/kg of the basal diet for reduced serum and yolk cholesterols contents and increased antioxidant capacity.     

Investigations on the effects of rape oil quality,choline and methionine concentration in diets for laying hens on the trimethylamine content of the eggs,on trimethylamine metabolism and on laying performance

Abstract

An experiment was conducted to study the effects of graded levels of choline addition (0, 500, 1000 and 4000 mg/kg diet) in laying hen diets prepared either with degummed or refined rape oil on the performance, sensory properties and trimethylamine (TMA) contents of the eggs. Furthermore, the diets containing no supplemented choline or 4000 mg choline/kg diet were tested with adequate or inadequate methionine supply (4.2 vs. 2.8 g methionine/kg diet). TMA metabolism and N-balance were measured for the latter diet types, but only with the diets containing refined rape oil. Therefore, a total of 12 and 4 diets were tested in the feeding (n = 60) and balance study (n = 9). Laying performance (23 – 75 weeks of age) was not significantly influenced by increasing choline additions with the exception of feed-to-egg mass ratio which decreased significantly linearly (p _linear = 0.003). However, a significant interaction between choline addition and laying month was detected which was caused by a depression of performance of the unsupplemented control group occurring from the sixth laying month. The most obvious effect of an inadequate methionine supply was a temporary drop in performance between the third and sixth laying months. The mean TMA-concentration in pooled egg yolks [μg/g] increased with dietary choline concentration [mg/kg] in an exponentially related fashion (y = 1.14 + 4E^?10 ? x^2.71, r² = 0.962) and suggested only a minor influence of total dietary choline on TMA content up to approximately 2000 mg choline/kg. Individual TMA-concentrations varied greatly from 0.4 – 1.5 μg/g, from 2.2 – 34 μg/g and from 18.4 – 75 μg/g for eggs with a normal, aberrant and heavily aberrant odour, respectively. It is concluded that a total choline concentration of at least approximately 1500 mg/kg is necessary to maintain a maximal laying performance. An inadequate methionine supply cannot be compensated by an increased addition of choline. Neither degummed nor refined rape oil influenced the TMA content of eggs.     

Investigations on the effects of rape oil quality, choline and methionine concentration in diets for laying hens on the trimethylamine content of the eggs, on trimethylamine metabolism and on laying performance

An experiment was conducted to study the effects of graded levels of choline addition (0, 500, 1000 and 4000 mg/kg diet) in laying hen diets prepared either with degummed or refined rape oil on the performance, sensory properties and trimethylamine (TMA) contents of the eggs. Furthermore, the diets containing no supplemented choline or 4000mg choline/kg diet were tested with adequate or inadequate methionine supply (4.2 vs. 2.8 g methionine/kg diet). TMA metabolism and N-balance were measured for the latter diet types, but only with the diets containing refined rape oil. Therefore, a total of 12 and 4 diets were tested in the feeding (n = 60) and balance study (n = 9). Laying performance (23 -75 weeks of age) was not significantly influenced by increasing choline additions with the exception of feed-to-egg mass ratio which decreased significantly linearly (P(linear) = 0.003). However, a significant interaction between choline addition and laying month was detected which was caused by a depression of performance of the unsupplemented control group occurring from the sixth laying month. The most obvious effect of an inadequate methionine supply was a temporary drop in performance between the third and sixth laying months. The mean TMA-concentration in pooled egg yolks [microg/g] increased with dietary choline concentration [mg/kg] in an exponentially related fashion (y = 1.14 + 4E(-10) x x(2.71), r2 = 0.962) and suggested only a minor influence of total dietary choline on TMA content up to approximately 2000mg choline/kg. Individual TMA-concentrations varied greatly from 0.4 - 1.5 microg/g, from 2.2 - 34 microg/g and from 18.4 - 75 microg/g for eggs with a normal, aberrant and heavily aberrant odour, respectively. It is concluded that a total choline concentration of at least approximately 1500 mg/kg is necessary to maintain a maximal laying performance. An inadequate methionine supply cannot be compensated by an increased addition of choline. Neither degummed nor refined rape oil influenced the TMA content of eggs.     

Dietary supplementation with selenium polysaccharide from selenium-enriched Phellinus linteus improves antioxidant capacity,immunity and production performance of laying hens

BackgroundSelenium (Se) plays a beneficial role in the physiological function of humans and animals. Selenium polysaccharide, improving enzyme activity and regulating immunity, is the extraction from selenium-rich plants or mushrooms. This study aimed to evaluate the effect of selenium polysaccharide from selenium-enriched Phellinus linteus on the antioxidative ability, immunity, serum biochemistry, and production performance of laying hens.MethodsThree hundred sixty adult laying hens were randomly assigned to 4 groups. The four groups were divided as follows: CK (control group), PS group (4.2 g/kg polysaccharide), Se group (0.5 Se mg/kg), and PSSe group (4.2 g/kg with 0.5 Se mg/kg, Selenium polysaccharide).ResultsAfter the 8 weeks, the hens were sampled and the antioxidant ability(total antioxidant (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and Nitric Oxide (NO)), immunity(Interleukin-2(IL-2), Immunoglobulin M(IgM), Immunoglobulin A(IgA), Immunoglobulin G(IgG) and interferon-gamma (IFN-γ) and secretory Immunoglobulin A(sIgA)), serum biochemistry(total protein, triglycerides, total cholesterol, glucose, glutamic-pyruvictransaminase (ALT), and aspartate transaminase (AST)) and production performance were assessed. Compared with the control group, T-AOC, SOD, CAT, GSH, IL-2, IgM, IgA, sIgA, IgG, IFN-γ, total protein, average laying rate, average egg weight, and final body were significantly increased in the PS, Se, and PSSe groups, however, the MDA and NO, triglyceride, cholesterol, glucose, AST, ALT, average daily feed consumption, and feed conversion ratio were significantly decreased in the PS, Se, and PSSe groups. The PSSe group in the immune index, antioxidant ability and serum biochemistry was improved the highest.ConclusionThe result suggested that selenium polysaccharide from selenium-enriched Phellinus linteus can enhance the antioxidant ability and immunity, change serum biochemistry, providing a new method for improving the production performance of laying hens.     

Low levels of organic compound trace elements improve the eggshell quality,antioxidant capacity,immune function,and mineral deposition of aged laying hens

In the egg production industry, trace elements are required as additional dietary supplements to play vital roles in performance and egg quality. Compared to inorganic microelements (ITs), appropriate dose of organic trace microelements (OTs) are environmentally friendly and sufficient to satisfy the needs of hens. In order to evaluate the extent to which low-dose OTs replace whole ITs, the effects of organic copper, zinc, manganese, and iron compound on the performance, eggshell quality, antioxidant capacity, immune function, and mineral deposition of old laying hens were investigated. A total of 1 080 57-week-old Jing Hong laying hens were assigned to five groups with six replicates of 36 layers each for an 8-week experimental period. The birds were fed either a basal diet (control treatment (CT)) or the basal diet supplemented with commercial levels of inorganic trace elements (IT 100%) or the equivalent organic trace elements at 20%, 30%, and 50% of the inorganic elements (OT 20%, OT 30%, and OT 50%, respectively). Results showed that compared with those in the CT treatment, feeding hens with inorganic or organic microelement diet had significant effects on the eggshell quality, antioxidant capacity, immune function, and mineral deposition of old laying hens (P < 0.05). The eggshell strength and ratio between OT 30%, OT 50%, and IT 100% were similar at weeks 4 and 8, and the eggshell thickness of these groups was also similar at weeks 6 and 8. At week 8, the eggshell colour in OT 50% was darker than that in IT 100%. The mineral content in the eggshells of OT 50% and IT 100% significantly increased (P < 0.001), with no significant difference in effective thickness, mammillary thickness, and mammillary knob width between groups. There were no differences in the malondialdehyde content, total antioxidant capacity, and total superoxide dismutase activity in serum between OT 30%, OT 50%, and IT100%. While the catalase activities, the interleukin-1β, interleukin-10, immunoglobulin G, and immunoglobulin M concentrations in serum were not significantly different between OT 50% and IT 100%. The mineral contents in the faeces of the organic groups were considerably reduced compared with those in IT 100% (P < 0.001). In conclusion, dietary supplementation with 30–50% organic compound microelements has the potential to replace 100% inorganic microelements in the hen industry for improving eggshell quality, mineral deposition in the eggshell, antioxidant capacity, and immune function, and reducing emissions to the environment without negative effects on laying performance.     

Effect of dietary organic versus inorganic selenium in laying hens on the productivity, selenium distribution in egg and selenium content in blood, liver and kidney.

We investigated the effect of organic versus inorganic dietary selenium in laying hens on the productivity, selenium distribution in egg and selenium content in blood, liver and kidney. Sixty Leghorn laying hens were fed a basic diet containing 0.23mg Se/kg DM (dry matter) for 2 weeks and then were allocated randomly into three groups. Thereafter, the hens were given the same basic diet without supplementation, or with 0.51 mg Se/kg DM as sodium selenite (SS) or Se-malt (SM). During the experiment, egg rate and dietary intake were recorded, blood was sampled on days 10 and 20, and six eggs were sampled on days 8, 16 and 24 from each treatment group for Se content determination. At the end of the experiment, 10 hens from each treatment were slaughtered, and liver and kidney were sampled for the determination of Se content. The result showed that with the increase of dietary Se level, the Se content in egg, blood, liver and kidney was elevated (P < 0.05), but the hens' productivity was not affected. SS increased liver Se content more than SM (P < 0.05), while the Se content both in blood and kidney did not differ significantly between the SS and SM treatments. Se from SM and SS mainly deposited in the egg yolk. This suggests that the metabolic route of Se from SM is similar to that of Se from SS in laying hens.     

The paradoxical effects of progesterone on the eggshell quality of laying hens

This study demonstrates the effects of progesterone on eggshell quality and ultrastructure by injecting progesterone into laying hens 2 and 5 h post-oviposition, respectively. Progesterone injected 2 h post-oviposition (P₄-2 h) improved eggshell quality with a significant decrease (P < 0.01) in the thickness of the mammillary layer and a significant increase (P < 0.01) in the thickness of the effective layer in the eggshell ultrastructure compared to the control. Progesterone injected 5 h post-oviposition (P₄-5 h) damaged the eggshell quality by significantly reducing (P < 0.01) the effective layer thickness. Progesterone injected delayed obviously (P < 0.01) the following oviposition. Moreover, the concentrations of Thr, Cys, Leu, Lys, and His in the eggshell membranes were significantly higher (P < 0.05) in the P₄-2 h treated hens whereas Val and Lys were significantly lower (P < 0.05) in P₄-5 h treated hens compared to the control. Therefore, progesterone shows paradoxical effects on eggshell quality depending on the injection time-points post-oviposition, which could explain the contradictions in previous related reports. P₄ injected affected the content of amino acids in eggshell membranes, especially lysine which contributed to eggshell quality. In addition, P₄ injected 2 h after oviposition improved eggshell quality by promoting the premature fusion of mammillary knobs. This work contributed to a novel insight to understanding the mechanism of improving eggshell quality.     

Effects of dietary chromium and zinc on egg production, egg quality, and some blood metabolites of laying hens reared under low ambient temperature

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO₄·H₂O) on egg production, egg quality, and serum insulin, corticosterone, glucose, cholesterol, and total protein concentrations of laying hens reared under a low ambient temperature (6.8°C). One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The laying hens were fed the control diet (T1) or the control diet supplemented with either 400 μg of Cr/kg of diet (T2), 30 mg of Zn/kg of diet (T3), or 400 μg of Cr plus 30 mg of Zn/kg of diet (T4). Although the dry matter intake (DMI) was similar (p>0.05) for all treatment groups, supplemental chromium and zinc either individually or together increased live-weight change, egg production, and improved feed efficiency (p<0.05). However, no significant differences were observed between T4 and T2 or T3. Compared to T1, supplemental chromium and zinc increased egg weight, eggshell weight, eggshell thickness, egg specific gravity, and Haugh unit (p<0.05) in T2, T3, and T4 groups, among which there was no significant difference. Serum insulin concentration increased (p<0.05) and corticosterone concentration decreased (p<0.05) with dietary chromium and zinc supplementation. Serum glucose and cholesterol concentrations decreased (p<0.05) and protein concentrations increased (p<0.001) with dietary chromium and zinc supplementation in all treatment groups. The results of this study indicated that either supplemental dietary chromium or zinc increased plasma insulin and decreased corticosterone concentrations and that had a positive effect on performance of laying hens under low ambient temperature.     

Influence of high vitamin E dosages on retinol and carotinoid concentration in body tissues and eggs of laying hens

The aim of the study was to contribute to the discussion of overdosing vitamin E in laying hens. A total of 45 laying hens, divided into 5 groups were fed diets supplemented with either 0; 100; 1000; 10 000 or 20 000 mg dl‐α‐tocopheryl acetate/kg diet over a period of 10 weeks. Concentrations of vitamins A and E were measured in plasma, various tissues and egg yolk. Furthermore egg yolk colour and some carotinoids were measured in egg yolks. None of the vitamin E doses significantly influenced performance of the hens. As expected, vitamin E concentration in plasma, all tissue samples and egg yolk was significantly increased with increasing tocopherol content in the diet. The egg yolk showed the highest vitamin E concentration, followed by liver and muscles. Feeding 1000 mg α‐tocopheryl acetate per kg diet resulted in an increase of vitamin A concentration in the liver. Very high doses (10 000 and 20 000 mg/kg diet) significantly decreased retinol concentration in the liver and egg yolk, as well as carotinoid concentration in the egg yolk. The lower carotinoid concentration in egg yolk resulted in a decreased intensity of egg yolk colour. A prooxidative and/or competitive effect of very high doses of vitamin E with other fat soluble substances has been discussed.     

Effects of magnolol and honokiol blend on performance,egg quality,hepatic lipid metabolism,and intestinal morphology of hens at late laying cycle

Magnolol and its isomer honokiol are polyphenols with anti-oxidative and anti-inflammatory activities. We evaluated the effects of magnolol and honokiol supplementation alone or in combination with hen diets during the late laying cycle. A total of 540 Jingfen pink-shell laying hens (50 weeks old) were randomly assigned to six treatments: a control diet and diets supplemented with 300 mg/kg magnolol (M₃₀₀), honokiol (H₃₀₀), or 300 mg/kg total phenols with a magnolol/honokiol ratio of 2:1 (M₂₀₀H₁₀₀), 1:2 (M₁₀₀H₂₀₀), and 1:1 (M₁₅₀H₁₅₀). Compared with that of the control, all supplementation groups had higher laying rates and the M₃₀₀, M₁₀₀H₂₀₀, and M₁₅₀H₁₅₀ groups showed comparatively lower feed conversion ratios. Magnolol and honokiol supplementation increased the Haugh units of fresh eggs at week 62 and alleviated the decline of the Haugh units of eggs stored for 14 days. Compared with that of the control group, the serum total antioxidant capacity of the M₁₀₀H₂₀₀ and M₁₅₀H₁₅₀ groups significantly increased, and all supplementation groups had higher total antioxidant capacity and lower malondialdehyde content in the liver. With respect to lipid metabolism, the M₂₀₀H₁₀₀ and M₁₅₀H₁₅₀ groups had lower total and relative liver weights compared with those of the control and H₃₀₀ groups. The mRNA expression levels of CCAAT enhancer binding protein alpha, sterol regulatory element binding protein-1, fatty acid synthase and stearyl coenzyme A desaturase 1 involved in lipogenesis; microsomal triglyceride transfer protein and apolipoprotein B involved in fatty acid transport; and the proinflammatory cytokine interleukin-1 beta were lower in all supplementation groups compared with those in the control. With respect to gut health, the heights of the jejunum and ileum villi significantly increased in all supplementation groups compared with those of the control, and the jejunum villus heights of the M₃₀₀ and M₁₅₀H₁₅₀ groups were higher than those of the H₃₀₀ and M₁₀₀H₂₀₀ groups. The H₃₀₀ and M₁₅₀H₁₅₀ groups had higher mRNA expression levels of zonula occludens-1 in the ileum compared with those in the control and M₃₀₀ groups, whereas all supplementation groups had higher mRNA levels of claudin-1 than that of the control group. In conclusion, magnolol and honokiol improved hen performance and the albumen quality of fresh and stored eggs by improving the antioxidant capacity, liver lipid metabolism, and intestinal health of laying hens. The combination of magnolol and honokiol at a 1:1 ratio may be an optimal choice for hen diet supplementation.     

Dietary inclusion of raw faba bean instead of soybean meal and enzyme supplementation in laying hens: Effect on performance and egg quality

An experiment was conducted with 160 Hisex Brown laying hens to evaluate the effect of different inclusion levels of faba bean (FB) and enzyme supplementation on productive performance and egg quality parameters. The experimental diets consisted of five levels of FB: 0% (control), 25%, 50%, 75% and 100%, substituting soybean meal (SBM), and two levels of enzyme supplementation (0 or 250 mg/kg). Each dietary treatment was assigned to four replicate groups and the experiment lasted 22 weeks. A positive relationship (P < 0.05) was found between FB inclusion and body weight (BW) change of hens when compared to those of the control treatment. Enzyme supplementation significantly affected the final hens’ BW. Feed consumption (FC) of hens was statistically increased with increasing FB level up to 50%. Supplementing dietary enzyme mixture at 250 mg/kg led to improvement in FC at all studied ages (P < 0.05). Inclusion of 25% or 50% FB in diets had no adverse effects on feed conversion ratio (FCR) compared to the higher FB inclusion levels (75% or 100%). Egg weight (EW), egg number (EN) and egg mass (EM) were significantly (P < 0.05) influenced by FB inclusion in diet during the entire experimental periods, except for EN and EM at 20–24 weeks of age. Egg productive parameters were not influenced by enzyme mixture supplementation (P > 0.05). The main effect of FB levels replacing for SBM affected (P < 0.05) yolk and shell percentages, yolk index, yolk to albumen ratio, shell thickness and egg shape index. It can be concluded that FB and enzyme supplementation could be included in hens diet at less than 50% instead of SBM to support egg productive performance, however higher raw FB levels negatively affected egg production indices and quality.     

Effects of dietary Bacillus subtilis and inulin supplementation on performance,eggshell quality,intestinal morphology and microflora composition of laying hens in the late phase of production

Eighty Lohmann White laying hens were used to investigate the effect of dietary inclusion of Bacillus subtilis and inulin, individually or in combination, on egg production, eggshell quality, tibia traits, Ca retention, and small intestine morphology and microflora composition from 64 to 75 weeks of age. Hens were randomly distributed into 4 treatment groups, with 5 replicates per treatment and 4 hens per replicate. Treatment groups were fed basal diet (control), basal diet plus 1 g/kg B. subtilis (2.3 × 10⁸ cfu/g), basal diet plus 1 g/kg inulin, or basal diet plus a synbiotic combination of 1 g/kg B. subtilis (2.3 × 10⁸ cfu/g) and 1 g/kg inulin. Dietary supplementation of B. subtilis, inulin or synbiotic improved (P<0.05) feed conversion, egg performance, eggshell quality and calcium retention compared with the control. B. subtilis and synbiotic groups exhibited the highest (P<0.05) increase in egg production and egg weight. Inulin and synbiotic groups exhibited the highest (P<0.05) increase in eggshell thickness and eggshell calcium content, and the lowest (P<0.05) eggshell deformations. Unmarketable eggs were 8.4% (P<0.05) of the total eggs produced by the control group compared to 3.5%, 1.7%, and 1.5% for the B. subtilis, inulin and synbiotic groups, respectively. Tibia density, ash, and Ca content increased (P<0.05) by inulin and synbiotic inclusions, compared with the control. B. subtilis, inulin, and their synbiotic combination increased (P<0.05) villus height and crypt depth in all intestinal segments, compared with the control. B. subtilis and inulin modulated the ileal and caecal microflora composition by decreasing (P<0.05) numbers of Clostridium and Coliforms and increasing (P<0.05) numbers of bifidobacteria and lactobacilli, compared with the control. Colonization of the beneficial microflora along with increasing the villi–crypts absorptive area were directly associated with the improvements in performance and eggshell quality. It can be concluded that egg production and eggshell quality of laying hens can be improved (P<0.05) in the late phase of production by dietary inclusion of B. subtilis and inulin.     

Effect of sodium selenite, Se-yeast and nano-elemental selenium on growth performance, Se concentration and antioxidant status in growing male goats

The objective of this experiment was to study the effect of inorganic, organic and elemental nano-selenium on growth performance, Se concentration and antioxidant status in growing male goats. A total of 40 weaned Taihang black goats were randomly divided into four equal groups, given the basal diet either unsupplemented (CTRL only received 0.03 mg/kg Se background) or supplemented with 0.3 mg/kg Se as sodium selenite (SS), Se-yeast (SY) or elemental nano-selenium (NS) for a 90 days experiment (from weaning to maturity). Average initial and finial body weight (BW) and average daily gain (ADG) were recorded. Serum and whole blood were collected for serum glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) activity and Se content analysis. At the end of the feeding trail five bucks in each group were killed and samples of heart, liver, spleen, lung, kidney, muscle and testis were collected for Se determination. The result showed that the final BW was increased (P < 0.05) in bucks supplemented with Se compared to the controls, and ADG in NS and SY were greater (P < 0.05) than SS or CTRL bucks. Whole blood, serum and tissue Se concentration, serum antioxidant enzymes activity were also affected by dietary Se supplementation. Serum GSH-Px, SOD and CAT in NS were higher (P < 0.05) than those in SS and SY, and Se retention of whole blood, serum and some organs in NS were also higher than SS or SY (P < 0.05). It could be concluded that supplementation of Se can improve growth performance, serum oxidant status and Se concentration in blood and tissues in growing male goat. The dietary supplementation of elemental nano-Se could be utilized more effectively when compared to inorganic or organic Se.     

Effect of Ligustrum lucidum and Schisandra chinensis on the egg production,antioxidant status and immunity of laying hens during heat stress

Abstract

The experiment was conducted to evaluate the effect of two plants belonging to Chinese herbal medicines, Ligustrum lucidum (LL) and Schisandra chinensis (SC), on the laying performance, antioxidant status and immunity of hens during heat stress. The results showed that diets supplement with 1% of either LL or SC had beneficial effects on egg production and FCR of hens during heat stress (p < 0.05), compared with the control group. Either LL or SC significantly reduced malondialdehyde (MDA) concentration of heart, liver, sera and egg yolk. In addition, glutathione reductase (GR) activity of tissues and sera of the birds was significantly elevated by supplementation LL or SC. Furthermore, LL or SC supplementation significantly elevated lymphoblastogenese of the birds and the antibody values against Newcastle disease virus (NDV). The results suggest that diets supplement with 1% of either LL or SC may enhance egg production, immune function, and antioxidant status of hens during heat stress.     

Discovery of the strong antioxidant selenoneine in tuna and selenium redox metabolism

A novel selenium-containing compound, selenoneine, has been isolated as the major form of organic selenium in the blood and tissues of tuna. Selenoneine harbors a selenium atom in the imidazole ring, 2-selenyl-N(α), N(α), N(α)-trimethyl-L-histidine, and is a selenium analog of ergothioneine. This selenium compound has strong antioxidant capacity and binds to heme proteins, such as hemoglobin and myoglobin, to protect them from iron auto-oxidation, and it reacts with radicals and methylmercury (MeHg). The organic cations/carnitine transporter OCTN1 transports selenoneine and MeHg, regulates Se-enhanced antioxidant activity, and decreases MeHg toxicity. Thus, the dietary intake of selenoneine, by consuming fish, might decrease the formation of reactive oxygen radicals that could oxidize nucleotides in DNA, and thereby inhibit carcinogenesis, chronic diseases, and aging.     

复合酶制剂降解黄曲霉毒素 B1对蛋鸡生产性能和蛋品质的影响

试验旨在研究葡萄糖氧化酶(Glucose Oxidase,GOD)和过氧化氢酶(catalase,CAT)复合酶制剂降解污染饲料中黄曲霉毒素B1(Aflatoxin B1,AFB1)对蛋鸡生产性能和蛋品质的影响。选用210只180日龄京粉蛋鸡,随机分为7组(CK、BA1、BA2、BA3、BD1、BD2和BD3),7个处理组分别是饲喂不添加污染玉米和复合酶的CK组,污染饲料中含有17.22,53.27和134.56μg/kg AFB1的BA1,BA2和BA3组,在有毒玉米中添加0.5%复合酶的BD1、BD2和BD3组。结果显示,蛋鸡的生产性能和蛋品质在BA1、BA2和BA3组均有不同程度下降,在BD1、BD2 3期(T1,T2和T3)和BD3组第1期(T1)均达到对照组水平,BD3组第3期与BA3组同期相比,蛋鸡月产量从9枚提高到17枚,受精蛋孵化率从41%提高到57%,蛋黄重量从14.34 g提高到15.53 g,单枚蛋重从42.39 g提高到48.49g,蛋壳厚度从0.28 mm提高到0.31 mm。由此可知,复合酶制剂基本消除或减轻了AFB1对蛋鸡生产性能和蛋品质不良影响。     

Effect of Ligustrum lucidum and Schisandra chinensis on the egg production, antioxidant status and immunity of laying hens during heat stress

The experiment was conducted to evaluate the effect of two plants belonging to Chinese herbal medicines, Ligustrum lucidum (LL) and Schisandra chinensis (SC), on the laying performance, antioxidant status and immunity of hens during heat stress. The results showed that diets supplement with 1% of either LL or SC had beneficial effects on egg production and FCR of hens during heat stress (p < 0.05), compared with the control group. Either LL or SC significantly reduced malondialdehyde (MDA) concentration of heart, liver, sera and egg yolk. In addition, glutathione reductase (GR) activity of tissues and sera of the birds was significantly elevated by supplementation LL or SC. Furthermore, LL or SC supplementation significantly elevated lymphoblastogenese of the birds and the antibody values against Newcastle disease virus (NDV). The results suggest that diets supplement with 1% of either LL or SC may enhance egg production, immune function, and antioxidant status of hens during heat stress.     

Effect of adding extracted hesperetin, naringenin and pectin on egg cholesterol, serum traits and antioxidant activity in laying hens

In this study three feed additives (hesperetin, naringenin and pectin) for laying hens were investigated on their influence on the egg yolk cholesterol, serum traits and antioxidant activities in hens. Additives were extracted from citrus and grapefruit peels and contained 31.5% crude hesperetin, 39% crude naringenin and 60% galacturonic acid (pectin). Eighty 30-week-old Leghorn laying hens were randomly assigned to four groups and received, for two months, a control diet or diets with 0.05% hesperetin, 0.05% naringenin or 0.5% pectin. All additives reduced the egg yolk cholesterol level significantly. Feeding diets with added flavonoids (hesperetin and naringenin) increased the yolk weight and the ratio of yolk weight/egg weight and the blood serum superoxide dismutase (SOD) activity was elevated. Total antioxidation capacity, the level of thiobarbituric acid-reactive substances and superoxide scavenging capacity in the naringenin group were greater than in the control group. Supplemented flavonoids reduced the serum cholesterol level significantly, while serum triglyceride concentration in the naringenin and pectin groups was reduced. Addition of flavonoids resulted in an enhanced cholesterol level in excreta. The results of this study indicated that intake of hesperetin, naringenin and pectin extracted from citrus and grapefruit peel in laying hens diet, may exhibit positive effects.     

Effects of dietary chromium propionate on laying performance,egg quality,serum biochemical parameters and antioxidant status of laying ducks under heat stress

Recent studies have shown that chromium (Cr) could alleviate the negative effects of heat stress on livestock and poultry, but there is little information available to laying ducks. This study aimed to investigate the effects of dietary addition of chromium propionate on laying performance, egg quality, serum biochemical parameters and antioxidant status of laying ducks under hot (average 32 °C) and humid (average 75% relative humidity) summer conditions. A total of 900 66-week-old weight- and laying-matched Shanma laying ducks were randomly divided into five treatments, each with 6 replicates of 30 individually caged birds. The birds were fed either a basal diet or the basal diet supplemented with either 200, 400, 600, or 800 μg/kg Cr as chromium propionate. All laying ducks were given feed and water ad libitum for 5 weeks. The results showed that dietary supplementation with chromium propionate significantly increased the laying rate and yolk colour score (P < 0.05). Treatment with 400 μg/kg Cr as chromium propionate significantly decreased the feed/egg ratio by 5.4% (P < 0.05). Increased supplemental Cr from 0 to 800 μg/kg resulted in an increase in albumen height and the Haugh unit linearly (P < 0.05). Increased supplemental Cr decreased serum cortisol (P < 0.001, linear; P = 0.008, quadratic), heat shock protein-70 (P < 0.001, linear; P = 0.007, quadratic) and glucose (P = 0.007, linear), whereas it increased serum insulin (P = 0.011, Linear), total protein (P = 0.006, linear; P = 0.048, quadratic) and albumin (P = 0.035, linear; P = 0.088, quadratic). Dietary Cr levels increased the activities of superoxide dismutase and glutathione peroxidase, the total antioxidant capacity linearly and quadratically (P < 0.05). A linear and quadratic (P < 0.05) decrease of the malondialdehyde concentrations in response to dietary Cr level was observed. These results indicated that dietary supplementation of Cr as chromium propionate, particularly at 800 μg/kg could beneficially affect the laying rate, egg quality and antioxidant function, as well as modulate the blood biochemical parameters of laying ducks under heat stress conditions.     

Effects of Enterococcus faecalis on egg production,egg quality and caecal microbiota of hens during the late laying period

This study was conducted to determine the effects of diet supplementation of laying hens with Enterococcus faecalis (EF) on egg production, egg quality and caecal microbiota. A total of 360 Hy-Line Brown laying hens (72 weeks old) were divided into three groups with four replicates of 30 birds each. The laying hens were fed with the basal diet (Control), the basal diet + 3.75 · 10⁸ cfu EF/kg (Group I) or the basal diet + 7.5 · 10⁸ cfu EF/kg (Group II). The experiment lasted for 45 d. Eggs and caecal samples were collected at the end of the experiment. Results showed that dietary supplementation with EF did not affect the average daily egg weight, cracked egg rate, mortality and egg quality. However, EF supplementation caused a significantly increased laying rate and decreased feed/egg ratio (p < 0.05). The differences in caecal microbiota between Group II and the Control were significant. The relative abundance of Verrucomicrobia and Cyanobacteria at the phylum level, Rikenellaceae, Christensenellaceae and Veillonellaceae at the family level, and the Faecalibacterium, Christensenellaceae R-7 group and Eubacterium coprostanoligenes group at the genus level changed significantly in Group II compared with the Control (p < 0.05). In conclusion, the tested dietary supplementations with EF improved product performance and affected the caecal microbial community structure of laying hens during the late laying period.