Dietary supplementation with sodium bicarbonate or sodium sulfate affects eggshell quality by altering ultrastructure and components in laying hens.

Dietary sodium (Na) levels were related to the content of the eggshell matrix. We therefore speculated that dietary Na supplementation as sodium bicarbonate (NaHCO3) or sodium sulfate (Na2SO4) may improve eggshell quality. Additionally, dietary NaHCO3 or Na2SO4 supplementation may further affect eggshell quality in different ways due to differences in anions. This study investigated and compared the effects of dietary Na supplementation in either NaHCO3 or Na2SO4 form on laying performance, eggshell quality, ultrastructure and components in laying hens. A total of 576 29-week-old Hy-Line Brown laying hens were randomly allocated to 8 dietary treatments that were fed a Na-deficient basal diet (0.07% Na, 0.15% Cl) supplemented with Na2SO4 or NaHCO3 at 0.08, 0.18, 0.23 or 0.33% Na for 12 weeks. No differences were observed in laying production performance with dietary Na supplementation. Dietary Na supplementation resulted in quadratic increases of eggshell breaking strength in both Na2SO4 and NaHCO3 added groups (P < 0.05), and Na2SO4-fed groups had a quadratic increase in the eggshell ratio at week 12 (P < 0.05). Compared with supplementing 0.08% Na, dietary supplementation of 0.23% Na increased the effective thickness (P < 0.05) in both Na2SO4 and NaHCO3 added groups, but decreased the thickness and knob width of the mammillary layer (P < 0.05). A linear increase on the calcium content of the shell was only observed with Na supplementation from NaHCO3 (P < 0.05). No differences were observed in Na contents of the shell with dietary Na supplemented by both sources. Dietary Na addition had a quadratic increase on uronic acid contents of shell membrane in NaHCO3-fed groups (P < 0.05). Moreover, the sulfated glycosaminoglycan (GAG) contents of shell membranes increased linearly with dietary Na supplementation (P < 0.05). Dietary supplementation of 0.23% Na from Na2SO4 increased the sulfated GAG contents of calcified eggshell (P < 0.05). Additionally, compared with NaHCO3-fed groups, Na2SO4-fed groups had higher eggshell breaking strength, thickness, eggshell weight ratio, effective thickness and the sulfated GAG contents of calcified eggshell at week 12. Overall, dietary supplementation of NaHCO3 or Na2SO4 could increase eggshell breaking strength, which may be related to increased sulfated GAG contents in eggshell membranes and improved ultrastructure. Higher eggshell breaking strength, thickness and eggshell ratio could be obtained when the diet was supplemented with 0.23% Na from Na2SO4.

Dietary manganese supplementation affects mammillary knobs of eggshell ultrastructure in laying hens.

This study evaluated the mechanism by which dietary manganese (Mn) supplementation-in either an organic or inorganic form-affects mammillary knobs of the eggshell ultrastructure in laying hens. A total of 225 54-week-old Hy-Line Brown laying hens were fed a basal diet containing 27.5 mg Mn/kg feed for 2 wk, after which they were randomly allocated into 3 groups and fed a basal diet (control) or a basal diet supplemented with 120 mg Mn/kg feed from monohydrate Mn sulfate (an inorganic source of Mn) or with 80 mg Mn/kg feed from an amino acid-Mn complex (an organic source of Mn) for 10 wk. For each group, 5 replicates of 15 hens each were used with 1 hen per cage. Compared with the control, dietary Mn supplementation increased the mammillary-knob density of eggs at 9.5 h post-oviposition (P < 0.05). The Mn content in both blood and eggshell gland was increased with the supplementation of Mn in inorganic and organic forms (P < 0.05), but the blood Mn content was higher after inorganic-Mn supplementation as compared with organic-Mn supplementation (P < 0.05). RNA sequencing and quantitative real-time PCR analysis of the eggshell gland showed that dietary Mn supplementation increased the expression of genes encoding some proteoglycans, glycoproteins, and calcium-binding proteins in the eggshell gland (P < 0.05), and involved in the process of the protein glycosylation and glycan metabolism in the eggshell gland (P < 0.05). Overall, dietary Mn supplementation can involve in the process of protein glycosylation and glycan metabolism and improve the expression of genes encoding proteoglycans and glycoproteins in the eggshell gland, thus increasing the mammillary-knob density during the initial deposition stage of shell formation.

Dietary manganese supplementation modulated mechanical and ultrastructural changes during eggshell formation in laying hens.

This study evaluated the mechanical and ultrastructural changes during eggshell formation in laying hens by using the optimal levels of organic and inorganic manganese (Mn). A total of 270 62-wk-old Hy-Line Brown laying hens were fed a basal diet containing 25.1 mg Mn per kg feed for 2 wks, after which they were randomly allocated into 3 groups and fed the basal diet (control) or the basal diet supplemented with 120 mg Mn per kg feed from monohydrate Mn sulfate (an inorganic source of Mn), or 80 mg Mn per kg feed from an amino acid-Mn complex (an organic source of Mn) for 12 wks. For each group, 6 replicates of 15 hens were used with one hen per cage. Dietary Mn supplementation significantly increased eggshell-breaking strength and thickness in laying hens (P < 0.05). In neither was the elasticity of their eggshell membranes, measured during the nucleation and mammillary knob formation stages, affected by dietary Mn compared with the control (P > 0.05), whereas the breaking strength of the eggshells was greater at the linear and terminate deposition stages compared with the control (P < 0.05). Dietary Mn supplementation decreased the width of the mammillary knobs and the proportion of mammillary thickness, and increased the proportion of effective thickness of the whole eggshells (P < 0.05). Ultrastructural changes during the eggshell formation indicated that dietary Mn supplementation increased the nucleation site and mammillary knob densities, decreased the mammillary thickness, and increased the proportion of effective thickness and total thickness of the eggshells compared with the control (P < 0.05). Therefore, dietary Mn supplementation can improve the breaking strength and ultrastructure of the eggshells during their formation, and the mammillary and palisade layers are both crucial structures affected by Mn.

Effects of dietary gallic acid supplementation on performance, antioxidant status, and jejunum intestinal morphology in broiler chicks.

Gallic acid (GA), widely distributed in plants and feeds, is known to have a diverse range of activities such as anti-oxidant, anti-inflammatory, antibacterial, anti-allergic, anti-mutagenic, and anti-carcinogenic. The purpose of this study was to investigate the efficacy of inclusion of dietary GA at levels 0, 25, 50, 75, 100, or 150 mg/kg on growth performance, antioxidant status, and jejunum intestinal morphology of broiler chicks. In total, 630 one-day-old Arbor Acres (AA) male broiler chicks were randomly allotted to 6 treatment groups for a period of 6 weeks. The results indicate that dietary addition of GA at 75 to 100 mg/kg improved feed conversion efficiency in both the grower (d 21 to 42, P = 0.045) and overall (d 1 to 42, P = 0.026) periods. Dietary addition of GA at a concentration ≥100 mg/kg was able to exhibit higher breast muscle ratio at 42 d (P = 0.043). Interestingly, dietary GA inclusion level from 50 to 100 mg/kg reduced the crypt depth (P = 0.009) and increased the villus height:crypt depth ratio (VCR) of the birds (P = 0.006). Dietary supplementation of GA at 100 mg/kg decreased plasma malondialdehyde (MDA) content at 42 d of age (P = 0.030). Moreover, dietary addition of GA linearly increased plasma total antioxidant capacity (P = 0.039) and plasma total superoxide dismutase activities (P = 0.049) at 21 d of age. However, analysis of plasma biochemical markers revealed that dietary supplementation of GA did not exhibit beneficial health effects. Overall, we conclude that 75 to 100 mg/kg of GA are suitable for enhanced growth performance and health benefits in a broiler diet.

Dietary choline and phospholipid supplementation enhanced docosahexaenoic acid enrichment in egg yolk of laying hens fed a 2% Schizochytrium powder-added diet.

The aim of this study was to evaluate the effect of dietary phospholipid supplementation on laying hen performance, egg quality, and the fatty acid profile of egg yolks from hens fed a 2% Schizochytrium powder diet. Three-hundred-sixty 28-wk-old Hy-line W-36 laying hens were randomly allocated to one of the 5 dietary treatments, each treatment with 6 replicates of 12 birds each. All diets included 2% Schizochytrium powder (docosahexaenoic acid [DHA], 137.09 mg/g). The control group was not supplemented with any additional phospholipids, whereas the other 4 experimental diets were supplemented with 1,000 mg/kg choline (CHO), 1,000 mg/kg monoethanolamine (MEA), 1,000 mg/kg lysophosphatidylcholine (LPC), or 500 mg/kg LPC + 500 mg/kg MEA (LPC + MEA). The experimental diets were isocaloric (metabolizable energy, 11.15 MJ/kg) and isonitrogenous (crude protein, 16.60%). The feeding trial lasted 28 days. Laying hen performance and egg quality were not affected (P > 0.05) by the diets used. The monounsaturated fatty acid (MUFA) level was reduced in the LPC group at d 28 (P < 0.01), whereas the polyunsaturated fatty acid (PUFA) level was increased (P < 0.05). The omega-6 (n-6) PUFA level of the egg yolks in the LPC group had a trend to increase in comparison to the control (P = 0.07). The CHO and LPC groups had higher omega-3 (n-3) PUFA and DHA levels and lower n-6/n-3 ratios than the other groups at d 28 (P < 0.01). The DHA content in egg yolk reached a plateau after the laying hens consumed the experimental diets for 14 days, and higher yolk DHA contents were observed in the CHO and LPC groups as compared with the other groups at d 14. It was concluded that dietary choline supplementation for more than 14 d enhanced egg yolk enrichment with n-3 PUFA and DHA when laying hen diets were supplemented with 2% Schizochytrium powder. All the diets had no adverse effect on hen performance, egg quality, or egg components under the experimental condition.

Effects of dietary rapeseed meal supplementation on cecal microbiota in laying hens with different flavin-containing monooxygenase 3 genotypes.

To evaluate the effect of dietary rapeseed meal (RM) supplementation on cecal trimethylamine and bacteria in laying hens with different flavin-containing monooxygenase 3 (FMO3) genotypes, a 3 × 2 2-factorial arrangement was employed using FMO3 genotypes (AA, AT, and TT) and dietary RM (0 and 14% of diet) as the main effects. At 50 wk of age, 36 hens of AT genotype and 36 hens of TT genotype were randomly allotted to one of the 2 dietary treatments, and each dietary treatment consisted of 3 replicates with 6 birds each. A total of 12 hens with AA genotype were allotted to one of the 2 dietary treatments that consisted of 3 replicates with 2 hens. Hens were fed 0% RM in a corn-soybean (SM) diet for one wk before the 6-week feeding trial period. Dietary RM supplementation increased trimethylamine (TMA) concentrations in both egg yolks (P < 0.0001) and cecal chyme (P < 0.0001). Dietary RM supplementation increased bacterial abundance and diversity (P < 0.0001). Weighted UniFrac, Nonmetric Multidimensional Scaling, and analysis of similarity (R-ANOSIM = 0.1516; P-value = 0.014) indicated distinct clustering was dependent on diets rather than FMO3 genotypes. Twenty-four phyla (most dominant, Bacteroides, Firmicutes, and Proteobacteria) and 229 genera were identified in the cecal samples. Compared with the SM diets, RM diets increased the proportion of Firmicutes (P = 0.004), Proteobacteria (P = 0.006), and Firmicutes:Bacteroides (P = 0.001), and some low-abundance phyla (P < 0.01), whereas the abundance of Bacteroides was lower (P = 0.0002). The abundance of 42 genera varied with dietary types. Six phyla and 35 genera were positively correlated with TMA concentration in the cecal chyme. In conclusion, the major TMA-producing bacteria in cecal were from Firmicutes and Proteobacteria phyla. The major TMA-producing bacterial genera could be from the genera that positively correlated with TMA concentration.

Effect of dietary supplementation of organic or inorganic zinc on carbonic anhydrase activity in eggshell formation and quality of aged laying hens.

This study evaluated the effects of different dietary levels and sources of zinc (Zn) on performance and carbonic anhydrase (CA) activity in eggshell formation and quality in aged laying hens. A total of 504 Hy-line Grey layers aged 59 wk were fed a basal diet (Zn, 28.4 mg/kg) for 4 wks, then randomly allocated to 7 groups that were fed a basal diet or a basal diet supplemented with inorganic (ZnSO4·H2O) or organic (amino acid metals, 9.58%) Zn at 35, 70, or 140 mg Zn per kg of feed for 6 weeks. Each group had 6 replicates of 12 hens. Results showed that egg weight decreased linearly with the supplemental level of organic Zn (P < 0.05). Dietary Zn supplementation had linear and quadratic effects on the CA activity in plasma (P < 0.05), and it was higher in the organic Zn-added groups at wks 2 and 4 (P < 0.05). Dietary Zn supplementation had a quadratic effect on the CA activity in the eggshell gland (P < 0.05). Shell thickness was greater in the organic Zn-added groups (P < 0.05), and its relationship with the supplemental level of Zn showed linearly and quadratically, increasing with the organic Zn and with the inorganic Zn at wk 4, while linearly increasing with the inorganic Zn at wk 6 (P < 0.05). At wk 4, the supplemental level of inorganic Zn had a linear effect on shell weight, and linear and quadratic effects on shell index and ratio (P < 0.05), while shell weight, the index, and ratio increased linearly and quadratically with the organic Zn level in the diet (P < 0.05), with more obvious effects in the organic Zn-added groups (P < 0.05). Overall, dietary Zn supplementation, up to 140 mg/kg feed, could increase eggshell thickness by enhancing CA activity in the plasma and eggshell gland of aged layers; thicker eggshells were found in the organic Zn-added groups, but the breaking strength did not increase despite the eggshell thickness increasing.

Effect of dietary supplementation of organic or inorganic manganese on eggshell quality, ultrastructure, and components in laying hens.

This study evaluated the effects of dietary supplemental levels and sources of manganese (Mn) on performance, eggshell quality, ultrastructure, and components in laying hens. A total of 1,080 46-wk-old Jing Brown hens were fed a basal diet (Mn, 32.7 mg/kg) for 2 wks laying and then randomly allocated to 9 groups that were fed a basal diet (control) or the basal diet supplemented with inorganic (MnSO4·H2O) or organic (amino-acid-Mn, 8.78%) Mn at 40, 80, 120, or 160 mg per kg of feed for 8 wks. Each group had 8 replicates of 15 hens. The results showed that dietary Mn supplementation did not affect the performance of hens (P > 0.05). Dietary Mn supplementation resulted in linear and quadratic increases of breaking strength and thickness in both inorganic and organic forms (P < 0.05), but fracture toughness increased quadratically only in organic groups (P < 0.05). Linear and quadratic effects on effective and mammillary thickness were observed with Mn supplementation from inorganic and organic sources (P < 0.05), and lower mammillary thickness was observed in organic groups (P < 0.05). However, the width of mammillary knobs decreased quadratically only with the supplementation of organic Mn (P < 0.05). Dietary Mn supplementation had a quadratic effect on the shell Mn content in both inorganic and organic forms (P < 0.05). Linear and quadratic effects on the content of sulfated glycosaminoglycans (GAGs) were observed only in calcified eggshell with inorganic Mn supplementation (P < 0.05), while the supplementation of organic Mn had a quadratic effect on sulfated GAGs content in both calcified eggshell and membranes (P < 0.05). Overall, dietary Mn supplementation, regardless of the source, could increase breaking strength and thickness by improving the ultrastructure, which partly results from increased sulfated GAGs content in the eggshell. Moreover, the supplementation of organic Mn could increase fracture toughness by decreasing the width of mammillary knobs, which is partially due to increased sulfated GAGs content in the membranes.

Effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and expression of genes related to the reproductive axis in laying hens.

This experiment was conducted to evaluate the effects of dietary octacosanol supplementation on laying performance, egg quality, serum hormone levels, and gene expression related to reproductive axis in laying hens to confirm the reproduction-promoting function of octacosanol. In total, 360 Hy-Line Brown (67-wk-old) laying hens were randomly assigned to one of three treatments with 0, 5, and 10 mg octacosanol (extracted from rice bran, purity >92%)/kg feed. The feeding trial lasted for 10 weeks. The results showed that the dietary addition of 5 and 10 mg/kg octacosanol improved feed efficiency by 4.9% and 3.4% (P < 0.01), increased the albumen height by 20.5% and 13.3% (P < 0.01), the Haugh unit score by 12.9% and 8.7% (P < 0.01), and the eggshell strength by 39.5% and 24.5% (P < 0.01), respectively, compared with the control diet. Dietary octacosanol addition significantly affected serum triiodothyronine, estradiol, follicle-stimulating hormone levels (P < 0.05), and progesterone and luteinizing hormone level (P < 0.01). Compared with the control, dietary addition of octacosanol at 5 mg/kg promoted the follicle-stimulating hormone receptor (FSHR) mRNA expression in different-sized follicles, and significantly increased the FSHR mRNA expression of granulosa cells from the F2 and F3 follicles (P < 0.05). Dietary supplementation with both 5 and 10 mg/kg octacosanol promoted the mRNA expression of luteinizing hormone receptor and prolactin receptor in different-sized follicles, and significantly up-regulated the expression levels in F1 granulosa cells (P < 0.05). The ovarian weight was significantly increased with the dietary addition of 5 mg/kg octacosanol (P < 0.05). The numbers of small yellow follicles and large white follicles were increased with the addition of dietary 5 and 10 mg/kg octacosanol (P < 0.01). This study provides evidence that octacosanol has the capacity to improve reproductive performance, indicating that it is a potentially effective feed additive in egg production.

Effects of dietary grape proanthocyanidins on the growth performance, jejunum morphology and plasma biochemical indices of broiler chicks.

Grape proanthocyanidins (GPCs) are a family of naturally derived polyphenols that have aroused interest in the poultry industry due to their versatile role in animal health. This study was conducted to investigate the potential benefits and appropriate dosages of GPCs on growth performance, jejunum morphology, plasma antioxidant capacity and the biochemical indices of broiler chicks. A total of 280 newly hatched male Cobb 500 broiler chicks were randomly allocated into four treatments of seven replicates each, and were fed a wheat-soybean meal-type diet with or without (control group), 7.5, 15 or 30 mg/kg of GPCs. Results show that dietary GPCs decrease the feed conversion ratio and average daily gain from day 21 to day 42, increase breast muscle yield by day 42 and improve jejunum morphology between day 21 and day 42. Chicks fed 7.5 and 15 mg/kg of GPCs show increased breast muscle yield and exhibit improved jejunum morphologies than birds in the control group. Dietary GPCs fed at a level of 15 mg/kg markedly increased total superoxide dismutase (T-SOD) activity between day 21 and day 42, whereas a supplement of GPCs at 7.5 mg/kg significantly increased T-SOD activity and decreased lipid peroxidation malondialdehyde content by day 42. A supplement of 30 mg/kg of GPCs has no effect on antioxidant status but adversely affects the blood biochemical indices, as evidenced by increased creatinine content, increased alkaline phosphatase by day 21 and increased alanine aminotransferase by day 42 in plasma. GPC levels caused quadratic effect on growth, jejunum morphology and plasma antioxidant capacity. The predicted optimal GPC levels for best plasma antioxidant capacity at 42 days was 13 to 15 mg/kg, for best feed efficiency during grower phase was 16 mg/kg, for best jejunum morphology at 42 days was 17 mg/kg. In conclusion, GPCs (fed at a level of 13 to 17 mg/kg) have the potential to be a promising feed additive for broiler chicks.

Dietary supplementation of pyrroloquinoline quinone disodium protects against oxidative stress and liver damage in laying hens fed an oxidized sunflower oil-added diet.

The protective effects of dietary pyrroloquinoline quinone disodium (PQQ.Na2) supplementation against oxidized sunflower oil-induced oxidative stress and liver injury in laying hens were examined. Three hundred and sixty 53-week-old Hy-Line Gray laying hens were randomly allocated into one of the five dietary treatments. The treatments included: (1) a diet containing 2% fresh sunflower oil; (2) a diet containing 2% thermally oxidized sunflower oil; (3) an oxidized sunflower oil diet with 100 mg/kg of added vitamin E; (4) an oxidized sunflower oil diet with 0.08 mg/kg of PQQ.Na2; and (5) an oxidized sunflower oil diet with 0.12 mg/kg of PQQ.Na2. Birds fed the oxidized sunflower oil diet showed a lower feed intake compared to birds fed the fresh oil diet or oxidized oil diet supplemented with vitamin E (P=0.009). Exposure to oxidized sunflower oil increased plasma malondialdehyde (P<0.001), hepatic reactive oxygen species (P<0.05) and carbonyl group levels (P<0.001), but decreased plasma glutathione levels (P=0.006) in laying hens. These unfavorable changes induced by the oxidized sunflower oil diet were modulated by dietary vitamin E or PQQ.Na2 supplementation to levels comparable to the fresh oil group. Dietary supplementation with PQQ.Na2 or vitamin E increased the activities of total superoxide dismutase and glutathione peroxidase in plasma and the liver, when compared with the oxidized sunflower oil group (P<0.05). PQQ.Na2 or vitamin E diminished the oxidized sunflower oil diet induced elevation of liver weight (P=0.026), liver to BW ratio (P=0.001) and plasma activities of alanine aminotransferase (P=0.001) and aspartate aminotransferase (P<0.001) and maintained these indices at the similar levels to the fresh oil diet. Furthermore, oxidized sunflower oil increased hepatic DNA tail length (P<0.05) and tail moment (P<0.05) compared with the fresh oil group. Dietary supplementation of PQQ.Na2 or vitamin E decreased the oxidized oil diet induced DNA tail length and tail moment to the basal levels in fresh oil diet. These results indicate that PQQ.Na2 is a potential antioxidant and is as effective against oxidized oil-related liver injury in laying hens as vitamin E. The protective effects of PQQ.Na2 against liver damage induced by oxidized oil may be partially due to its role in the scavenging of free radicals, inhibiting of lipid peroxidation and enhancing of antioxidant defense systems.

Characterization of the Ryanodine Receptor Gene With a Unique 3'-UTR and Alternative Splice Site From the Oriental Fruit Moth.

The ryanodine receptor (RyR), the largest calcium channel protein, has been studied because of its key roles in calcium signaling in cells. Insect RyRs are molecular targets for novel diamide insecticides. The target has been focused widely because of the diamides with high activity against lepidopterous pests and safety for nontarget organisms. To study our understanding of effects of diamides on RyR, we cloned the RyR gene from the oriental fruit moth, Grapholita molesta, which is the most serious pest of stone and pome tree fruits throughout the world, to investigate the modulation of diamide insecticides on RyR mRNA expression in G. molesta (GmRyR). The full-length cDNAs of GmRyR contain a unique 3'-UTR with 625 bp and an open reading frame of 15,402 bp with a predicted protein consisting of 5,133 amino acids. GmRyR possessed a high level of overall amino acid homology with insect and vertebrate isoforms, with 77-92% and 45-47% identity, respectively. Furthermore, five alternative splice sites were identified in GmRyR. Diagnostic PCR showed that the inclusion frequency of one optional exon (f) differed between developmental stages, a finding only found in GmRyR. The lowest expression level of GmRyR mRNA was in larvae, the highest was in male pupae, and the relative expression level in male pupae was 25.67 times higher than that of in larvae. The expression level of GmRyR in the male pupae was 8.70 times higher than in female pupae, and that in male adults was 5.70 times higher than female adults.

Application of low-gossypol cottonseed meal in laying hens' diet.

An experiment was conducted to evaluate the application of dietary low-gossypol cottonseed meal (LCSM) in layers' diets. A total of 432 40-week-old Hy-line W36 laying hens were allocated to one of the six dietary treatments with 6 replicates of 12 birds each. The control group was fed a corn-soybean meal basal diet, and the 4 experimental diets consisted of a basal diet with 50, 98.3, 144.2, or 189 g/kg LCSM, respectively (correspondingly 25%, 50%, 75%, 100% dietary protein provided by soybean meal were replaced by LCSM). The sixth group was fed a basal diet supplemented with free gossypol (FG group). The feeding trial lasted for 12 weeks. The results showed that no significant difference was observed on egg production or feed conversion ratio (FCR, feed/egg, g/g) among all groups, but feed intake and egg weight were significantly decreased in the 189 g/kg LCSM group in weeks 46 to 51 (P < 0.05). A significant decrease was not observed in shell strength, shell thickness, and yolk color in all periods, but Haugh unit, albumen height, and egg white protein content were reduced in 189 g/kg LCSM group in weeks 46 to 51 (P < 0.05). No significant differences were found between the control and FG group. There was no obvious difference on plasma levels of total protein, blood urea nitrogen, uric acid, and activities of albumen, alanine aminotransferase, aspartate aminotransferase and the histopathology of liver, kidney, and oviduct in all groups. In conclusion, decreasing feed intake, egg weight, and egg quality were observed in the 189 g/kg LCSM group. However, the adverse effect was not relevant to the presence of FG in LCSM. Dietary LCSM supplementation of 98.3 g/kg was recommended with optimum FCR and without adverse effect on egg production, quality, and health of layers.

Bioefficacy comparison of organic manganese with inorganic manganese for eggshell quality in Hy-Line Brown laying hens.

This study was aimed at investigating the bioefficacy of organic compared with inorganic manganese (Mn) for eggshell quality. An amino acid-Mn complex or Mn sulfate monohydrate was used as the organic or inorganic Mn source. A total of six hundred forty-eight 50-wk-old layers (Hy-Line Brown) were divided into 9 groups; each group consisted of 6 replicates with 12 layers each. The feeding trial lasted 12 wk. During the first 4 wk of the feeding trial, the groups were fed a basal diet, which met the nutrient requirements of the layers, except for Mn. During the following 8 wk, 9 levels of Mn (inorganic Mn: 0, 25, 50, 100, and 200 mg/kg; organic Mn: 25, 50, 100, and 200 mg/kg) were used to supplement, respectively, in the basal diet on an equimolar basis. An exponential regression model was applied to calculate the bioefficacy of organic Mn compared with the inorganic Mn. Dietary supplementation with either organic or inorganic Mn did not influence egg production and feed efficiency of (P > 0.05), and eggshell quality did not exhibit a significant response to dietary supplementation with Mn sources at 56 and 58 wk (P > 0.05). Dietary supplementation with either organic Mn or inorganic Mn significantly enhanced the thickness, breaking strength, and elastic modulus of the eggshells compared with the control group at the end of 62 wk (P < 0.05). At the end of 62 wk, the bioefficacy of organic Mn was 357% (shell thickness), 406% (breaking strength), 458% (elastic modulus), and 470% (eggshell Mn), as efficacious as inorganic Mn at equimolar levels. This study suggests that organic Mn enhances eggshell quality in aged laying hens compared with inorganic Mn.

Agonist of farnesoid X receptor protects against bile acid induced damage and oxidative stress in mouse placenta--a study on maternal cholestasis model.

INTRODUCTION: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disorder, which is characterized by raised serum bile acid level and potential adverse fetal outcome. Farnesoid X receptor (FXR), also known as a bile acid receptor, was found to be expressed in placenta with low level. Whether activation of FXR by specific agonists could regulate the pathogenesis of ICP is still unclear. METHODS: A model of maternal cholestasis was induced by administration of 17α-ethynylestradiol (E2) in pregnant mice for 6 days. We explored the regulatory effect of WAY-362450 (W450), a highly selective and potent FXR agonist on placenta. RESULTS: In this study, we demonstrated that administration of E2 increased bile acid levels in mouse serum, liver and amniotic fluid. Bile acid levels were significantly decreased after W450 treatment. W450 protected against the impairment of placentas induced by E2, including severe intracellular edema and apoptosis of trophoblasts. Moreover, W450 significantly induced the expressions of FXR target bile acid transport gene ATP-binding cassette, sub-family B (MDR/TAP), member 11 (Abcb11;Bsep) in placenta. W450 could also attenuate placental oxidative stress and increase the expressions of antioxidant enzymes Prdx1 and Prdx3. DISCUSSION AND CONCLUSION: In conclusion, our data demonstrated that FXR agonist W450 modulated bile acid balance and protected against placental oxidative stress. Thus, our results support that potent FXR agonists might represent promising drugs for the treatment of ICP.

Effects of dietary pyrroloquinoline quinone disodium on growth, carcass characteristics, redox status, and mitochondria metabolism in broilers.

The potential benefits of supplementing pyrroloquinoline quinone disodium (PQQ·Na2) in the diet of broiler chicks were explored. We first examined the effect of different levels of dietary PQQ·Na2 on growth performance, carcass characteristics, and plasma biochemical parameters (trial 1). A total of 490 1-day-old male Arbor Acres (AA) broiler chicks were randomly divided into 5 dietary groups supplemented with 0, 0.05, 0.1, 0.2, or 0.4 mg PQQ·Na2/kg feed. As the 0.2 mg/kg PQQ·Na2 supplement gave the best performance, we then investigated whether this level of PQQ·Na2 influenced the redox status of plasma samples and mitochondrial-related metabolism (trial 2). A total of 120 1-day-old male AA chicks were randomly divided into 2 groups supplemented with 0 or 0.2 mg PQQ·Na2/kg diet. In trial 1, birds fed a diet containing 0.2 mg PQQ·Na2/kg showed lower feed conversion ratio compared with those fed the control diet in the overall study (d 1 to 42, P=0.039). Breast muscle yield (d 42) increased quadratically in response to dietary PQQ·Na2 supplementation (P=0.021). Analysis of plasma biochemical parameters revealed that feeding broiler chicks with ≤0.4 mg/kg PQQ·Na2 did not cause adverse health effects. In trial 2, birds fed 0.2 mg/kg PQQ·Na2 again showed improved feed efficiency than the control birds in the grower and overall phases (P=0.038 and 0.016, respectively). In addition, dietary PQQ·Na2 supplementation resulted in a higher anti-oxidative capacity (P=0.001), lower redox potential (P=0.008), and higher hepatic citrate synthase activity (P=0.002). In contrast, no difference in hepatic mitochondrial DNA copy number was observed between the 2 experimental groups (P>0.1). These results indicate that PQQ·Na2 is a potentially effective feed additive for improving feed efficiency, stimulating breast muscle development, and maintaining redox status in broiler chicks. Enhancement of mitochondria efficiency, rather than modulating mitochondria numbers, may underlie the growth-promoting effect of PQQ·Na2.

Effects of dietary pyrroloquinoline quinone disodium on growth performance, carcass yield and antioxidant status of broiler chicks.

Pyrroloquinoline quinone (PQQ), a putative essential nutrient and redox modulator in microorganisms, cell and animal models, has been recognized as a growth promoter in rodents. Growth performance, carcass yield and antioxidant status were evaluated on broiler chickens fed different levels of PQQ disodium (PQQ.Na2). A total of 784 day-old male Arbor Acres (AA) broilers were randomly allotted into seven dietary groups: negative control group (NC) fed a basal diet without virginiamycin (VIR) or PQQ.Na2; a positive control group (PC) fed a diet with 15 mg of VIR/kg diet; and PQQ.Na2 groups fed with 0.05, 0.10, 0.20, 0.40 or 0.80 mg PQQ.Na2/kg diet. Each treatment contained eight replicates with 14 birds each. The feeding trial lasted for 6 weeks. The results showed that chicks fed 0.2 mg PQQ.Na2/kg diet significantly improved growth performance comparable to those in PC group, and the feed efficiency enhancement effects of dietary PQQ.Na2 was more apparent in grower phase. Dietary addition of PQQ.Na2 had the potential to stimulate immune organs development, and low level dietary addition (<0.1 mg/kg) increased plasma lysozyme level. Broilers fed 0.2 mg PQQ.Na2/kg diet gained more carcasses at day 42, and had lower lipid peroxide malondialdehyde content and higher total antioxidant power in plasma. The results indicated that dietary PQQ.Na2 (0.2 mg/kg diet) had the potential to act as a growth promoter comparable to antibiotic in broiler chicks.

Manganese supplementation enhances the synthesis of glycosaminoglycan in eggshell membrane: a strategy to improve eggshell quality in laying hens.

This study investigated the effect of dietary Mn supplementation on eggshell quality, ultrastructure, glycosaminoglycan (GAG), and uronic acid content, and mRNA and protein expression of Galß1,3-glucuronosyltransferase (GlcAT-I). A total of 216 layers (Hy-Line Grey) at age of 50 wk were divided into 3 groups. In the first 8 wk of the 12-wk feeding trial, all groups were fed a basal diet that met all layer nutrient requirements except for Mn. In the last 4 wk, each group was fed 1 of 3 diets supplemented with Mn levels at 0, 25, or 100 mg Mn/kg. Dietary Mn deficiency did not affect the egg performance of layers. Dietary Mn supplementation significantly improved the breaking strength, thickness, and fracture toughness of eggshells (P < 0.05). In photographs of eggshell ultrastructure, the size of mammillary cones and cracks in the outer surface were decreased by dietary Mn supplementation. The contents of GAG and uronic acids in eggshell membrane were significantly increased by dietary Mn addition (P < 0.05). This result was further confirmed by increased mRNA expression and protein expression of GlcAT-I when Mn was added to the diet. This study suggests that dietary Mn supplementation can improve eggshell quality by enhancing the GAG and uronic acid synthesis in the eggshell glands, which can affect the ultrastructure of eggshells.

Solexa sequencing of microRNAs on chromium metabolism in broiler chicks.

AIM: The aim of this study was to determine the effect of chromium picolinate (CrPic) on the differential expression of the known microRNAs (miRNAs) in broiler skeletal muscle. METHODS AND RESULTS: A total of 288 1-day-old male Arbor Acres broilers were randomly assigned to one of four dietary treatments supplemented with 0, 0.4, 2.0, or 10.0 mg·kg(-1) CrPic, respectively. Dietary CrPic supplementation at 10.0 mg·kg(-1) increased the average daily feed intake in broilers (p < 0.05). On day 42, the serum total protein level was highest in animals treated with 2.0 mg·kg(-1) (p < 0.05) and 10.0 mg·kg(-1) CrPic (p < 0.05). Dietary supplementation with 10.0 mg·kg(-1) CrPic decreased the levels of serum glucose (p < 0.05) on day 42 and of serum triglyceride (p < 0.05) on days 21 and 42. To further identify miRNAs from broiler skeletal muscles, we sequenced two small RNA libraries using the Solexa sequencing approach, and 57 miRNAs were found to be significantly differentially expressed (p < 0.05). Among them, 6 upregulated and 2 downregulated miRNAs were validated by real-time qPCR (p < 0.05). CONCLUSIONS: The results of the present study provide a valuable clue regarding the role of miRNA target genes in the mechanism of the dietary CrPic effect on protein synthesis in skeletal muscles of broilers.

Effect of ß-hydroxy-ß-methylbutyrate calcium on growth, blood parameters, and carcass qualities of broiler chickens.

Beta-hydroxy-ß-methylbutyrate (HMB), the metabolite of leucine, plays an important role in muscle protein metabolism. To investigate the effect of dietary HMB calcium (HMB-Ca) on growth performance, breast muscle development, and serum parameters in broiler chickens, a total of two hundred seventy 1-d-old Arbor Acres male broiler chicks were randomly allotted into 3 dietary treatments supplemented with 0, 0.05%, or 0.1% HMB-Ca during the starter (1 to 21 d) and grower (22 to 42 d) period. The results showed that broilers fed 0.1% HMB-Ca diet had higher ADG during the starter or the whole period, and gain 148 g more BW than the chicks fed the control diet at 42 d of age (P < 0.05). At 21 d of age, birds receiving 0.1% HMB-Ca had more breast muscle yield, less abdominal fat than the control, and more dressing percentage than birds fed the control or 0.05% HMB-Ca diet (P < 0.05). At 42 d of age, 0.1% HMB-Ca increased breast muscle yield than the control and decreased abdominal fat compared with the control or 0.05% HMB-Ca group (P < 0.05). In comparison with the control, feeding 0.1% HMB-Ca increased the triiodothyronine, thyroxine, triiodothyronine/thyroxine ratio and decreased the serum uric acid level at d 21 (P < 0.05). At 42 d of age, serum thyroxine level was elevated in the 0.05% HMB-Ca treatment, and the uric acid concentration was significantly decreased by the 0.1% HMB-Ca-supplemented diet (P < 0.05). Dietary HMB-Ca did not affect the growth hormone or insulin content. This study suggested that dietary supplementation of HMB-Ca improved growth performance, stimulated the breast muscle development, and decreased the abdominal fat deposition in broiler chickens, and the favorable effects were more pronounced in the starter phase. The growth promotion effect of HMB-Ca may be partly related to the increased serum thyroid hormones in broiler chickens.