Effects of stevia extract on production performance, serum biochemistry, antioxidant capacity, and gut health of laying hens.

In the present study, we aimed to elucidate the effects of stevia extract on production performance, serum immune indexes, intestinal structure, and cecum microbial structure. We randomly divided eight hundred 46-wk-old Roman hens into 5 groups, with 8 replicates in each group and 20 chickens in each replicate. The control group was fed a basal diet, whereas the 4 experimental groups were fed 50, 100, 200, and 400 mg/kg stevia extracts. The study period was 24 wk. The addition of different concentrations of the stevia extract to the diet resulted in significant secondary changes in the egg production rate at 1 to 12 wk (P < 0.05). Furthermore, the addition of 50 and 100 mg/kg stevia extract to the diet significantly increased serum IgM and IgG levels in laying hens (P < 0.05) but linearly decreased serum IL-1ß levels (P < 0.05). Serum T-SOD activity linearly increased (P = 0.057); however, serum biochemical indexes showed no significant differences. Stevia extract tended to increase the ratio of the duodenal villi height to the depth of the crypt (P = 0.067), with no obvious lesions in the duodenum, jejunum, and ileum. In addition, stevia extract increased the relative abundance of species at the phylum level, with the abundance of Bacteroides and Firmicutes exhibiting significant secondary changes (P < 0.05). The ACE and Chao1 indexes suggested that stevia extract addition significantly increased the alpha diversity of cecum microorganisms in laying hens. Furthermore, NMDS analysis based on operational taxonomic units revealed that stevia extract addition increased the beta diversity of cecum microorganisms in laying hens. Adding a certain amount of stevia extract to feed can improve the production performance, immune ability, and intestinal health of laying hens to some extent, and we recommend an effective level of 200mg/kg of stevia extract for laying hen diets.

The improving effect of soybean isoflavones on ovarian function in older laying hens.

Emerging evidence suggests an association between estrogen levels and reduced egg-laying performance as the layer became old. Since soy isoflavones (SF) have estrogen-mimic effects, whether it can enhance production performance and ovarian function of older layers is still not known. A total of 160 Lohmann pink layers (66-wk-old) were used in a 2 × 2 factorial design, which included 2 egg-laying levels [low (76.89 ± 1.65%; LOW) and normal (84.96 ± 1.01%; NOR)] and 2 different dietary groups [0 mg/kg SF, 20 mg/kg SF] were used. The results showed the NOR group had higher egg-laying rate, egg mass, and feed efficiency during the all phases (P(laying) < 0.05). The unqualified egg rate was lower in NOR group (9-12 wk, 1-12 wk) (P(laying) < 0.05). Dietary supplementation with SF increased the egg-laying rate and feed efficiency (5-8 wk, 9-12 wk, 1-12 wk), increased egg mass (9-12 wk, 1-12 wk) (P(SF) < 0.05). The NOR layers presented higher eggshell quality (redness, yellowness, brightness, eggshell ratio) at 12 wk (P(laying) < 0.05). Eggshell quality was found to be improved by SF (eggshell strength and eggshell thickness), egg albumen quality (higher albumen height and Haugh unit) at 12 wk (P(SF) < 0.05). Supplementing with SF led to an increase in eggshell strength in LOW group (P(laying*SF) < 0.05). The higher serum lever of glucose (GLU) and lower serum lever of follicle stimulating hormone (FSH) were in NOR group (P(laying) < 0.05). Supplementing SF in diets increased serum of estradiol (E2) and insulin-like growth factors-1 (IGF-1), decreased serum of FSH (P(SF) < 0.05). The NOR layers presented lower estrogen receptor α (ERα), estrogen receptor ß (ERß), B lymphoma 2 associated X protein (Bax), cytochrome c (Cytc), interleukin 6 (IL-6), caspase3, caspase9, IKKα, P50, and P65 expression in the ovary (P(laying) < 0.05). Dietary SF supplementation decreased the anti-Müllerian hormone receptor (AMHR), Bax, caspase3, caspase9, Cytc, IL-6, IKKα, P50, P65 expression in the ovary (P(SF) < 0.05). These findings indicated that layers with NOR group had higher production performance, egg quality, and ovarian function, while dietary supplementation with SF improved production performance and ovarian function by reducing inflammation and apoptosis-related genes expression in ovary.

Effects of dietary theabrownins on production performance, egg quality, and ovarian function of laying hens with different ages.

This experiment was conducted to investigate the effect of theabrownins (TB) on production performance, egg quality, and ovarian function of laying hens at different ages. A total of 240 Lohmann laying hens were assigned in a 2 × 2 factorial design, which encompassed 2 layers ages (47-wk-old and 67-wk-old) and 2 dietary levels of TB (0 and 100 mg/kg) for 12 wk. Results showed that older layers had lower laying rate, egg mass, and higher feed-to-egg ratio (F/E), egg weight and unqualified egg rate than the younger layers (P(AGE) < 0.01) during all the experimental period. The effect of TB was found to increase egg laying rate and feed efficiency during 5 to 8 wk, 9 to 12 wk and the overall phases and decreased unqualified egg rate during 1 to 4 wk and the overall phases (P(TB) ≤ 0.05). The eggshell quality (strength, thickness), albumen quality (albumen height and Haugh unit) of eggs from older layers were decreased during overall phases (P(AGE) ≤ 0.05). TB increased eggshell strength during all phases and enhanced eggshell thickness at the end of wk 4 and 8 and increased albumen height and Haugh unit at the end of wk 8 and 12 of older layers (P(Interaction) ≤ 0.05). In addition, TB also increased egg quality of older layers after 14 d storage. A decrease in the serum concentration of progesterone, melatonin, follicle stimulating hormone, estradiol was observed in the older compared to the younger ones (P(AGE) < 0.05), while the increase in serum concentration of progesterone, melatonin, anti-Müllerian hormone (AMH) were more emphasized when older hens received TB supplemented diet (P(Interaction) < 0.05). The older layer demonstrated lower the concentration of glutathione (GSH) (P(AGE) < 0.05). And the activity of glutathione-s-transferase (GST) was significantly decreased in layers under 67-wk-old (P(AGE) <0.05). The increase in concentration of GSH and the decrease in concentration of malondialdehyde (MDA) were more pronounced when TB were supplemented in 67-wk-old layers (P(Interaction) ≤ 0.05). Layers at 67-wk-old had lower mRNA expression of Heme oxygenase 1 (HO-1) (P(AGE) < 0.01) in ovary. Dietary TB supplementation upregulated mRNA gene expression of HO-1, Nuclear factor E2 related factor 2 (Nrf2), Quinone oxidoreductase 1 (NQO1) (P(TB) < 0.01). Dietary TB upregulated mRNA expression of ovarian reproductive hormone receptor (estrogen receptor 1 [ESR1] and steroidogenic acute regulatory protein 1 [StAR1]]; P(TB) < 0.01). The results suggest feeding TB (100 mg/kg) could improve the egg production rate, egg quality, and antioxidant capacity of the ovary. Moreover, the effect of TB was more pronounced in older layers (64-wk-old vs. 47-wk-old).

Dietary 25-hydroxyvitamin D improves productive performance and intestinal health of laying hens under Escherichia coli lipopolysaccharide challenge.

The effect of 25-hydroxyvitamin D (25OHD) on the immune response of laying hens is not well elucidated. This study investigated the effects of 25OHD on egg production, egg quality, immune response, and intestinal health of laying hens challenged with Escherichia coli lipopolysaccharide (LPS). One hundred and sixty laying hens at 45 wk of age were randomly divided into 4 dietary treatments with 10 replicates of 4 birds. Hens were fed the corn-soybean based diets contained either 0 or 80 µg/kg 25OHD for 8 wks. At wk of 53 wk, birds of each dietary treatment were injected into the abdomen with 1.5 mg/kg body weight of either LPS or saline a day at 24-h intervals for continuous 7 d. LPS injection significantly decreased (PLPS < 0.05) egg laying rate, feed intake and feed efficiency; while the supplementation of 25OHD increased (PInteraction < 0.05) egg laying rate, feed efficiency and decreased (PInteraction < 0.05) the broken egg rate in layers under LPS injection. LPS challenge decreased (PLPS < 0.05) eggshell strength, eggshell thickness, albumen height and Haugh unit, while dietary 25OHD supplementation increased eggshell strength and eggshell thickness (P25OHD < 0.05). The serum proinflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6)], endotoxin and diamine oxidase (DAO) levels were higher in layers under LPS challenge (PLPS < 0.05); whereas the dietary addition of 25OHD were shown to decrease (P25OHD < 0.05) serum IL-1ß and IL-6 concentration irrespective of LPS challenge and led to a higher serum 25OHD level and a reduction in endotoxin concentration in layers under LPS challenge (PInteraction < 0.05). The layers under LPS challenge had higher crypt depth and lower villus height/crypt depth (V/C) ratio in duodenum and jejunum (PLPS < 0.05), while feeding 25OHD were shown to have decreasing effect on crypt depth and increasing effect V/C ratio in layers under LPS challenge (PInteraction < 0.05). Layers under LPS challenge had lower mRNA expression of intestinal barrier associated proteins (claudin-1 and mucin-1) (PLPS < 0.05), while the addition of 25OHD up-regulated claudin-1 and mucin-1 expression (Pinteraction < 0.05). Lower antioxidant enzymes activities, including superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) and higher malondialdehyde (MDA) content in jejunum were found in layers challenged with LPS (P25OHD < 0.05). The effect of 25OHD reversed the effect of LPS on SOD, T-AOC, and MDA content (PInteraction< 0.05). These results suggest that supplementing 80 µg/kg 25OHD in diets may elevate laying performance and egg quality through the improvement of intestinal barrier function, antioxidant capacity, and decreased the proinflammatory cytokines levels in laying hens with Escherichia coli LPS challenge.

Comparison of zinc bioavailability in zinc-glycine and zinc-methionine chelates for broilers fed with a corn-soybean meal diet.

The objective of this study was to compare the bioavailability of zinc (Zn) from zinc-glycine (Zn-Gly) and zinc-methionine (Zn-Met) as compared with zinc sulfate (ZnSO4) used as a standard in broilers. A total of 1,200 one-day-old male broilers (Cobb 500) were randomly allotted to one of 10 treatments with eight replicate cages of 15 birds each. The broilers were fed a corn-soybean meal basal diet (containing 26.46 mg Zn/kg; control) or the basal diet added with 40, 80, and 120 mg Zn/kg as Zn-Gly, Zn-Met, or ZnSO4 for 14 days. The relative bioavailability value (RBV) was calculated based on multiple linear regression slope ratios of Zn concentrations in tibia and pancreas, pancreas metallothionein (MT) concentration, and pancreas MT mRNA abundance on added Zn intake. When comparing the control with all Zn-supplemented treatments, Zn addition did not significantly affect average feed intake and bodyweight gain during days 1-14 (p > 0.10). However, Zn concentrations in the tibia, pancreas, and liver and pancreas MT concentration and MT mRNA abundance increased in all Zn-supplemented treatments compared with the control (p < 0.05), and these indices increased linearly (p < 0.001) with increasing added Zn levels on days 7 and 14. The RBV of Zn as Zn-Met was similar to that as Zn-Gly or ZnSO4 (p > 0.40) on days 7 and 14, based on tibia and pancreas Zn. In contrast, on days 7 and 14, the RBVs of Zn were in the following order: Zn-Met > Zn-Gly > ZnSO4 (p < 0.05), based on pancreas MT concentration. The bioavailable Zn from Zn-Met was 1.20 or 1.25 times that from Zn-Gly on day 7 or 14, respectively, evaluated by pancreas MT content. The RBV of Zn as Zn-Met was similar to that as Zn-Gly or ZnSO4 on day 7, whereas it was higher than that as Zn-Gly or ZnSO4 on day 14, based on pancreas MT mRNA abundance. In conclusion, Zn-Met had higher bioavailable Zn than Zn-Gly for the starter broilers fed with the corn-soybean meal diet, using pancreas MT concentration as the response criterion.

Effects of coated sodium butyrate on performance, egg quality, nutrient digestibility, and intestinal health of laying hens.

This study determined the effects of coated sodium butyrate (CSB) on production performance, egg quality, nutrient digestibility, and intestinal health of laying hens. We divided a total of 800 Lohmann laying hens, aged 51 wk, into 4 treatment groups: 0 (CON), 300 (CSB1), 500 (CSB2), and 800 (CSB3) mg/kg of CSB. Each group comprised 20 birds, with 10 replicates set. A 12-wk monitoring process was conducted for each laying hen. Compared to CON, dietary supplementation of CSB did not affect the average daily feed intake or the egg weight. The CSB3 group demonstrated a linear increase in the production performance (P < 0.05), with decreased feed conversion ratio (P < 0.05). CSB2 and CSB3 exhibited markedly elevated egg mass (P < 0.05). The CSB supplementation markedly enhanced the yolk color (P < 0.05). CSB1 improved the digestibility of dry matter (P = 0.029). No significant differences were observed among dietary treatments in the duodenal morphology (P > 0.05). The three dosages of CSB reduced the crypt depth (P < 0.05) in the jejunum, whereas CSB3 exhibited an increase in the villus height (VH; P = 0.048). The CSB3 group showed a markedly elevated ileal VH (P = 0.011). CSB supplementation significantly increased the butyric acid content in the cecum (P = 0.009). The hens fed on the 800 mg/kg CSB diet showed a significant increase (P = 0.029) in butyric acid content in the ileum. The CSB3 group showed an elevation in microbial diversity (P < 0.05). Additionally, at the phylum level, the CSB3 increased the enrichment of Bacteroidetes, the CSB2 increased Firmicutes, and the abundance of Deferribacteres was increased in CSB2 and CSB3 groups (P < 0.05). An enrichment of Muribaculaceae (family) was observed in the CSB3 group. In conclusion, dietary supplementation of CSB improved production, yolk color, intestinal morphology, butyrate content, and microbial composition in laying hens.

Effects of Dietary Glucose Oxidase Supplementation on the Performance, Apparent Ileal Amino Acids Digestibility, and Ileal Microbiota of Broiler Chickens.

This study aimed to investigate the effects of glucose oxidase (GOD) supplementation on growth performance, apparent ileal digestibility (AID) of nutrients, intestinal morphology, and short-chain fatty acids (SCFAs) and microbiota in the ileum of broilers. Six hundred 1-day-old male broilers were randomly allotted to four groups of 10 replicates each with 15 birds per replicate cage. The four treatments included the basal diet without antibiotics (Control) and the basal diet supplemented with 250, 500, or 1000 U GOD/kg diet (E250, E500 or E1000). The samples of different intestinal segments, ileal mucosa, and ileal digesta were collected on d 42. Dietary GOD supplementation did not affect daily bodyweight gain (DBWG) and the ratio of feed consumption and bodyweight gain (FCR) during d 1-21 (p > 0.05); however, the E250 treatment increased DBWG (p = 0.03) during d 22-42 as compared to control. Dietary GOD supplementation increased the AIDs of arginine, isoleucine, lysine, methionine, threonine, cysteine, serine, and tyrosine (p < 0.05), while no significant difference was observed among the GOD added groups. The E250 treatment increased the villus height of the jejunum and ileum. The concentrations of secreted immunoglobulin A (sIgA) in ileal mucosa and the contents of acetic acid and butyric acid in ileal digesta were higher in the E250 group than in the control (p < 0.05), whereas no significant differences among E500, E1000, and control groups. The E250 treatment increased the richness of ileal microbiota, but E500 and E100 treatment did not significantly affect it. Dietary E250 treatment increased the relative abundance of Firmicutes phylum and Lactobacillus genus, while it decreased the relative abundance of genus Escherichina-Shigella (p < 0.05). Phylum Fusobacteria only colonized in the ileal digesta of E500 treated broilers and E500 and E1000 did not affect the relative abundance of Firmicutes phylum and Lactobacillus and Escherichina-Shigella genera as compared to control. These results suggested that dietary supplementation of 250 U GOD/kg diet improves the growth performance of broilers during d 22-42, which might be associated with the alteration of the intestinal morphology, SCFAs composition, and ileal microbiota composition.

Effects of Maternal and Progeny Dietary Vitamin E on Growth Performance and Antioxidant Status of Progeny Chicks before and after Egg Storage.

Two trials were conducted to investigate the effects of maternal and progeny dietary vitamin E (VE) supplementation on the growth performance and antioxidant status of offspring before and after egg storage. A total of 576 75-week-old Ross 308 breeder hens were assigned to three dietary VE treatments (100, 200, and 400 mg/kg) with 6 replicates of 32 hens for 12 weeks. Two trials were conducted with offspring hatched from eggs laid at weeks 9 and 12 of breeder feeding trial, respectively. Trial 1 was conducted by a 3 × 2 factorial arrangement of treatments with three levels of maternal dietary VE (100, 200, and 400 mg/kg) and two levels of progeny dietary VE (0 and 35 mg/kg). Trial 2 was conducted with three maternal dietary VE treatment (100, 200, and 400 mg/kg), and chicks were hatched from eggs stored for 14 d and received the same progeny diet with no addition of VE. Results showed that in trial 1, maternal (100, 200, and 400 mg/kg) and progeny (0 and 35 mg/kg) dietary VE supplementation did not affect the growth performance of offspring hatched from unstored eggs (p > 0.05). In trial 2, in the case of long-term egg storage, maternal dietary VE supplementation of 200 and 400 mg/kg increased the body weight (BW) of 21- and 42-d-old offspring and the body weight gain (BWG) of offspring from 1 to 21 d (p < 0.05), and decreased the feed conversion ratio (FCR) of offspring from 1 to 21 d (p < 0.05) compared to 100 mg/kg VE. As the maternal dietary VE levels increased, the liver and serum antioxidant status of offspring enhanced (p < 0.05). In conclusion, maternal dietary VE supplementation of 200 or 400 mg/kg could improve the growth performance and anti-oxidant status of offspring hatched from stored eggs, but not for that of offspring hatched from unstored eggs. The suitable VE level for the broiler breeder diet was 400 mg/kg in the case of long-term egg storage.

Dietary apple pectic oligosaccharide improves reproductive performance, antioxidant capacity, and ovary function of broiler breeders.

Reproduction performance is one of the most important economic traits for the poultry industry. Intriguingly, apple pectic oligosaccharide (APO) could promote gastrointestinal function and immune function to improve performance; however, literature about APO on reproduction performance in breeders is limited. This study aimed to determine whether APO administration can improve reproduction performance and ovary function of broiler breeders with different egg laying rates. Two hundred and fifty six Arbor Acres broiler breeders (48-week-old) were used in a 2 × 2 factorial design with 2 egg laying rates (average [AR] and low [LR]) and 2 dietary levels of APO (0 and 200 mg/kg APO). Results showed that the LR breeders presented higher egg weight but lower egg laying rate, qualified egg rate, and feed efficiency than the AR breeders (P(laying) < 0.05). Also, the LR breeders had decreased serum Anti-Müllerian hormone, leptin, and antioxidant enzyme (superoxide dismutase, total antioxidant capacity) levels than the AR breeders (P(laying) ≤ 0.05). Dietary supplementation with APO improved egg weight, feed efficiency, as well as egg albumen quality (higher albumen height and Haugh unit) (P(APO) < 0.05), and decreased the concentration of pro-inflammatory cytokine levels (interleukin [IL]-1ß, IL-8) in serum (P(APO) ≤ 0.05). The apoptosis rate and pro-apoptosis-related gene expression (caspase 9 and Bax) in the ovary of LR breeders were higher, while the anti-apoptosis-related gene expression (Bcl-2, PCNA) was lower in LR compared with the AR breeders (P(laying) < 0.05). Dietary supplementation with APO decreased the caspase 9 and Bax expression in LR breeders (P(interaction) < 0.05), and increased the Bcl-2 and PCNA expression in the 2 breeders (P(APO) < 0.05). These findings indicate that breeders with a lower egg laying rate exhibit lower antioxidant capacity and high cell apoptosis in the ovary. Dietary supplementation with APO might improve albumen quality and antioxidant capacity, and decrease the inflammatory factors and ovary apoptosis-related genes expression to improve ovary function. Moreover, the effect of APO on decreasing ovarian pro-apoptosis-related gene expression was more pronounced in lower reproductive breeders.

The Effects of Broiler Breeder Dietary Vitamin E and Egg Storage Time on the Quality of Eggs and Newly Hatched Chicks.

This study was conducted to investigate the effects of broiler breeder dietary vitamin E and egg storage time on the egg characteristics, hatchability, and antioxidant status of the egg yolks and newly hatched chicks. A total of 512 71-week-old Ross 308 breeder hens were fed the same basic diets containing 6 or 100 mg/kg vitamin E for 12 weeks. During this time, a total of 1532, 1464, and 1316 eggs were independently collected at weeks 8, 10, and 12, respectively, and subsequently stored for 0 or 14 d before hatching. The outcomes from three trials showed that prolonged egg storage time (14 vs. 0 d) negatively affected (p < 0.05) the egg characteristics, hatchability traits, and the yolk total antioxidant capacity (T-AOC) (p < 0.05). Chicks derived from the stored eggs exhibited higher malonaldehyde (MDA) and T-AOC in the serum and yolk sac (p < 0.05). Broiler breeder dietary vitamin E (100 vs. 6 mg/kg) increased (p < 0.05) the hatchability and the antioxidant status of the yolks as indicated by a higher α-tocopherol content and T-AOC and lower MDA level (p < 0.05). The supplementation of vitamin E also remarkably increased (p < 0.05) the total superoxide dismutase (T-SOD) activity (yolk sac, weeks 8 and 12) and T-AOC (serum, weeks 8, 10, and 12; yolk sac, weeks 8 and 12) and decreased (p < 0.05) the MDA content of chicks (yolk sac, week 10; serum, week 12). Interactions (p < 0.05) were found between the broiler breeder dietary vitamin E and egg storage time on the hatchability and antioxidant status of chick tissues. Broiler breeder dietary vitamin E (100 vs. 6 mg/kg) increased (p < 0.05) the hatchability and the T-AOC in the serum and liver of chicks, and decreased (p < 0.05) the early embryonic mortality and the MDA content in the yolk sacs of chicks derived from eggs stored for 14 d but not for 0 d. In conclusion, prolonged egg storage time (14 vs. 0 d) increased the embryonic mortality, decreased the hatchability, and impaired the antioxidant status of egg yolks and newly hatched chicks, while the addition of broiler breeder dietary vitamin E (100 vs. 6 mg/kg) could partly relieve these adverse impacts induced by long-term egg storage.

Tandem mass tag-based quantitative proteomics analysis and gelling properties in egg albumen of laying hens feeding tea polyphenols.

The tea polyphenol (TP) can improve the egg albumen quality in laying hens; however, our understanding of the molecular mechanisms and proteomic changes in the egg albumen remains limited. A total of 720 layers (35-wk-old) were allocated into 5 treatments with TP and were added at 0 (control), 200 (TP200), 400 (TP400), 600 (TP600), and 800 (TP800) mg/kg. It showed that 400 mg/kg TP increases albumen height and Haugh unit (quadratic effect, P < 0.01), while 400 mg/kg TP decreases gel strength, hardness, gumminess, and chewiness value in a quadratic manner (P = 0.01). Eggs from TP400-fed layers had highest reducing power and oxygen radical absorbance capacity, and lowest albumen malondialdehyde content (quadratic effect, P < 0.05). Through Tandem Mass Tag-based quantitative proteomics analysis, 258 proteins were identified and 31 differentially accumulated proteins in egg white affected by 400 mg/kg TP compared to control group, with 19 proteins upregulated and 12 proteins downregulated. A total of 11 binding proteins (A0A1D5PZE3, F1NTQ2, Q7SX63, F1NRV5, P24802, A0A1L1RM02, E1BTX1, A0A1L1RMF4, A0A1D5P1N3, A0A1L1RML6, A0A1L1RQF3), 9 immune response proteins (P10184, R4GI90, P01875, Q6IV20, Q64EU6, P02701, P08110, P0CB50, A0A1D5PQ63), and 3 cell redox homeostasis proteins (P0CB50, P20136, Q8JG64) were changed in albumen of laying hens fed TP400. The differentially expressed proteins mainly involved in pyruvate metabolism, cysteine and methionine metabolism, glutathione metabolism, glycolysis, and protein processing in endoplasmic reticulum pathway. The result gathered in this study suggested that the improving mechanism of TP on albumen quality may act through regulating binding mediation, immune function, and antioxidant activity-related proteins.

Impact of Dietary Manganese on Intestinal Barrier and Inflammatory Response in Broilers Challenged with Salmonella Typhimurium.

Growing concern for public health and food safety has prompted a special interest in developing nutritional strategies for removing waterborne and foodborne pathogens, including Salmonella. Strong links between manganese (Mn) and intestinal barrier or immune function hint that dietary Mn supplementation is likely to be a promising approach to limit the loads of pathogens in broilers. Here, we provide evidence that Salmonella Typhimurium (S. Typhimurium, 4 × 108 CFUs) challenge-induced intestinal injury along with systemic Mn redistribution in broilers. Further examining of the effect of dietary Mn treatments (a basal diet plus additional 0, 40, or 100 mg Mn/kg for corresponding to Mn-deficient, control, or Mn-surfeit diet, respectively) on intestinal barrier and inflammation status of broilers infected with S. Typhimurium revealed that birds fed the control and Mn-surfeit diets exhibited improved intestinal tight junctions and microbiota composition. Even without Salmonella infection, dietary Mn deficiency alone increased intestinal permeability by impairing intestinal tight junctions. In addition, when fed the control and Mn-surfeit diets, birds showed decreased Salmonella burdens in cecal content and spleen, with a concomitant increase in inflammatory cytokine levels in spleen. Furthermore, the dietary Mn-supplementation-mediated induction of cytokine production was probably associated with the nuclear factor kappa-B (NF-κB)/hydrogen peroxide (H2O2) pathway, as judged by the enhanced manganese superoxide dismutase activity and the increased H2O2 level in mitochondria, together with the increased mRNA level of NF-κB in spleen. Ingenuity-pathway analysis indicated that acute-phase response pathways, T helper type 1 pathway, and dendritic cell maturation were significantly activated by the dietary Mn supplementation. Our data suggest that dietary Mn supplementation could enhance intestinal barrier and splenic inflammatory response to fight against Salmonella infection in broilers.

Effects of maternal dietary vitamin E on the egg characteristics, hatchability and offspring quality of prolonged storage eggs of broiler breeder hens.

This research aims to evaluate the effects of maternal vitamin E (VE) dietary supplementation on the egg characteristics, hatchability and antioxidant status of the embryo and newly hatched chicks of prolonged storage eggs. A total of 576 75-week-old Ross 308 breeder hens were randomly allocated into three dietary VE treatments (100, 200 and 400 mg/kg) with 6 replicates of 32 hens, for a 12-week feeding trial. At week 12, a total of 710 eggs were collected over a 5-day period, and eggs per treatment were attributed into 5 replicates and stored for 14 days until incubation. The egg yolk, trunk and head of 7-day-old embryo and the serum, liver, brain and yolk sac of newly hatched chicks were sampled for the evaluation of antioxidant status. Results showed that as maternal dietary VE levels increased, yolk α-tocopherol concentration increased (p < .05). Compared with 100 mg/kg VE, the use of 200 and 400 mg/kg VE increased the hatchability of set/fertile eggs and total antioxidant capacity (T-AOC) of liver and serum in chicks (p < .05), and decreased both the early embryonic mortality and the malondialdehyde (MDA) content of trunk and head in 7-day-old embryos (p < .05); moreover, 400 mg/kg VE increased the yolk T-AOC (p < .05) and decreased yolk and brain MDA content of chicks (p < .05). Brain T-AOC of chicks in 200 mg/kg VE group was improved compared to that of chicks in 100 mg/kg VE group (p < .05). In conclusion, maternal dietary VE at 200 or 400 mg/kg could increase hatchability by decreasing early embryonic mortality and increasing the antioxidant status of egg yolk, embryo and newly hatched chicks as breeder egg storage was prolonged to 14-18 days. The suitable VE level for the broiler breeder diet was 200 mg/kg as breeder egg storage was prolonged.

Effects of Dietary Iron Concentration on Manganese Utilization in Broilers Fed with Manganese-Lysine Chelate-Supplemented Diet.

Dietary iron (Fe) influences manganese (Mn) utilization in chickens fed with inorganic Mn-supplemented diet. This study aimed to determine if dietary Fe levels affect Mn utilization in broilers fed with organic Mn-supplemented diet. Nine hundred 8-day-old broilers were randomly assigned to 1 of 6 treatments in a 3 (Fe level) × 2 (Mn source) factorial arrangement after feeding Mn- and Fe-unsupplemented diets for 7 days. The broilers were fed the basal diets (approximately 28 mg Mn/kg and 60 mg Fe/kg) supplemented with 0, 80, or 160 mg/kg Fe (L-Fe, M-Fe, or H-Fe), and 100 mg/kg Mn from Mn sulfate (MnSO4) or manganese-lysine chelate (MnLys) for 35 days. The H-Fe diet decreased (P < 0.05) body weight gain and feed intake as compared with L-Fe and M-Fe diets regardless of dietary Mn sources. Dietary Fe levels did not influence (P > 0.10) serum Mn concentration in MnLys-treated broilers, but serum Mn concentration decreased (P < 0.05) with dietary Fe increasing in MnSO4-treated broilers. The Mn concentration in the duodenum and tibia decreased (P < 0.05) with increasing dietary Fe levels regardless of dietary Mn sources, and MnLys increased (P < 0.04) these indices as compared with MnSO4. Dietary Fe levels did not significantly influence (P > 0.11) Mn concentration and activity and mRNA abundance of manganese-containing superoxide dismutase (MnSOD) in the heart of MnLys-treaded broilers, but the H-Fe diet decreased (P < 0.05) these indices in MnSO4-treated broilers as compared with M-Fe and L-Fe diets. The L-Fe diet increased (P < 0.001) duodenal divalent metal transporter 1 mRNA abundance when compared with the M-Fe and H-Fe diets on day 42, regardless of dietary Mn sources. The M-Fe and H-Fe diets decreased (P < 0.001) duodenal ferroportin 1 (FPN1) mRNA level when compared with the L-Fe diet in MnSO4-treated broilers, while dietary Fe levels did not significantly influence (P > 0.40) duodenal FPN1 mRNA abundance in MnLys-treated broilers. These results indicated dietary Fe levels decreased Mn utilization in MnSO4-treated broilers, but did not influence Mn utilization in MnLys-treated broilers evaluated by Mn concentrations in the serum and heart, and the activity and mRNA expression of heart MnSOD.

Dietary supplement of essential oil from oregano affects growth performance, nutrient utilization, intestinal morphology and antioxidant ability in Pekin ducks.

A study was conducted to investigate the effects of oregano essential oil (EO) on growth performance, nutrients utilization, intestinal morphology, intestinal barrier-related gene expression and antioxidant capability in meat ducks. A total of 360 1-day-old ducks were divided into three groups (12 replicates pens per diet of 10 ducks in each pen): negative control (no essential oil or antibiotic), positive control (antibiotic: 500 mg/kg aureomycin of diet) and oregano EO (100 mg/kg of diet). The experiment was carried out for 35 days. Ducks were given feed and water ad libitum. Ducks fed EO supplement showed similar body weight and feed to gain ratio to antibiotic fed ducks. EO supplementation significantly increased (p < .05) feed intake (day 1-35), jejunal villus height (VH) to crypt depth (CD) ratio, serum superoxide dismutase activities (SOD) and jejunal total antioxidant capacity (T-AOC) of ducks compared to controls. Ducks fed diets supplemented with oregano EO also had decreased (p < .05) jejunal CD, serum and hepatic malondialdehyde (MDA) concentration, and the mRNA expression of jejunal zonula occludens-3 (ZO-3) and secretory immunoglobulin A (sIgA) genes in comparison to the control group. Compared to the antibiotic supplementation group, the mRNA expression of claudin1 (CLND1) and CLND2 significantly increased (p < .05), but the mRNA expression of ZO-3 and mucin 2 markedly decreased (p < .05) in the jejunum of ducks in oregano EO supplementation group. These results suggest that oregano EO improves the antioxidant capacity and intestinal defence and structural measures and may aide in helping to maintain enteric health in production without growth-promoting antibiotics.

Dietary administration of resistant starch improved caecal barrier function by enhancing intestinal morphology and modulating microbiota composition in meat duck.

Resistant starch (RS) was recently approved to exert a powerful influence on gut health, but the effect of RS on the caecal barrier function in meat ducks has not been well defined. Thus, the effect of raw potato starch (RPS), a widely adopted RS material, on microbial composition and barrier function of caecum for meat ducks was determined. A total of 360 Cherry Valley male ducks of 1-d-old were randomly divided and fed diets with 0 (control), 12, or 24 % RPS for 35 d. Diets supplemented with RPS significantly elevated villus height and villus height:crypt depth ratio in the caecum. The 16S rRNA sequence analysis indicated that the diet with 12 % RPS had a higher relative abundance of Firmicutes and the butyrate-producing bacteria Faecalibacterium, Subdoligranulum, and Erysipelatoclostridium were enriched in all diets. Lactobacillus and Bifidobacterium were significantly increased in the 24 % RPS diet v. the control diet. When compared with the control diet, the diet with 12 % RPS was also found to notably increase acetate, propionate and butyrate contents and up-regulated barrier-related genes including claudin-1, zonula occludens-1, mucin-2 and proglucagon in the caecum. Furthermore, the addition of 12 % RPS significantly reduced plasma TNF-α, IL-1ß and endotoxin concentrations. These data revealed that diets supplemented with 12 % RPS partially improved caecal barrier function in meat ducks by enhancing intestinal morphology and barrier markers expression, modulating the microbiota composition and attenuating inflammatory markers.

Effects of Dietary Iron on Manganese Utilization in Broilers Fed with Corn-Soybean Meal Diet.

To investigate the effects of dietary iron (Fe) levels on manganese (Mn) utilization, 900 8-day-old broilers were randomly assigned to 1 of 6 treatments in a 3 (Fe level) × 2 (Mn level) factorial arrangement after feeding Mn- and Fe-unsupplemented diet for 7 days. The broilers were then fed with basal corn-soybean meal diets (approximately 28 mg Mn/kg and 60 mg Fe/kg) added with 0, 80, or 160 mg/kg Fe (L-Fe, M-Fe, or H-Fe), and 0 or 100 mg/kg Mn for 35 days. Body weight gain was lower for H-Fe broilers than that for L-Fe and M-Fe broilers. On day 42, H-Fe broilers had lower serum Mn concentration as compared with L-Fe and M-Fe broilers, and tibia Mn concentration decreased as dietary Fe increased. In Mn-supplemented broilers, liver Mn was lower in L-Fe and H-Fe treatments than that in M-Fe treatment. H-Fe treatment decreased Mn concentration and manganese-containing superoxide dismutase (MnSOD) activity in the heart when compared with L-Fe and M-Fe treatments. Dietary Fe did not significantly influence Mn concentrations in the liver and heart, and heart MnSOD activity in Mn-unsupplemented broilers. In the duodenum, L-Fe treatment decreased divalent metal transporter 1 (DMT1) mRNA abundance when compared with M-Fe and H-Fe treatments, and ferroportin 1 (FPN1) mRNA level was higher in M-Fe treatment than that in L-Fe and H-Fe treatments. These results suggested H-Fe diet decreased Mn status in broilers evaluated by Mn concentrations in serum and heart, and heart MnSOD activity. Dietary Fe influenced Mn absorption possibly through effects on duodenal DMT1 and FPN1 expression.

Uptake of Manganese from the Manganese-Lysine Complex in Primary Chicken Intestinal Epithelial Cells.

Organic manganese (Mn) sources can replace inorganic Mn as dietary Mn supplements in poultry. To compare the uptake of Mn from the Mn-lysine complex (MnLys) and MnSO4, we first established the primary chicken intestinal epithelial cells (IECs) model and used it to determine Mn uptake. The MnLys increased the uptake of Mn compared to MnSO4. The uptake of Mn decreased in the IECs with Fe addition in the medium regardless of the Mn sources. The MnLys decreased the Mn2+ efflux transporter ferroportin 1 (FPN1) mRNA level but did not influence the Mn2+ influx transporter divalent metal transporter 1 (DMT1) mRNA expression when compared to MnSO4. The results above indicated that the increase of Mn accumulation for MnLys at least partly was due to the decrease of Mn efflux by reduced FPN1 expression. The addition of N-ethylmaleimide, an L-lysine transport system y+ inhibitor, decreased the uptake of Mn from MnLys but did not affect the uptake of Mn from MnSO4. The cycloheximide, as an L-lysine transport system b0,+ activator, increased the uptake of Mn from MnLys, whereas they did not influence the uptake of Mn from MnSO4. The MnLys increased the system y+ members cationic amino acid transporter (CAT) 1 and CAT2, and system b0,+ components rBAT and b0,+AT mRNA expression when compared to MnSO4. These results suggested that the uptake of MnLys complex might be transported by CAT1/2 and system b0,+, which was different from the ionized Mn2+ uptake pathway. In conclusion, the uptake of Mn from MnLys complex not only might be uptake through the ionized Mn2+ pathway, but also appeared to be transported through the CAT1/2 and system b0,+ in primary chicken IECs.

Relative bioavailability of humate-manganese complex for broilers fed a corn-soya bean meal diet.

The experiment was conducted to investigate the bioavailability of manganese (Mn) from humate-Mn complex relative to Mn sulphate for the starter broilers fed a conventional corn-soya bean meal diet. A total of 560 1-day-old Arbor Acres male broiler chicks were randomly allotted to one of eight replicate cages (10 chicks per cage) for each of seven treatments in a completely randomized design involving a 2 × 3 factorial arrangement of treatments with two Mn sources (humate-Mn and Mn sulphate) and three levels of added Mn (60, 120 or 180 mg Mn/kg) plus a Mn-unsupplemented control diet containing 27.23 mg Mn/kg by analysis. At 14 days of age, the blood, liver, heart and tibia were collected for Mn analyses, and the activity and mRNA abundance of heart manganese superoxide dismutase (MnSOD). The results showed that humate-Mn supplementation decreased feed intake from day 1 to day 14, whereas it did not influence (p > 0.20) body weight at day 14 as compared to Mn sulphate. The Mn source did not influence Mn concentration in the liver, heart and tibia, and the activity and mRNA abundance of heart MnSOD, while humate-Mn decreased plasma Mn as compared to Mn sulphate. The Mn concentration in the plasma and heart, and the activity and mRNA abundance of heart MnSOD increased linearly as dietary Mn concentration increased. Based on slope ratios from multiple linear regressions of Mn concentrations in the plasma and heart, and the activity and mRNA abundance of heart MnSOD on daily intake amount of dietary analysed Mn, the bioavailability of humate-Mn complex relative to Mn sulphate (100%) was 82.8, 90.4, 82.8 and 81.9 respectively. These results indicated that the Mn from humate-Mn complex was just as bioavailable as the Mn from Mn sulphate for the starter broilers (day 1-14).

High Dietary Iron Differentially Influences the Iron Distribution in the Livers and the Spleens of Laying Hens After Salmonella Typhimurium Infection.

Salmonella and the host battle for iron (Fe), due to its importance for fundamental cellular processes. To investigate Fe redistribution of Salmonella-infected hens and the effects of high dietary Fe on it, Salmonella-free hens were randomly assigned to 1 of 4 treatments in 2 (two dietary Fe level) × 2 (Salmonella-inoculation or -noninoculation) factorial assignment. After feeding a basal diet supplemented with 60 (adequate, control) or 300 mg Fe/kg (high-Fe) for 4 weeks, 59-week-old Salmonella-free hens were orally inoculated with 5 × 107 colony-forming units of Salmonella Typhimurium (infection) or PBS (vehicle). Blood, spleen, and liver samples (n = 8) were collected at 14 days post-inoculation to determine Fe concentration and Fe transporters expression. Salmonella infection decreased (P < 0.05) hematocrit, serum Fe concentration, and splenic Fe concentration regardless of high-Fe or control hens, whereas increased (P < 0.05) Fe centration in the livers of high-Fe-treated hens. High dietary Fe increased hematocrit and serum Fe concentration, but did not affect (P = 0.11) splenic Fe concentration in Salmonella-infected hens. Salmonella infection did not influence (P = 0.31) liver Fe centration in control hens, but increased (P = 0.04) it in high-Fe-treated hens. High dietary Fe decreased (P < 0.01) the mRNA abundance of divalent metal transporter 1 and transferrin receptor, but increased (P < 0.02) ferroportin-1 (FPN1) mRNA and protein in the spleens and the livers regardless of Salmonella-infected or vehicle hens. Salmonella infection increased (P < 0.02) FPN1 mRNA and protein expression in the spleens, but did not influence its expression in the livers. These results suggested Salmonella infection and high dietary Fe differently influence the Fe distribution in the spleen and the liver of Salmonella-infected hens.