Zinc source influences the gene expression of zinc transporters in jejunum and cecal tonsils during broiler challenge with Eimeria maxima and Clostridium perfringens

Zinc glycinate alleviates LPS-induced inflammation and intestinal barrier disruption in chicken embryos by regulating zinc homeostasis and TLR4/NF-κB pathway

The effect of an immune challenge induced by a lipopolysaccharide (LPS) exposure on systemic zinc homeostasis and the modulation of zinc glycinate (Zn-Gly) was investigated using a chicken embryo model. 160 Arbor Acres broiler fertilized eggs were randomly divided into 4 groups: CON (control group, injected with saline), LPS (LPS group, injected with 32 µg of LPS saline solution), Zn-Gly (zinc glycinate group, injected with 80 µg of zinc glycinate saline solution) and Zn-Gly+LPS (zinc glycinate and LPS group, injected with the same content of zinc glycinate and LPS saline solution). Each treatment consisted of eight replicates of five eggs each. An in ovo feeding procedure was performed at 17.5 embryonic day and samples were collected after 12 hours. The results showed that Zn-Gly attenuated the effects of LPS challenge-induced upregulation of pro-inflammatory factor interleukin 1β (IL-1β) level (P =0.003). The LPS challenge mediated zinc transporter proteins and metallothionein (MT) to regulate systemic zinc homeostasis, with increased expression of the jejunum zinc export gene zinc transporter protein 1 (ZnT-1) and elevated expression of the import genes divalent metal transporter 1 (DMT1), Zrt- and Irt-like protein 3 (Zip3), Zip8 and Zip14 (P < 0.05). A similar trend could be observed for the zinc transporter genes in the liver, which for ZnT-1 mitigated by Zn-Gly supplementation (P =0.01). Liver MT gene expression was downregulated in response to the LPS challenge (P =0.004). These alterations caused by LPS resulted in decreased serum and liver zinc levels and increased small intestinal, muscle and tibial zinc levels. Zn-Gly reversed the elevated expression of the liver zinc finger protein A20 induced by the LPS challenge (P =0.025), while Zn-Gly reduced the gene expression of the pro-inflammatory factors IL-1β and IL-6, decreased toll-like receptor 4 (TLR4) and nuclear factor kappa-B p65 (NF-κB p65) (P < 0.05). Zn-Gly also alleviated the LPS-induced downregulation of the intestinal barrier gene Claudin-1. Thus, LPS exposure prompted the mobilization of zinc transporter proteins and MT to perform the remodeling of systemic zinc homeostasis, Zn-Gly participated in the regulation of zinc homeostasis and inhibited the production of pro-inflammatory factors through the TLR4/NF-κB pathway, attenuating the inflammatory response and intestinal barrier damage caused by an immune challenge.

Zinc glycine chelate ameliorates DSS-induced intestinal barrier dysfunction via attenuating TLR4/NF-κB pathway in meat ducks

BACKGROUND

Zinc glycine chelate (Zn-Gly) has anti-inflammation and growth-promoting properties; however, the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown. Three-hundred 1-day-old ducks were divided into 5 groups (6 replicates and 10 ducks per replicate) in a completely randomized design: the control and dextran sulfate sodium (DSS) groups were fed a corn-soybean meal basal diet, and experimental groups received supplements of 70, 120 or 170 mg/kg Zn in form of Zn-Gly. The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15-21, and the control group received normal saline. The experiment lasted 21 d.

RESULTS

Compared with DSS group, 70, 120 and 170 mg/kg Zn significantly increased body weight (BW), villus height and the ratio of villus to crypt, and significantly decreased the crypt depth of jejunum at 21 d. The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining. Compared with control, the content of intestinal permeability marker D-lactic acid (D-LA) and fluxes of fluorescein isothiocyanate (FITC-D) in plasma of DSS group significantly increased, and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes. Compared with control, contents of plasma, jejunum endotoxin and jejunum pro-inflammatory factors IL-1β, IL-6 and TNF-α were significantly increased in DSS group, and were significantly decreased by 170 mg/kg Zn supplementation. Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10, IL-22 and sIgA and IgG in jejunum. Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum, and decreased gene and protein expression of CLDN-2 compared with DSS group. The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA. Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8 and TNF-α expression levels and TNF-α protein expression in jejunum. Additionally, Zn significantly reduced the gene and protein expression of TLR4, MYD88 and NF-κB p65.

CONCLUSIONS

Zn-Gly improved duck BW and alleviated intestinal injury by regulating intestinal morphology, barrier function and gut inflammation-related signal pathways TLR4/MYD88/NF-κB p65.

Production and Evaluation of Encapsulated Zinc Oxide on Performance, Ileal Digestibility and Zinc Transporter Gene Expression in Broiler Chicken

The present study was undertaken for the production of encapsulated zinc and its evaluation in broiler chicken diet. The process of microencapsulation involved the use of polymers, gum arabic and maltodextrin with a maximum encapsulation of efficiency of 66%. Encapsulated material contained about 20% zinc oxide (ZnO) as core material following the freeze-drying process. One hundred and ninety-two-day-old broiler chicks were distributed in four groups in six replications having eight birds in each. The four groups comprised control (inorganic source of zinc), En-Zn-100 (encapsulated zinc at 100% of control), En-Zn-50 (encapsulated zinc at 50% of control), and Org-Zn-50 (Zn-methionine at 50% of control). The experiment was carried out for 35 days following standard management practices. The live weight gain, feed intake and FCR were comparable among groups. Plasma and muscle zinc (ppm) content was unaffected by the level or source of zinc supplementation. The zinc apparent ileal digestibility coefficient was significantly (P < 0.05) higher in En-Zn-50 fed groups, while crude protein digestibility was not affected by the level or form of Zn supplementation. Bone weight, length, and zinc content were comparable, and bone ash content was significantly different among the groups. Relative expression of ZnT2 was significantly upregulated in encapsulated zinc-fed groups. From the study, it could be concluded that supplementation of zinc either as encapsulated or organic form at 50% of inorganic source (ZnO) could be sufficient to maintain the growth performance, serum, tissue and bone mineral content in broiler chicken.

The organic zinc with moderate chelation strength enhances the expression of related transporters in the jejunum and ileum of broilers

Our previous study demonstrated that the zinc (Zn) proteinate with moderate chelation strength (Zn-Prot M) enhanced the Zn absorption in the small intestine partially via increasing the expression of some Zn and amino acid transporters in the duodenum of broilers. However, it remains unknown whether the Zn-Prot M could also regulate the expression of related transporters in the jejunum and ileum of broilers in the above enhancement of Zn absorption. The present study was conducted to investigate the effect of the Zn-Prot M on the expression of related transporters in the jejunum and ileum of broilers compared to the Zn sulfate (ZnS). Zinc-deficient broilers (13-d-old) were fed with the Zn-unsupplemented basal diets (control) or the basal diets supplemented with 60 mg Zn/kg as ZnS or Zn-Prot M for 26 d. The results showed that in the jejunum, compared to the control, supplementation of the organic or inorganic Zn increased (P < 0.05) mRNA and protein expression of b^0,+-type amino acid transporter (rBAT), Zn transporter 10 (ZnT10), and peptide-transporter 1 (PepT1) mRNA expression and Zn transporter 7 (ZnT7) protein expression on d 28, while y+L-type amino transporter 2 (y+LAT2) mRNA and protein expression, and protein expression of ZnT7 and ZnT10 on 28 d and zrt-irt-like protein 3 (ZIP3) and zrt-irt-like protein 5 (ZIP5) on d 39 were higher (P < 0.05) for Zn-Prot M than for ZnS. In the ileum, Zn addition regardless of Zn source up-regulated (P < 0.05) mRNA expression of Zn transporter 9 (ZnT9) and ZIP3, ZIP5, and y+LAT2 protein expression on d 28, and PepT1 mRNA and protein expression, ZIP3 and y+LAT2 mRNA expression and ZnT10 protein expression on d 39. Furthermore, Zn transporter 4 (ZnT4) and ZnT9 mRNA expression and Zn transporter 1 (ZnT1) protein expression on d 28, and y+LAT2 mRNA expression and ZnT10 and PepT1 protein expression on d 39 were higher (P < 0.05) for Zn-Prot M than for ZnS. It was concluded that the Zn-Prot M enhanced the expression of the ZnT1, ZnT4, ZnT9, ZnT10, ZIP3, ZIP5, y+LAT2, and PepT1 in the jejunum or ileum of broilers compared to the ZnS.

Morphological Assessment and Biomarkers of Low-Grade, Chronic Intestinal Inflammation in Production Animals

Simple Summary

Production animals are continuously exposed to environmental and dietary factors that might induce a state of low-grade, chronic intestinal inflammation. This condition compromises the productive performance and well-fare of these animals, requiring studies to understand what causes it and to develop control strategies. An intestinal inflammatory process is generally associated with alterations in the structure and functionality of its wall, resulting in the release of cellular components into the blood and/or feces. These components can act as biomarkers, i.e., they are measured to identify and quantify an inflammatory process without requiring invasive methods. In this review we discuss the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the identification of biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Abstract

The complex interaction between the intestinal mucosa, the gut microbiota, and the diet balances the host physiological homeostasis and is fundamental for the maximal genetic potential of production animals. However, factors such as chemical and physical characteristics of the diet and/or environmental stressors can continuously affect this balance, potentially inducing a state of chronic low-grade inflammation in the gut, where inflammatory parameters are present and demanding energy, but not in enough intensity to provoke clinical manifestations. It’s vital to expand the understanding of inflammation dynamics and of how they compromise the function activity and microscopic morphology of the intestinal mucosa. These morphometric alterations are associated with the release of structural and functional cellular components into the feces and the blood stream creating measurable biomarkers to track this condition. Moreover, the identification of novel, immunometabolic biomarkers can provide dynamic and predictors of low-grade chronic inflammation, but also provide indicators of successful nutritional or feed additive intervention strategies. The objective of this paper is to review the mechanisms of low-grade inflammation, its effects on animal production and sustainability, and the biomarkers that could provide early diagnosis of this process and support studies of useful interventional strategies.

Relative Bioavailability of Trace Minerals in Production Animal Nutrition: A Review

The importance of dietary supplementation of animal feeds with trace minerals is irrefutable, with various forms of both organic and inorganic products commercially available. With advances in research techniques, and data obtained from both in-vitro and in-vivo studies in recent years, differences between inorganic and organic trace minerals have become more apparent. Furthermore, differences between specific organic mineral types can now be identified. Adhering to PRISMA guidelines for systematic reviews, we carried out an extensive literature search on previously published studies detailing performance responses to trace minerals, in addition to their corresponding relative bioavailability values. This review covers four of the main trace minerals included in feed: copper, iron, manganese and zinc, and encompasses the different types of organic and inorganic products commercially available. Their impact from environmental, economic, and nutritional perspectives are discussed, along with the biological availability of various mineral forms in production animals. Species-specific sections cover ruminants, poultry, and swine. Extensive relative bioavailability tables cover values for all trace mineral products commercially available, including those not previously reviewed in earlier studies, thereby providing a comprehensive industry reference guide. Additionally, we examine reasons for variance in reported relative bioavailability values, with an emphasis on accounting for data misinterpretation.

Organic zinc with moderate chelation strength enhances zinc absorption in the small intestine and expression of related transporters in the duodenum of broilers

Our previous study demonstrated that the absorption of zinc (Zn) from the organic Zn proteinate with moderate chelation strength was significantly higher than that of Zn from the inorganic Zn sulfate in the in situ ligated duodenal segment of broilers, but the underlying mechanisms are unknown. The present study aimed to determine the effect of organic Zn with moderate chelation strength and inorganic Zn on the Zn absorption in the small intestine and the expression of related transporters in the duodenum of broilers. The Zn-deficient broilers (13 days old) were fed with the Zn-unsupplemented basal diets (control) containing 25.72 and 25.64 mg Zn/kg by analysis or the basal diets supplemented with 60 mg Zn/kg as the Zn sulfate or the Zn proteinate with moderate chelation strength (Zn-Prot M) for 26 days. The results showed that the plasma Zn contents from the hepatic portal vein of broilers at 28 days and 39 days of age were increased (p < 0.05) by Zn addition and greater (p < 0.05) in the Zn-Prot M than in the Zn sulfate. On d 28, Zn addition upregulated (p < 0.05) mRNA expression of zinc transporter 1 (ZnT1), Zrt-irt-like protein 5 (ZIP5), y + L-type amino transporter 2 (y + LAT2) and b^0,+-type amino acid transporter (rBAT), zinc transporter 4 (ZnT4) protein expression, and zinc transporter 9 (ZnT9) mRNA and protein expression in the duodenum. Moreover, ZnT9 mRNA expression, ZnT4, ZIP5, and rBAT protein expression, zinc transporter 7 (ZnT7), and y + LAT2 mRNA and protein expression in the duodenum of broilers on 28 days were higher (p < 0.05) in the Zn-Prot M than in the Zn sulfate. On d 39, supplemental Zn increased (p < 0.05) peptide-transporter 1 (PepT1) mRNA expression and y + LAT2 protein expression, while the mRNA expression of ZnT7 and Zrt-irt-like protein 3 (ZIP3) were higher (p < 0.05) for the Zn-Prot M than for the Zn sulfate in the duodenum. It was concluded that the Zn-Prot M enhanced the Zn absorption in the small intestine partially via upregulating the expression of ZnT4, ZnT7, ZnT9, ZIP3, ZIP5, y + LAT2, and rBAT in the duodenum of broilers.

Novel Models for Chronic Intestinal Inflammation in Chickens: Intestinal Inflammation Pattern and Biomarkers

For poultry producers, chronic low-grade intestinal inflammation has a negative impact on productivity by impairing nutrient absorption and allocation of nutrients for growth. Understanding the triggers of chronic intestinal inflammation and developing a non-invasive measurement is crucial to managing gut health in poultry. In this study, we developed two novel models of low-grade chronic intestinal inflammation in broiler chickens: a chemical model using dextran sodium sulfate (DSS) and a dietary model using a high non-starch polysaccharide diet (NSP). Further, we evaluated the potential of several proteins as biomarkers of gut inflammation. For these experiments, the chemical induction of inflammation consisted of two 5-day cycles of oral gavage of either 0.25mg DSS/ml or 0.35mg DSS/ml; whereas the NSP diet (30% rice bran) was fed throughout the experiment. At four times (14, 22, 28 and 36-d post-hatch), necropsies were performed to collect intestinal samples for histology, and feces and serum for biomarkers quantification. Neither DSS nor NSP treatments affected feed intake or livability. NSP-fed birds exhibited intestinal inflammation through 14-d, which stabilized by 36-d. On the other hand, the cyclic DSS-treatment produced inflammation throughout the entire experimental period. Histological examination of the intestine revealed that the inflammation induced by both models exhibited similar spatial and temporal patterns with the duodenum and jejunum affected early (at 14-d) whereas the ileum was compromised by 28-d. Calprotectin (CALP) was the only serum protein found to be increased due to inflammation. However, fecal CALP and Lipocalin-2 (LCN-2) concentrations were significantly greater in the induced inflammation groups at 28-d. This experiment demonstrated for the first time, two in vivo models of chronic gut inflammation in chickens, a DSS and a nutritional NSP protocols. Based on these models we observed that intestinal inflammation begins in the upper segments of small intestine and moved to the lower region over time. In the searching for a fecal biomarker for intestinal inflammation, LCN-2 showed promising results. More importantly, calprotectin has a great potential as a novel biomarker for poultry measured both in serum and feces.

Protective Effect of Grape (Vitis vinifera) Seed Powder and Zinc-Glycine Complex on Growth Traits and Gut Health of Broilers Following Eimeria tenella Challenge

The current study was conducted to evaluate the impact of grape (Vitis vinifera) seed powder and zinc-glycine complex on growth parameters and cecal health of broiler following Eimeria tenella challenge. A total of 250 day-old male broilers (Hubbard) were distributed into five treatments as follows: I-negative control (basal diet); II-positive control (E. tenella challenge); III-group infected + Amprolium; IV-group coccidial infection + organic zinc (OZ) at 50 ppm + grape seed powder (GSP) at 2.5 g/kg; V-coccidial infection + organic zinc (OZ) at 50 ppm + grape seed powder (GSP) at 5.0 g/kg. From findings, a lower (p < 0.05) feed intake was noted for positive control compared to the other treatment groups. Conversely, higher (p < 0.05) body weight, dressing percentage, and feed conversion ratio were observed in infected + Amprolium, GSP2.5 + OZ50, and GSP5 + OZ50 treatments in comparison to the positive control. Moreover, the positive control showed severe cecal lesions of thickness and hemorrhages with mild congestion. The lesion scores decreased (p < 0.05) in GSP and OZ treated groups compared to the positive control. Significant (p < 0.05) lower oocyst per gram of feces was found in infected + Amprolium, GSP2.5 + OZ50, and GSP5 + OZ50 in comparison to positive control. Supplementing diet with GSP and OZ at both levels showed restoration of intense sloughing of villi. From the present findings, it can be concluded that OZ and grape seed powder positively ameliorated the growth performance, lesion score, and oocysts shedding in broilers infected with E. tenella.

Dietary Application of Tannins as a Potential Mitigation Strategy for Current Challenges in Poultry Production: A Review

Simple Summary

There are diverse challenges in the poultry production industry that decrease the productivity and efficiency of poultry production, impair animal welfare, and pose issues to public health. Furthermore, the use of antibiotic growth promoters (AGP) in feed, which have been used to improve the growth performance and gut health of chickens, has been restricted in many countries. Tannins, polyphenolic compounds that precipitate proteins, are considered as alternatives for AGP in feed and provide solutions to mitigate challenges in poultry production due to their antimicrobial, antioxidant, anti-inflammatory and gut health promoting effects. However, because high dosages of tannins have antinutritional effects when fed to poultry, determining appropriate dosages of supplemental tannins is critical for their potential implementation as a solution for the challenges faced in poultry production.

Abstract

The poultry industry has an important role in producing sources of protein for the world, and the size of global poultry production continues to increase annually. However, the poultry industry is confronting diverse challenges including bacterial infection (salmonellosis), coccidiosis, oxidative stress, including that caused by heat stress, welfare issues such as food pad dermatitis (FPD) and nitrogen and greenhouse gasses emissions that cumulatively cause food safety issues, reduce the efficacy of poultry production, impair animal welfare, and induce environmental issues. Furthermore, restrictions on the use of AGP have exacerbated several of these negative effects. Tannins, polyphenolic compounds that possess a protein precipitation capacity, have been considered as antinutritional factors in the past because high dosages of tannins can decrease feed intake and negatively affect nutrient digestibility and absorption. However, tannins have been shown to have antimicrobial, antioxidant and anti-inflammatory properties, and as such, have gained interest as promising bioactive compounds to help alleviate the challenges of AGP removal in the poultry industry. In addition, the beneficial effects of tannins can be enhanced by several strategies including heat processing, combining tannins with other bioactive compounds, and encapsulation. As a result, supplementation of tannins alone or in conjunction with the above strategies could be an effective approach to decrease the need of AGP and otherwise improve poultry production efficiency.

Dietary Zinc and Fibre Source can Influence the Mineral and Antioxidant Status of Piglets

The study investigated the effect of dietary zinc glycine chelate and potato fibre on the absorption and utilisation of Zn, Cu, Fe, and Mn; the activity of Zn-containing enzymes (superoxide dismutase, SOD; alkaline phosphatase, ALP); and zinc transporter concentrations (metalothionein1, MT1; zinc transporter1, ZnT1) in tissues, with a special emphasis on the small intestine. Twenty-four barrows (Danbred × Duroc) were randomly allotted to four diets (supplemented with 10 g/kg of crude fibre and 120 mg Zn/kg) that consisted of cellulose and either zinc sulphate (C) or zinc glycinate (ZnGly), or contained potato fibre supplemented with ZnSO4 (PF) or ZnGly (PF + ZnGly). Feeding PF can influence the Zn absorption in the small intestine due to reduced zinc transporters MT1 and ZnT1 in the jejunum. The activity of antioxidant enzyme SOD and liver ZnT1, and duodenal iron concentrations were increased in the PF treatments. Dietary ZnGly did not significantly influence the Zn distribution, but it may alter the absorption of Fe and Mn. Given the elevated content of thiol groups and the Zn/Cu ratio in plasma, as well as the altered SOD activity and MT content in the tissues, we can conclude that feeding PF and ZnGly can influence the mineral and antioxidant status of growing piglets. However, further research is needed in order to elucidate the effect of both dietary sources on the transport systems of other minerals in enterocytes.