Effects of dietary substitution of zinc-methionine for inorganic zinc sources on growth performance, tissue zinc accumulation and some blood parameters in broiler chicks

Effects of Dietary Valine Chelated Zinc Supplementation on Growth Performance, Antioxidant Capacity, Immunity, and Intestine Health in Weaned Piglets

This study was conducted to investigate the effects of dietary valine chelated zinc (ZnVal) supplementation on growth performance, antioxidant capacity, immunity, and intestine health in weaned piglets. A total of 240 healthy 35-day-old weaned piglets (Duroc × Landrace × Yorkshire, average weight 10.70 ± 0.14 kg) were randomly divided into five groups with six replicate pens and eight piglets per pen. Dietary treatments were a corn-soybean meal basal diet supplemented with 0, 25, 50, 75, and 100 mg/kg ZnVal, respectively. The experiment lasted for 28 days. Results showed that average daily gain (ADG) was increased (P < 0.05) by ZnVal with 75-100 mg/kg supplementation on days 15-28 and with 50-100 mg/kg supplementation on days 1-28. Supplementation of 25-100 mg/kg ZnVal reduced (P < 0.01) the diarrhea rate of weaned piglets on days 1 to 14 and 1 to 28. Dietary supplementation with 25-100 mg/kg ZnVal increased (P < 0.05) copper/zinc-superoxide dismutase (Cu/Zn-SOD) and decreased malonaldehyde (MDA) activities in the serum on day 14 and 28. Supplementation of 25-100 mg/kg ZnVal increased (P < 0.05) glutathione peroxidase (GSH-Px) activity in serum on day 14. Additionally, the supplementation of 75 mg/kg ZnVal significantly increased the activity of superoxide dismutase (SOD) and Cu/Zn-SOD in the liver (P < 0.05). Furthermore, the supplementation of 25-100 mg/kg ZnVal significantly increased the total antioxidant capacity (T-AOC) in the liver (P < 0.05). Higher (P < 0.05) concentrations of IgG in the serum were measured from piglets supplemented with 75-100 mg/kg ZnVal on day 14 and dietary supplementation with 25-100 mg/kg ZnVal increased the level of immunoglobulin G (IgG) in serum on day 28 (P < 0.05). In addition, higher (P < 0.05) concentrations of immunoglobulin A (IgA) in the duodenum and ileum were measured from piglets supplemented with 75 mg/kg ZnVal and the supplementation of 25-100 mg/kg ZnVal also showed a higher (P < 0.05) concentration of immunoglobulin G (IgG) in duodenum. Supplementation of 50-100 mg/kg ZnVal increased the villus height and villus height/crypt depth of jejunum (P < 0.05). Moreover, dietary supplementation with 75-100 mg/kg ZnVal showed a higher (P < 0.05) concentration of zinc in the liver and supplementation of 50-100 mg/kg ZnVal increased (P < 0.05) the concentration of zinc in the heart, spleen, and kidney. In conclusion, the present research showed that supplementation of ZnVal improves growth performance by increasing antioxidant capacity and immunity and regulating intestinal morphology and the optimal inclusion level of ZnVal was 65~80 mg/kg.

Effect of Zinc Amino Acid Complexes on Growth Performance, Tissue Zinc Concentration, and Muscle Development of Broilers

The present study aimed to evaluate the effects of zinc amino acid complexes on growth performance, tissue zinc concentration, and muscle development in broilers. A total of 504 day-old male arbor acres broilers were randomly divided into seven treatments (fed with a basal diet or a basal diet supplemented with 120 mg kg-1 Zn as ZnSO4, 30, 60, 90 or 120 mg kg-1 Zn as ZnN, or 30 mg kg-1 Zn as ZnA separately). Each group had six replicates, with 12 birds per replicate. The results showed that the addition of 60 mg kg-1 ZnN significantly increased (P < 0.05) the average daily gain (ADG) and breast muscle percentage of broilers. Zinc concentration of ZnN and ZnA added groups were higher than (P < 0.05) that in the Zn sulfate group under the same addition dose. Except for the 30 mg kg-1 ZnN group, the muscle fiber diameter and cross-sectional area (CSA) were significantly increased (P < 0.05) in the ZnN addition groups. Compared with the basal diet group, adding ZnN significantly increased (P < 0.05) the expression of MTOR, MYOD, and MYOG at day 21 and decreased (P < 0.05) the expression of Atrogin-1. The expression levels of AKT, MTOR, P70S6K, and MYOD were increased at day 42, while the expression levels of MuRF1 and Atrogin-1 were decreased. Adhesion, backbone regulation of actin, MAPK, mTOR, and AMPK were significantly enriched as indicated by KEGG pathway enrichment analysis. In conclusion, zinc amino acid complexes could improve growth performance, tissue zinc concentration, and regulate breast muscle development.

Dietary zinc supplementation in breeding pigeons improves the carcass traits of squabs through regulating antioxidant capacity and myogenic regulatory factor expression

The purpose of this experiment was to explore the effects of zinc supplementation in breeding pigeons diet on carcass traits, meat quality, antioxidant capacity and mRNA expressions of myogenic regulatory factors of squabs. A total of 120 healthy White King pigeons were randomly assigned to 5 treatments, each involving 8 replicates. The experiment lasted for 46 d (18-d incubation period of eggs and 28-d growth period of squabs). The 5 groups were 0, 30, 60, 90, and 120 mg/kg zinc addition. Results showed that the 28-d body weight, breast muscle yield, zinc content in crop milk and myogenic factor 6 (MyF6) abundance of breast muscle were linearly increased (P < 0.050), but the abdominal fat yield linearly decreased (P = 0.040) with increasing dietary zinc supplementation. Both the linear (P < 0.050) and quadratic responses (P < 0.001) were observed in copper zinc superoxide dismutase (Cu-Zn SOD), total antioxidant capacity (T-AOC) and malondialdehyde (MDA) contents in liver and breast muscle. The 28-d body weight was increased by 90 mg/kg zinc supplementation (P < 0.05), and there is no significant difference between 90 and 120 mg/kg zinc addition. The breast muscle yield, Cu-Zn SOD and T-AOC contents in breast muscle and liver, zinc contents in crop milk and breast muscle, MyF6 mRNA expression in breast muscle were higher (P < 0.05) in the group supplemented with 120 mg/kg zinc than the control. The abdominal fat yield was numerically lowest, and MDA contents in breast muscle and liver were significantly lowest in the group fed 120 mg/kg zinc (P < 0.05). However, the meat quality traits were not affected (P > 0.05) by zinc supplementation, except for shear force. It should be stated dietary zinc supplementation at the level of 120 mg/kg for breeding pigeons increased body weight and breast muscle yield of squabs, which may be associated with the up-regulating MyF6 mRNA expression and antioxidant capacity in liver and breast muscle.

Effects of organic zinc on production performance, meat quality, apparent nutrient digestibility and gut microbiota of broilers fed low-protein diets

The high cost of feed and nitrogen pollution caused by high-protein diets have become major challenges restricting sustainable development in China's animal husbandry sector. Properly reducing protein levels and improving protein utilization in feed are effective approaches to solving this problem. To determine the optimal dose of methionine hydroxyl analogue chelated zinc (MHA-Zn) in broiler diets with a 1.5% reduction in crude protein (CP), a total of 216 1-day-old broilers were randomly assigned into 4 groups (each group consisted of 3 replications with 18 broilers per replicate), and growth and development indexes were assessed after 42 days. The broilers in control group were fed a basic diet, whereas those in the three test groups were fed diets with a 1.5% reduction in CP. The results showed no significant difference in the edible parts of broilers between low-protein (LP) diet group (90 mg/kg MHA-Zn) and normal diet group (p > 0.05), and adding 90 mg/kg MHA-Zn to LP diet significantly improved ileum morphology and apparent total tract digestibility (ATTD) of nutrient (p < 0.01; p < 0.05). A 16S rRNA sequencing analysis indicated that supplementing the LP diet with 90 mg/kg MHA-Zn was adequate for production performance of broilers and promoted beneficial bacteria in the cecum (Lactobacillus, Butyricoccus, Oscillospira, etc.) (p < 0.01). In summary, adding an optimal dose of organic zinc (90 mg/kg MHA-Zn) in low protein diets led to enhanced production performance of broilers and optimized cecum microbiota. Additionally, the reduction of crude protein consumption in broiler production proved to be a cost-effective measure, while also mitigated nitrogen pollutant emissions in the environment.

Impact of Maternal and Offspring Dietary Zn Supplementation on Growth Performance and Antioxidant and Immune Function of Offspring Broilers

The current study investigated the effects of the maternal Zn source in conjunction with their offspring’s dietary Zn supplementation on the growth performance, antioxidant status, Zn concentration, and immune function of the offspring. It also explored whether there is an interaction between maternal Zn and their offspring’s dietary Zn. One-day-old Lingnan Yellow-feathered broilers (n = 800) were completely randomized (n = 4) between two maternal dietary supplemental Zn sources [maternal Zn−Gly (oZn) vs. maternal ZnSO4 (iZn)] × two offspring dietary supplemental Zn doses [Zn-unsupplemented control diet (CON), the control diet + 80 mg of Zn/kg of diet as ZnSO4]. oZn increased progeny ADG and decreased offspring mortality across all periods, especially during the late periods (p < 0.05). The offspring diet supplemented with Zn significantly improved ADG and decreased offspring mortality over the whole period compared with the CON group (p < 0.05). There were significant interactions between the maternal Zn source and offspring dietary Zn with regards to progeny mortality during the late phase and across all phases as a whole (p < 0.05). Compared with the iZn group, the oZn treatment significantly increased progeny liver and serum Zn concentrations; antioxidant capacity in the liver, muscle, and serum; and the IgM concentration in serum; while also decreasing progeny serum IL-1 and TNF-α cytokine secretions (p < 0.05). Similar results were observed when the offspring diet was supplemented with Zn compared with the CON group; moreover, adding Zn to the offspring diet alleviated progeny stress by decreasing corticosterone levels in the serum when compared to the CON group (p < 0.05). In conclusion, maternal Zn−Gly supplementation increased progeny performance and decreased progeny mortality and stress by increasing progeny Zn concentration, antioxidant capacity, and immune function compared with the same Zn levels from ZnSO4. Simultaneously, Zn supplementation in the progeny’s diet is necessary for the growth of broilers.

Meta-analysis of Zinc Supplementation on Laying Performance, Egg Quality Characteristics, and Blood Zinc Concentrations in Laying Hens

There are inconsistent results on the influence of zinc (Zn) supplementation levels on productive indices of laying hens. This study, therefore, uses meta-analysis to synthesis evidence on the effect of inclusion of Zn in chicken diets on performance, egg quality, and blood Zn status of laying hens. Eleven studies were identified and used to analyze the effect of diets with or without Zn supplementation on feed intake, feed conversion ratio (FCR), hen day egg production (HDEP), egg weight (EW), egg mass (EM), Haugh unit (HU) scores, eggshell thickness (EST), eggshell weight (ESW), and blood Zn concentrations in laying hens. Data extracted from the 11 studies included in the meta-analysis were pooled using a random-effects model and expressed as standardized mean differences (SMDs) at a 95% confidence interval (CI). Results indicate that dietary Zn supplementation reduced FCR (SMD =  - 0.50 g feed/g egg; 95% CI: - 0.68 to - 0.31) and increased HDEP (SMD = 0.33%; 95% CI: 0.18 to 0.48), EW (SMD = 0.14 g; 95% CI: 0.03 to 0.25) and EM (SMD = 0.58 g/hen/day; 95% CI: 0.22 to 0.95), HU (SMD = 0.64; 95% CI: 0.42 to 0.85), EST (SMD = 0.84 mm; 95% CI: 0.45 to 1.23), and plasma Zn concentration (SMD = 4.20 mg/dl; 95% CI: 2.99 to 5.40) compared with the controls. In contrast, feed intake and ESW were not significantly different from controls. Restricted subgroup analysis indicated that chosen moderators (age of hen, inclusion level, chicken breed/strain, and supplementation duration) influenced the results of this meta-analysis. There was evidence of significant heterogeneity, and meta-regression indicated that moderators explained most of the sources of heterogeneity. We conclude that dietary zinc supplementation had positive effect on feed conversion ratio, laying performance, aspects of egg quality traits, and blood zinc concentrations in laying hens. The findings from this meta-analysis will help in policy advancements and sustainable use of zinc in the egg production industry.

Effects of Zinc Glycinate on Growth Performance, Serum Biochemical Indexes, and Intestinal Morphology of Yellow Feather Broilers

The purpose of this study was to investigate the effects of zinc glycinate (Gly-Zn) on growth performance, serum biochemical index, intestinal morphology, and hepatic metallothionein (MT) mRNA expression in the liver of yellow feather broilers. A total of 540 18-day-old yellow feather broilers were randomly divided into three groups: control group (basal diet), ZnSO4 group (basal diet plus 60 mg Zn/kg from ZnSO4), and Gly-Zn group (basal diet plus 60 mg Zn/kg from zinc glycinate). Each treatment group had 6 replicates with 30 birds in each replicate. The experiment lasted for 42 days (18 to 59 days of age). The results showed that Gly-Zn supplementation significantly improved the average daily gain (ADG) and average daily feed intake (ADFI) of broilers during 18 to 39 days of age compared with that in the control group (P < 0.05) but not different from the ZnSO4 group. The Gly-Zn group had higher glutathione peroxidase (GSH-Px) (P < 0.05) and lower malondialdehyde (MDA) concentrations than the broilers in the control and ZnSO4 group. It was also observed that zinc content in the tibia of Gly-Zn group broilers was higher than the control and ZnSO4 group (P < 0.05). The results of intestinal morphology parameters showed that the Gly-Zn group significantly increased the villus height in duodenum and jejunum (P < 0.05) and decreased crypt depth in duodenum and ileum compared to the control group. However, there were no significant differences between the Gly-Zn group and ZnSO4 group in duodenum and ileum regarding intestinal morphology parameters. The Gly-Zn group significantly increased mRNA expression of MT in the liver than both control and ZnSO4 groups (P < 0.05). Collectively, the results indicated that supplementing 60 mg Zn/kg through zinc glycinate improved growth performance and serum indexes as well as intestinal morphology of yellow feather broilers. It also regulates MT gene expression more effectively than the ZnSO4 group at the transcriptional level.

Feeding Zinc-Biofortified Wheat Improves Performance, Nutrient Digestibility, and Concentrations of Blood and Tissue Minerals in Quails

The present study aimed to investigate the effects of feeding zinc (Zn)-biofortified wheat on performance, digestibility, and concentrations of minerals in quails. Zinc biofortification of wheat has been realized in the field by ergonomically applying Zn to foliar two and three times, which increased grain Zn from 18 mg/kg (control) to 34 and 64 mg/kg. A total of 180 quails were divided into six groups, each containing 30 birds, and fed diets containing wheat grain with either 18, 34, or 64 mg/kg with or without zinc picolinate (ZnPic) supplementation. Bodyweight, feed intake, feed efficiency, and cold carcass weights were greater (P = 0.0001) when the quails were fed a diet containing the biofortified wheat-containing 64 mg Zn/kg. Nitrogen, ash, Ca, P, Zn, Cu, and Fe retentions were greater with the Zn-biofortified wheat-containing 64 mg Zn/kg (P ≤ 0.026). The nutrient excretions were low with feeding a diet containing biofortified wheat-containing 64 mg Zn/kg (P ≤ 0.023). Serum, liver, and heart Zn concentrations increased with feeding biofortified wheat-containing 64 mg Zn/kg (P ≤ 0.002). Thigh meat Fe concentrations increased with increasing Zn concentrations of the wheat samples used (P = 0.0001), whereas the liver Cu concentrations decreased with feeding the wheat-containing 64 mg Zn/kg (P = 0.004). The Zn-biofortified wheat-containing greater Zn concentrations, particularly 64 mg Zn/kg, is a good replacement for corn in the poultry diet as long as its availability and low cost for better performance, greater digestibility, and elevated tissue Zn and Fe concentrations.

Effect of Supplemental Zinc on Performance, Nutrient Digestibility, Jejunum Architecture, and Immune Response in Broiler chickens Fed Wheat-Soy Diets

The present study was conducted to evaluate the effect of dietary zinc (Zn) levels on growth performance, carcass characteristic, nutrient digestibility, jejunum architecture and immune responses in broiler chickens fed wheat-soy diets. In addition the Zn requirement to optimize responses were estimated through regression models. A total, of 250 day-old male Ross-308 broiler chicks were randomly allocated to a completely randomized design experiment with five dietary treatments of five replicates of 10 birds each. Birds were fed diets containing 30, 70, 110, 150, and 190 mg/kg Zn from 1 to 35 days of age. A Zn level of 70 mg/kg diet was adequate to acquire typical growth performance, the nutrient digestibility, and carcass yield. First antibody titres response to sheep red blood cell inoculation, cutaneous basophil hypersensitivity elicited by phytohemagglutinin-P intradermal injection increased linearly by the increase in dietary Zn level. The Zn requirement estimated by the quadratic and linear broken-line models was varied between 63-70 mg/kg to optimize growth performance criteria. It is concluded the basal Zn concentration in wheat-soy diet is inadequate to fulfill the broiler chickens genetic potential in growth and a minimum of 70 mg/kg dietary Zn concentration is suggested to optimize broiler chickens performance.

Zinc Methionine Improves the Growth Performance of Meat Ducks by Enhancing the Antioxidant Capacity and Intestinal Barrier Function

This study was conducted to investigate the effects of zinc methionine (Zn-Met) on the growth performance, antioxidant capacity and intestinal barrier function of meat ducks. Three hundred and sixty 1-day-old male Cherry Valley ducks were randomly divided into 6 groups with 6 replicates (10 birds each), and fed diets with 0, 30, 60, 90, 120 or 150 mg/kg Zn for 35 d. The results indicated that dietary supplementation with Zn-Met substantially increased the average daily gain (ADG), and reduced the feed to gain ratio (F/G) during 1–35 d (P &lt; 0.05). Dietary Zn-Met markedly increased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), and reduced the malondialdehyde (MDA) content in the jejunum (P &lt; 0.05). The mRNA expression levels of critical antioxidant enzymes such as SOD, CAT, and nuclear factor erythroid 2-related factor 2 (Nrf2) were increased by Zn in the jejunum (P &lt; 0.05). Supplementation with 60, 90, 120, and 150 mg/kg of Zn significantly reduced the diamine oxidase (DAO) activity in the serum (P &lt; 0.05). Different levels of Zn can increase the mRNA expression of occluding (OCLN) and zonula occludens-1 (ZO-1) in the jejunum (P &lt; 0.05). Diets supplemented with zinc significantly increased the content of mucin2 (MUC2), secretory immunoglobulin A (sIgA), immunoglobulin A (IgA) and immunoglobulin G (IgG) in the jejunum of meat ducks (P &lt; 0.05). The 16S rRNA sequence analysis indicated that 150 mg/kg of Zn had a higher relative abundance of Verrucomicrobia and Akkermansia in cecal digesta (P &lt; 0.05). In conclusion, Zn-Met improved the growth performance of meat ducks by enhancing intestinal antioxidant capacity and intestinal barrier function. This study provides data support for the application of Zn-Met in meat duck breeding.

Preparation and characterization of vanillin-chitosan Schiff base zinc complex for a novel Zn2+ sustained released system

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn²⁺ to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, ¹H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn²⁺ than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (R_i) of Zn²⁺, the highest R_i reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn²⁺ sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn²⁺ sustained released system shows great potential in the application in the field of trace elements supplements for animals.

Supplementation of different zinc sources to low-CP diets and its effect on performance, carcass traits, liver and kidney functions, immunological, and antioxidant parameters of quail chicks

The present study was performed to evaluate the influence of low crude protein (CP) levels, zinc sources (organic as zinc methionine-Zn-Met and inorganic as zinc oxide-ZnO) and their interactions on growth performance, carcass traits, and blood components of growing Japanese quail. A total of 450 one-wk-old Japanese quail with the same body weights were randomly distributed into 9 groups of 50 birds. The 9-diet treatments comprised 3 levels of CP (20, 22, and 24%) and 3 Zn source (0 g of Zn/kg diet, 0.1 g ZnO/kg diet, and 0.1 g Zn-Met/kg diet). The results obtained from this study showed that there were no significant differences among the groups, except for differences in body weight (BW) and body weight gain (BWG) at 3 to 5 – and 1 to 5 wk of age for quail supplemented with 24% and 20% CP. All the studied biochemical parameters were significantly influenced by different levels of CP and Zn, except urea and creatinine, which were affected by CP levels only. In conclusion, dietary protein level for growing Japanese quails could be reduced to 20% without negative effects on their performance, carcass traits, and blood metabolites.

Comparison of Zinc Sulfate and Zinc Threonine Based on Zn Bioavailability and Performance of Broiler Chicks

The purpose of this study was to compare zinc sulfate and zinc threonine chelate based on Zn bioavailability and performance of broiler chicks. The study was conducted in a completely randomized design with 256 day-old Ross 308 chicks and eight treatments including control treatment (no zinc supplementation), three levels of zinc sulfate and zinc threonine chelate (40, 80, and 120 mg zinc per kg feed), and a common commercial chelate (Bioplex Zn®) supply 40 mg zinc per kg feed. The results of total period showed that threonine chelate group had the highest live weight compared with other treatments and lowest feed conversion ratio belonged to 80 and 120 ppm of zinc threonine chelate (p < 0.05). Zinc threonine chelate and commercial chelate treatments had the lowest cholesterol and LDL levels compared with other treatments (p < 0.05). Zinc chelate threonine which contains 80 and 120 ppm of zinc had the highest HDL and superoxide dismutase enzymes and the lowest heterophile to lymphocyte ratio compared with other treatments (p < 0.05). Relative bioavailability of zinc threonine to zinc sulfate based on body weight, feed conversion ratio, cholesterol, LDL, HDL, superoxide dismutase enzyme, ash, and zinc content in tibia were 418.75, 173.91, 131.38, 159.43, 278.63, 193.45, 156.46, and 117.65%, respectively. According to the results of broiler performance and other traits measured in this study, it seems that the use of 80 ppm of zinc threonine chelate in the broiler diet is recommended in comparison with zinc sulfate levels and other threonine chelate levels.

Effect of dietary zinc nanoparticle supplementation on mineral balance, tissue minerals status and immune response in Guinea pigs

The present study was designed to examine the effect of dietary supplementation of zinc nanoparticles on mineral balance, tissue minerals status and immune response in guinea pigs. Depending upon the source of Zn, 30 weaned male guinea pigs were randomly allocated to five different groups having 6 animals in each group in CRD. Animals under group T1 (control) were fed with basal diet with inorganic Zn (ZnSO4), whereas, animals were fed with organic Zn (Zn methionine) in group T2, commercial zinc nanoparticle in group T3 and two other zinc nanoparticles prepared in our laboratory in groups T4 and T5, respectively. They were supplemented with 20 mg Zn/kg feed on dry matter basis for 90 days. Results revealed that intake and balance of nitrogen and minerals (calcium, phosphorus, Zn and Cu) was not affected (P>0.05) by supplementation zinc nanoparticles. The level of Zn in liver and testes was significantly higher (P<0.05) in the zinc supplemented groups, when compared to that of control group, however, the mean values of Cu, Fe and Mn were comparable (P>0.05) among different groups, irrespective of the source of Zn. The mean antibody titre was significantly (P<0.05) higher in the commercial nanoparticle supplemented group as compared to other groups. As evidenced in our study spanning 90 days of trial, zinc nanoparticles can be safely supplemented up to 20 ppm level in the diet of guinea pigs.

Effects of organic zinc on the performance and gut integrity of broilers under heat stress conditions

Heat stress (HS) has negative impacts on farm animals. Many studies have been conducted in order to ameliorate the effects of heat stress in farm animals. The current project investigated the effects of organic zinc supplementation under thermoneutral and heat stress conditions on the production, physiological, and histological parameters in broiler chickens. Three-hundred and sixty chicks in the current project were assigned randomly to six different treatments (n=60 chicks per treatment). The treatments were (1) a basal diet containing 40 mg kg-1 of Zn from an organic source and rearing under thermoneutral (TN) conditions (Ctrl); (2) a diet containing the amount of Zn from the basal diet +50 % of the Zn level (from the basal diet) and rearing under TN conditions (50 TN); (3) a diet containing the amount of Zn from the basal diet +100 % of the Zn level (from the basal diet) and rearing under TN conditions (100 TN); (4) a basal diet containing 40 mg kg-1 of Zn from an organic source and exposure to 3 d of cyclical HS at the age of 35 d (CHS); (5) a diet containing the amount of Zn from the basal diet +50 % of the Zn level (from the basal diet) and exposure to 3 d of cyclical HS at the age of 35 d (50 HS); and (6) a diet containing the amount of Zn from the basal diet +100 % of the Zn level (from the basal diet) and exposure to 3 d of cyclical HS at the age of 35 d (100 HS). Our results indicated that HS has decreased final body weight (fBW), average daily gain (ADG), and feed conversion ratio (FCR) relative to TN chicks. However, organic zinc had little or no effects on the production parameters measures in the current project. Overall, intestinal histological measurements were negatively altered under HS relative to TN chicks. Organic zinc inclusion in the diet had improved villus height in the duodenum and jejunum relative to the Ctrl and CHS chicks. Blood calcium and glucose levels were decreased and increased, respectively, in HS relative to TN chicks. In summary, the results discussed in the current project revealed that the inclusion rates of organic zinc used here had little or no effects on the productive parameters. However, it improved the morphological characteristics of the intestines which might maximized the intestinal efficiency in nutrient absorption under HS conditions.

Dietary zinc source impacts intestinal morphology and oxidative stress in young broilers

Zinc is an essential nutritional trace element for all forms of life as it plays an important role in numerous biological processes. In poultry, zinc is provided by in-feed supplementation, mainly as zinc oxide or zinc sulfate. Alternatively zinc can be supplemented as organic sources, which are characterized by using an organic ligand that may be an amino acid, peptide, or protein to bind zinc and have a higher bioavailability than inorganic zinc sources. There are limited number of studies directly comparing the effects of inorganic vs. organic zinc sources on performance and intestinal health in broilers. Therefore, a digestibility and a performance study were conducted to evaluate and compare the effect of an amino acid-complexed zinc source vs. an inorganic zinc source on intestinal health. The experiment consisted of 2 treatments: either a zinc amino acid complex or zinc sulfate was added to a wheat–rye based diet at 60 ppm Zn, with 10 replicates (34 broilers per pen) per treatment. Effects on performance, intestinal morphology, microbiota composition, and oxidative stress were measured. Supplementing zinc amino acid complexes improved the zinc digestibility coefficient as compared to supplementation with zinc sulfate. Broilers supplemented with zinc amino acid complexes had a significantly lower feed conversion ratio in the starter phase compared to birds supplemented with zinc sulfate_. A significantly higher villus length was observed in broilers supplemented with zinc amino acid complexes at days 10 and 28. Supplementation with zinc amino acid complexes resulted in a decreased abundance of several genera belonging to the phylum of Proteobacteria. Plasma malondialdehyde levels and glutathione peroxidase activity showed an improved oxidative status in broilers supplemented with zinc amino acid complexes. In conclusion, zinc supplied in feed as amino acid complex is more readily absorbed, potentially conferring a protective effect on villus epithelial cells in the starter phase.

Zinc and Copper with New Triazine Hydrazone Ligand: Two Novel Organic Complexes Enhanced Expression of Peptide Growth Factors and Cytokine Genes in Weaned V-Line Rabbit

Simple Summary

Zinc and Copper are two important trace minerals, which are involved in numerous vital biological activities in animal’s body, such as enzyme activation and enhancement of immune function, growth, reproduction, DNA synthesis, cell division, and neurotransmitters production. Recently, the application of trace mineral organic complexes in animal feed received much more attention than the inorganic sources. The organic sources can contribute significantly to improving animals’ health and reproduction, as the minerals are more biologically available and absorbable than they are when coming from the inorganic sources. In this study, three injectable varieties of Zn and Cu supplementation, sulfate, inorganic (loaded with montmorillonite), and novel organic (ligand with triazine hydrazone), were tested with weaned rabbits. The results revealed that these three mineral types vary at the most biological responses, and only one category of our novel organic complexes provided consistent animal performance improvement, including weight gain, serum antioxidant, meat quality, intestine morphometry, and the expression of peptide growth factors and cytokine genes. To our knowledge, this is the first work on the Zn and Cu with triazine hydrazone ligand as two organic complexes in rabbits.

Abstract

Two novel transitional organic Zn/Cu complexes based on a new biocompatible bidentate triazine–hydrazone ligand (Thz) was designed, synthesized, and evaluated in this study. This study evaluated the effects of injecting 60 mg of Zn and 40 mg of Cu in three different forms, twice per week, for eight weeks on growth performance, expression of growth factors and cytokine genes, carcass yield, blood biochemicals, and intestinal morphology in weaned rabbits. The tested complexes were sulfate (Cu/ZnSO₄), montmorillonite (Cu/Zn-Mnt), and triazine hydrazone (Cu/Zn-Thz). A total of 60 V-line weaned rabbits at four weeks of age were assigned to four treatments (n = 15), which were intramuscularly injected with 0.5 mL of either (1) saline (control) or saline containing (2) Cu/ZnSO₄, (3) Cu/Zn-Mnt, or (4) Cu/Zn-Thz. Compared to the controls, the rabbits injected with Cu/Zn-Thz showed a higher (p < 0.01) growth rate, carcass yield (p < 0.05), and liver expression of insulin like growth factor-1 (IGF-1), growth hormone receptor (GHR), fibroblast growth factor-1 (FGF1), and transforming growth factor beta-1 (TGFB1) (p < 0.05), as well as better jejunum morphometric variables (p < 0.05). On the other hand, mRNA of FGF1, TGF1, TCIRG1, and adenosine deaminase (ADA) were higher expressed (p < 0.05) in the spleen tissues of Cu/Zn-Mnt group. Collectively, the results indicated that our novel synthesized organic complexes of Zn/Cu-Thz proved to be a suitable feed supplement, as it increased rabbit productive performance through enhancing expression of peptide growth factors and cytokine genes.

Effects of zinc methionine supplementation on laying performance, zinc status, intestinal morphology, and expressions of zinc transporters' mRNA in laying hens

BACKGROUND

This study was conducted to investigate effects of dietary zinc methionine (Zn-Met) supplementation on laying performance, zinc (Zn) status, intestinal morphology, and Zn transporters in laying hens compared with zinc sulfate (ZnSO₄ ). A total of 384 Hyline Grey laying hens (38 weeks old) with similar performance (1.42 ± 0.07 kg) were randomly allotted to four dietary treatments and fed with a basal diet (control) or the basal diet supplemented with Zn, either as Zn-Met at 40 and 80 mg Zn/kilogram diet or as ZnSO₄ at 80 mg Zn/kilogram diet, for 10 weeks.

RESULTS

There was no difference in egg weight, egg production, feed intake, and feed conversation ratio among all groups (P > 0.05). Compared with the control, Zn contents were increased (P < 0.05) in the liver, duodenum, and jejunum of laying hens fed diets supplemented with different Zn sources. There was no difference (P > 0.05) in Zn contents in liver, duodenum, and jejunum between diets supplemented with Zn-Met or ZnSO₄ at 80 mg Zn/kilogram diet. Compared with the control and the ZnSO₄ group (80 mg Zn/kilogram diet), supplementation with Zn-Met of 80 mg Zn/kilogram diet increased (P < 0.05) villus height, villus area, and villus height/crypt depth ratio but reduced (P < 0.05) crypt depth in jejunum. Expression of metallothionein messenger RNA of jejunum in the group fed a diet containing Zn-Met (80 mg Zn/kilogram diet) was higher (P < 0.05) than that in the control.

CONCLUSION

These results indicated that Zn-Met has positive effects on the Zn status of liver, duodenum, and jejunum, intestinal morphology, and metallothionein messenger RNA expression in jejunum of laying hens compared with ZnSO₄ . © 2019 Society of Chemical Industry.

Zinc source modulates zootechnical characteristics, intestinal features, humoral response, and paraoxonase (PON1) activity in broilers

The current experiment was performed to find the potential effect of inorganic and organic forms of zinc (Zn) on growth, intestinal histomorphology, immune response, and paraoxonase (PON1) activity in broiler. In this experiment, a total of 450 broiler chickens were assigned to four experimental and control groups. The birds received organic Zn at the rate of 50 mg/kg (OZ-50) and 60 mg/kg (OZ-60) or inorganic Zn at the rate of 50 mg/kg (IZ-50) and 60 mg/kg (IZ-60) for an experimental period of 30 days. Significantly (P < 0.05) higher feed consumption, body weight, feed conversion ratio, and production efficiency factor (PEF) were recorded in OZ-50. Similarly, antibody titer against infectious bronchitis (IB) and PON1 activity was higher (P < 0.05) in OZ-50 compared with the control group. In addition, significantly (P < 0.05) higher villus dimensions and goblet cell count were recorded for the group OZ-50 compared with other treatments. It was concluded that the organic form of Zn was superior in improving the growth, histological features of intestines, humoral response, and PON1 activity in broiler.

Comparison of Inorganic and Organically Bound Trace Minerals on Tissue Mineral Deposition and Fecal Excretion in Broiler Breeders

This study investigated the effects of replacement of inorganic trace minerals (ITMs) by organic trace minerals (OTMs) on tissue mineral retention and fecal excretion in "Zhen Ning" yellow feather broiler breeders. Six hundred hens (initial BW: 1.70 ± 0.07 kg) aged 40 weeks were randomly divided into five treatments, with four replicates of 30 broiler breeders each. Experimental treatments were as follows: (1) ITM (Cu, Zn, Fe, Mn, Se providing commercially recommended concentrations), (2) L-ITM (50% of the ITM, except for Se), (3) VL-OTM (37.5% of the ITM, except for Se), (4) L-OTM (equivalent to L-ITM), and (5) OTM (62.5% of the ITM, except for Se). The duration of the study was 10 weeks including 2 weeks for adaptation. Compared with the L-ITM treatment, high-level supplementation of minerals in ITM and OTM increased the concentration of serum Mn and Se, pectoral Fe and pancreas Cu, and Fe (P < 0.05). Birds fed with OTM dietary exhibited comparable mineral retention in muscle compared with ITM. Differences were observed between L-ITM and L-OTM in serum Mn and Se, pectoral Fe, Zn, and Se, and heart Se with L-OTM retaining higher mineral concentrations than L-ITM (P < 0.05). L-OTM retained identical concentration with ITM treatment, except for the pancreatic Fe. All three organic diets reduced the Zn in excreta compared with the two inorganic diets (P < 0.05). This study indicates that replacement of dietary ITMs by OTMs improved mineral deposition in tissues and reduced fecal mineral excretion in broiler breeders under the conditions of this study.

Effects of organic zinc on tibia quality, mineral deposit, and metallothionein expression level of aged hens

The study aimed to determine the effects of methionine hydroxy analog chelate zinc on the tibia quality, mineral deposit, apparent retention of nutrients, and liver metallothionein (MT) expression level of aged laying hens. A total of 960 layers (Hy-Line Grey, 57 wk old) were randomly assigned into 4 groups, and each group had 8 replicates of 30 hens. During the first 2 wk, groups were fed a basal diet without extra zinc (Zn: 35.08 mg/kg). During the ensuing 14 wk, 4 levels of Zn (inorganic Zn: 80 mg/kg; organic Zn: 20, 40, 80 mg/kg) were added to the diet. The results indicated that both the Zn source and level did influence tibia strength and calcium (Ca) and Zn concentrations of tibia (P < 0.05), whereas there were no differences in the copper (Cu) and phosphorus (P) concentrations of the tibia and the tibia length (P > 0.05). Moreover, dietary supplementation with 40 or 80 mg/kg of organic Zn showed higher Zn and Ca concentrations in the tibia and higher tibia strength. The Cu concentration in the liver showed no difference among the 4 treatments, whereas the Zn concentration in the liver increased with the increasing Zn level. The apparent retention of P, iron (Fe), and manganese (Mn) was not affected by the Zn level or source (P > 0.05). However, the organic Zn group increased the apparent retention of Cu, Zn, Ca, crude protein (CP), and energy, and the group supplemented with 40 or 80 mg/kg of organic Zn obtained significant effects (P < 0.05). Moreover, dietary supplementation with 40 or 80 mg/kg organic Zn increased the MT mRNA expression of the liver at week 72, whereas 20 mg/kg of organic Zn decreased it (P < 0.05). In conclusion, this study suggested that an optimum dietary (40 mg/kg) organic Zn level plays a key role in promoting the apparent retention of minerals and nutrients, trace element deposit, and MT mRNA expression.

Heavy metal resistance in bacteria from animals

Resistance to metals and antimicrobials is a natural phenomenon that existed long before humans started to use these products for veterinary and human medicine. Bacteria carry diverse metal resistance genes, often harboured alongside antimicrobial resistance genes on plasmids or other mobile genetic elements. In this review we summarize the current knowledge about metal resistance genes in bacteria and we discuss their current use in the animal husbandry.

Safety evaluation of zinc methionine in laying hens: Effects on laying performance, clinical blood parameters, organ development, and histopathology

The study was conducted to investigate whether high-dose zinc methionine (Zn-Met) affected the safety of laying hens, including laying performance, hematological parameters, serum chemical parameters, organ index, and histopathology. A total of 540 20-week-old Hy-Line White laying hens was randomly allocated to 6 groups with 6 replicates of 15 birds each. Birds were fed diets supplemented with 0 (control), 70, 140, 350, 700, or 1,400 mg Zn/kg diet as Zn-Met. The experiment lasted for 8 wk after a 2-week acclimation period. Results showed that dietary supplementation with 70 or 140 mg Zn/kg diet as Zn-Met significantly increased average daily egg mass (ADEM), laying rate (LR), and feed conversion ratio (FCR) (P < 0.05) and lowered broken and soft-shelled egg ratio (BSER) (P < 0.05) in comparison with the control group; no significant differences were detected among hens fed with 0, 350, or 700 mg Zn/kg as Zn-Met (P > 0.05); hens administered 1,400 mg Zn/kg showed a significant increase in BSER and remarkable decreases in ADEM, LR, and FCR (P < 0.001). There were no significant differences among hens receiving 0, 70, 140, 350, or 700 mg Zn/kg as Zn-Met in serum chemical parameters (P > 0.05); supplementation with 1,400 mg Zn/kg as Zn-Met remarkably elevated the concentrations of serum total bilirubin (TBILI), glucose (GLU), uric acid (UA), and creatinine (CRE) (P < 0.001), and enhanced activities of serum glutamic oxalacetic transaminase (GOP) and alkaline phosphatase (AKP) (P < 0.001) compared with the control group. No significant histopathological changes were found in hens administered 0, 70, 140, 350, or 700 mg Zn/kg as Zn-Met, while significant histological lesions were observed in the heart, liver, lung, and kidney tissues of hens receiving 1,400 mg Zn/kg as Zn-Met. No significant differences were detected in hematological parameters or organ index (P > 0.05). In conclusion, a nominal Zn concentration of 700 mg/kg as Zn-Met is considered to be no-observed-adverse-effect level following daily administration to hens for 56 days.

Effect of dietary supplementation of organic zinc on laying performance, egg quality and some biochemical parameters of laying hens

This study was conducted to evaluate the effects of zinc methionine (Zn-Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34 weeks of age. A total of 120 Hisex Brown laying hens of 22-week-old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn-Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100 mg Zn-Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn-Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn-Met (100 mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p > .05 or .01) affected as a response to dietary Zn-Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100 mg Zn-Met/kg decreased serum triglyceride and LDL-cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn-Met in comparison with the control group. Dietary Zn-Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100 mg Zn-Met/kg diet. Dietary Zn-Met levels did not affect the antioxidant indices in blood serum except for the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD). The activity of Cu-Zn-SOD was increased with Zn-Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn-Met supplementation reduced serum triglyceride, LDL-cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100 mg Zn-Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.