Organic Zinc Sources Research Articles

Improvement of LiFePO4 electrochemical performance by organic zinc source doping in combination with crystalline carbon layer capping

In this paper, LiFePO4 cathode materials are prepared by hydrothermal method and co-modified using the synergistic effect of doping and capping. We investigate the effects of Zn[Formula: see text] doping and DPHP capping layer on the crystalline, microstructure, and electrochemical properties of LFP cathode materials, and the results indicate that the discharge capacity of the co-modified cathode material with 5% Zn[Formula: see text] doped and 7% DPHP capping layer is 162.1 mAh ⋅ g[Formula: see text], and the rate of capacity retention is still as high as 98.5% after 200 times of discharging and charging.

Synergistic enhancement of lithium iron phosphate electrochemical performance by organic zinc source doping and crystalline carbon layer capping

In this study, lithium iron phosphate (LFP) is prepared as cathode material by hydrothermal synthesis method and the combined effect of doping and capping is applied to co-modify it. We thoroughly investigate how Zn2+ doping and PA capping layer affect the crystal structure, microscopic morphology, and electrochemical properties of LFP cathode materials. The experimental results show that when co-modified with 5 % Zn2+ doping combined with 7 % PA capping layer, the resulting cathode material exhibits a discharge specific capacity of 165.5 mAh g−1, and the capacity retention rate can still be maintained at a high level of 98.6 % after 200 charge–discharge cycles.

Source-dependent effects of early-life zinc supplementation in milk on growth performance and starter intake of pre-weaned dairy calves

This study aimed to evaluate the effects of milk supplementation with different zinc (Zn) sources on growth rate, starter intake, diarrhea incidence, and nutrient digestibility in dairy calves during the pre-weaning period. Forty newborn Holstein heifer calves were assigned to four treatments: control (no Zn supplementation; CON) or supplementation with 80 mg/day Zn from zinc sulfate (Zn-Sul), chelated zinc (Zn-Bon), or zinc methionine (Zn-Met). The Zn supplements were provided via milk from days 3 to 14 of age. Body weight (BW) and starter intake (SI) were monitored until weaning on day 70. Serum metabolite concentrations were determined in blood samples collected on days 15 and 70. Fecal consistency index (FCI) and frequency of medical treatments were measured during the first 21 days of life. Apparent total tract digestibility (ATTD) was determined in the 10th week of life. Although the effects of Zn supplementation on BW gain or body measurements were non-significant, a tendency for treatment × time interaction on BW was observed, with variations among the experimental groups becoming more pronounced on days 56 and 70, showing higher values in Zn-supplemented calves compared to CON. SI was improved by Zn supplementation, with the greatest response in the Zn-Bon group. Compared to control, ATTD of organic matter, neutral detergent fiber, and starch tended to increase with Zn supplementation. Blood metabolites and FCI did not differ among the experimental treatments. Although no significant difference was detected between Zn-Met and CON, the frequency of medical treatment was significantly lower in Zn-Bon and Zn-Sul compared to CON calves. In conclusion, zinc supplementation in milk, particularly with the organic chelated zinc source (Zn-Bon), showed promising effects on increasing starter intake and reducing medical treatments, along with trends toward enhanced growth and nutrient digestibility in pre-weaned calves.

Effect of Organic, Nano, and Inorganic Zinc Sources on Growth Performance, Antioxidant Function, and Intestinal Health of Young Broilers.

The study aimed to determine the effects of different zinc sources on growth performance, antioxidant function, and intestinal health of broilers. In total, 240 Ross 308 male broilers with similar weight were randomly assigned to 4 treatments, including zinc sulfate, methionine zinc (Zn-Met), glycine zinc (Zn-Gly), and nano-zinc oxide (ZnO-NPs), with 80mg zinc/kg diet supplementation. The experiment lasted for 21days. Results showed dietary supplemental Zn-Gly and Zn-Met increased average daily gain during 1-14days (P = 0.011), and Zn-Gly, Zn-Met, and ZnO-NP supplementation decreased the ratio of feed to gain during 1-21days (P = 0.003) compared to zinc sulfate. ZnO-NPs supplementation tended to increase total SOD activity (P = 0.068) and had higher serum IgA content and lower MDA level than the other three groups (P < 0.05). Compared with zinc sulfate, Zn-Met and ZnO-NP supplementation decreased TNF-α mRNA expression (P = 0.048). However, serum biochemical indices, intestinal morphology, and mRNA expressions of tight junction proteins were not affected by different zinc sources (P > 0.05). A differential trend was observed in the beta diversity of bacterial communities among four groups (P = 0.082). The LEfSe analysis showed that bacterial genera Blautia, Ruminococcaceae, Clostridia, Anaerostipes, Eubacterium_ventriosum, Merdibacter, and Oscillospira were enriched in the ZnSO4 group, and the genera Eubacterium_hallii and Anaerotruncus were enriched in the Zn-Gly group. The genera UCG-009 and UCG010 were enriched in ZnO-NPs and Zn-Met groups, respectively. It should be stated dietary supplemental Zn-Met improved growth performance, ZnO-NPs promoted IgA production and reduced occurrences of oxidative stress and inflammation, and different zinc sources enriched different jejunal bacteria genera.

Effect of chronic cyclic heat stress and supplemented inorganic and organic zinc source levels on grow-finish pig growth performance and estimated body composition.

Zinc (Zn) supplementation has proved to mitigate the effects of heat stress with varying effects evident with Zn source during acute heat events. However, the effects of Zn supplementation during long-term summer weather patterns have yet to be explored. Therefore, the objective of this study was to identify the effects of supplementation source and level of Zn to mitigate the negative effects of long-term, cyclic heat stress in finishing swine. Six hundred cross-bred pigs were housed under thermoneutral (TN) or cyclic heat (HS) conditions simulating summer heat with acute 3-d heat waves for a 70-d study. Thermoneutral conditions were 16.7 to 18.9 °C throughout the study. HS pigs were housed at the same temperature as TN from days 0 to 18, then 28 °C/24 °C for 12h/12h on days 18 to 21, followed by 30 °C/26.7 °C for 12h/12h on days 24 to 70, except during acute heat (32 to 33 °C/29 to 30 °C, 12h/12h) on days 21 to 24, 42 to 45, and 63 to 66. Treatments were arranged in a 2 × 6 factorial with main effects of environment (HS vs. TN) and dietary available Zn supplementation: (1) 50mg/kg zinc oxide (ZnO), (2) 130mg/kg ZnO, (3) 50mg/kg of organic Zn (Availa Zn), (4) 50mg/kg ZnO + 40mg/kg organic Zn, (5) 50mg/kg ZnO + 60mg/kg organic Zn, and (6) 50mg/kg ZnO + 80mg/kg organic Zn. Pigs (5 pigs/pen) were blocked by initial body weight (72.2kg) and randomly allotted to 1 of 12 temperature and diet treatment combinations across 10 replicates. Body weight and feed intake were determined at the beginning and end of each acute heat event. All pigs were ultrasonically scanned at the 10th rib (TR) to predict loin muscle area (LMA), backfat (BF), and percent lean. Data were analyzed by the MIXED procedure in SAS with pen as the experimental unit. At day 63, HS pigs were lighter (P < 0.05), had lower overall average daily gain (ADG; P < 0.05) and average daily feed intake (P < 0.05). A diet-by-environment interaction was observed for overall ADG (P < 0.05) with diet 5 HS pigs having a 3.9% reduction in ADG whereas diet 6 had 14.4% reduction in ADG, while under TN temperatures diet 6 had the greatest overall ADG of all treatments. Other diets were intermediate in their ADG under both HS and TN conditions. Pigs under HS had less BF at the TR (P < 0.05) and a smaller LMA (P < 0.05), and a greater calculated percent lean (P < 0.05). Our results indicate that a blend of supplemental Zn sources at 50/60mg/kg may mitigate the reduction in growth performance due to HS. While not directly contrasted, the NRC requirement of 50mg/kg Zn may be too low to optimize finishing pig growth performance under both TN and HS conditions.

Comparative Effects of Including Inorganic, Organic, and Hydroxy Zinc Sources on Growth Development, Egg Quality, Mineral Excretion, and Bone Health of Laying Quails.

The purpose of this study was to determine the effects of the dietary addition of zinc (Zn) in the form of sulphate (Zn-S), glycine (Zn-G), and hydroxychloride (Zn-H) on quail performance, eggshell quality, antioxidant status, mineral excretion, biomechanical properties and mineralization of bone. A total of 75 female quails (10-weeks-old) were randomly distributed into 3 groups with 5 replications, each with 5 female quails. Treatment groups were set up by adding Zn-S and Zn-H as the inorganic form and Zn-G as the organic form of zinc to the corn-soybean basal diet (34.14mg/kg Zn) to obtain 50mg/kg Zn and the feeding experiment lasted for 12 weeks. Performance parameters and egg production were not impaired by the Zn source (P > 0.05). The inclusion of Zn-S in the diet produced a reduction in eggshell thickness, while an improvement in yolk antioxidant capacity (measured as MDA concentration) was detected compared to the other Zn sources (P < 0.05). Shear strength and cortical bone area increased (P < 0.05) with Zn-G supplementation, however, the mineral concentration of the tibia was higher (P < 0.01) in those quails who had received Zn-H. Lower levels of mineral excretion were observed in both types of supplementations compared to Zn-S. Therefore, it can be stated that Zn-G or Zn-H supplementation in the diet of laying quails could be an interesting strategy to reduce mineral excretion and improve bone mineralization without affecting performance compared to Zn-S. However, further studies are needed to determine the differences between Zn-G and Zn-H.

The Role of Zinc- Zeolite in the Growth and Yield of (Zea Mays L.) in Two Calcareous Soils

A field experiment was conducted at the research station of the College of Agriculture - University of Anbar to study the effect of zinc-zeolite on some growth and yield characteristics of maize in two calcareous soils that differ in clay ratio. It was carried out according to the randomized complete block design following the nested design, with three replications which include: natural and synthetic zeolite prepared from local kaolin. Both the natural and synthetic zeolite were ground and sieved using a sieve with a diameter of 63 µm and then the natural and synthetic zeolite were saturated with zinc. Natural and synthetic zeolite zinc was added to the soil at three levels: 4, 8, and 12 kg Zn ha−1. The mineral source of zinc (ZnSO47H2O) and the organic source of zinc (Zn-DTPA) were used at the level of 8 Kg Zn ha−1 for each of them as a comparison treatment, as well as the comparison treatment without the addition of zinc. The number of treatments in each sector is 9 experimental units, and the total number of experimental units for each site is 27 experimental units. The results showed that natural and synthetic zeolite-zinc at the level of 12 kg Zn ha−1 was significantly superior in plant height and grain weight at a rate of 183.3 cm (150.0 g) and the concentration of nitrogen, potassium and zinc at a rate of 19.98, 2.96 and 45.50 g kg−1.

Inorganic and Organic Zinc Sources and Piriformospora indica Fungus on Reducing the Risk of Cadmium and Lead Due to the Lettuce (Lactuca sativa) Consumption

Inorganic and Organic Zinc Sources and Piriformospora indica Fungus on Reducing the Risk of Cadmium and Lead Due to the Lettuce (Lactuca sativa) Consumption

Early supplementation with zinc proteinate does not change rectal microbiota but increases growth performance by improving antioxidant capacity and plasma zinc concentration in preweaned dairy calves.

The present study evaluated the effects of early supplementation with zinc proteinate (ZnP) or zinc oxide (ZnO) for 2 weeks on the growth performance, redox status, plasma trace element concentrations, and rectal microbiota of preweaned dairy calves. A total of 60 newborn healthy female Holstein dairy calves, with initial body weight (BW): 41.33 ± 0.62 kg, were randomly allocated to 5 groups of 12 each: a control group (CON); three groups supplemented with 261 (L-ZnP), 523 (M-ZnP), and 784 (H-ZnP) mg/day ZnP, equivalent to 40, 80, and 120 mg/day zinc, respectively; and one group supplemented with 232 mg/day ZnO, equivalent to 180 mg/day zinc (ZnO). Zinc supplements were administered on days 1-14, and the calves were followed up until day 70. Zinc supplementation increased total dry matter intake (DMI) and starter DMI compared with the CON group (p < 0.01). The final BW, average daily gain, and feed efficiency were higher in the M-ZnP, H-ZnP, and ZnO groups (p < 0.05). The incidence of diarrhea on days 1-28 was reduced by zinc administration (p < 0.01), whereas the incidence on days 29-56 was lower in the M-ZnP and ZnO groups (p < 0.05). Serum glutathione peroxidase activity, total antioxidant capacity, immunoglobulin G and plasma zinc concentrations were increased linearly (p < 0.05), while the serum concentration of malondialdehyde was decreased linearly (p < 0.01), as the dose of ZnP increased. ZnP yielding 80 mg/day zinc had similar effects as ZnO yielding 180 mg/day zinc, except that final BW was higher in the ZnO group (p < 0.05). At the phylum level, ZnO decreased the relative abundance of Firmicutes while increasing the abundance of Bacteroidetes (p < 0.05). At the genus level, ZnO increased the relative abundances of Prevotella, Subdoligranulum, and Odoribacter (p < 0.05). These findings indicated that early supplementation with ZnP did not affect the rectal microbiota of preweaned dairy calves but increased their growth performance, antioxidant capacity, and plasma zinc concentration. In summary, ZnP is an organic zinc source with greater bioavailability than ZnO for preweaned dairy calves. Early dietary supplementation with ZnP yielding 80 mg/day zinc is recommended.

Zinc supplementation modifies brain tissue transcriptome of Apis mellifera honeybees

BackgroundBees are the most important group of pollinators worldwide and their populations are declining. In natural conditions, Apis mellifera depends exclusively on food from the field to meet its physiological demands. In the period of scarcity, available resources are insufficient and artificial supplementation becomes essential for maintaining the levels of vitamins, proteins, carbohydrates, and minerals of colonies. Among these minerals, zinc is essential in all living systems, particularly for the regulation of cell division and protein synthesis, and is a component of more than 200 metalloenzymes.ResultsThe total RNA extracted from the brain tissue of nurse bees exposed to different sources and concentrations of zinc was sequenced. A total of 1,172 genes in the treatment that received an inorganic source of zinc and 502 genes that received an organic source of zinc were found to be differentially expressed among the control group. Gene ontology enrichment showed that zinc can modulate important biological processes such as nutrient metabolism and the molting process.ConclusionsOur results indicate that zinc supplementation modulates the expression of many differentially expressed genes and plays an important role in the development of Apis mellifera bees. All the information obtained in this study can contribute to future research in the field of bee nutrigenomics.

Effects of zinc glycinate on growth, immunity, and intestinal health in broiler chickens

The objective is to investigate the effects of dietary zinc form and concentration in broiler chickens. Day-old broiler chicks (n = 6) were allotted to treatments in a 2 × 3 factorial arrangement to examine supplemental zinc from sulfate (ZS) and glycinate (ZG) and concentration (40, 80, and 120 mg/kg). In healthy conditions, no difference in poultry performances is to be expected between organic and inorganic zinc sources, supplemented at the same zinc dose to the diets. We found that on day 21, zinc supplemented at 80 mg/kg increased body weight gain (BWG) by 113 g compared to zinc supplemented at 40 mg/kg (P < 0.01). Similarly, on day 35, zinc supplemented at 120 mg/kg increased BWG by 155 g compared to zinc supplemented at 40 mg/kg (P < 0.05). On day 35, zinc supplemented at 120 mg/kg increased feed intake by 239 g compared to zinc supplemented at 40 mg/kg (P < 0.05). The villi length on day 21 was increased by 63 µm in birds supplemented at 120 mg/kg compared to 40 mg/kg (P < 0.05). On day 21, cecal tonsil gene expression of interleukin 1 beta (IL-1β) was higher by 2.5 and 2.4-fold in the ZG-80 mg/kg group than the ZG-40 mg/kg and ZS-120 mg/kg groups (P < 0.01), and interleukin 10 (IL-10) was lower by 2-fold in the ZS-120 mg/kg group than ZS-40 mg/kg, while IL-10 was lower in the ZG-40 mg/kg than ZS-40 mg/kg group (P < 0.01). On day 35, cecal tonsil gene expression of IL-1β was overall higher by 1.3-fold in the ZG group compared to ZS (P < 0.05). On day 21, spleen gene expression of transforming growth factor-beta (TGF-β) was higher by 1.4-fold in the ZG-80 mg/kg group compared to ZG-40 mg/kg (P < 0.05). On day 35 spleen gene expression of lipopolysaccharide-induced TNF factor (LITAF) was lower in the ZG-80 mg/kg group compared to ZS-80 mg/kg (P < 0.05). On day 35 jejunum gene expression of claudin-2 was higher by 2.1-fold in the ZG-80 mg/kg group than ZS-80 mg/kg (P < 0.05). This study supports that zinc supplementation at 120 mg/kg improves the growth performance of broiler chickens. This is accompanied by improvements in intestinal morphology and modulation in immunity through an altered cytokine production profile.

Impact of Dietary Zinc Chloride Hydroxide and Zinc Methionine on the Faecal Microbiota of Healthy Adult Horses and Ponies

Zinc supplements are often used in equine nutrition to support skin and hoof quality or the immune function. However, no data on the effects of dietary zinc on the intestinal microbiota of horses and ponies are available so far. In the present study, varying dietary zinc concentrations (maintenance (4 mg/kg BW0.75/day), 120 mg/kg dry matter (DM)/day and 240 mg/kg DM/day) were achieved by the supplementation of either zinc chloride hydroxide or zinc methionine (six treatment periods of 4 weeks each). Eight healthy adult ponies and two healthy adult horses were included, and faecal samples were collected at the end of each treatment period to analyse the microbiota (16S rDNA sequencing) and microbial metabolites. With increasing dietary zinc concentrations, the richness of the faecal microbiota decreased, independently of the zinc compound used. In addition, a decrease of the relative abundance of Bacteroidetes and Fibrobacteres as well as of acetate and total short-chain fatty acids in the faeces of the animals was observed at high zinc intakes. Effects on the bacterial order, family and genus level were also detected, which were partly more pronounced for zinc chloride hydroxide. It can be concluded that high dietary zinc levels decrease the richness and fermentative activity of the faecal microbiota of horses and ponies. Although all animals were healthy throughout the study, the effects could be critical for gut health, and deserve more research. The detected differences between the zinc compounds used indicate differences in the bioavailability of organic and inorganic zinc sources in equines.

Effects of Zinc Lactate Supplementation on Growth Performance, Intestinal Morphology, Serum Parameters, and Hepatic Metallothionein of Chinese Yellow-Feathered Broilers

In poultry, organic zinc compounds have higher bioavailability than inorganic zinc sources. However, as an organic zinc source, the application of zinc lactate (ZL) on Chinese yellow-feathered broilers has been rarely reported. Hence, the present study aimed to investigate the effects of ZL supplementation on growth performance, small intestinal morphology, serum biochemical parameters, immune organ index, as well as hepatic metallothionein of Chinese yellow-feathered broilers. A total of 2100 broilers (19 days old) were randomly assigned to 5 treatment groups, including the control (fed basal diet), ZL40 (basal diet plus 40 mg/kg ZL), ZL60 (basal diet plus 60 mg/kg ZL), ZL80 (basal diet plus 80 mg/kg ZL), and ZS80 (basal diet plus 80 mg/kg ZS. Each treatment group had 6 replicates with 70 chickens per replicate. Compared to the control group, the ZL40 and the ZS80 groups had a lower feed to gain ratio (P < 0.05), ZL40 group had higher duodenum and ileum villus heights (P < 0.05), and ZS80 and ZL80 groups had a lower ratio of villus height to crypt depth in the jejunum (P < 0.01). In addition, the ZL60 group had a higher concentration of total protein (P < 0.05) and activity of glutathione peroxidase (GSH-Px) (P < 0.01) compared with the ZS80 and the control groups. Interestingly, the ZL40, ZL60, and ZL80 groups all had higher levels of hepatic metallothionein than the other groups (P < 0.01). In conclusion, zinc lactate had a higher bioavailability and could be used as an alternative to zinc sulfate.

Zinc in Dog Nutrition, Health and Disease: A Review

Simple SummaryThis work compiles the current state of knowledge regarding zinc requirements of healthy dogs and biomarkers of zinc status. To ensure an adequate zinc status, it is important to know the zinc content of foods and their bioavailability to assess the need and the ideal supplementation strategy regarding levels and sources of additives in complete dog foods. As zinc is required for enzymatic, structural, and regulatory functions in the animal body, its nutritional status has been associated with several pathologies that may be due to, or exacerbated by, a deficit of dietary zinc supply.Zinc is an essential trace element, required for enzymatic, structural, and regulatory functions. As body reserves are scarce, an adequate zinc status relies on proper dietary supply and efficient homeostasis. Several biomarkers have been proposed that enable the detection of poor zinc status, but more sensitive and specific ones are needed to detect marginal deficiencies. The zinc content of commercial dry dog foods has great variability, with a more frequent non-compliance with the maximum authorized limit than with the nutritional requirement. The bioavailability of dietary zinc also plays a crucial role in ensuring an adequate zinc status. Despite controversial results, organic zinc sources have been considered more bioavailable than inorganic sources, albeit the zinc source effect is more evident after a restriction period of dietary zinc. Many disorders have been associated with inadequate zinc status, not being clear whether the occurrence of the disease is the consequence or the cause. This review presents data on zinc requirements and biomarkers for zinc status, that can be applied for the development of supplementation strategies of zinc in complete pet foods. Moreover, it provides an understanding of the role zinc plays in the health of dogs, and how altered zinc status affects diseases in dogs.

Organic zinc supplementation modifies the metalloproteome of royal jelly produced by Apis mellifera

In this study, we analyzed Apis mellifera royal jelly proteome alterations induced by supplementation with different concentrations of dietary organic zinc (0, 25, 50, and 75 ppm). Proteins extracted from royal jelly were separated by electrophoresis and isoelectric focusing, and zinc-containing protein spots were identified by tandem mass spectrometry. Organic zinc-containing diets modified total royal jelly protein content and altered the expression of five major royal jelly proteins (MRJP1, MRJP2, MRJP3, MRJP5, and MRJP8). While the diet with the lowest tested zinc content (Zn25) increased total royal jelly protein content and expression of MRJP1, diets with higher zinc contents (Zn50 and Zn75) decreased MRJP expression. Our results demonstrate that important proteins and metabolic processes are modified in royal jelly produced by honey bees supplemented with different concentrations of organic zinc source, affecting nutrition and maintenance of colonies.

The effect of organic and inorganic zinc source, used with lignocellulose or potato fiber, on microbiota composition, fermentation, and activity of enzymes involved in dietary fiber breakdown in the large intestine of pigs

The study aimed at determining the effects of Zn sources, used with potato fiber (PF) or lignocellulose (LC), on microbiota ecology in the large intestine of pigs. The hypothesis was that organic Zn source, i.e. Zn glycinate (ZnGly), and PF improve polysaccharide digestibility via effects on microbiota involved in degradation of dietary fiber. Twenty four piglets of initial body weight 10.8 ± 0.82 kg were divided into 4 groups (n=6) fed diets with: LC and ZnSO4, LC and ZnGly, PF and ZnSO4, and PF and ZnGly. Fiber supplements introduced 10 g crude fiber/kg diet, while Zn additives provided 120 mg Zn/kg diet. After 4 weeks of feeding digesta was taken from 4 segments of the large intestine. Pigs fed ZnGly diets had greater population of Clostridium herbivorans in the cecum (P = 0.021) and proximal colon (P = 0.024), and reduced that of Clostridium spp. in the proximal colon (P = 0.037) in comparison with ZnSO4. ZnGly had no effect on bacterial enzymes activity but increased total phenols concentration in the proximal (P = 0.012) and distal colon (P = 0.008). Feeding PF diets decreased Clostridium spp. population in the distal colon (P = 0.010), while increased it in the proximal (P < 0.001) colon (P = 0.034) as compared to LC diets. In all parts of the colon, pigs fed PF diets had β-glucosidase activity twice as high as animals on LC diets (P < 0.05), while activity of cellulase did not differ between treatments. The interaction affected Clostridium spp. population in the cecum (P = 0.034) and middle colon (P = 0.005), ammonia concentration (P = 0.032) and β-glucosidase activity (P = 0.026) in the proximal colon, and isoacid concentrations in the distal colon (P < 0.05). The lack of interactive effect on most of the analyzed indices suggest that Zn source and fiber supplementation act independently on microbiota ecology and ZnGly and PF contribute to increase of fiber digestibility in different ways, i.e. by stimulation of C. herbivorans growth or by increase of β-glucosidase activity.

REPRODUCTIVE PERFORMANCE OF HEAT-STRESSED NEW ZEALAND WHITE RABBIT BUCKS IN RESPONSE TO DIFFERENT ZINC SOURCES

This study aimed to evaluate the effect of zinc supplementation from different sources to heat-stressed New Zealand White rabbit buck diets on some reproductive traits including semen quality, conception rate and litter size. Twenty four mature bucks were randomly assigned into four groups, with six males each. The first group reared under mild condition and received the basal diet with no supplementation. The other three groups were raised under heat stress condition and received the basal diet only or the basal diet supplied with 75 mg zinc either as zinc sulphate (inorganic zinc) or as zinc picolinate (organic zinc), for the second, third and fourth groups, respectively. It was found that dietary zinc supplementation reduced the heat stress-related increases in reaction time, and seminal plasma levels of alanine transaminase (ALT) and malondialdehyde (MDA). Decreased values of serum and seminal plasma testosterone, sperm count, sperm motility and conception rate induced by heat stress conditions were restored by zinc supplementation. Seminal plasma zinc and total antioxidant capacity (TAC) were significantly increased in zinc-treated groups when compared to both control groups in different conditions. Organic source of zinc was more potent than inorganic one in restoring levels of serum testosterone, seminal plasma MDA and testosterone, and sperm motility. From these results, it could be concluded that dietary zinc addition from different sources, especially zinc picolinate (organic form), is helpful in alleviating the negative effect of heat stress on reproductive traits of New Zealand White rabbit bucks.

Concentration and chemical form of dietary zinc shape the porcine colon microbiome, its functional capacity and antibiotic resistance gene repertoire

Despite a well-documented effect of high dietary zinc oxide on the pig intestinal microbiota composition less is it yet known about changes in microbial functional properties or the effect of organic zinc sources. Forty weaning piglets in four groups were fed diets supplemented with 40 or 110 ppm zinc as zinc oxide, 110 ppm as Zn-Lysinate, or 2500 ppm as zinc oxide. Host zinc homeostasis, intestinal zinc fractions, and ileal nutrient digestibility were determined as main nutritional and physiological factors putatively driving colon microbial ecology. Metagenomic sequencing of colon microbiota revealed only clear differences at genus level for the group receiving 2500 ppm zinc oxide. However, a clear group differentiation according to dietary zinc concentration and source was observed at species level. Functional analysis revealed significant differences in genes related to stress response, mineral, and carbohydrate metabolism. Taxonomic and functional gene differences were accompanied with clear effects in microbial metabolite concentration. Finally, a selection of certain antibiotic resistance genes by dietary zinc was observed. This study sheds further light onto the consequences of concentration and chemical form of dietary zinc on microbial ecology measures and the resistome in the porcine colon.

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.

Cytokine response after stimulation of culture cells by zinc and probiotic strain.

Intestinal porcine epithelial cells were used for an in vitro analysis of mRNA expression levels of inflammatory cytokines (IL-8, IL-18) and transcriptional factors (MyD88 and NF-κβ). Cells were exposed to inorganic and organic zinc sources (in two different concentrations-50μmol/L and 100μmol/L) alone or combined with Lactobacillus reuteri B6/1, which was also applied individually. The total exposure time was 4h. Quantitative reverse transcriptase PCR was used to determine expression levels of the aforementioned parameters. In general, upregulation was observed; however, a decrease of some mRNA's abundance was also determined. Differences in expression were analysed statistically using ANOVA and Tukey analyses. High relative expression was shown for IL-8, IL-18 and MyD88 in groups treated with 100μmol/L of inorganic sources of zinc (ZnSO4) (p < 0.05), while groups treated with the organic form did not exhibit significant changes in expression. Also, 50μmol/L of either zinc source did not significantly modify the transcriptional profile of the cytokines and transcription factors, showing that even inorganic sources, at lower concentrations, do not elicit a significant inflammatory reaction. In summary, supplementation of organic zinc source (Gly-Zn chelate) ensures that IL-8, IL-18, MyD88 and NF-κβ expression levels are not positively regulated. In contrast, inorganic sources of zinc (ZnSO4) could induce an inflammatory reaction. However, this response could be dampened if L. reuteri B6/1 is administered, showing the helpful aspect of using probiotics to modulate an inflammatory response. Conclusively, the use Gly-Zn chelate appears as an optimal alternative for Zn administration that does not compromise normal intestinal homeostasis.