Bioavailability of zinc sources and their interaction with phytates in broilers and piglets

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.

Review: Aspects of digestibility and requirements for minerals and vitamin D by growing pigs and sows

Some of the biggest changes in mineral nutrition for pigs that have occurred due to recent research were caused by the understanding that there is a loss of endogenous Ca and P into the intestinal tract of pigs. This resulted in development of the concept of formulating diets based on standardized total tract digestibility (STTD) rather than apparent total tract digestibility because the values for STTD of these minerals are additive in mixed diets. There are, however, no recent summaries of research on digestibility and requirements of macro- and microminerals and vitamin D for pigs. Therefore, the objective of this review was to summarize selected results of research conducted over the last few decades to determine the digestibility and requirements of some minerals and vitamin D fed to sows and growing pigs. Benefits of microbial phytase in terms of increasing the digestibility of most minerals have been demonstrated. Negative effects on the growth performance of pigs of over-feeding Ca have also been demonstrated, and frequent analysis of Ca in complete diets and raw materials is, therefore, recommended. There is no evidence that current requirements for vitamin D for weanling or growing-finishing pigs are not accurate, but it is possible that gestating and lactating sows need more vitamin D than currently recommended. Vitamin D analogs and metabolites such as 1(OH)D3 and 25(OH)D3 have beneficial effects when added to diets for sows in combination with vitamin D3. Recent research on requirements for macrominerals other than Ca and P is scarce, but it is possible that Mg in diets containing low levels of soybean meal is marginal. Some of the chelated microminerals have increased digestibility compared with sulfate forms, and hydroxylated forms of Cu and Zn appear to be superior to sulfate or oxide forms. Likewise, dicopper oxide and Cu methionine hydroxy analog have a greater positive effect on the growth performance of growing pigs than copper sulfate. The requirement for Mn may need to be increased whereas there appears to be no benefits of providing Fe above current requirements. In conclusion, diets for pigs should be formulated based on values for STTD of Ca and P and there are negative effects of providing excess Ca in diets. It is possible vitamin D analogs and metabolites offer benefits over vitamin D3 in diets for sows. Likewise, chelated forms of microminerals or chemical forms of minerals other than sulfates or oxides may result in improved pig performance.

Impact of Trace Mineral Source and Phytase Supplementation on Prececal Phytate Degradation and Mineral Digestibility, Bone Mineralization, and Tissue Gene Expression in Broiler Chickens

The objective of this study was to determine how different sources of Zn, Mn, and Cu in the feed without and with phytase affect prececal myo-inositol hexakisphosphate (InsP6) breakdown to myo-inositol (MI), prececal P digestibility, bone mineralization, and expression of mineral transporters in the jejunum of broiler chickens. A total of 896 male broiler chicks (Cobb 500) were distributed to 7 diets with 8 replicate pens (16 birds per floor pen). Experimental diets were fed from day 0 to 28. Diets were without or with phytase supplementation (0 or 750 FTU/kg) and were supplemented with three different trace mineral sources (TMS: sulfates, oxides, or chelates) containing 100 mg/kg Zn, 100 mg/kg Mn, and 125 mg/kg Cu. Prececal InsP6 disappearance and P digestibility were affected by interaction (phytase × TMS: P ≤ 0.010). In diets without phytase supplementation, prececal InsP6 disappearance and P digestibility were greater (P ≤ 0.001) in birds fed chelated minerals than in birds fed sulfates or oxides. However, no differences were observed between TMS in diets with phytase supplementation. Ileal MI concentration was increased by exogenous phytase but differed depending on TMS (phytase × TMS: P ≤ 0.050). Tibia ash concentration as well as Zn and Mn concentration in tibia ash were increased by phytase supplementation (P < 0.010), but the Cu concentration in tibia ash was not (P > 0.050). Gene expression of the assayed mineral transporters in the jejunum was not affected by diet (P > 0.050), except for Zn transporter 5 (phytase × TMS: P = 0.024). In conclusion, the tested TMS had minor effects on endogenous phytate degradation in the digestive tract of broiler chickens. However, in phytase-supplemented diets, the choice of TMS was not relevant to phytate degradation under the conditions of this study.

Zinc Oxide Nanoparticles Significant Role in Poultry and Novel Toxicological Mechanisms

Zinc oxide nanoparticles (ZnO NPs) have involved a lot of consideration owing to their distinctive features. The ZnO NPs can be described as particularly synthesized mineral salts via nanotechnology, varying in size from 1 to 100 nm, while zinc oxide (ZnO), it is an inorganic substrate of zinc (Zn). The Zn is a critical trace element necessary for various biological and physiological processes in the body. Studies have revealed ZnO NPs' efficient immuno-modulatory, growth-promoting, and antimicrobial properties in poultry birds. They offer increased bioavailability as compared to their traditional sources, producing better results in terms of productivity and welfare and consequently reducing ecological harm in the poultry sector. However, they have also been reported for their toxicological effects, which are size, shape, concentration, and exposure route dependent. The investigations done so far have yielded inconsistent results, therefore, a lot of additional studies and research are required to clarify the harmful consequences of ZnO NPs and to bring them to a logical end. This review explores an overview of efficient possible role of ZnO NPs, while comparing them with other nutritional Zn sources, in the poultry industry, primarily as dietary supplements that effect the growth, health, and performance of the birds. In addition to the anti-bacterial mechanisms of ZnO NPs and their promising role as antifungal, and anti-colloidal agent, this paper also covers the toxicological mechanisms of ZnO NPs and their consequent toxicological hazards to vital organs and the reproductive system of poultry birds.

Interactions of zinc with phytate and phytase in the digestive tract of poultry and pigs: a review

Phytase supplementation is gaining importance in animal nutrition because of its effect on phosphorus (P) digestibility and the increasing relevance of P for sustainable production. The potential inhibitors of phytase efficacy and phytate degradation, such as calcium (Ca) and zinc (Zn), have been a subject of intense research. This review focuses on the interactions of Zn with phytate and phytase in the digestive tract of poultry and pigs, with an emphasis on the effects of Zn supplementation on phytase efficacy and P digestibility. In vitro studies have shown the inhibitory effect of Zn on phytase efficacy. However, relevant in vivo studies are scarce and do not show consistent results for poultry and pigs. The results could be influenced by different factors, such as diet composition, amount of Zn supplement, mineral concentrations, and phytase supplementation, which limit the comparability of studies. The chosen response criteria to measure phytase efficacy, which is mainly tibia ash, could also influence the results. Compared to poultry, the literature findings are somewhat more conclusive in pigs, where pharmacological Zn doses (≥ 1000 mg kg-1 Zn) appear to reduce P digestibility. To appropriately evaluate the effects of non-pharmacological Zn doses, further studies are needed that provide comprehensive information on their experimental setup and include measurements of gastrointestinal phytate degradation to better understand the mechanisms associated with Zn and phytase supplements. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Too Much of a Good Thing: Rethinking Feed Formulation and Feeding Practices for Zinc in Swine Diets to Achieve One Health and Environmental Sustainability

The objectives of this review were to summarize current knowledge of Zn in swine nutrition, environmental concerns, potential contribution to antimicrobial resistance, and explore the use of alternative feeding strategies to reduce Zn excretion in manure while capturing improvements in productivity. Zinc is a required nutrient for pigs but is commonly supplemented at concentrations that greatly exceed estimated requirements. Feeding pharmacological concentrations of Zn from ZnO to pigs for 1 to 2 weeks post-weaning reduces post-weaning diarrhea and improves growth performance. Feeding elevated dietary levels of Zn to sows during the last 30 days of gestation can reduce the incidence of low-birth-weight pigs and pre-weaning mortality. Most of the dietary Zn consumed by pigs is not retained in the body and is subsequently excreted in manure, which led several countries to impose regulations restricting dietary Zn concentrations to reduce environmental impacts. Although restricting Zn supplementation in swine diets is a reasonable approach for reducing environmental pollution, it does not allow capturing health and productivity benefits from strategic use of elevated dietary Zn concentrations. Therefore, we propose feeding strategies that allow strategic use of high dietary concentrations of Zn while also reducing Zn excretion in manure compared with current feeding practices.

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.

Review: Bioavailability of trace elements in farm animals: definition and practical considerations for improved assessment of efficacy and safety

Currently, the authorisation procedure of trace elements as feed additives in the European Union according to Regulation (EC) No. 1831/2003 does not consider the bioavailability of trace element sources. This manuscript provides framework conditions for in vivo experiments that aim to estimate differences in the relative bioavailability between supplements of essential trace elements. Framework conditions encompass necessary technical information on the test substance, the experimental design and diet composition as well as the suitability of status parameters that allow for relative comparisons of regression variables. This manuscript evolves recommendations for researchers to conduct solid and reliable experiments on the matter as well as decision makers to interpret the value of studies submitted with authorisation applications regarding a certain trace element supplement.

Comparison of the Effects of Inorganic or Amino Acid-Chelated Zinc on Mouse Myoblast Growth in vitro and Growth Performance and Carcass Traits in Growing-Finishing Pigs

This study aimed to investigate the effects of the supplementation of different sources of zinc on mouse myoblast growth in vitro and the growth performance and carcass traits in growing-finishing pigs. In the in vitro trial, 25 or 75 mM zinc sulfate (ZnSO₄), methionine-chelated zinc (ZnMet), and glycine-chelated zinc (ZnGly) were co-cultured with the myoblast during proliferation and differentiation. The results showed that the amino acid-chelated zinc supplementation, especially ZnMet, enhances cell proliferation and differentiation in mouse myoblast, and regulates the distribution in S and G2/M phases (P < 0.05). Meanwhile, the protein expression levels of the mammalian target of rapamycin pathways were up-regulated after treatment with 25 μM ZnMet (P < 0.05), which is consistent with the results of the enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in the transcriptome analysis. In the in vivo trial, 27 Duroc × (Landrace × Large White) pigs with an initial average weight of 31.62 ± 0.36 kg were divided into three groups with nine replicates per treatment. The dietary treatment groups were as follows: (1) ZnSO4 group, basal diet +75 mg/kg ZnSO4; (2) ZnMet group, basal diet +75 mg/kg ZnMet; and (3) ZnGly group, basal diet +75 mg/kg ZnGly. The whole trial lasted for 75 days. Increased final body weight, average daily gain, and decreased F/G were noted in the ZnMet group (P < 0.05). Moreover, the ZnMet group had higher carcass weight and loin eye area (P = 0.05). The ZnMet and ZnGly group both had lower serum total protein (P < 0.05), while the ZnMet group had higher serum alkaline phosphatase (P < 0.05). Also, the addition of ZnMet showed higher concentrations of zinc and iron in muscle, kidney, and serum (P < 0.05), improving the deposition and availability of micronutrients. In conclusion, amino acid-chelated zinc, particularly ZnMet, had the best effect, which could improve growth in vitro and increase growth performance while boosting bioavailability in growing-finishing pigs, ultimately, enhancing muscle mass, providing a theoretical basis and guidance for the future use of amino acid-chelated zinc to effectively replenish energy in animal nutrition and production.

Improved Growth Performance, Antioxidant Status, Digestive Enzymes, Nutrient Digestibility and Zinc Bioavailability of Broiler Chickens with Nano-Sized Hot-Melt Extruded Zinc Sulfate

This experiment was conducted to investigate the effect of the supplementation of hot-melt extrusion (HME) processed zinc sulfate (ZnSO₄) on the growth performance, antioxidative activity, pancreatic digestive enzyme, small intestinal morphology, nutrient digestibility, and Zn content in broilers. The chicks were allocated to three treatments, each of which had five replicates of 15 chicks per replicate. The broiler chickens were assigned to three dietary treatments: the control (without supplemental Zn), IN-Zn (ZnSO₄, 80 mg/kg), and HME-Zn (HME processed ZnSO₄ as nano-Zn, 80 mg/kg). The broilers fed diets supplemented with 80 mg/kg of HME-Zn improved the BWG (P < 0.05) and FCR (P < 0.05) compared to the broilers fed the control and IN-Zn diets in phase 2. The Zn supplementation significantly enhanced the superoxide dismutase (SOD) activity in the serum (P < 0.05) and liver (P < 0.05), and HME-Zn supplementation significantly increased the SOD in the liver compared to the IN-Zn supplementation. Reduced malondialdehyde (MDA) concentration was seen with the Zn supplementation compared to the control (P < 0.05). The chickens fed diets supplemented with the HME-Zn had higher activity of amylase (P < 0.05) and trypsin (P < 0.05) than those of the chickens fed the control and IN-Zn diets. The villus height (VH) in the duodenum (P < 0.05) and jejunum (P < 0.05) increased with the ZnSO₄ and HME-Zn supplementation compared to the control. The VH and crypt depth rate (VH:CD) in the jejunum improved with the HME-Zn compared to the control (P < 0.05). The HME-Zn significantly increased the apparent ileal digestible crude protein (CP) (P < 0.05) and energy corrected by nitrogen (AIDEn) (P < 0.05) compared to the control or IN-Zn. In phases 1 and 2, the HME-Zn significantly increased Zn concentration in the liver and tibia compared to control and IN-Zn (P < 0.05). The excretion of Zn was significantly decreased in the HME-Zn compared to the IN-Zn (P < 0.05). In conclusion, supplementation of 80 mg/kg of HME-Zn in diets improved the growth performance, antioxidative activity, pancreatic enzyme activity, intestinal villus height, and nutrient digestibility with the improved Zn bioavailability in broilers.

Effects of different inorganic:organic zinc ratios or combination of low crude protein diet and feed additives in weaned piglet diets

Thirty-six weaned piglets with an initial body weight (BW) of 8.43 ± 0.40 kg (28 days of age, ([Landrace × Yorkshire] × Duroc) were randomly assigned to 6 treatments for a 2-week feeding trial to determine the effects of different inorganic zinc (IZ), organic zinc (OZ) or combination of low crude protein diet (LP) and Mixed feed additive (MFA) on diarrhea score, nutrient digestibility, zinc utilization, blood profiles, organ weight, and fecal microflora in weaned piglet diet. The pigs were individually placed in 45 × 55 × 45 cm stainless steel metabolism cages in an environmentally controlled room (30 ± 1°C). The dietary treatments included a negative control (NC), positive control (PC; zinc oxide, 1,000 mg/kg), T1 (IZ : OZ, 850 : 150), T2 (IZ : OZ 700 : 300), T3 (IZ : OZ, 500 : 500), and T4 (LP + MFA [0.1% Essential oils + 0.08% Protease + 0.02% Xylanase]). The daily feed allowance was adjusted to 2.7 times the maintenance requirement for digestible energy (2.7 × 110 kcal of DE/kg BW^0.75). This allowance was divided into two equal parts, and the piglets were fed at 08 : 30 and 17 : 30 each day. Water was provided ad libitum through a drinking nipple. The diarrhea score was significantly increased (p < 0.05) in NC treatment compared with other treatments. The apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and gross energy (GE) was significantly increased (p < 0.05) in the T2 treatment compared with the PC and NC treatments in week 1. In week 2, the ATTD of DM, N, and GE was significantly decreased (p < 0.05) in the NC treatment compared with other treatments. The T3 treatment had significantly higher (p < 0.05) ATTD and apparent ileal digestibility of zinc than the PC and T1 treatments. The Escherichia coli count in feces was significantly decreased in the T4 treatment compared with the NC and T2 treatments. The Lactobacillus count in feces was significantly increased in the T4 and T1 treatment compared with the T2 and T3 treatments. In conclusion, IZ : OZ 500 : 500 levels could improve nutrient digestibility and zinc utilization in weaned piglets, Moreover, MFA in LP diets could be used as a zinc alternative.

Investigations on the Effects of Different Calcium Supply Exceeding the Requirements on Mineral Serum Concentrations and Bone Metabolism in Young Warmblood Stallions

Simple Summary

In horse husbandry, it is a common practice to supplement roughages with mineral or complementary feeds, which contain, among others, macro elements. However, roughages usually fulfil the requirements for macro minerals but not of trace elements of horses at maintenance. Therefore, in the present feeding trial mineral feeds with different calcium levels moderately exceeding the requirements vs. 2-fold higher levels were tested in young stallions (2–3 years old) for five months under practical conditions. Blood samples of the stallions were analysed to prove whether the feeding regimes influence mineral status or bone metabolism. The results suggest that reduced calcium intake favours phosphorus levels in the blood, but does not affect serum levels of trace elements and bone metabolism in young, still growing stallions.

Abstract

Since mineral supplements for horses commonly contain macro minerals, although the requirement for such is usually covered by roughage-based diets, the aim of this study was to investigate the effects of different dietary calcium levels on mineral serum concentrations and bone metabolism. The trial was conducted in 30 young warmblood stallions (2–3 years) that were divided into two groups for a five-month feeding trial. The groups were fed a hay- and oat-based diet and were either supplied with high (Ca-High) or moderate (Ca-Moderate) calcium excess. While in Ca-High calcium supply was about 2–2.5-fold of the requirement, in Ca-Moderate calcium requirements were slightly surpassed (1.5–1.6-fold). In order to monitor the effects of the different calcium supply, blood samples were taken during the trial and analysed for levels of macro and trace elements as well as concentrations of two bone markers. In Ca-Moderate a trend towards higher phosphorus serum levels compared to Ca-High was observed which was significant at the end of the trial (p = 0.0002). Furthermore, results showed no influence of the diet on bone markers. Results support the idea that forage-based rations for horses do not necessarily have to be supplemented with macro minerals but with trace elements.

Effect of the physicochemical properties of zinc oxide sources on their bioavailability in broilers

1. The bioavailability of a trace mineral source is related to its intestinal solubility (bioaccessibility), which in turn is determined by its physicochemical properties. It is still not clear which characteristics are more relevant in affecting solubility and bioavailability of mineral sources. Zinc oxide (ZnO) is a common feed additive used to supplement zinc in the diet of monogastric animals. However, different sources have shown variable responses on animal bioavailability.2. This study hypothesised that different sources of feed grade ZnO have various physicochemical features that lead to distinct bioavailability values. Feed grade ZnO samples collected from the feed industry worldwide were characterised for their physicochemical features and tested in broilers to allow bioavailability determined.3. A total of 135 male Cobb broiler chickens were fed a standard starter diet from day 1 after hatching up to d 7. At d 8, animals were allocated in individual cages and fed one of the following dietary treatments during 15 days: a basal diet with 23.5 ppm of zinc and seven test diets with supplemented ZnO or zinc sulphate (ZnSO₄) at 6 or 12 ppm.4. Different sources of ZnO showed an effect of solubility in the stomach and supplementation influenced total Zn levels in the ileum. The bioavailability of the different sources varied from 49% to 160% in relation to ZnSO₄. Aggregate size of particles seems to explain most of the variability in the bioavailability of the different sources tested in broilers. In conclusion, physicochemical properties of ZnO can partly explain the variability observed in terms of biological value.

Effect of replacing inorganic trace minerals at lower organic levels on growth performance, blood parameters, antioxidant status, immune indexes, and fecal mineral excretion in weaned piglets

Organic trace minerals (OTMs) have the potential to replace inorganic trace minerals (ITMs), but the degree to which the dietary levels can be reduced is not well defined. This study aimed to investigate the effect of replacing of ITMs with lower levels of OTMs on growth performance, blood parameters, antioxidant status, and immune indexes in weaned piglets. The experiment was conducted in a subtropical city in Guangdong Province in South China (subtropical climate) from July to September 2018. A total of 600 pigs with an average initial BW of 8.90 kg were allotted by gender and weight to 5 treatments with 6 replicate pens per treatment. Experimental treatments: (A) Control group (a basal diet with iron, copper, manganese, and zinc from sulfates and sodium selenite providing commercially utilized levels in China of 150, 25, 40, 150, and 0.5 mg/kg, respectively). (B) 1/2 ITM group (inorganic trace minerals providing 1/2 control group levels). (C) 1/2 OTM group (1/2 control group trace mineral levels with manganese, iron, zinc, and selenium from Sel-Plex® and Cu from Bioplex®). (D) 1/3 ITM group (1/3 control group trace mineral levels from inorganic forms). (E) 1/3 OTM group (1/3 control group trace mineral levels from organic forms). The results suggest no significant effects of trace mineral sources or levels, on average daily gain (ADG) and average daily feed intake (ADFI) among different treatments during the entire experiment. The level of zinc in serum was significantly decreased in the 1/3 ITM group. The 1/3 OTM group had a significantly higher (P < 0.05) immunoglobulin G (IgG) level in serum. Fecal mineral excretion decreased significantly (P < 0.05) when decreased dietary levels of trace minerals were included at 1/2 and 1/3 levels regardless of sources. Fecal concentrations of zinc excretion were lower (P < 0.05) with 1/2 OTM supplementation than 1/2 ITMs. The present study shows that replacing high doses of ITMs with low concentrations (1/3) of OTMs does not adversely affect the growth performance of piglets. At low levels, total replacement of ITMs with OTMs improved IgG and reduced fecal excretion of copper, zinc, iron, and manganese, thereby mitigating environmental pollution.

Effects of two zinc supplementation levels and two zinc and copper sources with different solubility characteristics on the growth performance, carcass characteristics and digestibility of growing-finishing pigs

The present study was conducted to evaluate the effect of two Zn supplemented levels and two Zn and Cu sources (sulphate and hydroxychloride) on growing-finishing pigs. An in vitro study and an in vivo study were conducted. In the in vitro study, Zn solubility from each source at different Zn supplementation levels was evaluated, as well as the phytic phosphorus (PP) solubility derived from the interaction or not with phytic acid at similar conditions to those found in digestive tract. The most critical interaction of Zn with phytic acid was at pH 6.5 and with Zn sulphate, resulting in the reduction in PP solubility. In the in vivo experiment, a total of 444 pigs ([Duroc × Landrace]×Pietrain; initial BW: 18.7 ± 0.20 kg) were allotted to 36 pens in a randomized complete block design (2 × 2) factorial arrangement with two Zn and Cu sources and two Zn supplemental levels (20 and 80 mg/kg). The Cu supplementation was fixed at 15 mg/kg for all diets. There was no effect of the interaction between mineral source × Zn level or Zn level on growth performance or carcass characteristics (p > .10). Apparent total digestibility of Zn and Cu along with carcass yield was higher for pigs fed hydroxychloride than pigs fed the sulphate counterparts (p < .05). Feeding low levels of Zn decreased Zn (45.5%; p < .0001) and Cu(18.5%; p = .018) faecal excretion. In conclusion, under commercial conditions, feeding growing-finishing pigs with Zn levels below those established by the European Union regulation did not affect growth performance and carcass characteristics. Reducing dietary mineral (Zn and Cu) diet content resulted in a lower faecal mineral excretion. Pigs fed sulphate minerals had an improved performance during grower period, while pigs fed hydroxychloride minerals showed an improved performance during finishing period and a greater carcass yield and mineral digestibility than those fed sulphates.

Zinc Supplementation Forms Influenced Zinc Absorption and Accumulation in Piglets

The study aimed at determining the effect of different zinc (Zn) supplementation forms on Zn accumulation, activities of Zn-containing enzymes, gene expression of metallothionein (MT), and Zn transporters in piglets. Eighteen piglets were randomly divided into three groups: (a) a basal diet supplemented with 150 mg/kg Zn from Zn methionine (Zn-Met) in the feed (Zn-Met group), (b) a basal diet supplemented with 150 mg/kg Zn from Zn sulfate (ZnSO₄) in the feed (ZnSO₄, _feed group), and (c) a basal diet supplemented with the same dose of Zn as in ZnSO4,_feed group but in water (ZnSO₄, _water group). The results showed that Zn-Met added in feed and ZnSO₄ dissolved in drinking water significantly improved (p < 0.05) the Zn concentration in liver and jejunum and the apparent digestibility of Zn in comparison with the ZnSO₄ added in feed. In addition, dietary Zn supplementation as Zn-Met significantly increased (p < 0.05) the activity of alkaline phosphatase (AKP) in the jejunum of piglets in comparison with the ZnSO₄, _feed group. Furthermore, the Zn-Met and ZnSO₄, _water groups showed an improved total superoxide dismutase activity (T-SOD) in the ileum as compared to the ZnSO₄, _feed group. Meanwhile, the qPCR and western blot results showed that Zn-Met and ZnSO₄ dissolved in drinking water increased the expression of MT in the jejunum in comparison with the ZnSO₄ added in the piglets' feed. However, different Zn supplementation forms had no effect on the mRNA expressions of Zip4 and ZnT1 transporters. In conclusion, Zn-Met added in feed and ZnSO₄ dissolved in drinking water had higher bioavailability in piglets.

Effect of L-glutamic acid N,N-diacetic acid on the availability of dietary zinc in broiler chickens

Chelating agents can be used to improve the nutritional availability of trace minerals within the gastrointestinal tract. This study was conducted to determine the effect of a novel chelating agents, L-glutamic acid N,N-diacetic acid (GLDA), a biodegradable alternative to ethylenediaminetetraacetic acid on the nutritional bioavailability of zinc in broilers. Twelve dietary treatments were allocated to 96 pens in a randomized block design. Pens contained 10 Ross 308 male broilers in a factorial design with 6 incremental zinc levels (40, 45, 50, 60, 80, and 120 ppm of total Zn), with and without inclusion of GLDA (0 and 100 ppm) as respective factors. Experimental diets were supplied from day 7 to 21/22 and serum, liver and tibia Zn content were determined in 3 birds per pen. Growth performance and liver characteristics were not affected by dietary treatments, but both supplemental Zn and GLDA enhanced tibia and serum zinc concentration. The positive effect of GLDA was observed at all levels of the dietary Zn addition. The amount of zinc needed to reach 95% of the asymptotic Zn response was determined using nonlinear regression. When GLDA was included in the diet, based on tibia Zn, the same Zn status was achieved with a 19 ppm smaller Zn dose while based on serum Zn this was 27 ppm less Zn. Dietary GLDA reduces supplemental Zn needs to fulfill nutritional demands as defined by tibia Zn and serum Zn response. Considering the positive effect on the nutritional availability of Zn in broilers, GLDA presents an opportunity as biodegradable additive, to reduce Zn supplementation to livestock and thereby reducing Zn excretion into the environment, while fulfilling the nutrition Zn needs of farmed animals.

Comparative digestibility of polysaccharide-complexed zinc and zinc sulfate in diets for gestating and lactating sows

We hypothesized that the digestibility of a zinc polysaccharide complex is greater than zinc sulfate when sows consume high fiber diets containing corn dried distillers grains with solubles (DDGS). Gilts and sows (n = 32) were blocked according to parity and assigned randomly to one of four dietary treatments (n = 8 sows per treatments). Dietary treatments consisted of: 1) Control (ConZnSO4)-corn-soybean meal-based diet + 100 ppm supplemental Zn from ZnSO4; 2) Control PSZn (ConPSZn)-corn-soybean meal-based diet + 100 ppm supplemental Zn from Zn polysaccharide complex; 3) DDGS/ZnSO4-corn-soybean meal-40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from ZnSO4; 4) DDGS/PSZn-corn-soybean meal-40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from Zn polysaccharide complex. A fifth dietary treatment was imposed using a subset of sows (n = 20) to determine basal Zn losses in gestating and lactating sows fed corn-soybean meal-based diets containing no supplemental Zn. Nutrient balance experiments were conducted in both gestation and lactation to evaluate the digestibility of Zn sources of the four dietary treatments and to determine basal Zn losses when no supplemental Zn was provided. The statistical model included fixed effects of diet, Zn source, and their interaction, and random effects of parity. Estimated endogenous losses of Zn were used to adjust apparent total tract digestibility (ATTD) to true total tract digestibility (TTTD) of Zn in the four dietary treatment balance periods. There were no differences in Zn concentrations of urine, plasma, colostrum, or milk samples among treatments at any time of the experiment (P > 0.05). Gestating sows fed DDGS/PSZn had improved (P < 0.05) ATTD, TTTD, and overall retention of Zn compared with both Control treatments, with the DDGS/ZnSO4 treatment responses being intermediate. Lactating sows consuming diets without DDGS and supplemented with Zn polysaccharide complex had the greatest (P < 0.05) ATTD, TTTD, and retention of Zn, which were opposite to responses observed in gestation. Furthermore, ATTD, TTTD, and Zn retention for lactating sows consuming DDGS/PSZn were less (P < 0.05) than all other treatments. Overall, zinc digestibility of ZnSO4 and PSZn appears to be differentially influenced by the stage of the reproductive cycle and presence of dietary fiber from DDGS.

Effect of Zinc Source and Exogenous Enzymes Supplementation on Zinc Status in Dogs Fed High Phytate Diets

Zinc is an essential element, a cofactor of many enzymes, and performs catalytic, structural and regulatory functions. Once in the gastrointestinal tract, zinc can interact with food constituents. Phytic acid, the major phosphorus storage in plants, limits zinc availability from animal feeds due to the formation of insoluble complexes with phytates. This study tested the effect of supplemental zinc source (zinc sulfate and a chelate zinc proteinate) and the addition of exogenous enzymes from a solid-state fermentation product of Aspergillus niger to a high phytate diet. The study was designed according to three Latin Squares 4 × 4 with a 2 × 2 factorial arrangement of treatments, with four periods, four diets, and 12 young adult Beagles. Periods lasted 5 weeks each. Diets were supplemented with 75 mg/kg of zinc sulfate (IZ) or zinc proteinate (OZ), and without or with 200 mg/kg of exogenous enzymes (IZ+, OZ+). Results showed that zinc proteinate increased the bioavailability of phosphorus, yet the zinc biomarkers remained unaffected by the zinc source, with the exception of lymphocyte subsets that benefit from zinc proteinate. The use of exogenous enzymes did not affect zinc availability nor nutrient and energy digestibility.

Dietary Calcium to Digestible Phosphorus Ratio for Optimal Growth Performance and Bone Mineralization in Growing and Finishing Pigs

Simple Summary

Minimizing the use of dietary non-renewable mineral phosphates improves the sustainability of phosphorus use in growing-finishing pigs. As the phosphorus metabolism is closely linked to calcium, this experiment compared three dietary calcium to digestible phosphorus ratios within two phosphorus levels to determine the optimum levels for growth performance and bone mineralization. The lowest calcium level was insufficient for an efficient metabolic use of P, the medium level was sufficient to maximize growth performance and highest level further improved bone mineralization. The low digestible phosphorus level enabled a complete removal of supplemented mineral phosphates in the finisher period, which resulted, per pig, in a decrease of its use by 65% and a decrease of the calculated P excretion by 41%, without impaired growth performance. However, a reduced bone mineralization was observed. This study shows that there is potential to reduce the digestible phosphorus compared to practiced levels in grower–finisher pigs and shows that the optimal calcium to digestible phosphorus ratio needs to be maintained at the upper range of the actually available recommendations.

Abstract

Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P–) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P– diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P– reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P– without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

Effect of immobilized fungal phytase on growth performance and bone traits of broilers fed with low dietary calcium and phosphorus

AIM

The aim of this study was to investigate the effects of phytase which was laboratory produced by Aspergillus foetidus on the growth performance, mineral retention, and bone traits of broilers fed with low dietary calcium and phosphorus.

MATERIALS AND METHODS

The extracellular phytase enzyme secreted into the crude filtrate was concentrated by ammonium sulfate precipitation to obtain an activity of 500 phytase units (FTU). A total of 90 1-day-old chicks (Cobb 500) were randomly divided into three treatment groups with five replicates having six birds each. Dietary treatment, T1, was with 0.45% non-phytate P (NPP) during starter and 0.40% during finisher phase with 1% Ca. Dietary treatment, T2, had 0.37% NPP during starter and 0.32% in finisher phase with 1% Ca and supplemental lab phytase at 500 FTU/kg. Dietary treatment, T3, was similar to T2 with a lower Ca of 0.8%.

RESULTS

There was no significant difference among the dietary treatments with regard to body weight gain, feed intake, feed conversion ratio, and Ca retention (p>0.05). However, a significant improvement in retention of P by birds was observed in phytase supplemental groups T2 and T3 (p<0.05). Dry weight of tibia (2.58-2.78 g/kg live weight) and ash content (39.7-41.8%) was comparable among treatments. A similar trend was observed for bone Ca, P, and Mn content.

CONCLUSION

The study indicated that 500 FTU/kg phytase can be effectively supplemented in a broiler diet with low phosphorus (0.37% in starter and 0.32% NPP in finisher diet) and low calcium (0.8% in diet) for better growth performance and with successful replacement of dietary P by 0.08 % and reduced P excretion into the environment in broiler chicken.

Effects of zinc oxide nanoparticles on the egg quality, immune response, zinc retention, and blood parameters of laying hens in the late phase of production

The objective of this study was to evaluate the effects of dietary supplementation with zinc oxide nanoparticles (ZnO-NPs) on the performance, egg quality, Zn retention, immunity responses, superoxide dismutase activity (SOD), egg malondialdehyde (MDA) content, and serum parameters in laying hens in the late phase of production. A total of 288 laying hens at 64 weeks of age were randomly assigned to 4 treatments with 6 replicates, and 12 birds within each group. Experimental diets included a corn-soybean meal-based diet (without Zn supplementation) and a basal diet supplemented with 80 mg/kg of Zn-oxide, ZnO-NPs, and Zn-methionine. The results indicated that egg production and egg mass were significantly higher in the Zn-methionine and ZnO-NPs groups (p < .05). Also, eggshell thickness and shell strength increased in the ZnO-NPs group as compared with the other groups (p < .05). Moreover, Zn supplementation decreased egg loss (p < .05). There were significant differences among treatments in Zn deposition in tibiotarsus, liver, pancreas, eggs, and excreta (p < .01). Antibody titre, heterophil (%(, and phytohemagglutinin (PHA) were significantly higher in birds fed with Zn-supplemented diets (p < .05). In treatments supplemented with ZnO-NPs and Zn-methionine, the SOD activity in the liver, pancreas, and plasma was greater as compared with the other treatments (p < .05). The MDA content in eggs was significantly reduced in groups supplemented with Zn (p < .01). Moreover, dietary Zn supplementation significantly affected serum total protein, albumin, glucose, alkaline phosphatase activity, carbonic anhydrase activity, and Zn level (p < .05). In conclusion, this study demonstrated that dietary supplementation with ZnO-NPs can improve the performance of laying hens. Therefore, ZnO-NPs can enhance zinc absorption in the intestine of aged layers and can be a more suitable source of zinc than regular Zn-oxide in diets.

Subsequent somatic axis and bone tissue metabolism responses to a low-zinc diet with or without phytase inclusion in broiler chickens

Zinc is required for normal bone development and cartilage formation. The purpose of this study was to assess the effect of with adding organic Zn (alone or phytase inclusion) at the reduced dose to growing male Ross 308 chickens on somatic axis and bone tissue metabolism. 200 one-day old broilers were divided into the negative control group fed diet without Zn or phytase inclusion, positive control group receiving Zn in the 100% of daily recommended dose from ZnO, and two experimental groups fed diet introduced Zn in 25% of daily recommendation as a glycine chelate (Zn-Gly) with or without phytase inclusion (500 FTU·kg-1). Supplemental organic Zn increased bone Zn and Mg content, serum IGF-1, growth hormone and leptin concentration. Additional phytase inclusion increased body weight gain, blood plasma Ca, Fe, Zn and osteocalcin concentration and tibia ash percentage when compared to the Zn-deprived control. Bone geometry, yield and ultimate strengths were enhanced in both organic Zn supplemented groups, and the overall mechanical strength parameters of bone were better in these groups than in the positive control group supplemented with standard dose of inorganic Zn. Also marked improvements in the thickness of articular and the growth plate cartilages as well as real bone volume and thickness of metaphyseal trabeculae were achieved in all broilers fed Zn-supplemented diet irrespective of phytase inclusion, however, the highest cancellous bone mass and the best trabecular structure were noted after ZnO supplementation. In concludion, although dietary organic Zn given to growing broilers in 25% of daily recommended dose improved general bone properties and mechanical strength, the obtained results do not allow to unambiguously state that organic Zn supplementation at this level, even after phytase inclusion, is sufficient for proper bone development.

Intestinal fate of dietary zinc and copper: Postprandial net fluxes of these trace elements in portal vein of pigs

In pig, the assessment of bioavailability of dietary trace minerals with classical approaches such as relative bioavailability estimates or digestive tract balances have often generated inconsistent responses. In the present study, net portal-drained-viscera fluxes were monitored after a meal to assess intestinal absorption of zinc (Zn) or copper (Cu) according to dietary sources and levels of these trace minerals. Twelve pigs were surgically equipped with portal and carotid catheters and a portal ultrasonic flow probe for 12-h postprandial measurements. In a cross-over design, pigs received boluses of inorganic (I) or organic (O) dietary Cu and Zn at adequate (A, 20 and 200mg, respectively) or high (H, 40 and 400mg, respectively) level just before a 0.8-kg meal (semi-purified diet). Whatever treatments, arterial Zn increased by 72% at 45min postprandial and gradually declined thereafter (P<0.01). Arterial Zn were greater by 11% after O than I (P=0.02) and by 19% after H than A (P<0.01) meals. Net portal-drained-viscera fluxes of Zn during the first 240min postprandial were greater by 44% after O than I (P=0.10) and by 51% after H than A (P=0.07) meals. For Cu, portal-drained-viscera fluxes of Cu up to 240min postprandial were greater (P=0.03) after A than H meals. Those results suggest that Zn is absorbed rapidly, likely in the upper digestive tract of pigs and, whatever dietary levels, more efficiently after O meals. It appears that H levels of both Zn and Cu interfered with intestinal absorption of Cu and/or stimulate post-absorption enterocyte sequestration of this mineral.

The Expression of Zinc Transporters Changed in the Intestine of Weaned Pigs Exposed to Zinc Chitosan Chelate

This study was conducted to investigate the effect of zinc chitosan chelate (CS-Zn) on zinc transporter expression and content of tissue zinc in weaned piglets. A total of 90 weaned pigs (Duroc × Landrace × Yorkshire) were randomly allocated to treatment groups with supplementation of 100 mg/kg zinc as ZnSO₄, 100 mg/kg zinc as mixture of ZnSO₄ and chitosan, or 100 mg/kg zinc as CS-Zn, respectively. After 30 days of trial, 18 piglets (six pigs per treatment) were killed and the samples of duodenal mucosa were taken for analysis of zinc transporter mRNA expressions and protein abundance. The results show that CS-Zn more effectively increases (p < 0.05) the average daily gain (ADG) and serum zinc concentration. Zinc concentration in the liver and kidney did not differ between treatments. The mRNA expressions of ZnT1, ZIP4, and ZIP5 in CS-Zn treatment were all upregulated (p < 0.05) than ZnSO₄ or mixture of ZnSO₄ and chitosan groups. ZnT1 abundance was greater (p < 0.05) with CS-Zn as compared with ZnSO₄ and mixture of ZnSO4 and chitosan treatments, whereas ZIP4 and ZIP5 abundance was higher (p < 0.05) in ZnSO4 group. The results indicate that CS-Zn is more effective in serum zinc accumulation, and it might regulate zinc homeostasis by affecting zinc transporter mRNA expression and absorption mechanism might be different with ZnSO_4.

Zinc methionine and laminarin have growth-enhancing properties in newly weaned pigs influencing both intestinal health and diarrhoea occurrence

Three experiments were conducted to investigate the interaction between zinc methionine (ZnM) and laminarin (LAM) on piglet growth performance and intestinal health post-weaning. Experiment 1 was designed as 2 × 2 factorial with four treatments [n = 8, weaning age (WA) 24 days, live weight (LW) 7.15 kg]: (i) basal diet (BD); (ii) BD + 500 mg/kg ZnM; (iii) BD + 300 mg/kg LAM; and (iv) BD + 500 mg/kg ZnM + 300 mg/kg LAM. There was an interaction (p < 0.05) between LAM and ZnM. Pigs that were offered the LAM diet had a similar performance to the BD. However, when combining LAM with ZnM, pigs had reduced average daily gain (ADG), gain-to-feed ratio (G:F) and LW at slaughter at day 8 post-weaning compared to the ZnM. Both LAM and ZnM improved the small intestinal morphology of the pigs at day 8 post-weaning. Experiment 2 was designed as 2 × 2 factorial with four dietary treatments (n = 9, WA 24 days, LW 7.32 kg): (i) BD; (ii) BD + 500 mg/kg ZnM; (iii) BD + 175 mg/kg LAM; and (iv) BD + 500 mg/kg ZnM + 175 mg/kg LAM. The ADG and average daily feed intake were improved between day 0 and 31 PW when pigs were offered a LAM diet (p < 0.01). Faecal scores were reduced between day 0 and day 31 post-weaning with ZnM (p < 0.001). Experiment 3 consisted of four dietary treatments (n = 10, WA 24 days, LW 7.32 kg): (i) BD; (ii) BD + 3300 mg/kg zinc oxide (ZnO); (iii) BD + 500 mg/kg ZnM; and (iv) BD + 175 mg/kg LAM. Pigs that were offered the ZnO diet had an increased ADG compared to the BD or ZnM diets (p < 0.01). Pigs that were offered the LAM diet had increased ADG compared to the ZnM diet (p < 0.05). Faecal scores were reduced between day 0 and day 31 PW with ZnM or ZnO supplementation (p < 0.001). In conclusion, the inclusion of 175 mg/kg LAM and ZnO improved ADG while both ZnO and ZnM reduced the faecal scores post-weaning.

Comparative effects of zinc-nano complexes, zinc-sulphate and zinc-methionine on performance in broiler chickens

Micronutrients, especially zinc, have an important role in normal metabolism and growth of broilers. Using novel technologies helps to synthesise novel zinc complexes to deliver this micronutrient more efficiently. In the present study, the effects of different zinc complexes and nano complexes on broiler performance were compared. Broilers in 6 groups were given basal diet (without zinc) and basal diet supplemented with zinc-sulphate, zinc-methionine, zinc-nano-sulphate, zinc-nano-methionine and zinc-nano-max (that was synthesised based on nanochelating technology) at a concentration of 80 mg/kg of diet. At 1-42 d of age, dietary zinc-nano-sulphate supplementation decreased weight gain and feed intake. However, feed conversion ratio was not influenced by treatments. Carcass yield (%) of birds in the zinc-nano-sulphate and control groups were dramatically reduced at 42 d of age and abdominal fat (%) increased in these groups. Relative to the control group, the antibody titre, spleen and bursa of Fabricius (%) were significantly higher in groups supplemented with zinc. Heterophil (%) was also significantly higher in the zinc-nano-methionine group in blood on d 42 compared to the control, zinc-sulphate and zinc-nano-sulphate. Compared to the controls, the mean malondialdehyde content in thigh tissue was significantly reduced in groups supplemented with zinc at the time 0, 50, 100 and 150 min after oxidation. Tibia zinc concentration in nanoparticle zinc samples was significantly higher relative to the control and zinc-sulphate groups. Taken together, our data indicate that delivery of zinc in the structure of zinc-nano-methionine and zinc-nano-max at concentrations of 80 mg/kg of diet improves growth performance. However, dietary zinc-nano-sulphate decreased growth performance in broilers.

Multitrial analysis of the effects of copper level and source on performance in nursery pigs

A multitrial analysis was conducted to evaluate the effect of different levels of Cu from either Cu(2-hydroxy-4-(methylthio)butanoic acid [HMTBa])2 or CuSO4 on growth performance in nursery pigs. Six nursery trials were conducted from 2007 to 2012 under the same commercial conditions with initial BW of 5.75 ± 0.41 kg at 21 ± 3 d of age; the trials lasted for 42 d with a 3-phase feeding program (7 d in Phase I, 14 d in Phase II, and 21 d in Phase III). Diets were medicated with antibiotics and supplemented with 3,000 mg/kg Zn as ZnO during phases I and/or II. Treatments included a basal diet without added Cu or according to the NRC (1998) and supplemental levels of Cu (50 to 250 mg Cu/kg diet) from either Cu(HMTBa)2 or CuSO4; HMTBa was supplemented to make diets isomethionine. Treatments from each trial included 6 or 9 replicate pens/treatment with 22 to 25 piglets/pen. Mixed model analysis was conducted in which trial was considered a random effect, Cu level was considered a continuous fixed effect, and Cu source was a fixed effect. The basal diet within trial and statistical tests of the intercept between sources were not different, resulting in fitting a common intercept mixed model to the overall responses across phases. Cumulative ADG and ADFI quadratically responded (P < 0.05) with increasing Cu supplementation; predicted optimal ADG and ADFI occurred at 174 and 119 mg/kg, respectively. Increasing Cu supplementation linearly improved G:F (P = 0.054). No differences between sources were observed in ADG or ADFI. Numerically, pigs fed Cu(HMTBa)2 had higher ADG and lower ADFI compared to pigs fed CuSO4, resulting in better G:F for pigs supplemented with Cu(HMTBa)2 compared to pigs supplemented with CuSO4 (P < 0.01). The linear slope for increasing Cu supplementation on G:F was 2.1-fold higher for Cu(HMTBa)2 than that of CuSO4, with larger differences occurring in Phase II. In conclusion, Cu supplementation in nursery diets resulted in improved performance and Cu(HMTBa)2 is more effective than CuSO4 in improving feed efficiency.

Changes in diarrhea, nutrients apparent digestibility, digestive enzyme activities of weaned piglets in response to chitosan-zinc chelate

A total of 120 weanling barrows weighing 6.11 ± 0.20 kg were randomly allotted to four treatments with three replications (i.e. pen) of ten piglets per replicate. Pigs were received corn-soybean basal diet (control) or the same basal diet supplemented with the following sources of zinc: (i) 100 mg/kg of Zn as ZnSO4 ; (ii) 100 mg/kg of Zn as chitosan-Zn chelate (CS-Zn); and (iii) 100 mg/kg of Zn as ZnSO4 mixed with chitosan (CS + ZnSO4 ). The results showed that CS-Zn could highly improve average daily gain and average daily feed intake than those of ZnSO4 or CS+ ZnSO4 (P < 0.05). The pigs fed dietary CS-Zn had lower diarrhea incidence and higher apparent digestibility of crude protein than those of the pigs fed dietary ZnSO4 (P < 0.05). The protease activities in duodenal content of the pigs receiving CS-Zn diets was higher than that of the pigs fed dietary ZnSO4 or CS + ZnSO4 (P < 0.05). The amylase activity in duodenal content of the pigs fed dietary CS-Zn was higher than that of the pigs receiving ZnSO4 diets or basal diets (P < 0.05). These results indicated that dietary CS-Zn showed different bioactivities from ZnSO4 or CS + ZnSO4 in reducing the incidence of diarrhea, improving activities of digestive enzymes and growth performance of weaned pigs.

Effect of mineral source and mannan oligosaccharide supplements on zinc and copper digestibility in growing pigs

This study aimed to compare the effects of organic (proteinate) and inorganic (sulphate) copper (Cu) and zinc (Zn) supplements, in presence or absence of a mannan oligosaccharide (MOS) supplement, on mineral solubility and digestibility in pigs. Twenty-eight barrows (25 ± 4 kg) assigned randomly to four treatment groups were fed a corn-wheat-soya bean meal diet with 10 mg/kg of Cu and 100 mg/kg of Zn supplied as organic or inorganic supplement, and supplemented or not with 0.1% MOS. After an adaptation period, total faeces and urine were collected for a period of 6-7 days. Pigs were then euthanatised and digesta from ileum and caecum were collected. Apparent digestibility was calculated in ileum and caecum using titanium dioxide. The organic mineral supplement improved total (faecal) digestibility and retained/ingested ratio of Cu (p < 0.05) while reducing apparent digestibility of Zn in the ileum (p < 0.05) without effect on total digestibility of Zn. Solubilities of Cu and Zn in liquid fraction of ileum and caecum were not affected by mineral sources. Although MOS supplement increased Cu solubility in the ileum (p < 0.05), it had no effect on digestibility of Zn and Cu in ileum, caecum and faeces, retained/ingested ratio of Zn and Cu, or pH and volatile fatty acid concentration in ileal and caecal digesta. In conclusion, organic mineral supplement improved total digestibility and retained/ingested ratio of Cu in pigs but this cannot be attributed to its solubility in ileal and caecal digesta. The MOS supplement did not interfere with digestibility or dietary utilisation of Zn and Cu in pigs fed above the Zn and Cu requirements.

Effects of dietary zinc oxide nanoparticles on growth performance and antioxidative status in broilers

Broilers in four groups were fed a basal diet supplemented with 60 mg/kg zinc oxide (60-ZnO; control), or 20, 60, or 100 mg/kg ZnO nanoparticles (20-, 60-, and 100-nano-ZnO, respectively). Compared with the controls, after 14 days, birds in the 20- and 60-nano-ZnO groups had significantly greater weight gains and better feed conversion ratios. However, the body weight of birds in the 100-nano-ZnO group was dramatically reduced after 28 days. Relative to the control group, the total antioxidant capability (T-AOC) in serum and liver tissue was significantly higher in the 20-nano-ZnO group at all time points and also significantly higher in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues on days 21 and 28. Compared with the controls, the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD) was significantly greater in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues after 21 days. Catalase activity in serum samples was significantly higher in the 20- and 60-nano-ZnO groups relative to the control and 100-nano-ZnO birds, but catalase activity in liver tissue was not affected by different nano-ZnO levels. Malondialdehyde content in serum and liver tissues was significantly reduced in the 20-, 60-, and 100-nano-ZnO groups compared with that in the control group at all time points except day 42. Taken together, our data indicate that appropriate concentration of dietary ZnO nanoparticles improves growth performance and antioxidative capabilities in broilers, and 20 mg/kg nano-ZnO is the optimal concentration.

Effects of dietary supplementation of lipid-encapsulated zinc oxide on colibacillosis, growth and intestinal morphology in weaned piglets challenged with enterotoxigenic Escherichia coli

This study was aimed to evaluate the effect of dietary supplementation of lipid-encapsulated (coated) zinc oxide ZnO on post-weaning diarrhea (colibacillosis) in weaned piglets challenged with enterotoxigenic Escherichia coli (ETEC). Thirty-two 35-day-old weaned piglets were orally challenged with 3 × 10(10) colony forming units of ETEC K88 while eight piglets received no challenge (control). Each eight challenged piglets received a diet containing 100 ppm ZnO (low ZnO), 2500 ppm ZnO (high ZnO) or 100 ppm of lipid (10%)-coated ZnO (coated ZnO) for 7 days; control pigs received the low ZnO diet. Daily gain, goblet cell density in the villi of the duodenum, jejunum and ileum, and villus height in the jejunum and ileum, which decreased due to the challenge, were equally greater in the coated ZnO and high ZnO groups versus low ZnO group. Fecal consistency score, serum interleukin-8 concentration, subjective score of fecal E. coli shedding, and digesta pH in the stomach, jejunum and ileum, which increased due to the challenge, were equally low in the coated ZnO and high ZnO groups versus low ZnO. Results suggest that a low level of coated ZnO might well substitute for a pharmacological level of native ZnO in dietary supplementation to alleviate colibacillosis of weaned piglets.