Effects of Zinc Glycinate on Productive and Reproductive Performance, Zinc Concentration and Antioxidant Status in Broiler Breeders

Novel and safe debranched starch-zinc complexes with endoconcave structure as zinc supplements

Zinc deficiency is a serious risk to human health and growth, especially in children. The development of zinc supplements can effectively reduce this harm. Here, a series of debranched starch‑zinc complexes (DS-Zn) were prepared, whose zinc complexation was inversely proportional to the amylopectin content in the debranched starch (DS). The physicochemical properties of DS-Zn were characterized using the conductivity, XRD, iodine staining and thermogravimetry. Combined with XPS, solid-state 13C NMR and IR, it was elucidated that the structure of DS-Zn is endoconcave structure with 2-O and 3-O of DS on the inner side and 6-O of DS on the outer side, where zinc is located. The DS-Zn exhibits good biosafety including blood, cellular and mutagenicity. In vitro simulations of digestion and zinc-deficient cellular models showed that DS-Zn was more tolerant to the gastrointestinal environment and more effective in zinc supplementation (increased by 33 %) than inorganic zinc supplements. Utilizing the compressibility of starch, DS-Zn was prepared as a more palatable oral cartoon tablet for children. This study will provide important support to advance the development and application of novel starch-based zinc nutritional supplements.

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 (34.14 mg/kg Zn) to obtain 50 mg/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.

Effects of supplemental vitamin A on reproduction and antioxidative status of aged laying hens, and growth, blood indices and immunity of their offspring

The purpose of this investigation was to evaluate the impacts of vitamin A (VA) supplementation in feed at levels of 0 (control), 2,000, 4,000, 6,000, and 8,000 IU VA/kg diet on the reproductive efficiency and antioxidative properties of aged Sinai laying hens at 52 wk of age (n = 300 females and 30 males) in 6 replicates (10 females + 1 male/replicate). As well as blood biochemical indicators, carcass characteristics, growth performance, immunity, and the antioxidative status of their chicks. Results showed that diets supplemented with 2,000 or 6,000 IU/kg of VA increased fertility rate and decreased early embryonic mortality (P < 0.05). Increasing VA from 4,000 to 6,000 IU/kg significantly boosted hatchability rates. All VA levels significantly enhanced glutathione peroxidase (GPx) and reduced malondialdehyde (MDA) and late embryonic mortality. In the shell gland, dietary supplementation of 6,000 or 8,000 IU/kg of VA enhanced actions of GPx actions, catalase (CAT), and superoxide dismutase (SOD). In hatched chicks, all VA levels boosted (P < 0.05) hemoglobin, red blood cell count, and serum concentration of total proteins and IgA while decreasing eosinophils percentage and aspartate aminotransferase activity (AST) concentration. Dietary VA supplementations from 4,000 to 8,000 IU/kg improved lymphocytes, serum total antioxidant capacity (TAC), SOD, and IgM, while decreasing heterophils, heterophils/lymphocytes ratio, and creatinine in hatched chicks. Serum triglyceride concentration was reduced by adding 6,000 or 8,000 IU/kg of VA, while globulin and high-density lipoprotein concentrations were heightened only by 8,000 IU/kg of VA. It could be concluded that the dietary supplementation of VA (6,000 IU/kg) improved reproductive efficiency and antioxidative status in the liver and the shell gland of aged laying hens and improved hemato-biochemicals parameters, antioxidative status, and immunity of their offspring.

Complexed amino acid minerals vs. bis-glycinate chelated minerals: Impact on the performance of old laying hens

The present study was to evaluate the effect of trace minerals (Zn, Mn, and Cu) from complexed amino acid minerals (ZMCAA) and bis-glycinate chelated minerals (ZMCGly) in laying hen diets on performance, internal and external egg quality, yolk mineral deposition, intestinal morphometry, and bone characteristics. From 78 to 98 weeks of age, 400 White LSL-Lite strain laying hens were distributed in a randomized design with 4 treatments with 10 replicates per treatment. Treatments were distributed in a 2 × 2 factorial arrangement using either Zn, Mn, and Cu of ZMCAA or ZMCGly source at 2 levels: low (20, 20, and 3.5 mg/kg of Zn, Mn, and Cu, respectively) or high (40, 40, and 7 mg/kg of Zn, Mn, and Cu, respectively). The analysis of variance was performed, and in cases where differences were observed, the means were compared using Tukey's test (P < 0.05). The source and level of trace mineral supplementation had a significant impact on the performance of laying hens. Hens fed ZMCAA had higher egg production (P = 0.01), egg weight (P = 0.02), egg mass (P = 0.01), and lower feed conversion ratio (P = 0.05) compared to those fed ZMCGly. The ZMCAA supplementation showed higher albumen height (P = 0.01), albumen weight (P = 0.01), and eggshell thickness (P < 0.01). The deposition of Zn (P < 0.01), Mn (P < 0.01), and Cu (P < 0.01) in the egg yolk was greater for hens received ZMCAA. Tibia weight (P = 0.04) and bone densitometry (P < 0.01) in the tibia were higher with ZMCAA supplementation. In the small intestine, ZMCAA resulted in longer villi (P = 0.02) and shorter crypt depth (P = 0.01) in the duodenum. Jejunum and ileum measurements were influenced by the level and source of trace minerals (P < 0.05). Laying hens fed ZMCAA exhibited superior performance, egg quality, deposition of trace minerals in the egg yolk, and bone density compared to hens fed ZMCGly. In this study, older laying hens supplemented with ZMCAA at lower levels demonstrated adequate levels of supplementation.

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

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

The effects of chelated micro-elements feeding in broiler breeder hens and their progeny: A review

Micro-elements are essential for the optimal feeding of broiler hens. Since the chelated micro-elements negatively affect the content of micro- and macro-minerals, there has been a tendency to apply them as an alternative to common mineral forms of micro-elements in poultry diets. This paper reviews the effects of chelates of micro-elements (iron, copper, zinc, manganese, and selenium) on broiler breeder hens' internal and external egg quality and their egg products. The use of chelated micro-elements compared to the mineral forms does not have a significant effect on the performance of broiler breeder flocks, but they have significantly positive effects on the internal and external egg quality of broiler breeder flocks. The chelated micro-elements were also better than mineral resources of micro-elements in improving fertility (0.59%), hatchability (0.81%), and reducing mortality of progeny (2.25%). Chelated micro-elements have no negative impact on blood biochemistry or the immune system of broiler breeder hens and decrease cholesterol (0.84 mmol/l) and triglycerides (0.04 mmol/l) in most cases in comparison with the other mineral forms. Therefore, chelated forms of micro-elements instead of the inorganic mineral forms in diets of broiler breeder hens provide better protection for birds and the environment and also improve egg quality.

A perspective review on the effect of different forms of zinc on poultry production of poultry with special reference to the hazardous effects of misuse

Zinc (Zn) is a unique micro-mineral because it is an essential component in many enzymes such as superoxide dismutase, carbonic anhydrase, and alkaline phosphatase, as well as being important for regulation of proteins and lipids metabolism, and sex hormones. This mineral is applied in poultry production in three forms; inorganic, organic, and nanoparticle form. The nano-form of Zn is preferable in application to other conventional forms with regard to absorption, bioavailability, and efficacy. Broilers fed on diets supplemented with Zn showed improvement of growth performance, carcass meat yield, and meat quality. In addition, Zn plays an important role in enhancing of both cellular and humeral immune responses, beside its antimicrobial and antioxidant activities. In laying hens, dietary addition of Zn improves the eggshell quality and the quantity of eggs. Moreover, Zn has a vital role in breeders in terms of improving the egg production, fertility, hatchability, embryonic development, and availability of the hatched chicks. Therefore, this review article is focused on the effects of using Zn on the performance and immunity of poultry, as well as its antimicrobial and antioxidant properties with special reference to the hazardous effects of the misusing of this mineral.

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

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

The effect of Cu, Zn and Fe chelates on the antioxidative status of thigh meat of broiler chickens

The studies aimed to verify the effect of Cu, Zn and Fe glycine chelate on the antioxidative status in the thigh meat of broiler chickens. The study assumption was that due to the antioxidative or prooxidative effect of Cu, Zn and Fe, these elements supplemented to chickens in an easily assimilable form would modify the antioxidative status of meat and those having a prooxidative effect could deteriorate the quality of meat. The experiment involved three hundred and fifty Ross 308 chickens divided into seven equipotent experimental groups. Over 42 days of the experiment, the chickens were administered Cu, Zn and Fe glycine chelates in an amount corresponding to 50% of the requirement (experimental factor I) or 25% of the requirement (experimental factor II). The level of oxidative stress indicators such as superoxide dismutase, catalase, glutathione, glutathione peroxidase and malondialdehyde was determined in the muscles and blood. The groups receiving Zn or Cu chelate showed statistically confirmed higher activity of superoxide dismutase, catalase, and a higher level of glutathione in comparison to the group receiving Fe chelate. In order to increase the antioxidative stability of thigh meat, it is sufficient that broiler chickens receive Zn or Cu in the form of glycine chelate in an amount covering 25% of their requirement of such minerals. On the other hand, the use of Fe glycine chelates decreased antioxidative stability due to an increase in the level of malondialdehyde, so it should be considered whether the administration of pro-oxidative Fe chelate to broilers is advisable.

Zinc alleviates the heat stress of primary cultured hepatocytes of broiler embryos via enhancing the antioxidant ability and attenuating the heat shock responses

Zinc (Zn) has been shown to attenuate the adverse effects of heat stress on broilers, but the mechanisms involving this process remain unclear. We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress. Three experiments were conducted. In Exp. 1, hepatocytes were treated with 0, 50, 100, 200, or 400 μmol/L added Zn as inorganic Zn sulfate (iZn) for 12, 24 or 48 h. In Exp. 2, cells were exposed to 40 °C (a normal temperature [NT]) and 44 °C (a high temperature [HT]) for 1, 2, 4, 6, or 8 h. In Exp. 3, cells were preincubated with 0 or 50 μmol/L Zn as iZn or organic Zn lysine chelate (oZn) for 8 h under NT, and then incubated with the same Zn treatments under NT or HT for 4 or 6 h. The biomarkers of antioxidative status and heat stress in cells were measured. The results in Exp. 1 indicated that 50 μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes. In Exp. 2, the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes. In Exp. 3, HT elevated (P < 0.01) malondialdehyde content and expressions of heat shock protein 70 (HSP70) mRNA and protein, as well as HSP90 mRNA. However, Zn supplementation increased (P < 0.05) copper zinc superoxide dismutase (CuZnSOD) activity and metallothionein mRNA expression, and effectively decreased (P < 0.05) the expressions of HSP70 mRNA and protein, as well as HSP90 mRNA. Furthermore, oZn was more effective (P < 0.05) than iZn in enhancing CuZnSOD activity of hepatocytes under HT. It was concluded that Zn (especially oZn) could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.

Comparing the Influence of High Doses of Different Zinc Salts on Oxidative Stress and Energy Depletion in IPEC-J2 Cells

The current study aimed to investigate the influence of four supplemental zinc salts (chelated: Zn glycine; non-chelated: Zn sulfate, Zn citrate, Zn gluconate) among different zinc concentrations (30-300 μM) on cell proliferation, oxidative stress, and energy depletion in intestinal porcine jejunum epithelial cells (IPEC-J2). Different zinc salts affected cell viability in a time- and dose-dependent manner, which was mainly dependent on the uptake of intracellular Zn²⁺. Intracellular Zn²⁺ of Zn sulfate has taken up almost twice as high as Zn glycine when cells were loaded with 100-200 μM zinc. After loading cells with 300 μM zinc, Zn glycine and Zn sulfate had a similar trend in accumulation of Zn²⁺. When the intracellular Zn²⁺ overloads, cells will gradually be damaged and subsequently die bearing biochemical features of necrosis or late apoptosis. Meanwhile, obviously, increased levels of intracellular ROS, mitochondrial ROS, MDA, and NO and decreased levels of GSH were observed. Excessive intracellular Zn²⁺ significantly decreased mitochondria membrane potential accompanied by an obvious loss of ATP and NAD⁺ levels. Overall, exposure to high doses of zinc salts caused cell damage, which was mainly dependent on the uptake of Zn²⁺. Zinc overload induced oxidative stress and energy depletion in IPEC-J2 cells, and the cell damage with non-chelated zinc addition was more serious than Zn glycine.

Effects of inorganic trace minerals replaced by complexed glycinates on reproductive performance, blood profiles, and antioxidant status in broiler breeders

This study was conducted to investigate the effects of replacing inorganic trace minerals (ITM) with organic trace minerals (OTM; complexed glycinates) on reproductive performance, blood profiles, and antioxidant status in broiler breeders. A total of 648, 23-week-old healthy broiler breeders (ZhenNing), with similar body weight (1.40 ± 0.002 kg), were randomly divided into 4 groups with 6 replicates in each group (27 hens/replicate) and fed the respective experimental diets for 14 wk (including 2 wk for adaptation). The experimental treatments consisted of T1: Cont., commercially recommended levels of ITM (Cu, Zn, Fe, and Mn sulfates); T2: Mix, half trace minerals (TM) were provided from ITM and half from OTM (glycinates); T3: M-OTM, TM were provided from glycinates and reduced to 70% of T1; T4: L-OTM, TM were provided from glycinates and reduced to 50% of T1. The results showed that commercial level of inorganic trace minerals replaced by low-dose complexed glycinates (T3 and T4) exhibited no significant effects on laying performance, 50% ITM replaced by complexed glycinates (T2) numerically improved laying rate by 1.23% than cont. treatment (T1). Broiler breeders fed complexed glycinates tended to produce more qualified eggs (P = 0.05) in T3, with better yolk color (P < 0.01) and eggshell thickness (P = 0.05) in T2 treatment. Replacement of low-dose complexed glycinates reduced fertilization rate (P < 0.01), while it did not affect hatchability. There were no significant differences in serum reproductive hormones such as estrogen and progesterone among the treatments. Serum total protein, albumin, and phosphorus were increased respectively with the replacement of ITM by low-dose OTM from complexed glycinates (P < 0.05). Total liver antioxidant capacity in M-OTM and L-OTM treatment was higher than that of Cont. and Mix treatments (P < 0.01). In conclusion, replacement of high levels of ITM by lower levels of OTM in the form of complexed glycinates is beneficial for egg quality and liver antioxidant status in broiler breeders during the peak laying period.

Accurate quantification of metal-glycinates-sulphate complexes and free metals in feed by capillary electrophoresis inductively coupled plasma mass spectrometry

Traceability of metal-glycinate-sulphate complexes (Metal-GLY) in feed requires specific analysis to differentiate complexes from inorganic forms. A previously described method focused on the quantification of Metal-GLY at one single concentration but not on the quantification of free metal ion forms. The objective of this work was to extend the method to quantify both Metal-GLY and free metal ion forms of various metals at low inclusion levels. A 50/50 w/w mix of corn flour and soybean meal was used as feed. Copper-glycinate(Cu-GLY), Manganese-glycinate (Mn-GLY) and Zinc-glycinate (Zn-GLY) complexes (provided by Pancosma SA) were used for in-feed inclusions. The feed metal background concentrations and species repartitions were assessed. Cu-GLY was spiked on feed at levels matching 5, 15 and 45 mg/kg, corresponding to metal concentrations of 1.2, 3.6 and 10.8 mg/kg. Mn-GLY and Zn-GLY were spiked at 15, 45 and 100 mg/kg, corresponding to 3.3, 9.9, 22 mg/kg Mn and 3.9, 11.7, 26mg/kg Zn, respectively. The water soluble fraction of un-supplemented feed contained 0.06 mg/kg Cu, 0.05 mg/kg Mn and 0.12 mg/kg Zn, with 69.5% of Cu, 33.2% of Mn and 24.3% of Zn being present under free metal ions but 30.4% of Cu being present under Cu-GLY, 66.82% of Mn and 75.7% of Zn being present under Mn-GLY and Zn-GLY, respectively. The supplemented feeds at the 3 tested doses, from the lowest to the highest inclusion levels, contained in total respectively: 1.1, 3.05 and 9.06 mg/kg Cu; 2.99, 8.9 and 18.2 mg/kg Mn; 3.72, 10.9 and 23.4 mg/kg Zn. The M-GLY species recovered by analysis within the different supplemented feeds ranged from 76.26 to 89.32% for Cu-GLY, form 94.5 to 98.51% for Mn-GLY and from 76.05 to 98.96% for Zn-GLY. These results showed that CE-ICP-MS technique can be used to quantify low doses and to measure metal-species repartition between Metal-GLY and free metal ions, when included in feeds. For the first time, this study highlighted that the raw materials used contain Metal-GLY compounds. This raises the question of the occurrence of these compounds within the different raw materials used in feed production that could dramatically affect the way to supplement minerals in animal feed.

Optimization of Dietary Zinc Requirement for Broiler Breeder Hens of Chinese Yellow-Feathered Chicken

Simple Summary

China is the second-largest global producer of chicken meat, almost half of which is from the Chinese yellow-feathered breed; a systematic program has been initiated to improve its feeding standards. This study evaluated the optimal requirement of dietary zinc for maximal egg production, egg quality, tibial quality, and antioxidant indices of laying broiler breeders. The results revealed several beneficial effects of supplementary zinc on egg production, feed conversion ratio, yolk zinc content, tibial quality and the antioxidant indices in the serum, liver and ovary. The optimal zinc requirement was estimated based on a regression model.

Abstract

This study aimed to establish the optimal dietary zinc requirement of Chinese yellow-feathered Lingnan broiler breeders. A total of 576 breeder hens aged 58 weeks were randomly assigned to six treatments, each with 6 replicates of 16 birds (n = 96/treatment). The hens were fed either a basal diet (22.81 mg/kg Zn) or the same basal diet supplemented with additional 24, 48, 72, 96, and 120 mg Zn/kg up to 65 weeks of age. Compared to the results of birds fed the basal diet (22.81 mg Zn/kg), the dietary supplementation with additional Zn (mg/kg) showed higher egg laying rate (at 48–120 mg), EM (at 96 mg/kg), yolk Zn content (at 24–120 mg/kg), fertility (at 48–120 mg/kg), hatchability (at 48–96 mg/kg), tibial breaking strength (at 24–48 mg/kg), tibial ash content (at 48 mg/kg), serum CuZnSOD activity (at 72 mg/kg) and T-AOC (at 48 mg/kg), and ovarian CuZnSOD and GSH-Px activities (at 96–120 mg/kg), and lower FCR (at 96 mg/kg). The regression model showed that the optimal supplemental Zn for maximal egg laying rate, yolk Zn content, fertility, and hatchability of Chinese yellow-feathered broiler breeders aged 58 to 65 weeks were 71.09, 92.34, 94.44 and 98.65 mg/kg diet, respectively.

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

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

Nutritional requirements of meat-type and egg-type ducks: what do we know?

The demand for duck meat, duck eggs, and associated products is increasing each year. Classic and modern selection programs have been applied to enhance the economic traits of ducks to satisfy the requirements of consumers and enhance the incomes of producers. The nutritional requirements of unselected ducks may not be adequate, however, to fulfill the potential productivity performance of modern birds, including both meat-type and egg-type ducks. In particular, an imbalanced diet is associated with low productive performance and signs of nutritional deficiency (if insufficient nutrients are supplied), as well as with high feed costs and manure problems that reflect flock health and welfare (if excessive nutrients are supplied). Thus, the main aim of this review is to summarize the results of previous studies that estimated the nutrient requirements of meat-type and egg-type ducks in order to evaluate current knowledge and to identify further issues that need to be addressed. In addition, the results obtained in previous studies are compared in order to understand how to lower commercial feed costs, fulfill the genetic potential of selected ducks, protect the environment from pollution, and satisfy the welfare and health needs of ducks.