Comparative Studies On Adsorption Of Different Zinc Sources And Iron Sources In The Broiler

Amino acid chelated trace element, as the third generation of trace element additives, has many advantages, such as high biological and absorption rate, stable chemical structure, capable of increasing immunity, environmental protection, etc. Amino acid chelated trace element is currently a hot research and development application at home and abroad and a focus trace element animal in science. The above features were explained by scientists according to competitive absorption hypothesis and complete absorption hypothesis. So far, absorption mechanism of amino acid chelated trace element is still a "black box". In this experiment, the animal is broiler. The combination of synchrotron radiation μ-XRF and μ-XAFS technique were utilized in situ ligation and natural feeding, which purpose was to determine amino acid chelated zinc (iron) state, distribution in intestinal wall to explore amino acid chelated zinc (iron) absorption mechanism in the gut, and research influence of different factors impact on the amino acid chelated zinc (iron) absorption in the duodenum of broilers, according to μ-XRF mapping. According to measuring duodenal zinc concentration, MT concentration, related blood biochemical, related activity, the relative expression of related gene mRNA, the effect of amino acid chelated zinc absorption was explored in the broilers.Experiment1was performed to study the absorption characteristic and mechanism of different zinc sources in the duodenum of broilers.Experiment selects75AA broilers. Experiment was designed using single factor test completely randomized design. Five groups were ZnSO4group, ZnO group, ZnLys group, ZnMet group, Control group. Each treatment was repeated5times using3birds. Each chicken duodenum was used in situ ligation of a duodenal duplication. Perfusion fluid was40μg/mL zinc content of different zinc sources3mL, perfusion time30min. After the test, taking the middle bowel and small bowel mucosa, other relevant indicators of samples were analyzed.The results show that:(1) μ-XRF scan slices of duodenal wall fluorescence spectra of two dimensional. Zinc concentration of different zinc sources distribution was uneven in the intestinal wall. However, zinc content of perfusion four different zinc sources was higher than control group in the intestinal wall from four different zinc sources perfusion mapping. It is obviously high zinc content of each color image was concentrated in a specific region. This specific region was the main zinc absorption area in the intestinum. The amino acid chelated zinc had a higher zinc levels than inorganic zinc group in the specific region. ZnMet group had the highest zinc content. ZnO group had the lowest zinc content. This indicted amino acid chelated zinc had higher zinc content than inorganic zinc.(2) With respect to the XAFS absorption spectrum for4different zinc source. Zn K-edge absorption energy ranges were similar. This shows that the four kinds of zinc source valence were the same. There were significant differences in the absorption values of XAFS spectra. With respect to energy and local structure, the zinc environments of four zinc sources were different, and their compositions were also significantly different. However, according to zinc absorption the most amount area of μ-XRF mapping two-dimensional imaging determined μ-XAFS spectra for4different zinc sources, the μ-XAFS spectra of zinc element in the highest absorption areas for zinc sources were basically same in the intestinal wall. The shapes of the curves behind the absorption peak were similar for the4zinc sources. These indicated that organic zinc and inorganic zinc chemical state of zinc were absorbed in the intestinal wall were similar, the local structure of zinc were same. It showed different zinc sources had a same state in intestinal wall specific region.(3) Amino acid chelated zinc (ZnMet, ZnLys) groups duodenal gut sac zinc content, duodenal MT content, MT duodenal mucosa and ZnT1mRNA relative expression levels were significantly higher than that of inorganic zinc source (ZnO, ZnSO4) treatment groups (P<0.05).Experiment2was performed to study feed factors affect on zinc absorption about zinc sources in the duodenum of broilers.Experiment selects240AA broilers. Experiment was designed using two factor test completely randomized design (4x3). Four groups were ZnSO4group, ZnO group, ZnLys group, ZnMet group. The perfusion fluid was different zinc source solutions with40μg/mL zinc content3mL and the perfusion time was30min. Different levels of effect factors (phyticacid, Ca, citrate, histidine) were added to the test. Effect factors had three levels. Each treatment was repeated5times using1bird. Each chicken duodenum was used in situ ligation of a duodenal duplication. After the test, take the middle intestine duodenum analyze relevant indicators.The results showed that:(1) The higher levels of phytic acid, the amino acid chelated zinc groups were no significant difference (P>0.05), and zinc content was less affected by phytic acid level. Inorganic zinc source groups duodenum zinc content were significantly lower (P<0.05). Zinc sources and levels of phytic acid were significant interaction (P<0.05).(2) Highest levels of Ca, inorganic zinc groups duodenal zinc content was significantly lower (P<0.05). Zinc sources and levels of calcium on zinc absorption in the duodenum had no significant difference (P>0.05).(3) Zinc sources had a significant effect on broiler duodenum zinc content (P<0.05). Levels of citric acid and zinc sources were no significant interaction (P>0.05).(4) The inorganic zinc sources groups duodenum zinc content were significantly increased by adding histidine levels (P<0.05). However, the amino acid chelated zinc source groups zinc content in the duodenum (P<0.05). Zinc sources and histidine levels were significant interaction (P<0.05).Experiment3was natural feeding experiment of different zinc sources. Sixty AA broilers were selected in this experiment, which adopts one-factor completely random design. A total of four treatment groups were zinc sulfate group, zinc oxide group, the zinc lysine group and methionine zinc group respectively. Each group includes5replications and each replication consists of3broilers. At the end of the experiment, take the duodenum intestines, liver, pancreas, breast, leg, tibia and other related samples to analyze relative indicators.The results showed that zinc contents in blood, liver and tibia of zinc amino acid chelate groups were significantly higher than those of the inorganic zinc treatment groups (P<0.05). The effects of zinc amino acid chelate groups and inorganic zinc groups on the liver and pancreas metallothionein had no significant difference. Compared with inorganic zinc groups, the liver alkaline phosphatase of zinc amino acid chelate groups increased significantly (P>0.05). In the zinc amino acid chelate group, the liver copper-zinc superoxide dismutase of zinc methionine group was significantly higher than that of the other three groups, with significant differences (P<0.05). Treatment groups of different zinc sources had little effect on the morphology of broiler duodenum, with no significant difference. Compared with inorganic zinc (ZnSO4, ZnO) treatment group, the MT and ZnT1mRNA expression of zinc amino acid chelate (ZnMet, ZnLys) group increased significantly, with significant difference (P<0.05). According to duodenal gut sac zinc k-edge μ-XAFS spectra, zinc absorption value k-edge μ-XAFS spectra of4different zinc sources were basically consistent. Among different zinc sources, the zinc in duodenal gut sac was absorbed as the same form, which is divalent zinc ion. But the peak was significantly different. The Zn K-edge absorption peak from top to down was ZnMet, ZnLys, ZnSO4and ZnO, indicating that the relative concentrations of zinc absorption of organic zinc-treated group was significantly better than that of inorganic zinc group. ZnMet treatment group had the maximum value of zinc absorption, and ZnO treatment group had the minimum value of zinc absorption.Experiment4was performed to study the absorption characteristic and mechanism of different iron sources in the duodenum of broilers.Seventy AA broilers were selected in this experiment, which adopts one-factor completely random design. A total of five treatment groups were FeSO4group, Fe-Gly(II) group, FeCl3group, Fe-Gly(III) group and control group respectively. Each group includes5replications and each replication consists of3broilers. And each broiler’s duodenum was regarded as a replication of intestine in situ ligation. The perfusion fluid was different iron source solutions with40μg/mL iron content3mL and the perfusion time was30min. After the experiment, remove the intestinal segments and clean inside. Then quickly put them in liquid nitrogen for storage to determine the spectroscopy of synchrotron radiation μ-XRF and μ-XAFS.The results showed that:(1) According to μ-XRF two-dimensional spectra for duodenal wall. The amount and distribution of Fe in the duodenal wall were uniform. However, Perfusion Fe groups had more quantity Fe in the duodenal wall from Perfusion foure Fe groups mapping had perfusion groups without Fe. Fe absorption and accumulation areas mainly concentrated in a specific region for each figures. This area is the main area for intestinal iron absorption. Two iron groups had a more absorption than three iron source in the specific area, and Fe-Gly(II) was the highest levels in the specific area. It is showed that two iron source (FeSO4, Fe-Gly(II)) had a better absorption than three iron source.(2) With respect to the XAFS absorption spectrum for4Fe sources:K-edge absorption values of XAFS spectra were different energy range. It is showed that local structure and energy range were significantly different. So, the results indicate that there were different valences. K-edge absorption values of XAFS spectra for two valent iron source and three valent iron sources were significantly different. It can significantly distinguish ferrous and ferric from the near edge absorption values. According to Fe absorption the most amount regional of μ-XRF mapping two-dimensional imaging determined μ.-XAFS spectra, the p.-XAFS spectra of Fe element in the highest absorption areas for Fe sources of four Fe sources were basically the same in the intestinal wall. The shapes of the curves behind the absorption peak were similar for the four sources. It is showed that environment and structure were the same for4Fe sources in intestinal specific region. μ-XAFS spectrum indicate that the chemical state of iron absorption in this region was the same and equivalent to the iron ions are present in the form.Experiment5was performed to study feed factors affect on absorption in the duodenum of broilers.Experiment selects80broilers. Experiment was designed using two factor test completely randomized design (4x2). A total of four groups were FeSO4group, FeGly(Ⅱ) group, FeCl3group, FeGly(Ⅲ) group. The perfusion fluid was different Fe source solutions with40μg/mL Fe content3mL and the perfusion time was30min. Different levels of effect factors (phytic acid, histidine) were added to the test. Effect factors had two levels. Each treatment was repeated5times using1bird. Each chicken duodenum was used in situ ligation of a duodenal duplication. After the test, taking the middle intestine duodenum, The relevant indicators analyzed.The results showed that:(1) Aadding high phytate level, FeSO4group had a lower content in intestinal wall specific area, and Fe-Gly(Ⅱ) group had also a lower content in intestinal wall specific area. High phytate level decrease Fe-Gly(Ⅲ) and FeCl3absorption into the intestinal wall, especially into a specific area. The μ-XAFS spectra were analysised. Fe sources iron chemical valences were in the same valence.(2) Aadding high histidine level of the four perfusion fluid ligation intestinal wall dimensional map, which can promote FeSO4absorption. Adding high histidine levels, Fe-Gly(Ⅱ) group had a lower content in intestinal wall specific area. FeCl3was absorbed into the intestinal wall by adding high histidine levels did not increase the iron content contrast no adding histidine group. FeCl3was absorbed into the intestinal wall with a little change about iron content, especially iron absorption into the specific area. High histidine levels decreased Fe-Gly(Ⅲ) absorption into the intestinal wall, especially into a specific area. According to μ-XRF scanning duodenal wall two-dimensional for different iron sources of perfusion high histidine levels. Fe μ-XAFS absorption spectra were analysised in most regional intestinal. The shapes of the curves were similar for the four Fe sources, and iron chemical valences were in two valence.Conclusions: (1) In this experiment, in situ ligation techniques and synchrotron radiation (μ-XRF, μ-XAFS) technology, which proven amino acid chelated zinc (iron) absorption mechanism in in intestinal wall is the same.(2) Compared with inorganic zinc, amino acid chelated zinc significantly increased broiler blood, liver, tibia, duodenal gut sac Zn and metallothionein content, increased alkaline phosphatase activity in chicken liver and MT duodenal mucosa and ZnTl mRNA relative expression, indicating that the amino acid chelated zinc absorption than inorganic zinc.(3) In this experiment, atomic absorption spectroscopy and synchrotron radiation techniques, which proven dietary factors on the amino acid chelated zinc (iron) absorb had a less effect, and have a higher effect about the inorganic zinc (iron) greater impact.