Effects of dicopper oxide and copper sulfate on growth performance and gut microbiota in broilers

Influence of copper source and dietary inclusion level on growth performance of weaned pigs and expression of trace element related genes in the small intestine

Copper is routinely supplemented to weanling pig diets at concentrations above nutritional requirements to enhance growth performance. We hypothesised that this effect depends on the source of Cu and its dietary concentration. We tested this in weaned pigs (26 d of age) over a 35-d period using a 2 × 3 factorial arrangement with two Cu-sources (CuSO4 and Cu2O, monovalent copper oxide, CoRouge®) and three supplementary dietary Cu-levels (15, 80 and 160 mg Cu/kg) as respective factors. Increasing Cu level linearly increased (P < 0.001) final BW and daily gain. These effects tended (P = 0.09) to be greater with Cu2O than CuSO4. Feed conversion ratio decreased linearly (P < 0.001) with increasing dietary Cu content, independent of Cu source. Plasma Cu, Zn and Fe levels were unaffected, whereas liver Cu content increased quadratically (P < 0.001) with increasing dietary Cu content, with a larger increase (P < 0.001) with CuSO4 than Cu2O. Bile Cu content increased quadratically (P = 0.025) with increasing Cu content, irrespective of Cu source. RT-qPCR analysis revealed that increasing Cu content quadratically (P = 0.009) increased duodenal but not ileal metallothionein 1A (MT1A) mRNA, with greater effect (P = 0.010) of CuSO4. Regardless of the Cu source, increasing Cu dose linearly increased (P = 0.006) duodenal DMT1/SLC11A2 mRNA but decreased ZIP4/SLC39A4 mRNA in duodenum (P < 0.001) and ileum (P < 0.005). ZnT10/SLC30A10 mRNA was significantly (P = 0.021) and numerically (P = 0.061) greater with Cu2O compared to CuSO4, in duodenum and ileum, respectively. Copper content quadratically modulated duodenal but not ileal transferrin receptor (P = 0.029) and ferric reductase CYBRD1 mRNA (P = 0.022). In hypothalamus, high Cu dose (P = 0.024) and Cu2O as source (P = 0.028) reduced corticotropin-releasing hormone (CRH) mRNA. Low versus high CuSO4 increased corticotropin-releasing hormone receptor (CRHR2) mRNA, while low Cu2O had the opposite effect (P = 0.009). In conclusion, incremental Cu intake enhanced growth performance, with a tendency for a greater effect of Cu2O. The lower increase in duodenal MT1A mRNA and liver Cu content indicates that less Cu from Cu2O was absorbed by gut and sequestered in liver. Thus, high Cu absorption is not essential for its growth-promoting effect and dietary Cu may affect intestinal Fe and Zn absorption via the active, transcellular route. The effects on hypothalamic CRH and CRHR2 expression indicate a role for the hypothalamus in mediating the effects of Cu on growth performance.

Uncovering the effects of copper feed supplementation on the selection of copper-tolerant and antibiotic-resistant Enterococcus in poultry production for sustainable environmental practices

The use of antibiotics in animal production is linked to the emergence and spread of antibiotic-resistant bacteria, a threat to animal, environmental and human health. Copper (Cu) is an essential element in poultry diets and an alternative to antibiotics, supplementing inorganic or organic trace mineral feeds (ITMF/OTMF). However, its contribution to select multidrug-resistant (MDR) and Cu tolerant Enterococcus, a bacteria with a human-animal-environment-food interface, remains uncertain. We evaluated whether feeding chickens with Cu-ITMF or Cu-OTMF contributes to the selection of Cu tolerant and MDR Enterococcus from rearing to slaughter. Animal faeces [2-3-days-old (n = 18); pre-slaughter (n = 16)] and their meat (n = 18), drinking-water (n = 14) and feed (n = 18) from seven intensive farms with ITMF and OTMF flocks (10.000-64.000 animals each; 2019-2020; Portugal) were sampled. Enterococcus were studied by cultural, molecular and whole-genome sequencing methods and Cu concentrations by ICP-MS. Enterococcus (n = 477; 60 % MDR) were identified in 80 % of the samples, with >50 % carrying isolates resistant to tetracycline, quinupristin-dalfopristin, erythromycin, streptomycin, ampicillin or ciprofloxacin. Enterococcus with Cu tolerance genes, especially tcrB ± cueO, were mainly found in faeces (85 %; E. faecium/E. lactis) of ITMF/OTMF flocks. Similar occurrence and load of tcrB ± cueO Enterococcus in the faeces was detected throughout the chickens' lifespan in the ITMF/OTMF flocks, decreasing in meat. Most of the polyclonal MDR Enterococcus population carrying tcrB ± cueO or only cueO (67 %) showed a wild-type phenotype (MICCuSO4 ≤ 12 mM) linked to absence of tcrYAZB or truncated variants, also detected in 85 % of Enterococcus public genomes from poultry. Finally, < 65 μg/g Cu was found in all faecal and meat samples. In conclusion, Cu present in ITMF/OTMF is not selecting Cu tolerant and MDR Enterococcus during chickens' lifespan. However, more studies are needed to assess the minimum concentration of Cu required for MDR bacterial selection and horizontal transfer of antibiotic resistance genes, which would support sustainable practices mitigating antibiotic resistance spread in animal production and the environment beyond.

Unexpected Cu and Zn speciation patterns in the broiler feed-animal-excreta system revealed by XAS spectroscopy

Trace minerals such as copper (Cu) and zinc (Zn) are animal nutrition supplements necessary for livestock health and breeding performance, yet they also have environmental impacts via animal excretion. Here we investigated changes in Cu and Zn speciation from the feed additive to the broiler excreta stages. The aim of this study was to assess whether different Cu and Zn feed additives induce different Cu and Zn speciation patterns, and to determine the extent to which this speciation is preserved throughout the feed-animal-excreta system. Synchrotron-based X-ray absorption spectroscopy (XAS) was used for this investigation. The principal findings were: (i) in feed, Cu and Zn speciation changed rapidly from the feed additive signature (Cu and Zn oxides or Cu and Zn sulfates) to Cu and Zn organic complexes (Cu phytate and Zn phytate). (ii) in the digestive tract, we showed that Cu and Zn phytate were major Cu and Zn species; Cu sulfide and Zn amorphous phosphate species were detected but remained minor species. (iii) in fresh excreta, Cu sulfide and Zn amorphous phosphate were major species. These results should help to: (i) enhance the design of future research studies comparing different feed additive performances; (ii) assess Cu and Zn bioavailability in the digestive tract; (iii) gain further insight into the fate of Cu and Zn in cultivated soils when poultry manure is used as fertilizer.

Effect of lactic acid bacteria by different concentrations of copper based on non-target metabolomic analysis

Copper (Cu) is an essential element for mammals, but excess intake can have detrimental health consequences. However, Cu is no longer present in the "Limit of Contaminants in Foods" promulgated in 2022. The potential impact of different Cu (II) concentrations on human health remains unclear. In this study, a strain of lactic acid bacteria (LAB), namely, Lactiplantibacillus plantarum CICC 23121 (L23121), was selected as a prebiotic indicator strain to indirectly assess the effects of food-limited Cu (II) concentrations (issued by Tolerance limit of copper in foods in 1994) on the functions of intestinal microbes. We used non-target metabolomics, automatic growth curve detector, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) to investigate the effects of Cu (II) on L23121. The study revealed shows that the 50% minimum inhibitory concentration (MIC50) of Cu (II) for most lactic acid bacteria was 4 mg/L. At low Cu (II) concentrations (≤ 4 mg/L), the pentose phosphate pathway and pyrimidine metabolism of the lactic acid bacteria were affected, resulting in a decrease in the content of beneficial secondary metabolites and a significant decrease in the cell activity. As Cu (II) concentrations increase (≥ 6 mg/L), the key amino acid and lipid metabolisms were affected, leading to the inhibition of growth and primary metabolite production of the bacteria. Under high concentration of Cu (II) (6 mg/L), the surface adhesion of the bacteria was distorted and covered with significantly large particles, and the functional groups of the cells were significantly shifted. As a probiotic, the abundance of lactic acid bacteria in the intestine is significantly reduced, which will inevitably seriously damage intestinal homeostasis. Thus, to protect human intestinal microbes' health, it is recommended to limit the concentration of Cu in food to less than 4 mg/L.

Unraveling the Role of Metals and Organic Acids in Bacterial Antimicrobial Resistance in the Food Chain

Antimicrobial resistance (AMR) has a significant impact on human, animal, and environmental health, being spread in diverse settings. Antibiotic misuse and overuse in the food chain are widely recognized as primary drivers of antibiotic-resistant bacteria. However, other antimicrobials, such as metals and organic acids, commonly present in agri-food environments (e.g., in feed, biocides, or as long-term pollutants), may also contribute to this global public health problem, although this remains a debatable topic owing to limited data. This review aims to provide insights into the current role of metals (i.e., copper, arsenic, and mercury) and organic acids in the emergence and spread of AMR in the food chain. Based on a thorough literature review, this study adopts a unique integrative approach, analyzing in detail the known antimicrobial mechanisms of metals and organic acids, as well as the molecular adaptive tolerance strategies developed by diverse bacteria to overcome their action. Additionally, the interplay between the tolerance to metals or organic acids and AMR is explored, with particular focus on co-selection events. Through a comprehensive analysis, this review highlights potential silent drivers of AMR within the food chain and the need for further research at molecular and epidemiological levels across different food contexts worldwide.

Copper Super-Dosing Improves Performance of Heat-Stressed Broiler Chickens through Modulation of Expression of Proinflammatory Cytokine Genes

Continuous exposure to high ambient temperatures brings about a number of oxidative damages in chickens. Copper (Cu), an active component of a number of antioxidative defence components, should arrest these changes to take place although that may not be possible under the standard dosing regimen followed by the industry. To ascertain the optimum dose response that may be beneficial in sustaining the performance of chickens under heat stress (HS), broiler chickens (n = 400) were exposed to high ambient temperature (between 27.2°C and 35.3°C) during 1-35 d. Copper (Cu) as Cu proteinate (Cu-P) at concentrations of 37.5, 75, 112.5, and 150 mg/kg was supplemented to the diet. The negative control (NC) diet did not contain any supplemental Cu. Increasing dietary Cu improved (P < 0.001) body weight, feed intake, and conversion ratio. Serum concentrations of total cholesterol at 21 d (P = 0.009), HDL cholesterol at 35 d (P = 0.008), LDL cholesterol at 21 d (P = 0.015), and triacylglycerol at both 21 d (P = 0.033) and 35 d (P = 0.001) decreased as Cu in the diet increased. As Cu in the diet increased, hemoglobin increased (P = 0.003) at 21 d, and the heterophil to lymphocyte ratio decreased both at 21 d (P = 0.047) and 35 d (P = 0.001). Superoxide dismutase and glutathione peroxidase activities increased when dietary Cu increased to 150 mg/kg (P < 0.01). Liver Cu at 35 d increased linearly with the dose of Cu in the diet (P = 0.0001). Selected bacteria were enumerated in the digesta to ascertain if Cu super-dosing affected their population in any way in the absence of any enteric challenge. Escherichia coli and total Salmonella numbers decreased (P = 0.0001), and total Lactobacillus increased (P = 0.0001) proportionately with dietary Cu. Interleukin-6 and tumour necrosis factor-α gene expression increased linearly (P = 0.0001) as Cu in the diet increased though the response plateaued at 112.5 mg/kg. It was concluded from the present experiment that during conditions of impending HS, dietary supplementation of 112.5 to 150 mg Cu/kg diet as Cu-P may be a novel strategy to alleviate the negative effects of HS without involving any apparent risk of Cu toxicity.

Dietary supplementation of solubles from shredded, steam-exploded pine particles modulates cecal microbiome composition in broiler chickens

This study evaluated the effects of supplementing solubles from shredded, steam-exploded pine particles (SSPP) on growth performances, plasma biochemicals, and microbial composition in broilers. The birds were reared for 28 days and fed basal diets with or without the inclusion of SSPP from 8 days old. There were a total of three dietary treatments supplemented with 0% (0% SSPP), 0.1% (0.1% SSPP) and 0.4% (0.4% SSPP) SSPP in basal diets. Supplementation of SSPP did not significantly affect growth or plasma biochemicals, but there was a clear indication of diet-induced microbial shifts. Beta-diversity analysis revealed SSPP supplementation-related clustering (ANOSIM: r = 0.31, p < 0.01), with an overall lower (PERMDISP: p < 0.05) individual dispersion in comparison to the control group. In addition, the proportions of the Bacteroides were increased, and the relative abundances of the families Vallitaleaceae, Defluviitaleaceae, Clostridiaceae, and the genera Butyricicoccus and Anaerofilum (p < 0.05) were significantly higher in the 0.4% SSPP group than in the control group. Furthermore, the linear discriminant analysis effect size (LEfSe) also showed that beneficial bacteria such as Ruminococcus albus and Butyricicoccus pullicaecorum were identified as microbial biomarkers of dietary SSPP inclusion (p < 0.05; | LDA effect size | > 2.0). Finally, network analysis showed that strong positive correlations were established among microbial species belonging to the class Clostridia, whereas Erysipelotrichia and Bacteroidia were mostly negatively correlated with Clostridia. Taken together, the results suggested that SSPP supplementation modulates the cecal microbial composition of broilers toward a "healthier" profile.

Effect of Monovalent Copper Oxide and Potentiated Zinc Oxide on Growth Performance and Gut Morphology of Broiler Chickens Challenged with Coccidiosis

An experiment was conducted to evaluate the effect of copper oxide (Cu₂O) and potentiated zinc oxide (ZnO) on performance, intestinal morphology, oocyst excretion, coccidial lesion scores, and antioxidant properties in broilers during an Eimeria spp. challenge. A total of 288 1-day-old male broiler chickens (Ross 308) were divided into 18 treatments. Treatments included three levels of Cu (0, 15, or 150 mg/kg) from Cu₂O and three levels of Zn (0, 80, or 160 mg/kg) from potentiated ZnO which were added to the basal diet and fed to broilers with or without challenge, using a completely randomized design in a factorial arrangement for 42 days. Live body weight, feed intake, mortality, and the cause of death were recorded weekly and histomorphology of jejunum was measured at the end of the experiment. Results showed that birds fed Cu and Zn linearly decreased (P < 0.0001) oocyst shedding. The number of excreted oocysts was reduced eight times in broilers fed a diet containing 150 mg/kg copper from Cu₂O and 160 mg/kg zinc from potentiated ZnO, compared to the infected group without Cu and Zn supplementation (P < 0.0001). Microscopic features of both non-challenged and challenged broiler jejunum revealed significant improvement along with increased Cu₂O and potentiated ZnO doses. Supplementation of Cu₂O and potentiated ZnO decreased the jejunum structure damages and intestinal lesion score (P < 0.002). Eimeria caused a decrease (P < 0.006) in total antioxidant capacity. Superoxide dismutase increased by dietary zinc supplementation (P < 0.05). Results suggested that a combination of Cu₂O and potentiated ZnO could exhibit efficient anticoccidial activity.

Effects of bis-chelated copper in growth performance and gut health in broiler chickens subject to coccidiosis vaccination or coccidia challenge

Copper (Cu) is widely used at high levels as growth promoter in poultry, the alternative source of Cu to replace the high level of inorganic Cu at poultry farm remains to be determined. Three floor pen experiments were conducted to evaluate the effects of Cu methionine hydroxy-analogue chelate (Cu-MHAC, MINTREX^®Cu, Novus International, Inc.) on growth performance and gut health in broilers in comparison to CuSO₄ and/or tribasic copper chloride (TBCC). There were 3 treatments in experiment#1 (0, 30 and 75 ppm Cu-MHAC) and experiment#2 (15 and 30 ppm Cu-MHAC, and 125 ppm CuSO₄), and 4 treatments in experiment #3 (15 and 30 ppm Cu-MHAC, 125 ppm CuSO₄ and 125 ppm TBCC) with nine replicates pens of 10-13 birds in each treatment. The levels of other minerals were equal among all treatments within each experiment. All birds were orally gavaged with a coccidiosis vaccine at 1x recommended dose on d0 in experiment#1 and #2 and 10x recommended dose on d15 in experiment #3. Data were analyzed by one-way ANOVA, means were separated by Fisher's protected LSD test. A p ≤ 0.05 was considered statistically different. In experiment #1, 30 and 75 ppm Cu-MHAC improved FCR during grower phase, increased jejunal villus height and reduced jejunal crypt depth, 30 ppm Cu-MHAC increased cecal Lactobacillus spp. abundance in 41 days broilers. In experiment #2, compared to CuSO₄, 15ppm Cu-MHAC increased cumulative performance index in 28 days broilers, 15 and/or 30 ppm Cu-MHAC improved gut morphometry, and 30 ppm Cu-MHAC reduced the abundance of E. coli and Enterobacteriaceae in cecum in 43 days broilers. In experiment #3, 15 ppm and 30 ppm Cu-MHAC improved FCR vs. CuSO₄ during starter phase, reduced the percentage of E. coli of total bacteria vs. TBCC, 30 ppm Cu-MHAC increased the percentages of Lactobacillus acidophilus, Lactobacillus spp. and Clostridium cluster XIVa of total bacteria vs. both CuSO₄ and TBCC in the cecum of 27 days broilers. In summary, low doses of Cu-MHAC had comparable growth performance to high dose of TBCC and CuSO₄ while improving gut microflora and gut morphometry in broilers subject to coccidiosis vaccination or coccidia challenge, indicating that low doses of bis-chelated Cu could be used as a complimentary strategy to improve animal gut health.

Exposure to copper activates mitophagy and endoplasmic reticulum stress-mediated apoptosis in chicken (Gallus gallus) cerebrum

A large amount of copper (Cu) used in production activities can lead to the enrichment of Cu in the environment, which can cause toxicity to animals. However, the toxicity mechanism of Cu on the cerebrum is still uncertain. Hence, a total of 240 chickens were separated into four groups in this study to reveal the potential connection between mitophagy and endoplasmic reticulum (ER) stress-mediated apoptosis in the chicken cerebrum in the case of excess Cu exposure. The cu exposure situation was simulated by diets containing various levels of copper (11 mg/kg, control group; 110 mg/kg, group I; 220 mg/kg, group II and 330 mg/kg, group III) for 49 days. The results of histology showed that vacuolar degeneration was observed in the treated groups, and the mitochondria swell and autophagosomes formation were found under excess Cu treatment. Additionally, the expression of mitophagy (PINK1, Parkin, LC3I, LC3II and p62) and ER stress (GRP78, PERK, ATF6, IRE1α, XBP1, CHOP, and JNK) indexes were significantly upregulated under excess Cu exposure. Furthermore, the mRNA and protein expression of Bcl-2 were decreased, while Bak1, Bax, Caspase12, and Caspase3 were increased compared to the control group. In summary, this study demonstrated that an overdose of Cu could induce mitophagy and ER stress-mediated apoptosis in the chicken cerebrum. These findings revealed an important potential connection between Cu toxicity and cerebrum damage, which provided a new insight into Cu neurotoxicity.

Impacts of dietary copper on the swine gut microbiome and antibiotic resistome

Restrictions on antibiotic growth promoters have prompted livestock producers to use alternative growth promoters, and dietary copper (Cu) supplementation is currently being widely used in pig production. However, elevated doses of dietary Cu constitute a risk for co-selection of antibiotic resistance and the risk may depend on the type of Cu-based feed additives being used. We here report the first controlled experiment investigating the impact of two contrasting Cu-based feed additives on the overall swine gut microbiome and antibiotic resistome. DNA was extracted from fecal samples (n = 96) collected at four time points during 116 days from 120 pigs allotted to three dietary treatments: control, divalent copper sulfate (CuSO₄; 250 μg Cu g^-1 feed), and monovalent copper oxide (Cu₂O; 250 μg Cu g^-1 feed). Bacterial community composition, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) were assessed, and bioavailable Cu ([Cu]_bio) was determined using whole-cell bacterial bioreporters. Cu supplementation to feed increased total Cu concentrations ([Cu]_total) and [Cu]_bio in feces 8-10 fold and at least 670-1000 fold, respectively, but with no significant differences between the two Cu sources. The swine gut microbiome harbored highly abundant and diverse ARGs and MGEs irrespective of the treatments throughout the experiment. Microbiomes differed significantly between pig growth stages and tended to converge over time, but only minor changes in the bacterial community composition and resistome could be linked to Cu supplementation. A significant correlation between bacterial community composition (i.e., bacterial taxa present) and ARG prevalence patterns were observed by Procrustes analysis. Overall, results of the experiment did not provide evidence for Cu-induced co-selection of ARGs or MGEs even at a Cu concentration level exceeding the maximal permitted level for pig diets in the EU (25 to 150 μg Cu g^-1 feed depending on pig age).

Dietary trace mineral pattern influences gut microbiota and intestinal health of broilers

Dietary trace minerals can impact gut flora, which can further affect intestinal health. However, the dietary balance pattern of trace minerals for the intestinal health of broilers needs to be explored. The present study was conducted to investigate the effect of the dietary pattern of Cu, Fe, Mn, Zn, and Se on the intestinal morphology, microbiota, short-chain fatty acid concentrations, antioxidant status, and the expression of tight junction proteins in broilers. A total of 240 1-d-old Arbor Acres male broilers were randomly assigned to one of five treatments with six replicate cages of eight birds per cage for each treatment. The birds were fed the corn-soybean meal basal diet supplemented with five combination patterns of trace minerals for 42 d. The dietary treatments were as follows: the inorganic sources were added to the diet based on the recommendations of the current National Research Council (NRC, T1) and Ministry of Agriculture of P.R. China (MAP) (T2) for broiler chicks, respectively; the inorganic sources were added to the diet at the levels based on our previous results of inorganic trace mineral requirements for broilers (T3); the organic sources were added to the diet at the levels considering the bioavailabilities of organic trace minerals for broilers described in our previous studies (T4); and the organic sources were added to the diet based on the recommendations of the current MAP for broiler chicks (T5). The results showed that broilers from T1 had lower (P < 0.05) crypt depth (CD), and a higher (P < 0.05) villus height: CD in duodenum on day 21 and lower CD (P < 0.05) in jejunum on day 42 than those from T3 and T4. Broilers from T1, T3, and T5 had a higher (P < 0.05) Shannon index in cecum on day 21 than those from T4. Broilers from T1 had a higher (P < 0.05) abundance of Lactobacillus in ileum on day 21 than those from T2 and T3. Broilers from T1, T2, and T5 had a higher (P < 0.05) valeric acid concentrations in cecum on day 42 than those from T3 and T4. In addition, Birds from T2 had higher (P < 0.05) Claudin-1 mRNA levels in jejunum on day 42 than those from T3 and T4. And birds from T3, T4, and T5 had a higher (P < 0.05) Occludin protein expression levels in duodenum on day 42 than those from T2. These results indicate that dietary pattern of Cu, Fe, Mn, Zn, and Se influenced gut flora and intestinal health of broilers, and the appropriate pattern of Cu, Fe, Mn, Zn, and Se in the diet for intestinal health of broilers would be Cu 12 mg, Fe 229 mg, Mn 81 mg, Zn 78 mg, and Se 0.24 mg/kg (1 to 21 d of age), and Cu 11 mg, Fe 193 mg, Mn 80 mg, Zn 73 mg, and Se 0.22 mg/kg (22 to 42 d of age), when the trace minerals as inorganic sources were added to diets according to the recommendations of the current NRC.

Microbiome analysis reveals the effects of black soldier fly oil on gut microbiota in pigeon

The gut microbiota plays a vital roles in poultry physiology, immunity and metabolism. Black soldier fly oil is known to have a positive effect on the gut microbiota. However, the specific effect of black soldier fly oil on the composition and structure of the gut microbiota of the pigeon is unknown. In this experiment, 16S rDNA high-throughput sequencing was performed to study the effect of different doses of black soldier fly oil on the changes of pigeon intestinal microbes. Results indicated that the different doses of black soldier fly oil had no effect on the gut microbial diversity of the pigeon. Although the dominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria) and genus (uncultured_bacterium_f_Lachnospiraceae and Desulfovibrio) in control group and experimental group with different doses were the same, the abundances of some beneficial bacteria (Megasphaera, Intestinimonas, Prevotella_9, Lachnospiraceae_UCG-001, Faecalibacterium, Coprococcus_2, Parabacteroides, Megasphaera, Leuconostoc, Prevotellaceae_UCG-001, Lactococcus, Ruminococcaceae_UCG-014, and Coprococcus_2) increased significantly as the concentration of black soldier fly oil increased. Taken together, this study indicated that black soldier fly oil supplementation could improve gut microbial composition and structure by increasing the proportions of beneficial bacteria. Notably, this is the first report on the effects of black soldier fly oil on the gut microbiota of pigeon, which contribute to understanding the positive effects of black soldier fly oil from the gut microbial perspective.

How copper can impact pig growth: comparing the effect of copper sulfate and monovalent copper oxide on oxidative status, inflammation, gene abundance, and microbial modulation as potential mechanisms of action

The beneficial effect of elevated concentrations of copper (Cu) on growth performance of pigs has been already demonstrated; however, their mechanism of action is not fully discovered. The objective of the present experiment was to investigate the effects of including Cu from copper sulfate (CuSO₄) or monovalent copper oxide (Cu₂O) in the diet of growing pigs on oxidative stress, inflammation, gene abundance, and microbial modulation. We used 120 pigs with initial body weight (BW) of 11.5 ± 0.98 kg in 2 blocks of 60 pigs, 3 dietary treatments, 5 pigs per pen, and 4 replicate pens per treatment within each block for a total of 8 pens per treatment. Dietary treatments included the negative control (NC) diet containing 20 mg Cu/kg and 2 diets in which 250 mg Cu/kg from CuSO₄ or Cu₂O was added to the NC. On day 28, serum samples were collected from one pig per pen and this pig was then euthanized to obtain liver samples for the analysis of oxidative stress markers (Cu/Zn superoxide dismutase, glutathione peroxidase, and malondialdehyde, MDA). Serum samples were analyzed for cytokines. Jejunum tissue and colon content were collected and used for transcriptomic analyses and microbial characterization, respectively. Results indicated that there were greater (P < 0.05) MDA levels in the liver of pigs fed the diet with 250 mg/kg CuSO₄ than in pigs fed the other diets. The serum concentration of tumor necrosis factor-alpha was greater (P < 0.05) in pigs fed diets containing CuSO₄ compared with pigs fed the NC diet or the diet with 250 mg Cu/kg from Cu₂O. Pigs fed diets containing CuSO₄ or Cu₂O had a greater (P < 0.05) abundance of genes related to the intestinal barrier function and nutrient transport, but a lower (P < 0.05) abundance of pro-inflammatory genes compared with pigs fed the NC diet. Supplementing diets with CuSO₄ or Cu₂O also increased (P < 0.05) the abundance of Lachnospiraceae and Peptostreptococcaceae families and reduced (P < 0.05) the abundance of the Rikenellaceae family, Campylobacter, and Streptococcus genera in the colon of pigs. In conclusion, adding 250 mg/kg of Cu from CuSO₄ or Cu₂O regulates genes abundance in charge of the immune system and growth, and promotes changes in the intestinal microbiota; however, Cu₂O induces less systemic oxidation and inflammation compared with CuSO₄.

The Application of Copper Waterline on Laying Performance and Gut Health of Aged Laying Hens

The effect of the application of copper waterline on the performance and gut health of aged laying hens was evaluated in this study. Forty-eight 70-week-old laying hens were divided into two groups (three replicates of eight hens each): control and copper (Cu) groups provided with normal polyvinyl chloride (PVC) waterline or Cu waterline. The laying performance was measured during the four-week period of the experiment. The intestinal antioxidant status and the microbiota diversity of the cecal content were determined. Moreover, a bacteriostasis test on Escherichia coli and Salmonella enteritidis was conducted after inoculation in waterline and hens, respectively. The water Cu²⁺ content was increased by Cu waterline compared to the control (P<0.05). Cu waterline had no detectable effect on most production performances, however, it increased the egg weight (P<0.05). Cu waterline increased the Cu level in the eggshell. Cu level in excreta increased with time, especially in the final two weeks, however, there was no significant change in fecal Cu excretion. The lipid peroxidation product malondialdehyde content in ileum decreased (P<0.01), while the activities of CuZn-superoxide dismutase (SOD) of ileum and glutathione peroxidase (GSH-PX) activity of jejunum and ileum increased after Cu treatment. The relative abundance and richness of cecal microbiota increased after Cu treatment (P<0.05). Cu waterline changed the microbial composition, including the increased proportion of Methanocorpusculum, Paludibacter, and decreased proportion of Fucobacterium, Anaerobiospirillum, and Campylobacter. The colonization of E. coli and S. enteritidis in Cu waterline was suppressed by Cu treatment, indicating that Cu waterline had potential antibacterial properties. The result suggests that Cu waterline could inhibit the colonization of pathogenic microorganisms such as E. coli and Salmonella and facilitate the enrichment of cecal microbiota diversity.

Hot-melt extruded copper sulfate affects the growth performance, meat quality, and copper bioavailability of broiler chickens

Objective

This study was conducted to evaluate the effects of the supplementation of diets of broiler chickens with hot-melt extruded CuSO₄ (HME-Cu) on their growth performance, nutrient digestibility, gut microbiota, small intestinal morphology, meat quality, and copper (Cu) bioavailability.

Methods

A total of 225 broilers (Ross 308), one-day old and initial weight 39.14 g, were weighed and distributed between 15 cages (15 birds per cage) in a completely randomized experimental design with 3 treatments (diets) and 5 replicates per treatment. Cages were allotted to three treatments including control (without supplemental Cu), IN-Cu (16 mg/kg of CuSO₄), and HME-Cu (16 mg/kg of HME processed CuSO₄).

Results

The HME-Cu treatment tended to increase the overall body weight gain (p<0.10). The apparent digestibility of Cu was increased by supplementation of HME-Cu at phase 2 (p<0.05). The Escherichia coli count in cecum tended to decrease with the supplementation with Cu (p<0.10). In addition, the HME-Cu treatment had a higher pH of breast meat than the control and IN-Cu treatments (p<0.05). Significant increases in the cooking loss, water-holding capacity, and lightness in the breast were observed in the HME-Cu treatment compared to the control (p<0.05). The Cu content of excreta increased with the Cu supplementation (p<0.05). The concentration of excreta Cu in broilers was decreased in the HME-Cu compared to the IN-Cu in phase 2 (p<0.05). The Cu concentration in the liver was increased with the HME-Cu supplementation, compared with the control diets (p<0.05).

Conclusion

This study showed that HME-Cu supplementation at the requirement level (16 mg/kg diets) in broiler diets did not affect the growth performance and the physiological function of Cu in broilers. However, supplementation of Cu in HME form improved the meat quality and the bioavailability of Cu.