Minqi Wang

Effects of copper-loaded chitosan nanoparticles on growth and immunity in broilers

Effects of dietary copper-loaded chitosan nanoparticle (CNP-Cu) supplementation on growth performance, hematological and immunological characteristics, and the cecal microbiota in broilers were investigated. Three hundred healthy Avian × Avian (1-d-old) broilers were randomly assigned into 5 dietary groups (20 birds per replicate with 3 replicates per group). Birds were fed with 0 (the control group), 50, 100, 150 mg/kg of CNP-Cu and 50 mg/kg chlorotetracycline (CTC, a positive control group) for 42 d. Results indicated that supplemental CNP-Cu could improve growth performance, affect the immune system, enhance protein synthesis, and be beneficial to cecal microbiota of Avian broilers, especially the dietary supplementation with 100 mg/kg of CNP-Cu. Supplementation with 100 mg/kg of CNP-Cu increased the average daily gain(P < 0.05) and the contents of IgA (P < 0.01), IgG (P < 0.01), IgM (P < 0.01), complement C3 (P < 0.05), and complement C4 (P < 0.05). Thymus, spleen, and bursa of Fabricus indexes and the populations of Lactobacillus and Bifidobacterium in cecal digesta were increased (P < 0.05) by 100 mg/kg of CNP-Cu supplementation, and the population of coliforms was decreased (P < 0.05). Dietary supplementation with 100 mg/kg of CNP-Cu increased (P < 0.05) concentrations of serum total protein and albumin, and decreased (P < 0.05) the content of urea nitrogen in serum. Effects of dietary supplementation with 100 mg/kg of CNP-Cu were similar to 50 mg/kg of CTC supplementation. These results may indicate that CNP-Cu could be a new substitute for CTC in dietary supplementation.

Toxicity of selenium nanoparticles in male Sprague-Dawley rats at supranutritional and nonlethal levels.

AIMS We synthesized selenium nanoparticles (SeNPs) and examined their toxicity in male rats at supranutritional and nonlethal doses. MAIN METHODS The SeNPs were administered daily by gavage at doses of 0.0, 0.2, 0.4, 0.8, 2.0, 4.0, or 8.0 mg Se/kg-body weight (bw) in 2 mL of 0.9% saline for 14 consecutive days. Body weight, viscera index and blood biochemical parameters were measured. Histopathological examination was performed on selected tissues, and liver tissue was examined for apoptotic cells. KEY FINDINGS Body weight decreased considerably in the groups given doses of 2.0, 4.0, and 8.0 mg Se/kg-bw, but increased in the groups given doses of 0.2 and 0.4 mg Se/kg-bw. The viscera index and some biochemical parameters in the 8.0 mg Se/kg-bw group differed from the control group. Lesions in the liver, kidneys, lungs, and thymus, and apoptotic liver cells were observed in the 4.0 and 8.0 mg Se/kg-bw groups. SIGNIFICANCE From this study, we conclude that supranutritional levels of SeNPs had no obvious toxic effects in rats, and could be used as potential candidates for cancer chemoprevention, although doses greater than 2.0 mg Se/kg-bw induced chronic toxicity.

Effects of in ovo feeding of carbohydrates on hatchability, body weight, and energy status in domestic pigeons (Columba livia)

The effects of in ovo feeding of carbohydrates on hatchability, BW, yolk sac weights (YSW), pectoral muscle weights (PMW), liver and pectoral muscle glycogen concentration, serum glucose level, and hepatic glucose-6-phosphatase activity of domestic pigeons, hatched from eggs laid by a 40-wk-old breeder flock, were investigated. At 14.5 of incubation, fertile eggs were injected with 200 μL of 1.5% maltose (M) + 1.5% sucrose (S), 2.5% M + 2.5% S, 3.5% M + 3.5% S, or 4.5% M + 4.5% S in 0.75% saline, with controls not injected. Results showed that in ovo injection with 1.5% M + 1.5% S or 2.5% M + 2.5% S increased the hatchability compared with the control, whereas injection of 4.5% M + 4.5% S decreased the hatchability. The BW at hatch was quadratic, and BW was maximized by injecting 2.5% M + 2.5% S. The YSW at hatch decreased linearly by the injection with 3.5% M + 3.5% S compared with the control group. In ovo injection of 2.5% M + 2.5% S increased the PMW at hatch. There were no significant differences between any of the treatment groups for liver glycogen reserves. Serum glucose level at hatch was quadratic, and the glucose level was maximized between supplemental 2.5% M + 2.5% S and supplemental 3.5% M + 3.5% S. The pectoral muscle glycogen reserves increased quadratically as supplemental carbohydrates increased, and the response was maximized by injecting 2.5% M + 2.5% S. In conclusion, the present results demonstrate that the injected carbohydrates are available for use and storage. In ovo feeding of carbohydrates, especially at the level of 2.5% M + 2.5% S, on 14.5 d of incubation can improve the hatchability, BW, and PMW by elevating the pectoral muscle glycogen reserves in domestic pigeons at hatch. Results also suggested that in ovo injection of carbohydrates could increase the yolk sac nutrient utilization and hence might enhance the pigeon enteric development.

Effects of dietary zinc oxide nanoparticles supplementation on growth performance, zinc status, intestinal morphology, microflora population, and immune response in weaned pigs: Effects of dietary zinc oxide nanoparticles on weaned pigs

BACKGROUND This study evaluated the effects of dietary zinc oxide nanoparticles (nano-ZnOs) on growth performance, zinc status, intestinal morphology, microflora population, and immune response in weaned piglets. A total of 150 weaned piglets (9.37 ± 0.48 kg) were randomly allotted to five dietary treatments and fed with a basal diet (control), or the basal diet supplemented with nano-ZnOs at 150, 300, or 450 mg kg-1 , and 3000 mg kg-1 ZnO for 21 days. After a feeding test, six pigs from the control, 450 mg kg-1 nano-ZnOs and 3000 mg kg-1 ZnO groups were slaughtered. RESULTS Compared with the control, dietary supplements of nano-ZnOs and ZnO could improve (P < 0.05) average daily weight gain (ADG), average daily feed intake (ADFI), and villus height to crypt depth ratio in the duodenum and jejunum, and decrease (P < 0.05) diarrhea incidence. Zinc retention in the serum, heart, liver, spleen and kidney of pigs supplemented with nano-ZnOs and ZnO was increased (P < 0.05). Nano-ZnOs decreased (P < 0.05) the zinc excretion compared with conventional ZnO. Lower Escherichia coli counts in the cecum, colon, and rectum were observed (P < 0.05) in the nano-ZnOs group compared with the other groups. Compared with the control, ZnO and nano-ZnOs increased (P < 0.05) the serum concentration of IgA, IL-6, and TNF-α, and decreased (P < 0.05) the concentration of IgM. CONCLUSION These results indicated that low doses of nano-ZnOs can have beneficial effects on growth performance, intestinal morphology and microflora, and immunity in weanling pigs, which are similar to the effects of pharmacological dosages of conventional ZnO. Nano-ZnOs may reduce mineral excretion, which may reduce environmental challenges.

Clostridium Tyrobutyricum Protect Intestinal Barrier Function from LPS-Induced Apoptosis via P38/JNK Signaling Pathway in IPEC-J2 Cells

Background/Aims: The intestinal mucosa forms a physical and metabolic barrier against the diffusion of pathogens, toxins, and allergens from the lumen into the circulatory system. Early weaning, a critical phase in swine production, can compromise intestinal barrier function through mucosal damage and alteration of tight junction integrity Maintenance of intestinal barrier function plays a pivotal role in optimum gastrointestinal health. In this study, we investigated the effects of Clostridium tyrobutyricum (C.t) on intestinal barrier dysfunction induced by lipopolysaccharide (LPS) and the underlying mechanisms involved in intestinal barrier protection. Methods: A Transwell model of IPEC-J2 cells was used to imitate the intestinal barrier. Fluorescence microscopy and flow cytometry were used to evaluate apoptosis. Real-time PCR was used to detect apoptosis-related genes and the downstream genes of the p38/c-Jun N-terminal kinase (JNK) signaling pathways. Western blotting was used to measure the expressions of tight junction proteins and mitogen-activated protein kinases. Results: C.t efficiently maintained trans-epithelium electrical resistance values and intestinal permeability after LPS-induced intestinal barrier disruption. The expressions of tight junction proteins (ZO-1, claudin-1, and occludin) were promoted when IPEC-J2 cells were treated with C.t. Fluorescence imaging and flow cytometry revealed that C.t qualitatively and quantitatively inhibited LPS-induced cell apoptosis. C.t also increased the relative expression of the anti-apoptotic gene Bcl-2 and decreased that of the apoptotic genes Bax and caspase-3/-8. Moreover, the protective effect of C.t on damaged intestinal cell models was associated with suppression of p38 and JNK phosphorylation, negative regulation of the relative expressions of downstream genes including AP-1, ATF-2, ELK-1, and p53, and activation of Stat3 expression. Conclusions: These findings indicate that C.t may promote intestinal integrity, suggesting a novel probiotic effect on intestinal barrier function.