Insurk Jang

Telomeric DNA quantity, DNA damage, and heat shock protein gene expression as physiological stress markers in chickens

In this longitudinal study with Single Comb White Leghorn chickens, we investigated the effects of stress conditions in birds that were subjected to a high stocking density with feed restrictions on the quantity of telomeric DNA, the rate of DNA damage, and the expression levels of heat shock proteins (HSP) and hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) genes. The telomere length and telomere-shortening rates were analyzed by quantitative fluorescence in situ hybridization on the nuclei of lymphocytes. The DNA damage rate of lymphocytes was quantified by the comet assay. The expression levels of HSP70, HSP90, and HMGCR genes were measured by quantitative real-time PCR in lymphocytes. The telomere-shortening rate of the lymphocytes was significantly higher in the stress group than in the control. The DNA damage also increased in birds raised under stress conditions, as compared with the control group. The stress conditions had a significant effect on the expressions of HMGCR and HSP90α in lymphocytes but had no significance on HSP70 and HSP90β in blood. We conclude that the telomere length, especially the telomere-shortening rates, the quantification of total DNA damage, and the expression levels of the HMGCR and HSP90α genes can be used as sensitive physiological stress markers in chickens.

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.

Effects of a Blend of Prunus Mume Extract as an Alternative to Antibiotics on Growth Performance, Activity of Digestive Enzymes and Microflora Population in Broiler Chickens

The current study was designed to define whether a blend of prunus mume extract (25%) containing lactic acid (75%) and grape seed extract (10 ppm) could affect in vitro antimicrobial activity and growth performance, intestinal microflora, plasma biochemical profiles and digestive enzymes activities in broiler chickens. In paper disc agar diffusion test, we clearly observed antimicrobial activity against E. coli in response to prunus mume extract or a blend of prunus mume extract. For in vivo test, a total of ninety six 3-d-old male broiler chicks were assigned to basal diet (CON), basal diet supplemented with antibiotics (ANTI) and 0.5% a blend of prunus mume extract (PRNUS) until 35 days of age. Throughout the entire experimental period (3-35 days), there were no differences in BW and FCR between the birds fed the basal diet with antibiotics and the diet supplemented with a blend of prunus mume. However, ANTI group showed a significant increase in BW and total gain compared to CON group. The weights of digestive organs such as the pancreas and mucosal tissues were not affected by dietary treatments. There was no difference in plasma levels of glucose, cholesterol, AST and ALT activity. However, triglyceride in plasma increased (P<0.05) in the birds fed the diet supplemented with 0.5% a blend of prunus mume extract compared to those fed antibiotics supplemented diet. The activities of pancreatic trypsin and amylase, and intestinal hydrolase including disaccharidase were not affected by dietary treatment. The colony forming units (CFU) of lactobacillus in the lower ileal-cecum of the birds fed the diet supplemented with a blend of prunus mume extract was significantly (P<0.05) higher than that of birds fed antibiotic supplemented diet without affecting the CFU of E. coli. In conclusion, the birds fed the diet supplemented a blend of prunus mume as an alternative to antibiotics showed a similar growth performance and an significant increase in lactobacillus population compared with the birds fed basal and antibiotics supplemented diets.

Effects of dietary supplementation of lipid-coated zinc oxide on intestinal mucosal morphology and expression of the genes associated with growth and immune function in weanling pigs

Objective The present study was conducted to investigate the effects of a lipid-coated zinc oxide (ZnO) supplement Shield Zn (SZ) at the sub-pharmacological concentration on intestinal morphology and gene expression in weanling pigs, with an aim to gain insights into the mechanism of actions for SZ. Methods Forty 22-day-old weanling pigs were fed a nursery diet supplemented with 100 or 2,500 mg Zn/kg with uncoated ZnO (negative control [NC] or positive control [PC], respectively), 100, 200, or 400 mg Zn/kg with SZ for 14 days and their intestinal tissues were taken for histological and molecular biological examinations. The villus height (VH) and crypt depth (CD) of the intestinal mucosa were measured microscopically following preparation of the tissue specimen; expression of the genes associated with growth and immune function was determined using the real-time quantitative polymerase chain reaction. Results There was no difference in daily gain, gain:feed, and diarrhea score between the SZ group and either of NC and PC. The VH and VH:CD ratio were less for the SZ group vs NC in the jejunum and duodenum, respectively (p<0.05). The jejunal mucosal mRNA levels of insulin-like growth factor (IGF-I) and interleukin (IL)-10 regressed and tended to regress (p = 0.053) on the SZ concentration with a positive coefficient, respectively, whereas the IL-6 mRNA level regressed on the SZ concentration with a negative coefficient. The mRNA levels of IGF-I, zonula occludens protein-1, tumor necrosis factor-α, IL-6, and IL-10 did not differ between the SZ group and either of NC and PC; the occludin and transforming growth factor-β1 mRNA levels were lower for the SZ group than for PC. Conclusion The present results are interpreted to suggest that dietary ZnO provided by SZ may play a role in intestinal mucosal growth and immune function by modulating the expression of IGF-I, IL-6, and IL-10 genes.

Effects of coenzyme Q 10 on the antioxidant system in SD rats exposed to lipopolysaccharide-induced toxicity

The study was performed to see the effects of coenzyme Q10 (CoQ10) on blood biochemical components and hepatic antioxidant system in rats exposed to lipopolysaccharide (LPS)-induced toxicity. A total of 24 rats were allocated to four groups: control (CON), 100 mg/kg BW of LPS (LPS), 100 mg of CoQ10/kg BW with LPS (LCQI) and 300 mg of CoQ10/kg BW with LPS (LCQII). The LPS and LCQI groups showed a significant (P<0.05) increase in the relative spleen weight compared with the CON group without affecting body and liver weights. The blood alanine aminotransferase (ALT) level in the LPS group was significantly (P<0.05) greater than that in the CON group, while supplementation with 100 or 300 mg CoQ10 to rats injected with LPS normalized the ALT level in the CON group. In antioxidant systems, the LPS group showed a significantly (P<0.05) higher mRNA and activity of superoxide dismutase (SOD) than the CON group. The supplementation with CoQ10 to the LPS-treated group normalized the level of SOD, which was comparable to the level of the CON group. Both the mRNA expression and activity of glutathione peroxidase in the LCQI and LCQII groups were higher (P<0.05) than that of the LPS group. However, administration of LPS or CoQ10 unaffected the level of catalase and total antioxidant power. The level of lipid peroxidation in the LCQII group was lower (P<0.05) than that in the LPS group. In conclusion, CoQ10 exerted its favorable effect against liver damage by modulation of antioxidant enzymes in LPS treated rats.

The Effect of Stocking Density and Strain on the Performance and Physiological Adaptive Responses in Broiler Chickens

The aim of this study was to determine the effects of stocking density and strain on the performance and physiological adaptive responses including the plasma corticosterone content and the level of mRNA expression of pro- inflammatory cytokines and antioxidant enzymes in broiler chicks. A total of 300 birds of two strains (150 Ross strain vs. 150 Cobb strain) aged 3-d old were allotted into two stocking densities (standard stocking density, 0.046 m 2 /bird vs. high stocking density, 0.023 m 2 /bird) in battery cages by 2×2 factorial designs with ten replicates until 35 d of age. There was no significant strain effect on body weight, feed intakes and feed to gain ratio and the relative organ weights. However body weight, feed intakes and relative organ weight were found to be significantly (P<0.05) affected by the effect of stocking density. Plasma corticosterone level was not affected by both stocking density and strain effects. Hepatic mRNA expression of pro-inflammatory cytokines including interleukin-1β (IL-1β), IL-6, IL-18 and interferon-gamma (IFN-γ) was not significantly changed by the effects of strain and stocking density. However, the mRNA expression of glutathione peroxidase (GPX) was affected by strain, showing that Ross strain decreased (P<0.05) the GPX expression. With respect to the effect of stocking density, there was a significant (P<0.05) increase in superoxide dismutase (SOD) and catalase (CAT) and GPX mRNA expression in the liver from high stocking density group. Splenic pro-inflammatory cytokine expression was not also affected by stocking density and strain, except that IL-18 mRNA significantly (P<0.05) decreased in Cobb strain under high stocking density. The mRNA expression of SOD and CAT was significantly (P<0.05) affected by the effects of stocking density and strain. In conclusion, growth performance was not affected by strain but stocking density. Although mRNA expression of major pro-inflammatory cytokines was not changed by stocking density and strain, antioxidant enzyme was significantly affected by stocking density, strain or even organ in birds under summer conditions. More detailed studies still needed to be explored to elucidate the effects of environmental conditions and genetic background on physiological responses in birds.

Effects of dietary lipid-coated zinc on the antioxidant defense system in the small intestine and liver of piglets

The purpose of the study was to investigate the effects of lipid-coated ZnO (LCZ) and the level of LCZ compared with ordinary zinc oxide (ZnO) on antioxidant defense system in the intestine and liver of piglets. A total of forty piglets (n=8) were fed a diet supplemented with 100 ppm Zn with ZnO (ZnO-1), 2,500 ppm Zn with ZnO (ZnO-2), 100 ppm Zn as LCZ (LCZ-1), 200 ppm Zn as LCZ (LCZ-2), or 400 ppm Zn as LCZ (LCZ-3) for 14-d, respectively. The LCZ-3 group resulted in higher (P<0.05) mRNA expressions and activities of CuZn-superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and glutathione S-transferase (GST) in jejunal mucosa compared with the ZnO-1 and LCZ-1 groups, while no difference was observed in the mRNA level of antioxidant genes between the ZnO-1 and ZnO-2 groups. Within the LCZ groups, the LCZ level linearly and quadratically (P<0.01) increased antioxidant enzymes in the jejunum. The maximum response of jejunal antioxidant enzymes to Zn supplementation was achieved by 400 ppm of LCZ. Hepatic mRNA expression of antioxidant enzymes was unaffected by Zn source and level, while hepatic SOD and GST activities were greater (P<0.05) in the LCZ-3 group than in the ZnO-1 group. No difference was observed in lipid peroxidation of the jejunum and liver and the total antioxidant power of plasma among groups. In conclusion, a supplementation with 400 ppm of LCZ resulted in a maximum increase in antioxidant enzymes, indicating that LCZ may affect antioxidant defense system more profoundly than ZnO.

Effects of the lipid-coated zinc oxide dietary supplement on intestinal mucosal morphology and gene expression associated with the gut health in weanling pigs challenged with enterotoxigenic Escherichia coli K88

Abstract: Effects of a lipid-coated zinc oxide (ZnO) Shield Zn® (SZ) vs. ZnO were evaluated. Forty 25-d-old weanling pigs were fed a nursery diet supplemented with 100 mg kg-1 Zn with ZnO (ZnO-100), ZnO-2500, SZ-100, -200, or -400. All piglets were challenged orally with 5 × 108 colony-forming units of enterotoxigenic Escherichia coli K88 on day 7 and euthanized on day 14. The fecal consistency score (FCS) was less for the SZ group vs. ZnO-100 (P < 0.05). The intestinal villus height:crypt depth ratio and goblet cell density were greater for the SZ group vs. ZnO-100. By regression analyses, SZ-100 to -200 and SZ-300 to -400 were comparable to ZnO-2500 in the FCS and intestinal variables, respectively. The jejunal mucosal mRNA level did not differ between the SZ group and either ZnO group in insulin-like growth factor-I and multiple structural proteins and cytokines including zonula occludens protein (ZO) 1 and interleukin (IL) 10 except for lower ZO-1 and IL-10 mRNA levels for the SZ group than for ZnO-2500 and ZnO-100, respectively. The ZO-1 mRNA level regressed positively on the supplemental SZ concentration. Results suggest that SZ play a role in epithelial barrier function and inflammation by modulating the expression of ZO-1 and IL-10.

Correction to: effects of dietary supplementation of a lipid-coated zinc oxide product on the fecal consistency, growth, and morphology of the intestinal mucosa of weanling pigs

Due to a technical issue this article [1] was accidentally published in volume 59, the correct volume for this article is volume 60.

Effects of Stocking Density and Lipopolysaccharide on Immune Organ Weights, Blood Biochemical Profiles and the mRNA Expression of Pro-inflammatory Cytokines in Chicks

This study was performed to investigate the effects of the stocking density (standard stocking density (SSD, 495 cm/bird)) vs. high stocking density (HSD,245cm/bird) and challenge with lipopolysaccharide (LPS, 5mg/kg BW) on the stress-related physiological indicators in chicks. There was a significant (p<0.05) decrease in body weight, but not in the weight of immune organs, between the SSD and HSD groups. The LPS group resulted in a significant (p<0.05) increase in the weights of the thymus and bursa of fabricius compared with the SSD group. Plasma biochemical components, including aspartate transaminase (AST), alanine transaminase (ALT), blood urea nitrogen, Ca, P, creatine kinase and uric acid, markedly (p<0.05) increased in the LPS birds, although no difference in these parameters was observed between the SSD and HSD birds. Furthermore, the birds challenged with LPS showed a significant (p<0.05) increase in the plasma corticosterone level, although this hormone did not differ between the SSD and HSD groups. In the mRNA expression of pro-inflammatory cytokines, hepatic IL-1β, IL-6 and iNOS in the LPS group significantly (p<0.05) increased compared with those in the SSD group. Thymic mRNA expression of IL-1β, IL-6 and IL-18 in the LPS group also significantly (p<0.05) increased compared with those in the other groups. In addition, mRNA expression of IL-1β in the bursa of fabricius of the LPS group increased (p<0.05) without affecting the other cytokines. Under high stocking density, thymic IL-1β was the only cytokine that was up-regulated compared with the SSD group. In conclusion, an acute stress induced by LPS challenge profoundly affected immune organ weight, blood biochemical profiles and pro-inflammatory cytokine expression, while chronic stress did not markedly affect biochemical and immunological parameters, suggesting that chicks under high stocking density could be adapted to prolonged stressors. (