Jianyun Zhang

Effects of Lipoic Acid on Immune Function, the Antioxidant Defense System, and Inflammation-Related Genes Expression of Broiler Chickens Fed Aflatoxin Contaminated Diets

This study was designed to evaluate the effect of low level of Aflatoxin B1 (AFB1) on oxidative stress, immune reaction and inflammation response and the possible ameliorating effects of dietary alpha-lipoic acid (α-LA) in broilers. Birds were randomly allocated into three groups and assigned to receive different diets: basal diet, diet containing 74 μg/kg AFB1, and 300 mg/kg α-LA supplementation in diet containing 74 μg/kg AFB1 for three weeks. The results showed that the serum levels of malondialdehyde, tumor necrosis factor alpha (TNFα) and interferon gamma (IFNγ) in the AFB1-treated group were significantly increased than the control group. In addition, the increased expressions of interleukin 6 (IL6), TNFα and IFNγ were observed in birds exposed to the AFB1-contaminated diet. These degenerative changes were inhibited by α-LA-supplement. The activities of total superoxide dismutase and glutathione peroxidase, the levels of humoral immunity, and the expressions of nuclear factor-κB p65 and heme oxygenase-1, however, were not affected by AFB1. The results suggest that α-LA alleviates AFB1 induced oxidative stress and immune changes and modulates the inflammatory response at least partly through changes in the expression of proinflammatory cytokines of spleen such as IL6 and TNFα in broiler chickens.

Dietary Lipoic Acid Influences Antioxidant Capability and Oxidative Status of Broilers

The effects of lipoic acid (LA) on the antioxidant status of broilers were investigated. Birds (1 day old) were randomly assigned to four groups and fed corn-soybean diets supplemented with 0, 100, 200, 300 mg/kg LA, respectively. The feeding program included a starter diet from 1 to 21 days of age and a grower diet from 22 to 42 days of age. Serum, liver and muscle samples were collected at 42 days of age. For antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in serum, liver and breast muscle significantly increased in chickens fed with LA. The concentration of malondiadehyde (MDA), an indicator of lipid peroxidation, was significantly lower in serum, liver and leg muscle in birds that received LA than in the control group. Treatments with LA significantly increased glutathione (GSH) content in liver and increased α-tocopherol content in leg muscle as compared to the control. These results indicate that dietary supplementation with 300 mg/kg LA may enhance antioxidant capability and depress oxidative stress in broilers.

Protective effect of Bacillus subtilis ANSB060 on egg quality, biochemical and histopathological changes in layers exposed to aflatoxin B1

Bacillus subtilis ANSB060 from the fish gut had strong ability to detoxify aflatoxins. The aim of this research was to investigate the protective effect of B. subtilis ANSB060 (ANSB060) on egg quality and biochemical and histopathological changes of liver and kidney in laying hens when exposed to aflatoxin B(1). Treatments (C20, C40, and C60) were prepared by substituting corn contaminated by aflatoxin B(1) (AFB1) at different proportions (20, 40, and 60%) for normal corn in basic diets. The aflatoxin degradation enzyme (E) treatments (E20, E40, and E60) were mixed with the fermentation liquor of ANSB060 with C20, C40, and C60, respectively. The results showed that ANSB060 can improve the eggshell strength in E60 compared with C60 (P ≤ 0.05), and toxin reduced the content of total protein (in groups C20, C40, and C60) and albumin (in C20 and C40; P < 0.05) and heightened the activities of GPT (in C60) and GOT (in C40 and C60) in serum (P < 0.05). In the liver, AFB1 inhibited the activity of superoxide dismutase and glutathione peroxidase (C40 and C60; P < 0.05) and increased the content of malonaldehyde (in C40 and C60), which induced the damage in the liver and kidney as shown in the photomicrographs of hematoxylin and eosin-stained sections. The addition of ANSB060 can enhance the activity of antioxidant enzymes, and it recovered the protein synthesis in liver. Moreover, ANSB060 also ameliorated the damage of liver and kidney tissue and restored them to normal. Hence, ANSB060 had the ability to inhibit the damage induced by AFB1; it will have a great potential in industrial applications.

Molecular Mechanisms of Lipoic Acid Protection against Aflatoxin B1-Induced Liver Oxidative Damage and Inflammatory Responses in Broilers

Alpha-lipoic acid (α-LA) was evaluated in this study for its molecular mechanisms against liver oxidative damage and inflammatory responses induced by aflatoxin B1 (AFB1). Birds were randomly allocated into four groups with different diets for three weeks: a basal diet, a 300 mg/kg α-LA supplementation in a basal diet, a diet containing 74 μg/kg AFB1, and 300 mg/kg α-LA supplementation in a diet containing 74 μg/kg AFB1. In the AFB1 group, the expression of GSH-PX mRNA was down-regulated (p < 0.05), and the levels of lipid peroxide and nitric oxide were increased (p < 0.05) in the chicken livers compared to those of the control group. Additionally, the mRNA level of the pro-inflammatory factor interleukin-6 was up-regulated significantly (p < 0.05), the protein expressions of both the nuclear factor kappa B (NF-κB) p65 and the inducible nitric oxide synthase were enhanced significantly (p < 0.05) in the AFB1 group. All of these negative effects were inhibited by α-LA. These results indicate that α-LA may be effective in preventing hepatic oxidative stress, down-regulating the expression of hepatic pro-inflammatory cytokines, as well as inhibiting NF-κB expression.

Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins

Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize), M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize), M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060). The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB1 (M0) exhibited a decreasing tendency in average daily gain (ADG) and total superoxide dismutase (T-SOD) activity in serum, and T-SOD and glutathione peroxidase (GSH-Px) activities in the liver significantly decreased along with the appearance of AFB1 and AFM1 compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks (p > 0.05), significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

Detection of Transgenic and Endogenous Plant DNA Fragments and Proteins in the Digesta, Blood, Tissues, and Eggs of Laying Hens Fed with Phytase Transgenic Corn

The trials were conducted to assess the effects of long-term feeding with phytase transgenic corn (PTC) to hens on laying performance and egg quality, and investigate the fate of transgenic DNA and protein in digesta, blood, tissues, and eggs. Fifty-week old laying hens (n = 144) were fed with a diet containing 62.4% PTC or non-transgenic isogenic control corn (CC) for 16 weeks. We observed that feeding PTC to laying hens had no adverse effect on laying performance or egg quality (P>0.05) except on yolk color (P<0.05). Transgenic phyA2 gene and protein were rapidly degraded in the digestive tract and were not detected in blood, heart, liver, spleen, kidney, breast muscle, and eggs of laying hens fed with diet containing PTC. It was concluded that performance of hens fed diets containing PTC, as measured by egg production and egg quality, was similar to that of hens fed diets formulated with CC. There was no evidence of phyA2 gene or protein translocation to the blood, tissues, and eggs of laying hens.

Protective Effects of Bacillus subtilis ANSB060 on Serum Biochemistry, Histopathological Changes and Antioxidant Enzyme Activities of Broilers Fed Moldy Peanut Meal Naturally Contaminated with Aflatoxins

The aim of this study was to investigate the toxic effects of aflatoxins and evaluate the effectiveness of Bacillus subtilis ANSB060 in detoxifying aflatoxicosis in broilers. A total of 360 one-week-old male broilers (Ross 308) were assigned to six dietary treatments for five weeks. The treatment diets were: C0 (basal diet); C1.0 (C0 + 1.0 g B. subtilis ANSB060/kg diet); M0 (basal diet formulated with moldy peanut meal); M0.5, M1.0 and M2.0 (M0 + 0.5, 1.0 and 2.0 g B. subtilis ANSB060/kg diet, respectively). The contents of aflatoxin B1, B2, G1 and G2 in the diets formulated with moldy peanut meal were 70.7 ± 1.3, 11.0 ± 1.5, 6.5 ± 0.8 and 2.0 ± 0.3 µg/kg, respectively. The results showed that aflatoxins increased (p < 0.05) serum aspartate transaminase activity, decreased (p < 0.05) serum glutathione peroxidase activity, and enhanced (p < 0.05) malondialdehyde contents in both the serum and liver. Aflatoxins also caused gross and histological changes in liver tissues, such as bile duct epithelium hyperplasia, vacuolar degeneration and lymphocyte infiltration. The supplementation of ANSB060 reduced aflatoxin levels in the duodenum and counteracted the negative effects of aflatoxins, leading to the conclusion that ANSB060 has a protective effect against aflatoxicosis and this protection is dose-related.

Degradation of zearalenone in swine feed and feed ingredients by Bacillus subtilis ANSB01G

Zearalenone (ZEA) and its derivatives are mycotoxins that can cause oestrogenic effects and impair the reproductive physiology of animals, especially in female swine. Strategies to reduce or eliminate ZEA contamination in foods and feeds are very much needed. Among 36 bacterial isolates obtained from a variety of animal intestinal chyme, mouldy foods and feeds, soils, etc., five isolates demonstrated the ability to reduce more than 50% of ZEA in a liquid medium; ANSB01G isolate taken from normal broiler intestinal chyme reduced ZEA the most, by 88.65%. Using physiological, biochemical, and 16S rRNA gene sequence analysis methods, the ANSB01G isolate was identified as Bacillus subtilis. Under simulated intestinal tract conditions, the ANSB01G B. subtilis isolate degraded 84.58, 66.34 and 83.04% of ZEA in naturally contaminated maize, dried distillers’ grains with solubles, and swine complete feed, respectively. The highest degradation of ZEA occurred when the mycotoxin was co-incubated with the whole bacte...

Effects of dietary α-lipoic acid, acetyl-l-carnitine, and sex on antioxidative ability, energy, and lipid metabolism in broilers

An experiment was conducted to evaluate the effects of dietary α-lipoic acid (LA), acetyl-l-carnitine (ALC), and sex on antioxidative ability, energy, and lipid metabolism in broilers. A total of 972 one-day-old broilers with equal sex were randomly assigned in a 3 × 3 × 2 factorial design using 3 LA, 3 ALC levels, and 2 sexes (6 replications, 9 birds/replication). The LA and ALC levels were 0, 50, and 100 mg/kg, respectively. Results showed that increased LA or ALC resulted in increased total antioxidant capacity and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and decreased levels of malondialdehyde in serum and liver of birds (P < 0.05). In addition, with increasing addition of LA or ALC, an increased (P < 0.01) level of insulin (Ins), as well as decreased (P < 0.05) levels of glucose and glucagon (Glu), were observed in serum of broilers. Total cholesterol and triglyceride (TG) levels decreased (P < 0.05) and nonesterified fatty acid, lipoprotein lipase, and lipase levels increased (P < 0.05) in serum with increased administration of LA or ALC. Moreover, a significant (P < 0.05) interaction of LA × ALC was observed for serum and liver SOD, serum GSH-Px, glucose, and TG levels. Birds fed diets containing 50 mg/kg of LA and 50 mg/kg of ALC had higher serum and liver SOD activities and lower serum glucose and TG levels than those fed diets containing 100 mg/kg of LA or ALC alone. The main effect of sex and all interactions among main effects (except LA × ALC) were not significant (P > 0.05) for all of the above parameters. Overall, the present data indicate that LA or ALC supplementation, or both, at low levels (50 or 100 mg/kg) improved antioxidative ability, energy metabolism, and lipid metabolism in broilers, and synergistic effects by the combined supplementation of LA and ALC were indicated by serum and liver SOD activities and serum glucose and TG levels.

Ameliorative effects of Bacillus subtilis ANSB01G on zearalenone toxicosis in pre-pubertal female gilts

The purpose of this research was to investigate the toxicity of zearalenone (ZEA) on the growing performance, genital organs, serum hormones and histopathological changes of pre-pubertal female gilts, and to evaluate the efficacy of Bacillus subtilis ANSB01G in alleviating ZEA toxicosis in gilts. Eighteen pre-pubertal female gilts were randomly allocated to three treatments with one replicate per treatment. The gilts were fed following three diets for 24 days: the Control group was given a basic diet with normal corn; Treatment 1 (T1) was prepared by substituting corn naturally contaminated with ZEA for all normal corn in the basic diet (with a final concentrations of 238.57 μg kg−1 of ZEA); and Treatment 2 (T2) was prepared by mixing the T1 diet with 2 kg T−1 of fermented–dried culture of ANSB01G. The results showed that the presence of ZEA in diets significantly increased the vulva size and reproductive organ weight of the T1 gilts as compared with the Control group, and the addition of ANSB01G to diet naturally contaminated with ZEA obviously ameliorated these symptoms, as was observed in the T2 group. The presence of low doses of ZEA in the T1 diet had no significant effect on the level of follicle-stimulating hormone (FSH), luteotrophic hormone (LH) or serum oestradiol (E2) in the serum of gilts, but the prolactin (PRL) level in group T1 increased significantly. The gilts of the T1 group exhibited conspicuous cell enlargement and fatty degeneration of the corpus uteri, swelling, inflammation and lymphocyte infiltration of liver cells as compared with the Control group. The presence of ANSB01G can alleviate these hyperoestrogenic effects caused by ZEA, maintaining the body of gilt in a normal and healthy status. It is suggested that reproductive organs of gilts are seriously affected even if they are fed a low dose of ZEA in less time, and the addition of B. subtilis ANSB01G can effectively alleviate ZEA toxicosis in gilts.