Longmei Zhao

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.

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.

Effects of alpha-lipoic acid supplementation on antioxidative ability and performance of sows and nursing piglets.

The current study was carried out to determine the effects of alpha-lipoic acid (LA) supplementation during late-gestation and lactation on antioxidative ability and performance of sows and their nursing piglets. A total of 160 multiparous sows were randomly allocated to four treatments with 40 replicates per treatment according to parity number and backfat (BF) thickness. Sows were fed 1 of 4 diets from day 85 of gestation to day 21 of lactation. Diets were control without LA; 400 ppm LA supplementation; 600 ppm LA supplementation; and 800 ppm LA supplementation. BF thickness of sows was determined on day 85 and 110 of gestation and days 1 and 21 of lactation. Piglet bodyweight was measured at birth, days 7, 14 and 21. Blood samples were obtained from the sows, and average daily feed intake (ADFI) of the sows during lactation was recorded. There were no differences in BF thickness or ADFI among treatment groups. Dietary LA supplementation resulted in a decrease in blood urea nitrogen (p < 0.01) concentration at days 110 of gestation. Dietary 800 ppm LA increased serum glutathione peroxidase (GSH-Px) activity (p < 0.05) and reduced maleic dialdehyde levels (p < 0.01) of sows compared with the control diet at days 21 of lactation. Alpha-lipoic acid supplementation increased the birthweight and weaning weight of piglets (p < 0.01) compared with the control group. Weight gains of piglets from sows fed the 800 ppm LA diets were greater (p < 0.01) between days 7 and 14 compared with piglets from control sows. Weight gains of piglets from sows fed the LA-supplemented diets were greater between days 14 and 21 (p < 0.05) and between days 1 and 21 (p < 0.01) compared with piglets from control-fed sows. In conclusion, the results indicate that antioxidant LA was effective in enhancing antioxidant enzymes activity and improving the performance of sows and their nursing piglets.

High-Level Overproduction of Thermobifida Enzyme in Streptomyces lividans Using a Novel Expression Vector

In this study, we constructed a novel Streptomyces-E.coli shuttle vector pZRJ362 combining the xylose isomerase promoter and amylase terminator. A gene encoding the endoglucanase Cel6A in Thermobifida fusca was amplified by PCR, cloned into Streptomyces lividans host strain using the novel expression vector and Pichia pastoris GS115 host strain using the vector pPICZα-C, respectively. Afterwards, the expression pattern and the maximum expression level were comparatively studied in both expression systems. The maximum enzyme activity of Cel6A-(His)6 secreted in S. lividans supernatant after 84-h of cultivation amounted to 5.56 U/mL, which was dramatically higher than that secreted in P. pastoris about 1.4 U/mL after 96-h of cultivation. The maximum expression level of Cel6A-(His)6 in S. lividans supernatant reached up to 173 mg/L after 84-h of cultivation. The endoglucanase activity staining SDS-PAGE showed that there were some minor proteins in S. lividans supernatant which may be the Cel6A derivant by proteolytic degradation, while there was no proteolytic product detected in supernatant of P. pastoris.

Phytase transgenic corn in nutrition of laying hens: Residual phytase activity and phytate phosphorus content in the gastrointestinal tract

The residual activities of transgenic corn-derived and 2 commercial microbial phytases (PA and PB) along the gastrointestinal tract (GIT) of laying hens were compared to evaluate their relative resistance to hydrolysis in the GIT when added to P-deficient diets. The treatments consisted of a negative control (NC) diet containing 0.10 nonphytate P and an NC diet supplemented with transgenic corn-derived phytase (TCDP), PA, and PB at 500 to 5,000 FTU/kg of diet, respectively. Seven diets were fed to Hy-Line Brown laying hens (n = 504; 8 replicates of 9 hens per treatment) for 21 d. At the end of the experiment, the hens were killed and digesta samples from the crop, proventriculus and gizzard, jejunum, and ileum were collected and analyzed for residual phytase activities and phytate P content. Phytase activity in the transgenic corn was determined to be 8,980 FTU/kg of DM. The residual phytase activities along the GIT had increased (P < 0.01) with the addition of TCDP, PA, and PB to the NC diets. The TCDP had higher residual activity (P < 0.05) in the crop, proventriculus and gizzard, jejunum, and ileum as compared with the PA and PB activity. There was a decrease (P < 0.01) in the phytate P content of the digesta from all sources of phytase supplementation in the NC diets. Residual phytate P content decreased caudally along the GIT of hens. The results of this research indicate that phytase expressed in corn is as efficacious as the commercial microbial phytases (PA and PB) in P-deficient diets for the improvement of phytate P digestibility, which would eliminate the need for supplemental phytase and corn separately in laying hen diets.

Effect of sodium selenite and selenium yeast on performance, egg quality, antioxidant capacity, and selenium deposition of laying hens

ABSTRACT This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. Two‐hundred‐eighty‐eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (corn‐soybean meal diet) were supplemented with 0 [blank control (BC)], 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se‐supplemented diets and the BC diet. The serum glutathione peroxidase (GSH‐Px) activity was increased (P < 0.01) in hens fed Se‐supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se‐supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition.

Response surface optimization of enzymatic hydrolysis of duck blood corpuscle using commercial proteases

With the rapid development in livestock and poultry husbandry and increasing shortage of protein sources, recycling of wastes from agricultural and food processing such as blood corpuscles has been regarded as an important industrial procedure to obtain protein sources. This study aimed to find an appropriate method for recycling the considerable amounts of blood corpuscle so as to improve its nutritional value and organoleptic quality. An effective production process for enzymatic hydrolysis of duck blood corpuscle was successfully developed and optimized by response surface methodology. Optimal conditions based on achieving a high value of trichloroacetic acid solubility index were substrate concentration of 14 g/100 mL, temperature 51°C, initial pH 7.0, and time 7.5 h. The electrophoretic patterns of the protein hydrolysate were investigated, and a large diffuse band was observed in the vicinity of 5 kDa. The organoleptic quality of spray-dried blood corpuscle hydrolysate was also evaluated, indicating that enzymatic hydrolysis and decoloration methods were feasible and cost-effective to achieve the desirable bright yellow product without bitterness. In vitro protein digestibility of blood corpuscle hydrolysate was 96.32 ± 0.50%, which was better than that of soybean, fish meal, and casein. Based on the amino acid composition and nutritional parameters, we found that the spray-dried blood corpuscle hydrolysate had abundant nutritional value and high potential for application as an ingredient in nonruminant animal feed.

No copper supplementation in a corn-soybean basal diet has no adverse effects on late-phase laying hens under normal and cyclic high temperatures

ABSTRACT Over supplementation of copper (Cu) in animal diets may cause serious pollution in soil, water and harvested crops. To minimize the potential pollution, the effects of corn‐soybean basal diet with or without supplementation of 8 mg Cu/kg on laying performance, plasma biochemical metabolic indices, and antioxidant status in laying hens were evaluated under normal and cyclic high temperatures. A total of 240 Hy‐Line Brown laying hens were randomly allotted to 4 treatments with 6 replicates of 10 hens per replicate according to factorial design involved in 2 temperatures [normal temperature (NT) vs. cyclic high temperature (CHT)] and 2 dietary Cu addition amount [Cu0 (0 mg/kg) vs. Cu8 (8 mg/kg in the form of CuSO4·5H2O)]. The experimental period included 1‐week adaptation, 2‐week heat stress and 2‐week convalescence. The temperatures of NT groups in the same period or any groups during other periods were kept at 26 ± 2°C except that of CHT groups were 26 ± 2°C˜33 ± 2°C cyclically during heat stress period. CHT groups increased (P < 0.05) the rectal temperature and plasma glucose content under heat stress, but decreased (P < 0.01) the egg yield at the second week of heat stress and the first week of convalescence, and the plasma triglyceride, uric acid, and triiodothyronine levels under heat stress. Cu8 groups increased (P < 0.05) egg weight at the first week of convalescence, and plasma thyroxin level during the whole convalescence. Interactions between temperature and Cu content existed (P < 0.05) in the laying rate at the first week of convalescence, and the plasma lactic dehydrogenase level under heat stress. Conclusively, the CHT impaired laying performance. The Cu content (10.3 mg/kg) in corn‐soybean basal diet might be sufficient for meeting the maintenance and production requirements of late‐phase laying hens, and no Cu supplementation had no adverse effects on egg production and antioxidant indices under cyclic high (26 ± 2°C˜33 ± 2°C) or normal (26 ± 2°C) temperatures.