Effect of chicken egg yolk immunoglobulins on serum biochemical profiles and intestinal bacterial populations in early‐weaned piglets

This study was conducted to test the hypothesis that dietary supplementation with anti‐E. coli, chicken egg yolk immunoglobulins (IgY), may affect early weaned piglet (EWP) intestinal functions and enteric micro‐organisms. One hundred and forty‐eight ([Landrace × Yorkshire] × Duroc) piglets, weaned at age day 21, were randomly assigned to receive one of three diets for 14 days. Treatment group one (control group) was fed the base diet. Treatment group two (antibiotics group) was fed the base diet which was supplemented with 100 ppm colistin sulphate and 15 ppm enramycin; treatment group three (IgY group) was fed the base diet which was supplemented with 500 mg/kg anti‐E. coli IgY. The study evaluated the effects on EWPs of IgY on growth, serum biochemical, inflammatory profiles and also digestion content intestinal bacterial populations. Results showed no significant difference in diarrhoea rates between IgY‐fed EWPs and antibiotic‐treated EWPs. Serum biochemical analysis showed that EWPs fed an IgY‐containing diet had both lower (p < 0.05) cholesterol and low‐density lipoprotein compared to antibiotic‐treated EWPs. Escherichia coli populations measured in IgY‐fed EWP ileal contents, compared to the control group, were significantly reduced (p < 0.05). Enterococcus, Lactobacillus, Clostridium and Bifidobacterium populations were unaffected by the IgY treatment. Larger (p < 0.05) Enterococcus populations and lower (p < 0.05) expression levels of heat‐stable enterotoxin b (STb) were observed in IgY‐fed EWP caecal digesta compared to the control group. Enteric Lactobacillus significantly decreased (p < 0.05) in EWPs fed antibiotics while it was unaffected by IgY treatment. Dietary supplementation with anti‐E. coli IgY has the potential to suppress enteric E. coli growth, but not Lactobacillus, Clostridium and Bifidobacterium. This promotes and maintains a healthy EWP intestinal environment. These findings suggest that IgY may be used as an alternative to antibiotics in EWP diets.     

复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响

为研究探讨肉仔鸡日粮中添加不同剂量的复合微生态制剂对肉仔鸡生长性能、肠道菌群和免疫功能的影响,以期为复合微生态制剂的临床应用提供参考依据,将150只AA白羽肉仔鸡随机分成5个处理组(对照组、抗生素组、复合微生态制剂Ⅰ组、复合微生态制剂Ⅱ组、复合微生态制剂Ⅲ组),对照组饲喂基础日粮,抗生素组在基础日粮中添加0.05%的肉鸡饲用金霉素,复合微生态制剂Ⅰ、Ⅱ和Ⅲ组分别在基础日粮中添加0.05%、0.1%、0.2%的复合微生态制剂,测定平均日增重、平均日采食量、料重比、大肠杆菌数、沙门氏菌数、双歧杆菌数、乳酸杆菌数、胸腺指数、法氏囊指数、IgG含量、IgA含量、IgM含量等指标。结果显示,与对照组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加平均日采食量、平均日增重、乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。与抗生素组相比,复合微生态制剂Ⅱ组、Ⅲ组可显著增加乳酸杆菌数、双歧杆菌数、胸腺指数、脾脏指数、法氏囊指数、IgA含量和IgG含量(P<0.05),显著降低料重比、大肠杆菌和沙门菌数(P<0.05)。表明肉仔鸡饲料中添加0.1%、0.2%的复合微生态制剂可显著改善提高肉仔鸡的生长性能、肠道菌群和免疫功能,其在改善肠道菌群和免疫功能方面的作用效果显著优于抗生素。     

饲料中添加枯草芽孢杆菌对团头鲂幼鱼生长性能、肝脏抗氧化指标、肠道菌群结构和抗病力的影响

本试验旨在研究饲料中添加枯草芽孢杆菌对团头鲂幼鱼生长性能、肝脏抗氧化指标、肠道菌群结构和抗病力的影响。选取初始体重为(1.81±0.01)g的团头鲂幼鱼360尾,随机分为4组(每组3个重复,每个重复30尾),分别饲喂添加0(T0组,作为对照组)、2×10~7(T1组)、2×10~8(T2组)、2×10~9CFU/g枯草芽孢杆菌(T3组)的等氮等脂饲料。试验期为8周。结果表明:1)与对照组相比,T1组和T2组团头鲂幼鱼的增重率、特定生长率显著升高(P0.05),且T1组的饲料系数显著降低(P0.05)。2)与对照组相比,T1组团头鲂幼鱼的肝脏抗氧化酶(超氧化歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶)活性显著升高(P0.05),同时该组肝脏丙二醛含量显著降低(P0.05)。3)各组全鱼水分、粗蛋白质、粗脂肪和粗灰分含量均无显著差异(P0.05)。4)变性梯度凝胶电泳(DGGE)图谱显示摄食不同添加量枯草芽孢杆菌饲料的团头鲂幼鱼的肠道菌群结构发生了改变。5)采用嗜水气单胞菌对鱼体进行攻毒,各组96 h后的累积死亡率未产生显著差异(P0.05),但T1组和T2组的累积死亡率低于对照组和T3组。由此可见,饲料中添加2×10~7CFU/g的枯草芽孢杆菌能够提高团头鲂幼鱼的生长性能、抗氧化能力,并改变肠道菌群结构,但对其体成分和抗病力没有显著影响。     

Salmonella enterica infections in Spanish swine fattening units

The present study is the first conducted in Spain to estimate the bacteriological herd prevalence of Salmonella enterica in fattening units and to describe the Salmonella serovar diversity on these farms using a sample representative of the entire swine population. For this purpose, 10 faecal samples were collected from 10 different pens containing pigs close to market weight in a total of 232 fattening units. Total sample size was proportionally distributed according to the fattener census in each of the regions of the country and all the samples were examined by culture of 25 g of faecal material. One hundred (43.1%) farms had at least one Salmonella-positive sample (95% CI: 37-49.1%). Salmonella enterica was detected in 290 (12.5%) pooled faecal floor samples (95% CI: 11.2-13.8%). The apparent herd prevalence of salmonellosis was similar among multi-site, finishing and farrow to finish farms. Overall, 24 different serovars were identified, with S. Typhimurium, S. Rissen and S. Derby being the most common both at herd and sample level. Results of phage typing were available for the 91 isolates of S. Typhimurium. A total number of 10 different phage types were identified, with DT 193 being the most frequent. Phage types DT 104, DT 104b and DT U302, which have been associated with several multi-resistant patterns, accounted for 23% and 29% of the Typhimurium total isolates or Typhimurium infected farms respectively.     

鸡空肠和盲肠微生物区系的研究

应用２０日龄白来航小母鸡的肠道内容物,研究消化道部分区段微生物区系,分离鉴定出需氧菌和厌氧菌,并进行了毒力试验。结果表明,每克肠内容物含细菌的对数值（ｌｏｇｎ／ｇ）为：空肠中消化球菌９．６±０．２、双歧杆菌９．４±０．５、拟杆菌１０．６±０．６、葡萄球菌６．６±０．６、乳杆菌９．３、肠杆菌６．８±０．４;盲肠中葡萄球菌６．７±０．６、消化球菌９．８±０．３、双歧杆菌９．２±０．８、拟杆菌１０．２±０．２、棒状杆菌８．７±０．４、肠杆菌６．８±０．３、链球菌７．２±０．２、乳杆菌９．６±０．４、酵母菌４．２±１．４．     

Effect of dietary thiamin supplement on immune responses and intestinal microflora in juvenile Jian carp (Cyprinus carpio var. Jian)

This study was to investigate the effect of dietary thiamin on the immune response and intestinal microflora in juvenile Jian carp (Cyprinus carpio var. Jian). Seven diets (0.25, 0.48, 0.79, 1.06, 1.37, 1.63 and 2.65 mg thiamin kg^?1) were fed to Jian carp (8.20 ± 0.02 g). At the end of feeding trial, red blood cell counts and white blood cell counts increased with increasing dietary thiamin levels up to 0.79 and 1.06 mg kg^?1 diet, respectively (P < 0.05); Lactobacillus counts in intestine increased gradually, and maximum values obtained when the thiamin level was at 0.79 mg kg^?1 diet (P < 0.05). After the feeding trial, fish were injected with Aeromonas hydrophila only one time on the first day of the challenge trial and fed the same diets as the growth trial for 17 days. The survival rate, leucocyte phagocytic activity, lectin potency, acid phosphatase activity, lysozyme activity, total iron‐binding capacity and immunoglobulin M content of fish after being injected with A. hydrophila were all improved with increasing dietary thiamin levels up to a point, respectively (P < 0.05). These results suggested that thiamin could improve immune response and the balance of intestinal microflora of juvenile Jian carp.     

Validation of enzyme-linked immunosorbent assay for measurement of faecal cortisol in fish

Quantification of glucocorticoid (GC) levels in faeces has become an established method for the non-invasive assessment of adrenocortical activity. These hormones are frequently determined in plasma samples as parameters of adrenal activity and response to stress. Because GCs are metabolized and excreted with both intact hormone and their metabolites present in faeces, the concentration of GCs can be measured in excreta. Faecal samples present the advantages of easy collection, no stress to the animal and elimination of the issue of potentially misleading acute GC spikes. The aim of this study was to determine if an enzyme-linked immunosorbent assay (ELISA) for cortisol was appropriate for monitoring adrenocortical activity in faecal casts of fishes. Performance of the cortisol ELISA was validated by comparison to high-performance liquid chromatography, which is an established method for measuring free GCs and GC metabolites in faeces. Parallelism and sample extraction efficiency were compared for the two methods. Pearson's correlation across samples for these methods was 0.996. Results demonstrated that the ELISA was an efficient, sensitive and reliable method for cortisol measurement in faecal extracts, which should permit integration of non-invasive stress monitoring into studies of fish behaviour and physiology.     

Effects of dietary pyridoxine on disease resistance,immune responses and intestinal microflora in juvenile Jian carp (Cyprinus carpio var. Jian)

This experiment was conducted to evaluate the effects of dietary pyridoxine on disease resistance, immune responses and intestinal microflora of fish. A total of 1050 Jian carp (11.71 ± 0.05 g) were randomly distributed into seven groups, feeding diets containing graded levels of pyridoxine (0.2, 1.7, 3.2, 5.0, 6.3, 8.6 and 12.4 mg kg^?1 diet). After 80 days of feeding, a challenge trial was conducted by injection of Aeromonas hydrophila for 17 days. Results indicated that with increasing dietary pyridoxine concentration up to 5.0 mg kg^?1 diet, survival rate after challenge with A.hydrophila and phagocytic activity of leukocyte were improved (P < 0.05), and plateaued thereafter (P > 0.05). Red blood cell and white blood cell counts were lowest when fed the diet containing 1.7 mg pyridoxine kg^?1 diet. Haemagglutination titre, lysozyme activity, acid phosphatase activity, total iron‐binding capacity, antibody titre and immunoglobulin M content followed the similar pattern to that observed with survival rate. Aeromonas hydrophila, Escherichia coli and Lactobacillus counts in intestine were not affected by dietary pyridoxine concentration (P > 0.05). These results suggested that pyridoxine could enhance immune response of fish.     

Effect of disinfection with peracetic acid on the microbial community of a seawater aquaculture recirculation system for Pacific white shrimp (Litopenaeus vannamei)

When tropical shrimps are kept in recirculating aquaculture systems (RAS), one of the limiting factors is the maintenance of a sufficient water quality, and therefore, often disinfectants like peracetic acid (PAA) are added to the water either as prophylactic or treatment measure. In this study, PAA in concentrations of 0.1 mg/L, 1 mg/L and 10 mg/L was applied continuously for 56 days to small-scale seawater RAS stocked with Litopenaeus vannamei. Treatment with 0.1 mg/L did not result in a reduction in the total bacterial amount and therefore was not effective. A concentration of 10 mg/L led to significant changes in the chemical water parameters already after 2 days and was therefore not recommendable. A concentration of 1 mg/L led to increased levels of ammonia and nitrite within 2 days and to a significant increase in the bacterial amount in the water, most probably due to an enhanced growth of heterotrophic bacteria. The microflora showed significant fluctuations, and there were indications that the welfare of the shrimps was affected. Using 1 mg PAA/L for prophylactic use is therefore also not recommendable but might be an alternative option for short-term treatment in cases of disease outbreaks.