壳寡糖对肉仔鸡肠道主要菌群、小肠微绒毛密度、免疫功能及生产性能的影响

本试验研究目的是研究壳寡糖对肉仔鸡肠道主要菌群、微绒毛密度、免疫功能及生产性能的影响。方法 :对48只艾维因(Avian)肉仔鸡按2处理单因子设计 ,壳寡糖组和对照组各24只 ,雄、雌各半。试验日粮添加0.1 %壳寡糖 ,试验期56天。用MicrosoftExcel和Photoshop软件进行处理分析。结果表明 :壳寡糖组盲肠内容物中大肠杆菌、双歧杆菌和乳酸杆菌的数量均呈下降趋势 ;回肠微绒毛密度增加(P<0.05) ;胸腺和法氏囊相对重量增加(P<0.05) ,血清新城疫抗体效价提高(P<0.05) ;增重和料重比得到明显改善(P<0.05)。结论 :壳寡糖可抑制肉仔鸡肠道菌 ,促进微绒毛生长发育 ,提高免疫能力和生产性能。     

Dietary nucleotides enhance growth performance,feed efficiency and intestinal functional topography in European Seabass (Dicentrarchus labrax)

Nucleotides, nucleosides and nucleic acids (NU) have many critical functions in supporting life and increasing evidence suggests that exogenous supply can benefit the health of mammals and fish. For these reasons, a 6‐week feeding trial was conducted on juvenile European seabass (Dicentrarchus labrax) with diets containing 0%, 0.15% and 0.3% inclusion of a NU mixture (Laltide^®) derived from the yeast Saccharomyces cerevisiae. At the end of the study no significant differences were found in fish performance, although a tendency towards better performance was indicated in fish fed the Nu0.3 diet. In relation to histological assessment, a significantly greater perimeter ratio; internal to outer (IP/OP) was observed in the posterior intestine of fish fed supplemental NU. Microvilli heights in the posterior intestine were also shown to be significantly promoted in fish fed NU diets (p < 0.05). Goblet cell abundance was shown to be unaffected by the inclusion of NU in the diet (p > 0.05). Overall, this study indicates that orally administered NU may be effective promoters of gut functional topography with marginal associated improvements to fish performance. Nonetheless, longer exposure and/or commercial scale application, and in diets that were challenging in use of high inclusion levels of plant by‐products would potentially amplify improvements in production characteristics, in turn benefiting fish culturists.     

卡拉胶寡糖对肉仔鸡肠道菌群、小肠微绒毛及免疫功能和生产性能的影响

选择艾维因 (Avian)肉仔鸡 12 0只 ,随机分为卡拉胶寡糖组和对照组 ,每组 6 0只 ,雄、雌各半。试验日粮添加0 .1%卡拉胶寡糖 ,试验期 5 6 d。研究了卡拉胶寡糖 (Oligo- carrageenan)对肉仔鸡肠道主要菌群、微绒毛密度、免疫功能及生产性能的影响。结果表明 ,卡拉胶寡糖组鸡盲肠内容物中大肠杆菌、双歧杆菌和乳酸杆菌的数量均下降 (P<0 .0 5 ) ;回肠微绒毛密度增加 (P<0 .0 5 ) ;法氏囊相对重量增加 (P<0 .0 5 ) ,血清新城疫抗体效价提高 (P<0 .0 5 ) ;增重提高 9% ;料重比降低 2 .9%。结论 :卡拉胶寡糖可抑制肉仔鸡肠道菌的增殖 ,促进小肠微绒毛生长发育 ,提高免疫反应和生产性能     

Effects of gelatin or carboxymethyl cellulose supplementation during pelleting processing on feed quality,intestinal ultrastructure and growth performance in gibel carp (Carassius gibelio)

Gelatin and carboxymethyl cellulose (CMC) were often used as binders due to their binding ability. To investigate the effects of gelatin and CMC supplementation on feed quality, intestinal ultrastructure and growth performance of gibel carp, six pelleted feed were formulated: control; supplemented with gelatin (10 g/kg, 30 g/kg and 50 g/kg); and supplemented with CMC (10 g/kg and 30 g/kg). Increased gelatin supplementation levels reduced feed solubility and pellet softening (p < .05) and decreased chemical oxygen demand in the surrounding water after pellets were immersed (p < .05). Increased levels of gelatin supplementation enhanced digesta viscosity and reduced intestinal microvilli length and digestive enzymes activities (chymotrypsin and amylase; p < .05) of fish. Fish‐fed diets supplemented with 30 g/kg gelatin had higher levels of plasma total free amino acids and glucose (p < .05) than fish fed 10 g/kg and 50 g/kg gelatin. Feed supplemented with 10 g/kg CMC were softer than those supplemented with 30 g/kg CMC (p < .05); fish‐fed diets supplemented with 10 g/kg CMC had longer intestinal microvilli (p < .05) than fish fed 30 g/kg CMC. Thus, our results indicated that either gelatin or CMC is applicable to supplement in the feed for improving feed quality and without negative effect on growth performance of gibel carp.     

Effects of fraxinellone on the midgut ultrastructural changes of Mythimna separata Walker

Extracted from the dried root bark of Dictamnus dasycarpus Turcz., Family Rutaceae, fraxinellone exhibited multiple bioactivities, e.g. feeding-deterrent, growth-control and toxic activities against insects. We investigated the effect of fraxinellone on fifth instar larvae of eastern armyworm, Mythimna separata Walker. Through traditional stomach-poison method, fraxinellone showed the delayed and strong stomach-poison activity. Light and electron microscope observations revealed, treatment with 20 mg/mL fraxinellone, increasing damages of the larvae midgut epithelium along with time. Fraxinellone destroyed the peritrophic membrane of the midgut of larvae of M. separata. The organelles of treated larvae of M. separata changed obviously, e.g. the rough endoplasmic reticulum dilated, some of mitochondrial cristaes disappeared and got vacuolated, the wall of globet cell invaginated, the inner organelle disordered, the chromatin became concentrated, and the quantities of secondary lysosome increased. Meanwhile, fraxinellone could let microvilli rupture or incline, even partially fall off.     

Effect of dietary mannan oligosaccharide on growth,body composition,haematology and biochemical parameters of Asian seabass (Lates calcarifer)

A feeding trial was conducted to study the effect of mannan oligosaccharide (MOS) supplementation on growth, body composition, haematology, biochemical parameters and histology of Asian seabass (Lates calcarifer) fingerlings (8.13 ± 0.06 g average weight). Mannan oligosaccharide was supplemented at five different concentrations viz., 0%, 0.5%, 1%, 1.5% and 2% levels in the diet (40% protein and 9% lipid) of L. calcarifer. The results of the 60 days feeding trial showed that there was a significant (P < 0.05) increase in the final body weight, weight gain (WG), WG%, average daily gain, survival, specific growth rate, daily growth coefficient, hepatosomatic index and viscerosomatic index in the fish fed diet containing 1% MOS. Whole body composition of post‐fed animals showed non‐significant differences (P > 0.05) among the various treatment groups. The analysis of haematological parameters showed that there was no significant (P > 0.05) differences among different treatments but for the haemoglobin content which was significantly (P < 0.05) higher in the fish fed 1% MOS. Biochemical parameters revealed that glucose, urea, cholesterol and triglyceride content showed significant (P < 0.05) difference between control and MOS‐supplemented group. Histological observations of post‐fed animals revealed that MOS supplementation resulted in increased absorptive surface area of the intestine and increased glycogen deposition in liver. The result of this experiment infers that MOS supplementation has got a beneficial effect in the diet of seabass and supplementation at 1% level is optimal for improving the growth.