Effect of inland water salinity on growth,feed conversion efficiency and intestinal enzyme activity in growing grey mullet, <Emphasis Type="Italic">Mugil cephalus</Emphasis> (Linn.): Field and laboratory studies

Two experiments were conducted to investigate the effect of inland water salinity on growth performance, feed conversion efficiency and intestinal enzyme activity in grey mullet. In experiment I, a 90 day monoculture of grey mullet at different salinity levels (0, 10, 15, 20 and 25%) was carried out. The fingerlings were stocked at 5000 per hectare and fed on a supplementary diet at 5% BW d^–1. This Study revealed that fish growth mean body weight (90.5 ± 4.5 g) and mean length (21.6 ± 0.4 cm), SGR (4.70%) and growth per day (0.99 g d^–1) were significantly (p < 0.05) enhanced in fish maintained at 10% salinity in comparison with other treatments. Nutrient levels, phytoplankton population, NPP and chlorophyll a all decreased with an increase in salinity (>10%). In addition, zooplankton populations increased with an increase in the salinity level. Most of the other hydrochemical characteristics remained at optimal levels in all other treatments. Fish weight gain showed a significant positive correlation with productivity indicating parameters viz. alkalinity (r = 0.53), turbidity (r = 0.62), NPP (r = 0.75) and chlorophyll a (r = 0.46), clearly revealing that fish growth is also related to the trophic status of the ponds. In the second experiment (Experiment II), mullet fry were exposed to five different salinity levels (10, 15, 20, 25 and 30%) and maintained for 70 days in the laboratory. Significantly (p < 0.05) high growth, (SGR and per cent increase in body weight), feed conversion efficiency and intestinal enzyme activity were observed in the group maintained at 10 salinity in comparison with other groups maintained at similar salinity levels. Carcass composition, musc1e and liver glycogen levels were also significantly (p < 0.05) affected by salinity changes.     

A study of the pattern of digestive enzymes in Diplodus puntazzo (Cetti, 1777) (Osteichthyes, Sparidae): evidence for the definition of nutritional protocols

The digestive enzymes (proteases, carbohydrases and lipases) present along the alimentary tract of juveniles and adults of Diplodus puntazzo were studied. The data obtained showed a different distribution of the enzymatic activities in the different parts of the alimentary tract. Levels of enzymatic activity in the adults were higher than those measured in juveniles, suggesting that adults have a greater ability to digest larger pieces of food. The enzymatic pattern of D. puntazzo justifies its omnivorous habit and suggests an high potential for digesting vegetable polysaccharides. The results of this study suggest the need to adapt the diet to the digestive potential of this new farming species, thus contributing to the attainment of a product that is qualitatively more similar to the wild one.     

伊维菌素驱除黄牛消化道线虫试验

试验选择自然感染多种消化道线虫的黄牛１６头，分为４组，一组为对照组，其余３组为对照组，分别按０．１ｍｇ／ｋｇ、０．２ｍｇ／ｋｇ、０．３ｍｇ／ｋｇ体重的剂量颈部皮下注射１％伊维菌注射液。结果表明，按０．１ｍｇ／ｋｇ体重的剂量给药，伊维菌素对黄牛多种消化道线虫有驱除作用，其中，对捻转血矛线虫、蛇形毛圆线虫、仰口线虫有高效；对食道口线虫、奥斯特线虫、细颈线虫、指形长刺线虫为中效或低效，按０．２ｍｇ／ｋｇ     

间歇性干旱对福寿螺生长、抗氧化能力和消化酶活性的影响

福寿螺(Pomacea canaliculata)是首批列入我国外来入侵物种黑名单的生物。本文采用干旱后复水方式喂养福寿螺48 d,研究间歇性干旱处理下福寿螺摄食生长、肝胰脏抗氧化能力及胃消化酶活力变化。结果显示:间歇性干旱能够显著降低福寿螺的体重增长率,对存活率影响不明显;福寿螺在恢复摄食期间出现部分补偿生长现象,主要是通过复水后增大摄食量来实现的,当间歇性干旱时间间隔延长到8 d时,则是通过增大摄食量和提高食物转化率的双重作用来实现的;除间隔4 d间歇性干旱下SOD酶活力以外,福寿螺在短间隔(1~4 d)间歇性干旱下SOD和CAT活力均出现不同程度的增加,而MDA含量明显降低;在长间隔(8 d)间歇性干旱下,SOD和CAT活力均低于对照组,且MDA含量与对照组无差别;间歇性干旱降低了福寿螺肝胰脏中GST和GSH-PX活性,对GSH含量无明显影响;除间隔1 d的处理组胃脂肪酶外,间歇性干旱能够不同程度地提高福寿螺胃淀粉酶和胃脂肪酶活力。总体而言,在间歇性干旱胁迫下,福寿螺可通过提高摄食率、食物转化率、抗氧化能力、消化酶活性等,在一定程度上来缓解胁迫带来的影响,但间歇性干旱能够明显抑制福寿螺的正常生长,表明通过农田水位交替性变化可在一定程度上防控福寿螺的暴发与危害。     

稻谷型日粮添加非淀粉多糖酶对生长猪消化道结构和功能的作用研究

 用 90头 (35± 0 .4 0kg)长嘉二元生长猪为试验对象 ,研究了稻谷型日粮中添加非淀粉多糖 (NSP)酶对其消化道结构和功能的影响。结果表明 ,(1)添加非淀粉多糖酶组日增重提高 8.78% (P <0 .0 5 ) ,料重比降低9.4 2 % (P <0 .0 5 ) ,与玉米组相比无差异 ;(2 )添加非淀粉多糖酶使十二指肠内容物中的总蛋白水解酶、淀粉酶活性分别升高了 99.0 7% (P <0 .0 1)和 18.4 1% (P <0 .0 5 ) ;胃内容物中胃蛋白酶 ,十二指肠内容物中胰蛋白酶、脂肪酶 ,空肠粘膜和回肠粘膜中二糖酶、氨肽酶活性均有升高趋势 (P >0 .0 5 ) ;(3)添加非淀粉多糖酶组十二指肠、空肠、回肠绒毛高度分别提高了 2 3.6 8% (P <0 .0 5 )、5 6 .0 0 % (P <0 .0 1)和 76 .90 % (P <0 .0 1) ;微绒毛排列较规则且高度有升高趋势 (P >0 .0 5 )。本研究结果揭示 ,非淀粉多糖酶能显著改善生长猪消化道结构和功能 ,提高饲料养分的消化吸收 ,促进其生长。     

消化法培养山羊乳腺上皮细胞

为了寻找更加有效的山羊乳腺上皮细胞分离纯化方法。用2 g/L胶原酶和0.5 g/L胰蛋白酶相结合的消化法培养山羊乳腺上皮细胞,2~3 d细胞铺满单层,形态如铺路石。所得细胞再经0.5 g/L胰蛋白酶/0.2 g/L EDTA纯化3~4次,得到比较纯净的山羊乳腺上皮细胞。细胞鉴定结果表明,所得到的细胞角蛋白染色呈阳性,阳性率大于90%,波形蛋白染色呈阴性,具有典型的上皮细胞特性。消化法适用于山羊乳腺上皮细胞的体外培养。     

Pancreatic and intestinal enzyme activities in rats in response to balanced and unbalanced plant diets

To simulate the effects of nutritionally adequate and inadequate vegetariandiets, rats were fed, for 28 days, an isonitrogenous, isocaloric, amino acidunbalanced cereal diet (CD) deficient in lysine and tryptophan or abalanced cereal-legume diet (CLD). The impact of these diets on enzymesresponsible for digestion of proteins and carbohydrates were measured.Neither experimental diet significantly affected the animal's final weight orfeed consumption in comparison with controls fed a standard mixed dietfrom plant and animal sources. However, during the first three weeks, theweight gain of rats fed the CD was significantly lower (p<0.01;p<0.05) than that of the controls. CD fed rats also had a higher feedefficiency ratio (p<0.05), demonstrating increased feed consumptionper unit of body weight. They also had decreased pancreatic-amylase activity (p<0.05), serum phytolytic and zoolytic-amylase activity (p<0.05) and serum protein level(p<0.05) than the controls. Activity of pancreatic trypsin and intestinalenzymes (sucrase, maltase, aminopeptidase N) were the same as in thecontrols. In rats fed CLD, growth, food consumption, and enzyme activitiesdid not change, however serum protein and glucose levels were higher(p<0.025; p<0.005) than in the controls. It is hypothesized thatdecrease in -amylase activity was mostly related to the tryptophandeficiency in the CD because this enzyme contains the highest amount oftryptophan units among all tested enzymes.     

凡纳对虾(Litopenaeus vannamei Boone)幼体淀粉酶(Amylase)和脂肪酶(Lipase)活力的研究

本文以酶学分析方法测定了凡纳对虾状幼体,糠虾和仔虾三个发育期淀粉酶和脂肪酶的活力。实验结果表明,糠虾期淀粉酶比活力显著高于状幼体和仔虾两期(P<0.05);脂肪酶比活力状幼体显著高于糠虾幼体(P<0.05)。在食性转化过程中,凡纳对虾幼体消化酶活力与其食性相适应,不同发育阶段消化酶调节机制不同。     

不同水平饲料镉对罗非鱼生长性能和肠道消化酶活性影响的研究

为研究不同水平饲料镉对罗非鱼生长性能和肠道消化酶活性的影响。将300尾罗非鱼随机分为5个处理,饲料镉添加水平分别为0、50、100、200、400 mg/kg,试验期为8周。结果表明：与对照组相比,饲料镉添加组增重率和特定生长率均逐渐降低,200、400 mg/kg添加水平组显著降低(P＜0.05);各处理组之间摄食率、饲料系数和成活率均无显著差异(P＞0.05)。饲料镉添加水平组罗非鱼肠道淀粉酶活性和蛋白酶活性均显著低于对照组(P＜0.05),当饲料中添加50 mg/kg镉时,罗非鱼肠道淀粉酶活性和蛋白酶活性即可显著降低(P＜0.05);罗非鱼脂肪酶活性仅在饲料镉添加水平400 mg/kg时显著低于对照组(P＜0.05),其余各处理组间差异不显著(P＞0.05)。表明罗非鱼对饲料镉耐受程度较高,饲料中镉达到200 mg/kg时,才可显著影响罗非鱼增重率和特定生长率。饲料中不同水平镉对罗非鱼肠道消化酶活性具有不同程度的抑制作用,饲料中添加50 mg/kg镉时即可显著降低肠道淀粉酶和蛋白酶的活性,肠道脂肪酶活性仅在400 mg/kg时显著降低。     

斑嘴鸭消化系统形态学观察

[目的]了解斑嘴鸭消化系统与食性关系。[方法]对6只成体斑嘴鸭（Anas poecilorhyncha）消化系统进行解剖,并对各器官进行测量。[结果]斑嘴鸭消化管总长为（1 889.30±102.11）cm,是体长的（3.700±0.197）倍,其中小肠占消化管总长的73.4%±1.5%,是体长的（2.723±0.196）倍。斑嘴鸭喙扁平,肌肉肥厚,肌胃较发达,小肠最发达,具双侧盲肠但并不发达,仅占消化管的13.0%±0.8%。[结论]该研究结果为斑嘴鸭的保护和形态学研究提供了参考。