对虾的营养需求

不同品种的对虾营养需求不同,本文根据一些文献资料概括对虾的营养需求,供参考。1　蛋白质和氨基酸蛋白质是对虾营养的主要成分,表1列出不同对虾最适饵料蛋白质含量。总体看来,不同品种的饵料蛋白质含量为30%～57%。最近研究表明,对虾蛋白质需求也受环境因素的影响。海水养殖的斑节对虾,最适饵料蛋白质含量为40%,而在盐度为16的半咸淡水养殖的对虾,最适饵料蛋白质含量为44%。这可能是由于在不同盐度中对虾对饵料蛋白质利用率不同。表1　各种对虾对蛋白质的需求量%对虾品种需求量褐对虾40～51加洲对虾35印度对虾43日本对虾45～57墨吉对虾34～…     

斑节对虾饲料营养需求研究进展

综述近年来国内外斑节对虾饲料营养研究进展,包括斑节对虾对饲料中蛋白质和氨基酸、脂肪和脂肪酸、糖类、维生素及矿物质元素等的需求量及其他一些饲料添加剂的应用；并展望其饲料研究的前景和方向；以期为斑节对虾的高效健康养殖和饲料开发提供理论参考.     

斑节对虾的营养需要

斑节对虾(Penaeus monodon)是重要的海水养殖对虾之一,在我国广东、广西和海南等省也有广泛养殖.本文就近年来国内外学者关于斑节对虾的营养生理的研究结果进行综述,以期为斑节对虾营养生理研究及饲料配制提供科学参考.     

斑节对虾营养需求与功能性饲料添加剂研究进展(二)

斑节对虾是一种重要的水产经济动物,生长快、营养丰富肉质鲜美,易干、活运销。文章综述了斑节对虾基本营养需求研究概况,以及功能性饲料添加剂应用等方面的研究进展。     

斑节对虾营养需求与功能性饲料添加剂研究进展(一)

斑节对虾是一种重要的水产经济动物,生长快、营养丰富肉质鲜美,易干、活运销。文章综述了斑节对虾基本营养需求研究概况,以及功能性饲料添加剂应用等方面的研究进展。     

对虾饲料配方研究

<正> 对虾在生长发育过程中需要的营养素有蛋白质、脂质、糖、维生素、矿物质等,其中以蛋白质最为重要。此文主要论述用多种原料制成的对虾饲料中蛋白质的含量,其它营养素亦力求在饲料中配平。有关对虾饲料中蛋白质含量的研究很多,但由于研究所采用的方法和原料不同,得出的结果不尽相同。据弟子丸修(1978)报道,当以体重和饵料效率为依据时,日本对虾(P.jponilus)饲料中的蛋白质含量以52％～57％最好,墨吉对虾(P.mergainsis)饲料中的蛋白质含量需要34％～42％。谢宝华等的研究结果认为,中国对虾(P.orientalis)饲料的蛋白质含量需要27％～39％。李爱杰提出,中国对虾饲料的蛋白质含量需要40％以上。台湾的斑节对虾(P.monodon)饲料的蛋白质含量为     

对虾幼体微胶囊饲料的基础营养含量

为研制对虾幼体微胶囊饲料,先后以斑节对虾幼体和中国对虾幼体做试验，分别以蛋白质4水平、脂肪3水平和淀粉3水平组成两个试验。为利用脂肪在饲料中的悬浮力，又做了斑节对虾幼体对脂肪最大容量的试验。总结分析三个试验结果认为，蛋白质是对虾幼体的主要营养物质。淀粉含量对对虾幼体也有促进生长和提高成活率作用。蛋白质和淀粉对对虾幼体的成活率有协同作用，但蛋白质对成活率的影响大于淀粉，若要提高对虾幼体成活率关键是提高蛋白含量。对虾幼体的生长和成活率随脂肪含量提高而略有提高，但不显著，这为调节幼体饲料的脂肪含量提供了依据。     

对虾蛋白质、氨基酸和糖类需要量

1　对虾对蛋白质的需要量对虾对饲料中蛋白质的需要量受饲料中蛋白质的品质 (必需氨基酸的含量和比例 )、对虾发育阶段、生理状况以及环境条件 (水温、盐度、溶氧度等 )的影响。一般来讲对虾饲料中蛋白质的品质越高 ,即蛋白质中必需氨基酸含量和比例越适宜 ,对虾对饲料中蛋白质的需要量越低。王吉桥等(2 0 0 2 )总结学者的研究认为 ,在同种对虾中 ,幼虾对饲料中蛋白质的需要量可能低于青年虾或成虾 ,这需要进一步的试验验证。Lei等 (1 989)报道 ,饲养在海水中的青年斑节对虾对饵料中蛋白质的需要量仅为 40 % ,而饲养在咸淡水中 (盐度1 6ppt…     

饲料蛋白质水平对斑节对虾（Penaeus monodon）生长性能、消化酶活性和血清生化指标的影响

试验旨在研究饲料中不同蛋白质水平对斑节对虾（Penaeus monodon）生长性能、消化酶活性和血清生化指标的影响。以鱼粉、鸡肉粉和豆粕等为主要蛋白源,通过调整豆粕的添加量配制成38%、40%、42%、44%、46%、48%蛋白水平的饲料,分别命名为PD1、PD2、PD3、PD4、PD5、PD6,饲喂平均初始体重为（12.5±0.2）g的斑节对虾8周,每种试验饲料投喂4个水族箱,每个水族箱放养25尾斑节对虾。结果表明：(1)各组斑节对虾的存活率无显著差异（P>0.05）,均在98%及以上;随着饲料中蛋白质水平的升高,试验虾的增重率和特定生长率升高,在PD4组试验虾增重率和特定生长率达到最大值。(2)虾体的水分、灰分和粗脂肪含量在各组之间无显著差异（P>0.05）,但虾体的粗蛋白含量随着饲料蛋白质水平的升高呈现出先升高后降低的趋势,最高值出现在PD4和PD5两组,且显著高于PD1、PD2组和PD3组（P<0.05）。(3)肝脏蛋白酶活性PD4组显著高于其余各组（P<0.05）。淀粉酶的活性最高值出现在PD1组且显著高于PD3、PD4、PD5组和PD6组（P<...     

中国对虾营养生理的研究进展

<正> 近十年来,我国对虾养殖业有了迅猛的发展。伴随着对虾养殖业的发展,对中国对虾的营养需要和营养生理进行了大量研究。研究成果为研制对虾配合饵料提供了依据,为发展对虾饲料工业奠定了基础。配合饲料是对虾养殖系统工程中的关键一环,因此也可以说,对虾营养需要和营养生理的研究为我国对虾养殖生产的成倍增长起到了积极作用。现将研究进展概况报道如下。一、蛋白质在对虾的营养物中,主要组成成分是蛋白质、脂肪、碳水化合物、维生素和无机盐。各种营养物     

Concentrations of strontium,barium, cadmium,copper, zinc,manganese, chromium,antimony, selenium,and lead in the liver and kidneys of dogs according to age,gender, and the occurrence of chronic kidney disease

This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.     

Antibacterial action of combinations of oxytetracycline, dimethyl sulfoxide, and EDTA-tromethamine on Proteus, Salmonella, and Aeromonas

Antibacterial effects against Proteus mirabilis, Salmonella typhimurium, and Aeromonas hydrophila were obtained with subminimal inhibitory concentrations of oxytetracycline and EDTA-tromethamine. Antibacterial effects were not observed with subminimal inhibitory concentrations of dimethyl sulfoxide plus oxytetracycline or with dimethyl sulfoxide plus EDTA-tromethamine. Using a 2-dimensional Microtiter checkerboard technique, inhibitory activities of the various combinations of solutions were studied, and isobolograms were plotted. A synergistic effect was seen with combinations of oxytetracycline and EDTA-tromethamine. The greatest synergistic effect was observed when the mixture was caused to react with P mirabilis. These findings were confirmed by kinetic studies of microbial death, using one-fourth minimal inhibitory concentrations of these preparations.     

Comparisons of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, and Shorthorn breeds for weight, weight adjusted for condition score, height, and condition score of cows

Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n = 12,188) of 2- to 6-yr-old cows (n = 744) from Cycle IV of the U.S. Meat Animal Research Center's Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breedgroup as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects associated with the cow. Differences among breed groups were significant (P < 0.05) for all traits and were maintained through maturity with few interchanges in ranking. The order of F1 cows for weight was as follows: Charolais (506 to 635 kg for different ages), Shorthorn and Salers, reciprocal Hereford-Angus (HA) with 1980s sires, Nellore, HA with reference sires, Galloway, Piedmontese, and Longhorn (412 to 525 kg for different ages). Order for height was as follows: Nellore (136 to 140 cm), Charolais, Shorthorn, Salers, HA with 1980s sires, Piedmontese, Longhorn, Galloway and HA with reference sires (126 to 128 cm). Hereford and Angus cows with reference sires were generally lighter than those with 1980s sires. In general, breed differences for height followed those for weight except that F1 Nellore cows were tallest, which may in part be due to Bos taurus-Bos indicus heterosis for size.     

Echocardiography, electrocardiography, and radiography of cats with dilatation cardiomyopathy, hypertrophic cardiomyopathy, and hyperthyroidism

The echocardiographic, ECG, and radiographic findings of sequentially examined cats with dilatation cardiomyopathy (DCM, n = 7), hypertrophic cardiomyopathy (HCM, n = 8), and hyperthyroidism (HT, n = 20) were compared with those of healthy control cats (n = 11). Cats with DCM were easily differentiated from healthy cats by echocardiography and from cats with HCM and HT by a dilated left ventricle at end-diastole with a mean +/- SD of 2.20 +/- 0.36 cm, reduced fractional shortening (2.9% +/- 3.7%), reduced aortic amplitude (0.07 +/- 0.05 cm), reduced left ventricular wall amplitude (0.09 +/- 0.09 cm), and increased E-point septal separation (0.83 +/- 0.29 cm). The cats with HCM were most consistently recognized echocardiographically by increased left ventricular wall thickness at end-diastole (0.75 +/- 0.12 cm). Some cats with HT had abnormal echocardiograms with left ventricular wall hypertrophy. These cats could usually be differentiated from the cats with HCM because of normal or increased ventricular wall amplitude, aortic amplitude, or percentage of thickening of the left ventricular wall and interventricular septum. Left atrial enlargement (left atrial diameter greater than 1.57 cm or left atrium/aorta greater than 1.75) was commonly detected by the echocardiogram in cats with DCM, HCM, or HT. The echocardiogram was helpful in differentiating the type of cardiomyopathy (DCM, HCM, or HT) when plain thoracic radiographs indicated that cardiomegaly existed. The ECG may have indicated incorrectly that there was left ventricular enlargement in some cats with HT, and it did not indicate consistently that left ventricular enlargement existed when present in cats with DCM or HCM. The ECG was a poor indicator of left atrial enlargement in all cats.     

Genetic parameters among weight, prolificacy, and wool traits of Columbia, Polypay, Rambouillet, and Targhee sheep

Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models for prolificacy, weight, and wool traits. All bivariate analyses included a covariance between additive genetic effects for the two traits plus appropriate additional covariances. Number of observations by breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for weight traits, and from 4,603 to 34,746 for wool traits. Heritability estimates ranged from .03 to .11 for prolificacy traits (litter size at birth and litter size at weaning), from .09 to .26 for weight traits (birth weight and average daily gain), and from .25 to .53 for wool traits (fleece weight, fleece grade and staple length). Estimates of direct genetic correlations among prolificacy and among weight traits were positive and ranged from .58 to 1.00 and .18 to 1.00, respectively. Estimates of direct genetic correlation between fleece weight and staple length were positive (.50 to .70) but were negative between fleece weight and fleece grade (-.60 to -.34) and between staple length and fleece grade (-.72 and -.40). Prolificacy and wool traits were essentially uncorrelated. Weight and prolificacy traits were slightly positively correlated. Weight traits had a moderate positive direct genetic correlation with fleece weight and staple length, but were uncorrelated with fleece grade. These estimates of genetic parameters between prolificacy, weight, and wool traits can be used to construct multiple-trait selection indexes for dual-purpose sheep.     

Toxicology of selected pesticides, drugs, and chemicals. Anticoagulant, cholecalciferol, and bromethalin-based rodenticides

The control of rodent pests is a continuing goal of mankind. To this end, a multitude of rodenticides have been produced, each designed to kill rodents by exerting their toxic effects on various body systems. As examples, veterinarians have had to manage companion animal poisonings due to anticoagulant, sodium fluoroacetate (compound 1080), thallium, barium carbonate, and zinc phosphide-based rodenticides. Many of these rodenticides were introduced because of their anticipated safety in relation to nontarget species; unfortunately, this has not been the case. Veterinarians must attempt to identify the specific rodenticide involved in poisoning cases. Therapeutic success in these poisonings is often more dependent upon symptomatic and supportive care rather than the use of antidotal therapy.     

Comparative cardiovascular, analgesic, and sedative effects of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol in dogs

OBJECTIVE: To compare sedative, analgesic, and cardiopulmonary effects after IV administration of medetomidine (20 microg/kg), medetomidine-hydromorphone (20 microg of medetomidine/kg and 0.1 mg of hydromorphone/kg), and medetomidine-butorphanol (20 microg of medetomidine/kg and 0.2 mg of butorphanol tartrate/kg) in dogs. ANIMALS: 6 dogs healthy mixed-breed dogs. PROCEDURE: Instruments were surgically inserted, and heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), core body temperature, and cardiac output (CO) were measured 0, 5, 10, 15, 30, 45, and 60 minutes after injection. Cardiac index (CI), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were calculated. Arterial samples for blood gas analysis were collected 0, 15, and 45 minutes after injection. Intensity of analgesia, degree of sedation, and degree of muscle relaxation were evaluated at aforementioned time points and 75, 90, 120, 150, 180, and 210 minutes after injection. RESULTS: Administration of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol was associated with increases in SAP, MAP, DAP, MPAP, PCWP, CVP, SVR, PVR, core body temperature, and PaCO2 and decreases in HR, CO, CI, SV, SI, RR, pH, and PaO2. Clinically important differences were not detected among treatments. Medetomidine-hydromorphone and medetomidine-butorphanol provided a longer duration of sedation and better quality of analgesia, compared with medetomidine alone. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine-hydromorphone or medetomidine-butorphanol is associated with improved analgesia and sedation but has cardiopulmonary effects comparable to those for medetomidine alone.