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1.
Abstract.— Quantitative changes in the protein, lipid and carbohydrate were studied in the early larval stages of developing freshwater prawn Macrobrachium rosenbergii reared under fed and starved conditions to understand the relative importance of these nutrients in energy metabolism of the growing larvae. Larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii. Protein was always the major organic constituent followed by lipids and then carbohydrates of both fed and starved larvae. Protein levels of both fed and starved larvae increased during development, suggesting an important role in morphogenesis. The decline of lipid during the larval growth that was more rapid for starved larvae, suggests a probable utilization of lipid as the major metabolic source of energy. Carbohydrates formed less than 5 and 2.4% of the larval dry weight of fed and starved larvae, respectively, suggesting their limited role in larval metabolism.  相似文献   
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额河银鲫食性的初步研究   总被引:3,自引:0,他引:3  
对额河银鲫的食性和年龄与生长关系进行了调查研究。结果表明:额河银鲫是一种杂食性鱼,它的主要食物组成是藻类、水生植物、原生动物、水生混虫、轮虫以及小鱼等。在食物成分上有性变化。在春季和夏季主要摄性食物而秋季主要摄食动物性食物。  相似文献   
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Tropical Animal Health and Production - A study was conducted with the objective to characterize the morphology of Socorro Island Merino sheep. A total of 67 sheep, 62 females, 26 purebred and 36...  相似文献   
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Ninety culled dairy cows were used in this study and were paired by weight and conformation similarity. Forty-five cows were arterially infused immediately after bleeding with 10% volume by weight of a solution composed of dextrose (.23%), glycerin (.21%), a phosphate blend (.14%) and maltose (.1%). The remaining cows (45) served as controls. In infused carcasses, some quantity of solution retained was in the following order: supraspinatus, chuck greater than longissimus, loin greater than semitendinosus, round muscles. Accordingly, percentage of protein, ether-extractable fat, and protein fat-free amounts were lowered (P less than .05) and percentage of moisture and moisture protein ratio were raised (P less than .05) in the supraspinatus muscle. Tenderness (P less than .01) and protein extractability (P less than .15) were improved. No difference was observed in water-holding capacity between infused and control carcasses. Percentages of moisture fat-free (r = .85) and protein fat-free (r = -.97) were highly correlated to moisture-protein ratio. Moisture percentage of the fat-free tissue was shown to be a more consistent indicator of added moisture in infused whole carcasses compared with moisture:protein ratio and percentage of protein fat-free. Very low correlations were observed between tenderness, percentage of moisture, percentage of water-holding capacity, and ether-extractable fat. The economics of the infusion process to the beef industry is discussed.  相似文献   
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The purpose of this study was to determine if ginseng fed at low levels enhances a horse's antibody response to vaccination against Equid herpesvirus 1 (EHV-1). For 28 d, 5 horses received ground, powdered ginseng (35 mg/kg body weight, 1.7 mg/kg total ginsenosides) in molasses as a carrier, and 5 received molasses only. On day 14, each horse was vaccinated against EHV-1. The time course of the antibody response to vaccination was significantly altered in the horses receiving ginseng, a clinically relevant increase in antibody titer being observed by postvaccination day 2 compared with day 6 in the control horses. The horses receiving ginseng also had a significant decrease in serum levels of sodium and a significant increase in serum levels of potassium. No adverse effects of ginseng treatment were identified by hematologic and blood biochemistry profiles. Thus, low-dose dietary supplementation with ginseng in healthy horses may be a useful adjunct to vaccination.  相似文献   
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BackgroundThe predominant infectious bronchitis virus (IBV) strains detected in chickens in Malaysia are the Malaysian variant (MV) and QX-like, which are associated with respiratory distress, nephropathy, and high mortality. On the other hand, the antigenic relatedness and efficacy of IBV vaccines against these 2 field IBV strains are not well characterized.ObjectivesThis study aimed to determine the antigen relatedness and efficacy of different IB vaccine strains against a challenge with MV and QX-like strains.MethodsThe antigen relatedness and the ability of different IB vaccine strains in conferring protection against MV and QX-like were assessed based on the clinical signs, macroscopic lesions, and ciliary activity.ResultsThe MV strain IBS037A/2014 showed minor antigenic subtype differences with the vaccine virus Mass H120 and 4/91 strains but showed major antigenic subtype differences with the K2 strain. The Malaysian QX-like strain IBS130/2015 showed major antigenic subtype differences with the MV strain IBS037A/2014 and the vaccine strains except for K2. Chickens vaccinated once with Mass (H120) or with non-Mass (4/91 and K2) developed antibody responses with the highest antibody titer detected in the groups vaccinated with H120 and 4/91. The mean ciliary activities of the vaccinated chickens were between 56 to 59% and 48 to 52% in chickens challenged with IBS037A/2014 and IBS130/2015, respectively. The vaccinated and challenged birds showed mild to severe lesions in the lungs and kidneys.ConclusionsDespite the minor antigenic subtype differences, a single inoculation with Mass or non-Mass vaccines could not protect against the MV IBS037A/2014 and QX-like IBS130/2015.  相似文献   
10.
The in situ distribution of NK cells in rat liver during the first 28 days of an experimental infection with F hepatica was investigated. NK cells were distributed homogeneously throughout the hepatic parenchyma in uninfected animals. The total number of hepatic mononuclear cells increased significantly following infection, but the proportion of NK cells did not change. After infection, these cells were found around the portal space, around the centrolobular vein, in the periportal fibrosis and in the band of collagen. However, no NK cells could be detected in or around the granuloma during infection. The frequency of both I L-2- and IFNgamma-producing NK cells was higher on day 7 postinfection (pi) but only the percentage of IFNgamma -CD161+ subsets remained elevated thereafter, whereas the percentage of both IL-2+CD161+ and IL-4+CD161+ subsets returned to the baseline. The number of CD161+IL10+ cells did not change significantly. These results suggest that NK cells could be another source for the early production of IFNgamma but provide no evidence that these cells are involved in early events associated with granuloma formation.  相似文献   
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