Pathogenicity of Enterococcus hirae for chicken embryos and betamethasone-treated chicks

An isolate Enterococcus hirae was used to determine its pathogenicity for chicken embryos and for chicks treated with betamethasone. E hirae was inoculated intravenously into four-day-old chicks which had been treated for three consecutive days with betamethasone, and chick embryos were inoculated into the allantoic cavity with 10² and 10³ bacteria. E hirae was not pathogenic for the chicks or for the embryos.     

Effect of altering linoleic acid and linolenic acid dietary levels and ratios on the performance and tissue fatty acid profiles of Nile tilapia <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> fry

This experiment was conducted to study the effect of altering the linoleic acid (LA) and linolenic acid (LNA) levels and ratios in the diet of Nile tilapia (Oreochromis niloticus) on fry performance. Twelve diets were formulated to be isonitrogenous, isocaloric, and differed only in their main lipid source. An oil rich in n-3 fatty acids [linseed oil (L)] and two oils rich in n-6 fatty acids [soybean oil (S) and corn oil (C)] were added at 6% of the basal diet either separately or in equal combinations (L1:S1 or L1:C1 or S1:C1) or at ratio 2:1 (L2:S1 or L2:C1 or C2:L1 or C2:S1 or S2:L1 or S2:C1). The fish were fed twice daily (09 and 16 h) to apparent satiation throughout the duration of the trial (16 weeks). Survival rates increased in a linear pattern with increasing the LA level in the diets (R ² = 0.764). Final body weight was significantly higher in fish fed S, S2:L1, and L2:C1 diets, being 14.29, 14.14, and 14.09 g/fish, respectively. However, tilapia fed C, S1:C1, and C2:S1 diets exhibited low final body weight (11.41, 11.60, and 11.76 g/fish, respectively). The final body weight was negatively affected by increasing the LA/LNA ratios (R ² = 0.647). Either LA or arachidonic acid (%) in the whole body of fish increased in a linear patterns (R ² = 0.641 and 0.746, respectively) with increasing dietary LA. Besides, LNA, eicosapentaenoic, acid and docosahexaenoic acid (%) in the whole body increased in a linear pattern (R ² = 0.777, 0.501, and 0.8148, respectively) the increasing dietary LNA level. The present study indicated that LA/LNA ratio less than 13 is recommended for nutrition of tilapia fry.     

Effect of phosphogypsum application and bacteria co-inoculation on biochemical properties and nutrient availability to maize plants in a saline soil

Phosphogypsum (PG), which contains Ca, P and S and has an acidic effect, may be applied to manage soil constraints such as alkalinity and salinity. For increasing nutrients bioavailability, biofertilizers are commonly applied. Therefore, the aim of this study was to assess PG effect either alone or in combination with the mixed co-inoculation of plant growth promoting rhizobacteria on a saline soil. In a greenhouse pot experiment with maize (Zea mays L.), the inoculated and non-inoculated saline soils were treated with PG at 10 g kg^?1 (PG10), 30 g kg^?1 (PG30), and 50 g kg^?1 (PG50). The soil pH, electrical conductivity (EC_e), and macro-(NPK) and micronutrients (Fe, Mn, Zn, and Cu) availability to mays were examined. Applying PG reduced soil pH and co-inoculation induced significant decreases in soil EC_e. Applying PG increased significantly soil available P. Applying PG combined with co-inoculation effectively increased the soil available K. The soil available micronutrients decreased significantly with PG. However, the inoculated maize treated with PG showed significant higher dry weight (82.1–127.4%) and nutrients uptake than the control. It could be concluded that PG along with co-inoculation may be an important approach for alleviating negative effects of salinity on plant growth.     

肉种鸡葡萄球菌性关节炎的防治

目前,尽管许多细菌与关节炎或腱鞘炎有关,但从患病肉种鸡关节中常可分离到金黄色葡萄球菌。葡萄球菌性关节炎(尤其是跗关节炎和足关节炎)虽然在肉种鸡群中呈散发流行,但却成为引起淘汰增多而造成经济损失的重要疫病。金黄色葡萄球菌和其他葡萄球菌(特别是表皮葡萄球菌)分布广泛,是家禽皮肤和粘膜的常在寄生菌,在禽舍环境中也无处不有。只要加强环境的管理,提高家禽免疫系统的功能,一般而言金黄色葡萄球菌是不会引起鸡群发病的。但由于金黄色葡萄球菌可通过皮肤的受伤处(如明显的伤口或擦伤)侵害皮下组织,经血液或直接扩散到关节,进而引发关…     

Effect of mixed protein schedules combined with choline and betaine on the growth performance of Nile tilapia (Oreochromis niloticus)

Reducing feed cost has been a major issue in fish nutrition. Mixed protein schedules have been proposed as one of the methods successfully tested in many fish species to reduce feed cost. Meanwhile, the effect of dietary choline and betaine supplementation on fish performance was assessed. The aim of the present study was to investigate the effect of mixed protein schedules, combined with choline and betaine, on Nile tilapia performance. This experiment was conducted in a (4 × 3) factorial arrangement of treatments. Four mixed protein schedules were examined, in the presence of choline 0.3% and/or betaine 0.5%. The four mixed protein schedules were achieved by alternating diet (A; 31%CP) and diet (B; 24%CP) as follows: (6 days‐A), (5 days‐A/1 day‐B), (4 days‐A/2 days‐B) and (3 days‐A/3 days‐B). The results indicated that in the presence of betaine 0.5% and choline 0.3%, the optimal mixed protein schedule for tilapia was (3A/3B). Fish fed on the 4A/2B or 3A/3B schedules utilized protein more efficiently than fish fed on the (6A) schedule. Fish fed diets supplemented with betaine (b) only showed the highest energy retention. The lowest feed cost was recorded for fish fed on (3A/3B) in the presence of betaine 0.5% and choline 0.3% in fish diet.     

Pathology of the trachea in turkeys exposed by aerosol to lentogenic strains of Newcastle disease virus

Five groups of 4-week-old turkey poults were each infected by aerosol with a different lentogenic strain of Newcastle disease virus. Four days postinfection, sections of tracheas were collected for histopathologic characterization and virus titration. The most prominent lesions were fibrinopurulent exudate in tracheal lumens, hyperplasia of epithelial cells, and infiltration by lymphocytes. All strains multiplied to high titers and produced similar microscopic lesions, but the number of poults with severe microscopic lesions varied among groups.     

Pneumonia of turkey breeder hens associated with Mycoplasma synoviae

Turkey breeder hens showed an increase in mortality beginning at 38 wk of age with no other clinical signs or changes in egg production. While no respiratory signs were observed in live turkeys, those that died consistently had gross lesions of pneumonia. Histopathology of lungs revealed serofibrinous bronchopneumonia, lymphofollicular reaction, and other features suggesting a bacterial etiology. However, except for incidental findings, bacteria were not visualized in the sections examined, and none were isolated in meaningful numbers on routine bacteriologic media. At 42 wk of age the flock showed serologic evidence of infection with Mycoplasma synoviae (MS), and MS was identified by both mycoplasma culture and polymerase chain reaction (PCR) procedures in samples from choanal clefts and tracheas. Results of lung histopathology and PCR tests were consistent with a diagnosis of pneumonia caused by MS.