Use of Diet Crossover to Determine the Effects of β‐glucan Supplementation on Immunity and Growth of Nile Tilapia,Oreochromis niloticus

Juvenile Nile tilapia were fed either a basal (control) diet (n = 6 aquaria) or a diet supplemented with 1 g/kg β‐glucan (n = 24 aquaria) for 4 wk. At the end of this period, fish receiving β‐glucan were continued on the same diet (n = 12 aquaria) or switched to the control diet (n = 12 aquaria) for 2 wk. After 6 wk, tilapia continuously fed the β‐glucan supplemented diets had improved weight gain and feed efficiency than those fed the control diet uninterrupted or switched from the β‐glucan diet to the control after 4 wk. Feeding tilapia β‐glucan for 4 wk and then switching to the basal diet for 2 wk caused a significant increase in the respiratory burst of polymorphonuclear lymphocytes (17.77 × 10³ units/1000 white blood cells [WBC]) compared to catfish fed the control diet (13.50 × 10³ units/1000 WBC) or the β‐glucan diet continuously (13.57 × 10³ units/1000 WBC), but other immune parameters were unaffected. Tilapia were then challenged with Streptococcus iniae. The two groups were divided again (n = 6 aquaria) postchallenge and continued on the same diet or switched to the other diet (β‐glucan or control) for another 3 wk. No differences in survival to S. iniae infection occurred between dietary groups.     

Metabolism, uptake and translocation of 14C-paraquat in resistant and susceptible biotypes of Crassocephalum crepidioides (Benth.) S. Moore

The metabolism, uptake and translocation of paraquat in resistant (R) and susceptible (S) biotypes of Crassocephalum crepidioides (Benth.) S. Moore (redflower ragleaf) at the 10-leaf stage was investigated. A study on the properties of leaf surface was carried out to examine the relationship between leaf surface characters and paraquat absorption. The extractable paraquat was not metabolized by the leaf tissue of either the resistant or susceptible biotypes. Differential metabolism, therefore, does not appear to play a role in the mechanism of resistance. Both biotypes did not show any significant difference in the amount of cuticle and trichome densities. Furthermore, both biotypes are identical in the structure of stomata, trichomes and epicuticular wax. The results of the leaf surface studies are in agreement with the findings of the uptake study. Both biotypes demonstrated no significant difference in absorption between the resistant and susceptible biotypes. However, 10% of the absorbed ¹⁴C-paraquat into the S biotype was translocated basipetally, but not in the R biotype. The results of this study suggest that in C. crepidioides , differential translocation may contribute to the mechanism of resistance at the 10-leaf stage.     

Effects of root diffusates of some weeds associated with corn plantations on the hatchability of the corn cyst nematode,Heterodera zeae

Twenty two summer weeds belonging to fifteen plant families and twelve winter weeds from eight plant families were tested to compare the effects of their root diffusates with the corn root diffusates (CRD) of cv. Giza 2 on the hatchability of the corn cyst nematode (CCN),Heterodera zeae.All tested weed root diffusates (WRD) successfully stimulated the hatchability of the cysts, but less than CRD did except the root diffusates (RD) ofRumex dentatus which failed to stimulate the nematode cysts.     

Inhibin and reproduction. First communication: changes to inhibin level in Barki ewes after artificial infection with bluetongue virus

Bluetongue virus type 16, isolated from sheep in Egypt, was injected to 4 normally cycling Barki ewes and caused high levels of inhibin. This was assayed by a biological method, using suppression of the luteinising hormone (LH) of castrated rats. Albumin (fraction 2) was injected to normally cycling ewes. The sera of injected ewes were investigated 1 day after injection and weekly up to the 4th one injection. There was a gradual decrease of LH (4.8 +/- 0.52 I.U./ml serum) until the minimum level (1.17 +/- 0.25 I.U./ml serum) was reached, in comparison to the control serum LH which was 5.26 +/- 0.52 I.U./ml serum during the dioestrous phase.     

Effects of probiotics: alone and in a mixture of Biosacc plus Zinc Bacitracin on the caecal microflora of Japanese quail

The aim of this study was to investigate the effects of two commercially available probiotics, alone and in combination with an antibiotic, on the caecal flora of Japanese quail (Coturnix coturnix japonica) reared under unstressed conditions. Thirty-four 90-day-old Japanese quail were selected for this study. The birds were divided into four groups, two groups of nine birds and two groups of eight birds. The animals in these groups were given feed containing 0.5 kg per tonne of probiotics alone (Protexin or Biosacc), a mixture of probiotic plus antibiotic (Biosacc plus Zinc Bacitracin at 0.5 and 0.0525 ppm, respectively), and a group where no supplement was added to be used as controls. The total count of aerobic bacteria, lactobacilli, enterobacteriaceae, coliforms, enteroccoci, salmonellae, sulphite-reducing anaerobic bacteria (clostridia), and pH values in the caecal content of the birds were examined. No significant differences were detected among the four groups for pH values and bacterial number (p>0.05), except for sulphite-reducing anaerobic bacteria (p<0.001). These results suggest that the use of probiotics alone and/or a mixture of a probiotic plus antibiotic as a feed supplement does not have a major suppressing effect on the majority of bacterial groups in the caecal flora of mature, healthy Japanese quail reared in unstressed conditions.     

Influence of some hardwood barks as soil amendments onRotylenchulus reniformis reproduction and growth response of sunflower

Four hardwood barks (HWB) i. e.Acacia arabica (AA),Ficus sycomorus (FS),Morus alba (MA) andZiziphus spinachristi (ZS) were tried as soil amendments at 0.5, 1.0 and 1.5% rates w/w for control ofRotylenchulus reniformis and improvement of cv. Giza 1 sunflower growth under greenhouse conditions. All HWB with various concentrations significantly (P≤0.01) reduced numbers of larvae in soil, both females and eggmasses on roots, total final nematode population as well as the nematode build-up as compared to control. 1.5% rate of ZS, AA and MA barks were most effective in reducing numbers of larvae in soil, total final nematode population and the nematode build-up. Also, 1.5% rate of each of FS and AA barks were most effective in reducing numbers of females or eggmasses, respectively. On the other hand, the least reduction in the previous nematode stages and rate of build-up was observed with 0.5% dose of FS bark. Shoot weights were increased significantly with both of 1.0% and 1.5% doses of each of FS and ZS barks and only with 1.5% dose of MA bark. Both shoot lengths and root weights increased significantly with 1.5% dose of all HWB or with 1.0% dose of each of AA and ZS barks as compared to control. No significant increase in root lengths was observed. Generally, there were positive significant correlations between doses of HWB, each of the reductions in the previous nematode stages and increases in sunflower growth criteria.     

Stimulation of the bronchus-associated lymphoid tissue of goats and its effect on in vitro colonization by Pasteurella haemolytica

Twenty goats of about 7 months of age were divided into five groups. The goats in groups 1 and 2 were exposed once, using an intranasal spray to 2 ml of an inoculum containing 10⁶ colony-forming units/ml of living or dead Pasteurella haemolytica A2, respectively. The goats in groups 3 and 4 were similarly exposed twice at a 2-week interval. Group 5 was the untreated control. The number and size of the bronchus-associated lymphoid tissue (BALT) in goats exposed twice to either living or dead organisms were significantly (p>0.05) increased compared with those exposed once and with the unexposed control. In vitro colonization by living P. haemolytica A2 onto the lung tissue in which the BALT had been stimulated by two exposures of either living or dead organisms was significantly (p>0.05) reduced. The study indicates that stimulation of the respiratory mucosal immunity may prevent P. haemolytica A2 infection.     

Pathogenicity of peste des petits ruminants virus isolated from Egyptian goats in Egypt

2 Egyptian goats and Boscat rabbits were experimentally inoculated with peste des petits ruminants (PPR) local Egyptian strain (PPR, Egypt 87). The inoculated animals contracted the disease with minor clinical manifestations, accompanied by rise of neutralizing antibodies to PPR virus. Virus was isolated from ocular and nasal secretions, buffy coat, spleen, and liver. No contact infection was observed between inoculated and healthy goats.     

Evidence of identification of peste des petits ruminants from goats in Egypt

Peste des petits ruminants virus was isolated from young goats in an outbreak of the disease for the first time in Egypt. Affected goats showed symptoms simulating rinderpest, disease in cattle. The mortality rate was about 30%, and morbidity reached 90%. History, clinical symptoms, postmortem lesions, and diagnosis were discussed.     

Kinetic modeling of malonylgenistin and malonyldaidzin conversions under alkaline conditions and elevated temperatures

The conversion and degradation of malonylglucosides were kinetically characterized under elevated pH/heat conditions. Malonylgenistin and malonyldaidzin were heated at 60, 80, and 100 degrees C and pH values of 8.5, 9, and 9.5. A simple kinetic model was developed, which adequately predicted the conversion and degradation reactions. The conversion and degradation rates increased as temperature and pH increased. The rates of conversion of both malonylglucosides into their respective beta-glucosides were comparable under all pH/heat treatments. However, at 100 degrees C, the rates of degradation of malonyldaidzin were approximately double those of malonylgenistin, under all pH treatments. When malonlydaidzin was heated at 100 degrees C and pH 9.5, degradation of the produced daidzin occurred. Therefore, an alternative kinetic model was developed to better predict the conversion and degradation of malonyldaidzin occurring at 100 degrees C and pH 9.5. The models developed provide soy food manufacturers with guidelines for better control of the profile and level of isoflavones..