Differential effects of experimental hyperthyroidism on declined immunity of broiler chicken

Thyroid hormones (THs) are involved in the development of lymphoid organs and regulation of immune function in birds. However, their role as an immune‐modulator in the hyperthyroid state is still debatable. To explore the interrelationship of thyroxine (T₄) and the immune system, chicks were divided into three groups. Group I was comprised of control birds, who received the basal diet while group II and III were given diets supplemented with 5 μg and 10 μg thyroxine/kg feed, respectively, from 15 to 28 days of age. Cell‐mediated immune response was evaluated through in vitro abdominal macrophage phagocytosis assay, macrophage nitric oxide (NO) production, heterophil‐to‐lymphocyte (H:L) ratio and delayed‐type hypersensitivity response against phytohemagglutinin (PHA). Humoural immune response was assessed through serum IgG and IgM antibody production against sheep red blood cells (SRBCs) and antibody production against infectious bronchitis virus (IBV). Sampling was carried out at 7, 14 and 21 days of treatment. Results have shown higher levels (p < .001) of circulating T₄ in both treatment groups compared to the control group. There was a lower (p < .05) macrophage engulfment percentage, an increase in H:L ratio (p < .001) in treated birds, while their NO production remained higher (p < .05) in thyroxine supplemented groups after bacterial lipopolysaccharide stimulation. The humoural immune response revealed a significant decline (p < .001) in IgG, IgM antibody production against SRBCs but IBV circulating antibodies increased with age. In conclusion, hyperthyroidism has a strong co‐relation with decreased immune performance of birds.     

Combining ability analysis to identify suitable parents for heterosis in seed cotton yield,its components and lint % in upland cotton

Combining ability and heterosis were studied in a 6 × 6 diallel cross to see the nature of gene action in Upland cotton (Gossypium hirsutum L.) during 2002 to 2004. Analysis of variance revealed highly significant differences among all the F₁ and F₂ hybrid means and their respective six parental values for all the traits examined. In both generations, the mean squares due to general combining ability (GCA) and specific combining ability (SCA) were also highly significant. SCA genetic variances were greater than GCA and more important for the traits, i.e. boll weight, boll number and seed cotton yield per plant, showing the predominance of non-additive gene action. Lint % in both generations and boll weight in F₂s only were controlled by additive type of gene action due to maximum GCA variances. Cultivar CIM-1100 was found to be the best general combiner and its utilization produced valuable hybrids with desirable SCA in both generations. F₁ and F₂ hybrids, viz., CIM-1100 × CRIS-9, CIM-1100 × FH-682, CIM-1100 × BH-36 and CIM-109 × CIM-1100 as high × low and low × high parents performed well in SCA determination, outstanding mean performance and heterosis. Better SCA effects associated with useful heterosis were more pronounced for yield traits. In F₁ hybrids, maximum heterosis was observed for seed cotton yield followed by boll number, boll weight and lint %. The heterosis over better parent was +3.13 to +65.63% for bolls per plant, +0.75 to +24.40% for boll weight, +0.82 to +115.22% for seed cotton yield and +0.27 to +3.88% for lint %. Involvement of CIM-1100 in most of the F₁ and F₂ hybrids resulted in the synthesis of superior genotypes for most of the traits studied. Inbreeding depression was elevated in good performing hybrids and was the highest for seed cotton yield. Highest yielding F₁ hybrids yielded lesser in the subsequent generation due to over-dominance and inbreeding depression, whereas moderate yielding F₁ hybrids were found more stable even passing through process of segregation due to additive gene action. The combined performance of F₁ and F₂ hybrids could be a good indicator to identify the most promising populations to be utilized either as F₂ hybrids or as a resource population for further selection.     

Antibacterial activities of some constituents from oleo-gum-resin of Commiphora mukul

The essential oil, chloroform extract and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora mukul showed a wide range of inhibiting activity against both Gram (+) and Gram (-) bacteria.     

Effects of cow manure and sewage sludge on the activity and kinetics of <Emphasis Type="SmallCaps">l</Emphasis>-glutaminase in soil

A study was conducted to investigate the effects of cow manure and sewage sludge application on the activity and kinetics of soil l-glutaminase. Soil samples were collected from a farm experiment in which 0, 25, and 100 Mg ha⁻¹ of either cow manure or sewage sludge had been applied annually for 4 consecutive years to a clay loam soil (Typic Haplargid). A chemical fertilizer treatment had also been applied. Results indicated that the effects of chemical fertilizer and the solid waste application on pH in the 18 surface soil (0–15 cm) samples were not significant. The organic C content, however, was affected significantly by the different treatments, being the greatest in soils treated with 100 Mg ha⁻¹ cow manure, and the least in the control treatment. l-Glutaminase activity was generally greater in solid-waste applied soils and was significantly correlated (r = 0.939, P < 0.001) with organic C content of soils. The values of l-glutaminase maximum velocity (Vmax) ranged from 331 to 1,389 mg NH₄ ⁺–N kg⁻¹ 2 h⁻¹. Values of the Michaelis constant (K _m) ranged from 35.1 to 71.7 mM. Organic C content of the soils were significantly correlated with V _max (r = 0.919, P < 0.001) and K _m (r = 0.763, P < 0.001) values. These results demonstrate the considerable influence that solid waste application has on this enzymatic reaction involved in N mineralization in soil.     

The relationship between serum level of thyroid hormones,trace elements and antioxidant enzymes in dromedary camel (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>)

Thyroid hormones might be able to regulate the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX). The role of thyroid hormones in metabolic pathways and antioxidant enzyme activities are well known in many species. Nevertheless, there is no report describing probable relationship between thyroid hormones status, erythrocyte antioxidant enzymes and serum profiles of trace elements. This study was undertaken to investigate the relationship between these parameters in Iranian dromedary camels. Blood samples were taken from the jugular vein of 30 clinically healthy Iranian dromedary camels under aseptic conditions during 6 consecutive days of summer. The serum was analyzed for serum profile of thyroid hormones, trace elements, SOD and GPX activity. There were no significant differences in serum thyroid hormones, serum level of zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), selenium and antioxidant enzymes in different days (P > 0.05). There was a significant negative correlation between SOD and Fe (P < 0.01, r = -493). There was no significant correlation between other parameters. In case of copper deficiency likewise the present study, the copper was used to produce more SOD, so there was a decrease in Fe transportation, and it might be a cause of decrease in Fe amount. On the other hand, a relatively small quantity of Fe is present in tissue myoglobin, catalase, peroxidases, and cytochromes. So it might be another cause of decrease in Fe amount. The explanation for these finding is not possible at this moment and further investigations are needed to interpret these changes.     

The use of receiver operating characteristic (ROC) analysis to assess the diagnostic value of serum amyloid A, haptoglobin and fibrinogen in traumatic reticuloperitonitis in cattle

Acute phase proteins (APPs) such as serum amyloid A (SAA), haptoglobin (Hp), and plasma fibrinogen (Fb) are diagnostic and prognostic biomarkers. This study determined the pattern of SAA in traumatic reticuloperitonitis (TRP) in cows, and compared the findings with Hp, and plasma Fb concentrations in the differential diagnosis of TRP using receiver operating characteristic (ROC) analysis. Blood samples were collected from 89 cows: 53 cases of TRP, 16 animals with other internal disorders and 20 healthy controls.SAA and Hp had a similar pattern and magnitude of changes in TRP. Using the ROC method, the optimal cut-off for the diagnosis of TRP was 68 μg/mL for SAA and 0.74 g/L for Hp, with 100% sensitivity and 86.1% specificity; either of these parameters may therefore be used as a sensitive and relatively specific tool for the differential diagnosis of TRP in cattle. The diagnostic accuracy of plasma Fb was significantly lower than either SAA or Hp (P < 0.01). The combined use of these APPs (whilst aware of their conditional interdependence) may not provide any additional diagnostic information than can be obtained using either SAA or Hp alone.     

Serum lipid profile in Iranian fat-tailed sheep in late pregnancy, at parturition and during the post-parturition period

Blood samples were obtained from 12 Iranian fat-tailed sheep during 7 weeks pre-partum, at parturition and 7 weeks post-partum. The lipids measured were cholesterol, triglyceride, total lipid, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and very low-density lipoprotein (VLDL)-cholesterol. The concentrations of cholesterol, triglyceride, HDL-cholesterol and VLDL-cholesterol during the 7 weeks pre-partum, at parturition and the 7 weeks post-partum were significantly different (P < 0.05). One week before parturition, the concentrations of cholesterol, triglyceride, HDL-cholesterol and VLDL-cholesterol were higher (P < 0.05) than at other periods. The lowest concentrations of these parameters were observed 2-3 weeks after parturition. In this study, significant positive correlations were observed between the time of sampling (pre-partum, parturition and post-partum) and serum cholesterol (r = 0.22; P < 0.01) and HDL-cholesterol (r = 0.25; P < 0.01).     

Disease Progress Based on Effects of Verticillium dahliae and Pratylenchus penetrans on Gas Exchange in Russet Burbank Potato

ABSTRACT The interactive effects of concomitant infection by the nematode Pratylenchus penetrans and the fungus Verticillium dahliae on symptom expression in Russet Burbank potato was studied in growth chamber experiments. Treatments were P. penetrans at three initial densities, V. dahliae at one inoculum density, the combination of the nematode at these three densities and the fungus, and a noninfested control. Gas exchange was measured nondestructively in leaf cohorts of different ages, one to three times weekly, with a LI-COR portable photosynthesis system. The single-pathogen treatments had no effect on assimilation or transpiration rates, but joint infection had a significant impact. In concomitant infection, photosynthesis was impaired more than transpiration, so estimates of leaf health were based on carbon assimilation rates only. Reductions in assimilation rate were apparent before the onset of visual symptoms. Assimilation rates decreased as much as 44% in the top, and newest, leaves of concomitantly infected plants, compared to rates in control plants. Even so, the health of newly produced leaves did not become progressively worse through time. With light use efficiency less than 0.20 mol of CO(2) fixed per mol of photosynthetically active radiation used as the criterion for disease incidence, disease progressed acropetally from the oldest to the youngest leaves. In plants infected with P. penetrans (0.8 nematodes per cm(3) of soil) in combination with V. dahliae, all leaves in cohorts 1 and 2 were symptomatic by 45 days after planting, and leaves in cohorts 3 to 6 became symptomatic at weekly intervals thereafter. For the control and single-pathogen treatments, the first time that light use efficiency fell below 0.20 in all leaves in cohort 1 was 71 days after planting. Concomitant infection reduced leaf life span by about 3 weeks. Both visual and physiological symptom expression were invariant to differences in initial nematode inoculum densities ranging from 0.8 to 2.5 nematodes per cm(3) of soil in one experiment and from 1.3 to 4.1 nematodes per cm(3) of soil in a second experiment.