The effects of dietary calcium iodate on productive performance,egg quality and iodine accumulation in eggs of laying hens

The aim of this study was to examine the effects of various levels of supplemental calcium iodate (CI) on productive performance, egg quality, blood indices and iodine (I) accumulation in the eggs in commercial laying hens. A total of 240 White Leghorn layers (Hy‐line W36) were divided through a completely randomized design into six treatments with five replicates and eight hens per each at 32 weeks of age. This experiment lasted for 12 weeks. Concentrations of I in the mash diets were 0.74, 3.13, 5.57, 8.11, 10.65 and 12.94 mg I/kg of feed in treatments 1–6 respectively. The added doses of CI were included 0.0 (control), 2.5, 5.0, 7.5, 10.0 and 12.5 mg/kg of diet for treatments 1–6 respectively. There were no significant differences in productive performance among the treatments. The highest eggshell strength was observed in group fed diet containing 3.13 mg I/kg (p = .014). The highest percentage of calcium and lowest percentage of phosphorus in eggshell were observed in group fed diet containing 12.94 mg I/kg (p = .0001). Feeding hens with diet containing 12.94 mg I/kg increased serum triiodothyronine‐to‐thyroxine ratio (p = .0001). Serum alanine aminotransferase activity in hens fed diet containing 12.94 mg I/kg was significantly more than control (p = .041). Blood Serum triglycerides in hens fed diet containing 8.11 mg I/kg were significantly higher than control (p = .0001). Edible fraction of the eggs of birds fed diet containing 12.94 mg I/kg was enriched by I almost 3 times more than those fed diet containing 0.74 mg I/kg. The results suggested that egg production, egg mass, feed intake and feed conversion ratio were not significantly affected by dietary I levels. Iodine accumulation in the eggs were increased by increasing dietary I levels and the level of 10 mg/kg CI could supply I enrichment of the eggs.     

Effect of Rosmarinus officinalis Essential Oil and Nisin on Streptococcus iniae and Lactococcus garvieae in a Food Model System

The effects of concentrations of Rosmarinus officinalis essential oil (EO) and nisin (N) as well as temperature and storage time on growth of Streptococcus iniae and Lactococcus garvieae in Oncorhynchus mykiss were evaluated. According to analysis of the rosemary EO, the 1, 8-cineol and α-pinene were the predominant components. The growth of S. iniae was significantly decrease by EO concentrations at 4 ºC. For L. garvieae, the viable count was significantly inhibited by EO and N singly and in combinations, incubated at bath storage of 0.25 and 0.5 µg/mL proved insufficient to act against S. iniae and L. garvieae. The combinations of the rosemary EO at 0.0015% with N at 0.5 µg/mL showed stronger antimicrobial effect against two bacterial than the rosemary EO at 0% but lower than the combination with N at 0.5 µg/mL and EO at 0.045% which in turn was lower than of the rosemary EO at 0.135%. In its turn, rosemary EO showed lower antimicrobial activity than its combinations with N, which showed a bactericidal effect against the pathogens. The best inhibitory effects of EO in combinations with N for two bacterial were obtained at combinations of EO=0.135% and N=0.5 µg/mL.     

Quality preservation of salted,vacuum packaged and refrigerated mahi sefid (Rutilus frisii kutum) fillets using an onion (Allium cepa) extract

The combined effect of light salting, vacuum packaging and onion extract on the shelf life of mahi sefid (Rutilus frisii kutum) fillets under refrigeration was assessed using chemical, microbiological and sensory methods. The shelf life of control, air‐packaged, salted (APS), vacuum‐packaged, salted (VPS) and vacuum‐packaged, salted with onion extract (VPSOE) samples was determined to be up to 6, 9, 15 and 18 days respectively. The values of total volatile basic nitrogen, free fatty acid and thiobarbituric acid increased progressively during the storage period for all the treatments. However, the preservative methods applied led to an extended shelf life of fillets based on chemical indices and sensory attributes in the following order: VPSOE>VPS>APS>control group. The assay of the total viable count (TVC) revealed that 2% and 4%VPSOE produced a decrease in TVC throughout the storage period. According to the results obtained, the best method to preserve the mahi sefid fillet was by 4%VPSOE treatment.     

Fingerprinting sediment sources in the outlet reservoir of a hilly cultivated catchment in Tunisia

Purpose

Approximately 74 % of agricultural soils in Tunisia are affected by water erosion, leading to the siltation of numerous human-made reservoirs and therefore a loss of water storage capacity. The objective of this study was to propose a methodology for estimating the relative contributions of gully/channel bank erosion and surface topsoil erosion to the sediment accumulated in small reservoirs.

Materials and methods

We tested an approach based on the sediment fingerprinting technique for sediments collected from a reservoir (which has been in operation since 1994) at the outlet of a catchment (Kamech, 2.63 km²). Sampling concentrated on the soil surface (in both cropland and grassland), gullies and channel banks. A total of 17 sediment cores were collected along a longitudinal transect of the Kamech reservoir to investigate the origin of the sediment throughout the reservoir. Radionuclides (particularly caesium-137, ¹³⁷Cs) and nutrients (total phosphorus, total nitrogen and total organic carbon (TOC)) were analysed as potential tracers.

Results and discussion

The applications of a mixing model with ¹³⁷Cs alone or ¹³⁷Cs and TOC provided very similar results: The dominant source of sediment was surface erosion, which was responsible for 80 % of the total erosion within the Kamech catchment. Additionally, we showed that the analysis of a single composite core provided information on the sediment origin that was consistent with the analysis of all sediment layers in the core. We demonstrated the importance of the core sampling location within the reservoir for obtaining reliable information regarding sediment sources and the dominant erosion processes.

Conclusions

The dominance of surface erosion processes indicates that conservation farming practices are required to mitigate erosion in the agricultural Kamech catchment. Based on the results from 17 sediment cores, guidelines regarding the number and location of sampling cores to be collected for sediment fingerprinting are proposed. We showed that the collection of two cores limited the sediment source apportionment uncertainty due to the core sampling scheme to <10 %.     

Influence of Plant Growth Promoting Rhizobacteria,Compost, and Biochar of Azolla on Rosemary (Rosmarinus Officinalis L.) Growth and Some Soil Quality Indicators in a Calcareous Soil

In order to study the effect of plant growth promoting rhizobacteria (PGPR), Azolla compost and Azolla biochar on some soil quality indicators and rosemary growth, a greenhouse experiment was conducted in a completely randomized design with six replications. Treatments consisted of T₁ (control), T₂ (1% Azolla compost), T₃ (1% Azolla biochar), T₄ (PGPR (P. fluorescens), T₅ (1% compost + PGPR) and T₆ (1% biochar + PGPR). Rosemary growth parameters and nutrients concentration increased in all treatments compared to control. Treatments increased soil nutrient concentrations, soil microbial respiration (SMR) and microbial biomass C (MBC) but decreased soil metabolic quotient (qCO₂) compared to control treatment. A significant enhancement in rosemary growth occurred due to the improved soil quality as a result of organic fertilizers application, particularly by co-application of P. fluorescens and compost or biochar of Azolla.     

Immunohistochemical and polymerase chain reaction studies in Neospora caninum experimentally infected broiler chicken embryonated eggs

The diagnostic characteristics of immunohistochemistry (IHC) and polymerase chain reaction (PCR) methods were studied in the tissues of broiler chicken embryos experimentally infected by Neospora caninum. An infection with N. caninum NC-1 isolate was conducted in 70 broiler chicken embryonated eggs randomly divided into seven equal groups. After 8 days of incubation, six groups were inoculated with 10, 10(2), 10(3), 10(4), 10(5), and 10(6) doses of tachyzoites/embryonated egg. The 7th group was considered as control. The mortality rate and pathological changes of the dead embryos and hatched chickens up to 60 days old were noticed. Consecutive sections to those used for histopathological examination including the liver, heart, brain, and chorioalantoic (CA) membrane were subjected to IHC. The intensity and distribution of the immunostaining was graded as highly to mildly positive. For PCR procedure, DNA was extracted from 50mg of the tissues and primer pair Np21/Np6 was used for amplification of the Nc-5 gene. The results of the immunosignaling ranged from variable degrees of mild to moderate staining as dark-brown to brown and coarsely to finely granular, mostly within the cytoplasm of infected cells such as the endothelial cells of blood vessels. The parasite aggregation was more predominant in the heart than other tissues. Immunoreactivity for N. caninum antigen was multifocally moderate positive in the heart, liver and CA of the 10(3) dose, and also heart, liver, brain and CA of the 10(4) dose. IHC showed mildly positive in the liver and heart of the chicken embryos infected with 10 and 10(2) tachyzoites, as well. The results of the PCR confirmed the existence of the parasite in all of the examined tissues from the 10(3) and 10(4) doses. In conclusion, the results indicate a good agreement between IHC and PCR in diagnosis of neospora antigen in the infected tissues.     

Growth and Survival of Blackslip Pearl Oyster Larvae Fed Different Densities of Microalgae

This paper reports on an experiment to determine growth and survival of blacklip pearl oyster, Pinctada margaritifera (L.), larvae fed a 1:1 mixture of Isochrysis aff. galbana clone T-ISO and Pavlova salina at six different densities (1, 2, 5, 10, 20 and 30 × 10³ cells ml^-1. Larval growth and survival were assessed every four days over a 20–day period. Exponential and logistic regression models were fitted to the growth and survival responses, respectively. Overall growth of larvae fed 5 × 10³ cells ml^-1 was significantly greater (p > 0.01) than growth of larvae reared at other algal densities. The optimal food ration for maximum larval growth was 20 × 10³ cells ml^-1, which resulted in larvae with antero-posterior shell length of 230 m after 20 days. These larvae were significantly larger (p > 0.05) than those in all other treatments at the end of the experiment. Survival of larvae fed 0, 1 and 2 × 10³ cells ml^-1 was significantly lower than that of larvae in all other treatments at the end of 15 days (p > 0.01). Maximal survival (8%) over the 20 day period was shown by larvae fed 10 × 10³ cells ml^-1, while lower survival was shown by larvae fed 2 × 10³ cells ml^-1 (2%) and 1 × 10³ cells ml^-1 (0%).     

Basaltverwitterung und Bodenentwicklung seit dem mittleren Tertiär auf Lanzarote,Kanarische Inseln (Profil Malaya Chica)

Basalt Weathering and Soil Development since the Middle Tertiary on Lanzarote, Canary Islands - The Profile Malaya Chica A polygenetic soil on tertiary (miocene) basalt in the north of Lanzarote (Canary Islands, Spain) was examined. Soil development was reconstructed, which took place in a semiarid climate since the end of the tertiary period. The interpretation of field and laboratory results (carbonate, grainsize distribution, oxalate and dithionithe soluble oxides, CEC, clay minerals, micromorphology) explained the history of development. Since the miocene at least seven consecutive phases of soil development took place induced by erosion, volcanic and colluvial sedimentation and/or climatic changes.