Influence of graded levels of calcium and vitamin K in the diets of laying hens during the growing phase and their effects on the laying phase

The aim of this study was to evaluate the effect of dietary supplementation of vitamin K (vit K) and Ca in the diets of laying hens on bone and blood parameters and performance during the growing phase and the effects on the laying phase up to 32 weeks. The study utilized 120 Hy‐Line W‐36 pullets in the growing phase (13–18 weeks), 80 laying hens in the production phase (20–32 weeks), distributed in a completely randomized design in a 2 × 5 factorial arrangement, two levels of Ca (0.8 and 1.4%) and five levels of vit K supplementation (0, 2, 8, 16 and 32 mg/kg) with four experimental units. An experimental diet was fed during the growing phase, and the commercial diet was fed during the production phase and were analysed for biochemistry and bone variables at 18 and 32 weeks. In pullets, a significant interaction of levels of vit K and Ca was observed for total serum calcium (mg/dl), Seedor index, Ca in the bones (%) and medullary bone (%). Pullets at 18 weeks of age, receiving diets with 1.4% Ca, displayed a quadratic effect of vit K with better results for these variables with 17.86, 14.59, 14.48 and 16.80 mg/kg of vit K, respectively. For level 0.8% Ca no effect of vit K was observed. The treatments during the growing phase had no effect on egg production, performance and biochemistry serum until 32 weeks. Medullary bone (%), there was a significant interaction for 1.4% Ca and a quadratic effect for vit K, with greater medullary bone areas observed with 6.09 mg/kg vit K in the diet. Supplementation with vit K in a diet with 1.4% Ca during the growing phase allowed for an increase in the area of medullary bone at 18 weeks, which was maintained until 32 weeks.     

Characterization of atypical Enteropathogenic Escherichia coli (aEPEC) isolated from dogs

Enteropathogenic Escherichia coli (EPEC), an important human pathogen has the ability to form attaching and effacing lesions on the intestinal epithelium and has been isolated from a wide range of species. Two EPEC subgroups are recognized: typical (tEPEC) and atypical (aEPEC) strains, differing by the presence of EAF plasmid and bundle-forming pilus (BFP) in typical strains and their absence in atypical strains. This study searched the presence of EPEC strains in 101 fecal samples of diarrheic (n=65) and non-diarrheic (n=36) dogs from two cities in Rio de Janeiro State, Brazil. The isolates were evaluated for the presence of eae, tir, espA, espB and bfpA genes, EAF plasmid, and for the insertion site of the LEE locus. Cell-adherence assays, fluorescent actin staining (FAS) test, hemolysin production and serotyping were also performed. Twenty eight aEPEC isolates were recovered from 48 eae-positive fecal samples, 24 from diarrheic animals and 4 from non-diarrheic ones. PCR showed that most isolates was positive for β or γ intimin, and for β or α subtypes of tir, espA and espB. Six isolates showed a selC insertion of locus LEE. Only two isolates from the same diarrheic animal harbored the bfpA gene, and none presented the EAF plasmid. Most isolates was FAS-positive and showed a localized adherence-like (LAL) in a 6h HeLa cell-adherence assay. A wide diversity of serotypes was detected including O4:H16 and O51:H40, previously described in human disease. The phenotypic and genotypic markers of aEPEC isolated from diarrheic and non-diarrheic dogs were similar to those found in isolates recovered from human disease.     

Nutrition and production of Helianthus annuus in a function of application of leaf silicon

Silicon (Si) is important as it increases plant tolerance to abiotic stresses. However, studies on in foliar fertilization are still scarce. The objective of this research was to evaluate the effect of foliar application of silicon on nutrition and production of Helianthus annuus. The study was carried with a completely randomized design, consisting of five doses of silicon (0; 0.84; 1.68; 2.52 and 3.36?mg L^?1) applied as silicate, with four replicates. Biometric evaluations and relative chlorophyll index (RCI) measurements were performed, being also observed the dry matter production and the silicon use efficiency by plants. The RCI is not affected by the foliar application of Si, while the height and leaf area increase by 8.3 and 25.4%, respectively. Foliar Si application up to the dose of 3.36?g L^?1 promotes linear increases in the dry matter production of shoots (32%), capitulum (19%) and the whole plant of sunflower (27%).     

Silicon mitigates boron deficiency and toxicity in cotton cultivated in nutrient solution

Silicon (Si) application, both via foliar application and via roots, may be promising to improve plant growth under different biotic or abiotic stresses. In the present study, we investigated whether application of Si can also mitigate the harmful effects of boron (B)‐related nutritional disorders, such as B deficiency, when the application of B is inefficient or insufficient, and B toxicity, when the soil presents high levels of B. This may enable producers to apply Si preventively, if there is a low availability of B in the environment or if B deficiency is induced during the growth season due to a water deficit reducing the plant's B absorption. The objective of this study was to investigate the influence of leaf and root Si application on alleviating the harmful effects of B deficiency and toxicity in cotton. Three experiments were carried out with cotton plants (Gossypium hirsutum cv. Bayer FM910®), using a soilless system. In a first experiment, we determined that highest plant Si concentrations were obtained with application of stabilized sodium and potassium silicate at concentrations of 0.8 g L^?1 (foliar) and 0.056 g L^?1 (roots). Experiment 2 indicated that the B concentrations in the nutrient solution associated with moderate B deficiency, sufficiency and moderate toxicity were 33.7, 83.6, and 130.5 µM B L^?1, respectively. In Experiment 3 we evaluated the effect of optimum Si applications on the physiology and dry weight production of cotton plants subjected to B deficiency, sufficiency, and toxicity. Silicon mitigated the harmful effects of both B deficiency and toxicity by increasing whole‐plant biomass production and levels of chlorophyll a, chlorophyll b, and total chlorophyll, and reduced initial and maximum fluorescence, thereby improving the quantum efficiency of photosystem II. Collectively, these results indicate that the greatest benefit of Si in mitigating B deficiency occurred with foliar B application, while Si supplied via the nutrient solution was more effective against B toxicity.     

Silicon Leaf Fertilization Promotes Biofortification and Increases Dry Matter,Ascorbate Content,and Decreases Post-Harvest Leaf Water Loss of Chard and Kale

This study aimed to evaluate the effects of silicon (Si) leaf fertilization in different concentrations and sources on the production and quality of chard and kale. We carried out two experiments with chard and kale under a completely randomized design with four replicates in a 2 × 4 factorial scheme and two sources of silicon: potassium silicate and stabilized sodium potassium silicate with four concentrations of Si: 0.00; 0.84; 1.68 and 2.52 g L^?1. We performed three leaf sprays every 10 days. The chard and kale were harvested at 48 and 54 days after transplanting the seedlings, respectively. Silicon leaf fertilization is important for leafy vegetables like chard and kale because it increases the content and the accumulation of Si and the growth and production of the vegetables. It also improved growth, productivity, and quality. The Silicon leaf fertilization of 2.52 g L^?1 in the form of potassium silicate was the most notable.     

Comparison of inhibitory effects of glucosamine and mannosamine on bovine articular cartilage degradation in vitro

OBJECTIVE: To compare the inhibitory effects of glucosamine and mannosamine on articular cartilage degradation and the effects on chondrocyte viability in vitro. SAMPLE POPULATION: Bovine articular cartilage explants. PROCEDURES: Explants were cultured in commercial medium for 48 hours. Cartilage was exposed to medium containing 10% fetal bovine serum, 10 microg of lipopolysaccharide/mL, and 0.5, 1.0, 2.5, 5.0, and 10.0 mg of glucosamine or mannosamine/mL for 24 hours. Nitric oxide (NO) production (nitrite concentration) and proteoglycan (PG) release (PG concentration) in media were measured. Cartilage extracts were analyzed via zymography to detect gelatinolytic activity. At the end of the experiment, explants were assessed for chondrocyte viability. RESULTS: Addition of lipopolysaccharide resulted in increased NO production and PG release, but no increase in gelatinolytic activity, compared with controls. Glucosamine and mannosamine at concentrations as low as 0.5 mg/mL inhibited NO production. Glucosamine inhibited PG release at a minimum concentration of 1.0 mg/mL, whereas mannosamine inhibited PG release at a concentration of 0.5 mg/mL. Concentrations of glucosamine < or = 5.0 mg/mL did not adversely affect chondrocyte viability; however, at a concentration of 10.0 mg/mL, cell death was evident. Mannosamine had a toxic effect at a concentration of 5.0 mg/mL and was associated with pronounced chondrocyte death at a concentration of 10.0 mg/mL. CONCLUSIONS AND CLINICAL RELEVANCE: Glucosamine and mannosamine inhibit selected indices of bovine articular cartilage degradation at concentrations that do not affect chondrocyte viability. The potential for cytotoxic effects at higher concentrations underscores the importance of establishing appropriate dosage regimens for these aminomonosaccharides.     

Determination of the Genital Tubercle Migration Period in Morada Nova Sheep Foetuses by Ultrasonography

The aim of this study was to determine the period of genital tubercle (GT) migration using ultrasonography in Morada Nova sheep foetuses (n = 117) from natural mating (NM) and frozen embryo transfer (ET) to determine the window when foetal sexing can be determined. The examinations were performed using transrectal ultrasonography with a dual-frequency linear transducer (6.0 and 8.0 MHz) from day 30-54 of pregnancy at 48-h intervals. The period of GT migration of foetuses produced by NM varied from 36 to 46 days of pregnancy, resulting in an average of 39.5 +/- 2.9 days. For foetuses derived from ET, GT migration varied from 42 to 52 days of pregnancy with an average of 48.5 +/- 3.3 days, being possible the GT of foetuses from ET start to migrate 96 h later even if they are of the same gender. Migration of the GT occurred earlier (p < 0.05) in foetuses produced by NM and sexing accuracy for triplet pregnancies (77.8%) was significantly inferior (p < 0.05) to single (100%) and twin (92.9%) pregnancies for foetuses derived by NM. The results allow one to conclude that foetal sexing can be done from the 50th day onwards in foetuses produced by NM and from the 55th day onwards in foetuses derived from ET, and that multiple pregnancies compromise the sexing accuracy by ultrasonography.     

Genetic requirements for inheritance of RNAi in C. elegans

In Caenorhabditis elegans, the introduction of double-stranded RNA triggers sequence-specific genetic interference (RNAi) that is transmitted to offspring. The inheritance properties associated with this phenomenon were examined. Transmission of the interference effect occurred through a dominant extragenic agent. The wild-type activities of the RNAi pathway genes rde-1 and rde-4 were required for the formation of this interfering agent but were not needed for interference thereafter. In contrast, the rde-2 and mut-7 genes were required downstream for interference. These findings provide evidence for germ line transmission of an extragenic sequence-specific silencing factor and implicate rde-1 and rde-4 in the formation of the inherited agent.     

Combined GnRH and PGF2α Application in Cows with Endometritis Puerperalis Treated with Antibiotics

The investigations were carried out on a total of 70 cows with puerperal endometritis. In addition to intrauterine antibiotic treatment, 30 experimental animals were administered 20 μg GnRH analogue, buserelin, between days 10 and 12 post‐partum followed by 500 μg PGF_2α analogue, cloprostenol, 10 days later. Forty control cows were treated only with intrauterine antibiotics. Blood samples for progesterone determination were collected from the tail vein twice weekly until day 70 post‐partum. The first rise in progesterone level above 3.18 nmol/l occurred significantly earlier in the experimental than in control cows (21.6 ± 9.2 versus 27.8 ± 12.3 days; p ≤ 0.05). The duration of the first cycle post‐partum was 15.0 ± 4.3 days in experimental and 19.7 ± 7.3 days in control animals (p ≤ 0.05). However, no significant differences were observed in the occurrence of first oestrus post‐partum. The involution of the uterus was improved after hormone treatment. At day 42 post‐partum, completion of uterine involution was found in 93.3% of hormone‐treated cows and in 82.5% of those treated with antibiotic only (p ≤ 0.05). Clinical recovery was 96.6% in the experimental and 82.5% in the control group (p ≤ 0.05). First service pregnancy rate was significantly better in hormone‐treated than control cows (51.7 versus 36.4%; p ≤ 0.05). Total pregnancy rate and insemination index values were not significantly improved following GnRH and PGF_2α treatment. The average service period was 89.8 ± 21.2 days in cows after hormone treatment, and 112.6 ± 24.5 days in control cows. The difference was statistically significant (p ≤ 0.05). These results indicate, that the sequential GnRH and PGF_2α application in cows with puerperal endometritis positively affected ovarian function and uterine involution, resulting in improved fertility performance.