Performance and intestinal microbiota of chickens receiving probiotic in the feed and submitted to antibiotic therapy

The purpose of this study was to verify the ability of a probiotic in the feed to maintain the stability of the gut microbiota in chickens after antibiotic therapy and its association with growth performance. One thousand six hundred twenty 1‐day‐old Cobb male were housed in floor pens (36 pens, 45 birds/pen) and were fed corn‐/soya bean meal‐based diets supplemented with or without probiotic (Bacillus subtilis) during the entire rearing phase. From 21 to 24 days of age (three consecutive days), the chickens were submitted to antibiotic therapy via drinking water (bacitracin and neomycin) in order to mimic a field treatment and induce dysbiosis. Growth performance was monitored until 42 days of age. At 2, 4 and 6 days after antibiotic therapy, three chickens from each pen were euthanized and the contents of the small intestine and caeca were collected and pooled. The trial was conducted with four treatments and nine replicates in a 2 × 2 factorial arrangement for performance characteristics (with and without probiotic × with and without antibiotic therapy); for the intestinal microbiota, it was in a 2 × 2 × 3 factorial arrangement (with and without probiotic × with and without antibiotic therapy × 2, 4 and 6 days after the antibiotic therapy) with three replicates per treatment. Terminal restriction length polymorphism (T‐RFLP) analysis showed that the structure of gut bacterial community was shaped by the intestinal segment and by the time after the antibiotic therapy. The number of 16S rDNAs copies in caecum contents decreased with time after the therapeutic treatment. The antibiotic therapy and dietary probiotic supplementation decreased richness and diversity indexes in the caecal contents. The improved performance observed in birds supplemented with probiotic may be related to changes promoted by the feed additive in the structure of the intestinal bacterial communities and phylogenetic groups. Antibiotic therapy modified the bacterial structure, but did not cause loss of broiler performance.     

Insect Pests

The fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), is a major pest of maize and frequently demands control measures. The timing of insecticide application is a key factor in determining its efficiency, so an experiment was designed to investigate this. Application of insecticide was based on three criteria: (i) the number of trap-caught moths in a Delta-type trap with a commercial sex pheromone lure placed in the center of the target area, soon after plant emergence; (ii) the percentage of plants exhibiting pinhole-type damage (10% or 20%) and (iii) the percentage of plants exhibiting shot hole-type damage (10% or 20%) compared to a check plot without any control measures. We found that the number of trap-caught moths was, compared to the other methods, the best means of deciding on insecticide application in maize to control the fall armyworm. Using pheromone traps, we obtained the best performance of the insecticide Spinosad, causing >90% larval mortality. Without insecticide application, maize yield reduction due to fall armyworm larva damage was 39%.     

Evaluation of the Perkins® handheld applanation tonometer in the measurement of intraocular pressure in dogs and cats

Objective  To evaluate and to validate the accuracy of the Perkins^® handheld applanation tonometer in the measurement of IOP in dogs and cats.
Animals  Twenty eyes from 10 dogs and 10 cats immediately after sacrifice were used for the postmortem study and 20 eyes from 10 clinically normal and anesthetized dogs and cats were used for the in vivo study. Both eyes of 20 conscious dogs and cats were also evaluated.
Procedure  Readings of IOP postmortem and in vivo were taken using manometry (measured with a mercury column manometer) and tonometry (measured with a Perkins^® handheld applanation tonometer). The IOP measurement with Perkins^® tonometer in anesthetized and conscious dogs and cats was accomplished by instillation of proxymetacaine 0.5% and of 1% fluorescein eye drops.
Results  The correlation coefficient ( r ²) between the manometry and the Perkins^® tonometer were 0.982 (dogs) and 0.988 (cats), and the corresponding linear regression equation were y  = 0.0893 x  + 0.1105 (dogs) and y  = 0.0899 x  + 0.1145 (cats) in the postmortem study. The mean IOP readings with the Perkins^® tonometer after calibration curve correction were 14.9 ± 1.6 mmHg (range 12.2–17.2 mmHg) in conscious dogs, and were 15.1 ± 1.7 mmHg (range 12.1–18.7 mmHg) in conscious cats.
Conclusion  There was an excellent correlation between the IOP values obtained from direct ocular manometry and the Perkins^® tonometer in dogs and cats. The Perkins^® handheld tonometer could be in the future a new alternative for the diagnosis of glaucoma in veterinary ophthalmology.     

Physico-chemical and antioxidant properties of six apple cultivars (Malus domestica Borkh) grown in southern Brazil

The objective of this study was to compare the physico-chemical properties and antioxidant activity of six apple cultivars grown in southern Brazil. Apple peel color, dry matter, total soluble solids, pH, total sugars, titratable acidity, total phenolics, total monomeric anthocyanin and total antioxidant activity were measured in the apple cultivars Imperatriz, Daiane, Fred Hough, Fuji Suprema, Galaxy and Baronesa. The results showed great quantitative differences in the composition of the apple cultivars. Of all the cultivars, the peel of Galaxy was slightly more red-colored and that of Fred Hough was the least red-colored. The dry matter varied from 15.24% (Galaxy) to 19.55% (Fuji Suprema), the soluble solids content was between 11.8 (Fred Hough) and 14.0 (Daiane) °Brix, pH values varied from 3.90 (Imperatriz) to 4.27 (Fred Hough), the total sugar content (g 100 g⁻¹) ranged from 11.54 (Imperatriz) to 14.78 (Fuji Suprema) and the titratable acidity content (g 100 g⁻¹) varied from 0.20 (Baronesa) to 0.36 (Imperatriz). The total phenolic content (GAE 100 g⁻¹ fresh matter) observed in the apple cultivars was between 105.4 (Baronesa) and 269.7 mg (Imperatriz). The values of the total anthocyanin content (mg 100 g⁻¹ FM) ranged from 4.79 (Fred Hough) to 41.96 (Galaxy). The highest total antioxidant activity was observed in Imperatriz (739 μmol TEAC 100 g⁻¹ FM), while the lowest value was found in Fuji Suprema (335 μmol TEAC 100 g⁻¹ FM). There was a strong correlation between total monomeric anthocyanin content and all peel color measurements and between antioxidant activity and total phenolic content. The results suggested that genotype is the main factor that determines the composition of bioactive compounds in apples and this provides important information on how to make the best use of the apple cultivars investigated.     

Selection of Al-resistant plants from a sensitive rice cultivar, using somaclonal variation, in vitro and hydroponic cultures

A selection procedure is described that isolated Al-resistant individuals from a sensitive rice (Oryza sativa L.) genotype. Somaclonal variation was used as the only source of variability and selection pressures were applied at both callus and regenerated plant levels. When 10 week-old, embryo-derived calli were submitted to different Al stresses for a period of 20 weeks. After this in vitro stress period, selected calli were grown during 18 weeks, without selection pressure, on regeneration media. Selection pressures were applied on regenerated plants (R0), and 9 R0 plants which produced seeds were selected. The transmission of the Al-resistant character to the R1, R2, R3 and R4 generations was then investigated, and three plant lines which had an increased percentage of Al-resistant plants till the fourth generation of self-pollination, were identified. One was from a callus maintained on an Al-free medium. The efficiency of in vitro selection pressures was therefore debated. This revised version was published online in July 2006 with corrections to the Cover Date.     

Direct comparison of individual substrate utilization from a CLPP study: A new analysis for metabolic diversity data

For over a decade, community level physiological profile (CLPP) assays, which assess a microbial community's capacity to metabolize specific sole carbon sources under defined laboratory conditions, have been popular for study of environmental soil samples. One such assay, BiOLOG™ allows for the colorimetric measurement of metabolism through the reduction of a tetrazolium dye, which yields optical density (OD) data for each substrate. Bacterial communities are extracted from soil and 150 μL of this extract is inoculated directly into each well of the microtitre plate. The combined metabolic data obtained are most often analyzed with multivariate statistical analyses, such as principal component analysis (PCA). The objectives of this study were (1) to develop a simple, visual, statistically valid method of determining community capabilities to utilize specific substrates in CLPP studies and (2) to test the number of samples needed for such discrimination to be reliable. This was done by direct comparison of the OD values obtained for two closely related microbial communities (surface and subsurface soil), plotted against a one-to-one (y=x) line. Due to variability in the portion of the soil microbial community inoculated into the individual test wells, the accuracy of the method was dependent on the number of replicates analyzed. A variety of data set sizes were tested, from n=3 samples/soil depth to n=40 samples/depth. The method was statistically valid for all data sets tested. Those substrates that deviated from the one-to-one line consistently had F values greater than 1. Additionally, data sets of n=30,35 and 40 samples/depth consistently allowed identification of the eight substrates whose metabolism varied significantly between the two test soil communities. In conclusion, this one-to-one comparison has been shown to be a statistically valid analytical method to compare individual substrate usage between soils.     

Isolation and characterization of enzymes involved in lysine catabolism from sorghum seeds

Lysine is an essential amino acid synthesized in plants via the aspartic acid pathway. The catabolism of lysine is performed by the action of two consecutive enzymes, lysine 2-oxoglutarate reductase (LOR, EC 1.5.1.8) and saccharopine dehydrogenase (SDH, EC 1.5.1.9). The final soluble lysine concentration in cereal seeds is controlled by both synthesis and catabolism rates. The production and characterization of high-lysine plants species depends on knowledge of the regulatory aspects of lysine metabolism and manipulation of the key enzymes. We have for the first time isolated, partially purified, and characterized LOR and SDH from developing sorghum seeds, which exhibited low levels of activity. LOR and SDH were only located in the endosperm and were very unstable during the isolation and purification procedures. LOR and SDH exhibited some distinct properties when compared to the enzymes isolated from other plant species, including a low salt concentration required to elute the enzymes during anion-exchange chromatography and the presence of multimeric forms with distinct molecular masses.     

First successful frozen semen of the maned wolf (Chrysocyon brachyurus)

This study aimed to describe successful cryopreservation of sperm from maned wolves (Chrysocyon brachyurus). Three ejaculates from 2 maned wolves were collected by digital manipulation of the penis and evaluated subjectively, centrifuged and frozen in BotuCrio^® (Botupharma, Botucatu, Brazil) or Tris–yolk egg extender. Spermatozoa were thawed at 37ºC/30s or 70ºC/4s and evaluated for kinetics, morphology, plasma and acrosome membrane integrity, mitochondrial potential, hydrogen peroxide, superoxide anion and lipid peroxidation. From 5 thawed samples, two had sperm total motility >55% (56.0% and 64.0%) and progressive motility ~35% (35% and 40%), both frozen with Tris–yolk egg. Plasma and acrosome membrane integrity decreased and percentage of sperm defects increased post-thawing. We concluded that is possible to freeze spermatozoa from maned wolves using semen collection and processing methods applied for domestic dogs.