The Influence of Body Weight on Semen Parameters in Apis mellifera Drones.

The quantity and quality of the honey bee drone semen have a significant determination on the performance of bee colonies. The existence of a smaller number of mature drones to participate in the mating of queens, as well as a sufficient number of drones but with poor quality semen can have serious implications for the productivity of bee colonies. Our study aimed to investigate the correlation between two body weight ranges of drones and semen parameters in the Buckfast honey bee, data that could be integrated into the optimization of instrumental insemination in been queens. Semen was collected from two groups of drones with different body weights (200−240 mg and 240−280 mg). Semen volume, semen concentration, motility, morphology and membrane integrity of spermatozoa were analyzed. The phenotype indicator related to body weight in correlation with the main semen parameters studied gives a weak influence or causality ratio. In drones with 240−280 mg body weight, a higher percentage of spermatozoa with abnormal morphology (>9.60%) was recorded, compared to drones with 200−240 mg body weight. The study reveals that a higher weight of honey bee drones is correlated with higher sperm concentration and total number of spermatozoa/ejaculate, with an increase in the percentage of spermatozoa with abnormal morphology.

Chemical Composition, Antioxidant and Antimicrobial Activity of Some Types of Honey from Banat Region, Romania.

Honey is a natural product with multiple health benefits. The paper presents the chemical characterization and the antioxidant and antimicrobial potential of ten types of honey (knotweed, linden, wild cherry, acacia, honeydew, oilseed rape, sunflower, phacelia, plain polyflora and hill polyflora) from the Banat region, Romania. We studied the water content, dry matter, impurities, acidity and pH of honey. We also determined the content of reducing sugar, minerals and flavonoids and the total phenolic content. All honey samples analysed showed good nutritional characteristics according to the standard codex for honey. From the analysis of the mineral content of the honey samples, we observed a variability in the macro and microminerals, influenced by the botanical origin, ranging between 0.25% (wild cherry honey) and 0.54% (honeydew). The toxic metals' (Cd and Pb) levels met the standard for almost all samples analysed except for knotweed. The flavonoid content of the samples ranged from 9.29 mg QE/100 g for wild cherry honey to 263.86 mg QE/100 g for linden honey, and for polyphenols between 177.6 mgGAE/100 g for acacia honey and 1159.3 mgGAE/100 g for honeydew. The best antioxidant capacity was registered in the case of linden honey (79.89%) and honeydew (79.20%) and the weakest in acacia (41.88%) and wild cherries (50.4%). All studied honey samples showed antimicrobial activity, depending on the type of honey, concentration and strain analysed. The novelty of this study is given by the complex approach of the study of honey quality, both from the perspective of chemical attributes and the evaluation of the antimicrobial potential on specific strains in correlation with the botanical and geographical origin of the analyzed area.

The In Vitro and In Vivo Effect of Carvacrol in Preventing Campylobacter Infection, Colonization and in Improving Productivity of Chicken Broilers.

The current trend in reducing the antibiotic usage in animal production imposes urgency in the identification of novel biocides. The essential oil carvacrol, for example, changes the morphology of the cell and acts against a variety of targets within the bacterial membranes and cytoplasm, and our in vitro results show that it reduces adhesion and invasion of chicken intestinal primary cells and also biofilm formation. A trial was conducted to evaluate the effects of dietary supplementation of carvacrol at four concentrations (0, 120, 200, and 300 mg/kg of diet) on the performance of Lactobacillus spp., Escherichia coli, Campylobacter spp., and broilers. Each of the four diets was fed to three replicates/trial of 50 chicks each from day 0 to 35. Our results show that carvacrol linearly decreased feed intake, feed conversion rates and increased body weight at all levels of supplementation. Plate count analysis showed that Campylobacter spp. was only detected at 35 days in the treatment groups compared with the control group where the colonization occurred at 21 days. The absence of Campylobacter spp. at 21 days in the treatment groups was associated with a significant increase in the relative abundance of Lactobacillus spp. Also, carvacrol was demonstrated to have a significant effect on E. coli numbers in the cecum of the treatment groups, at all supplementation levels. In conclusion, this study shows for the first time that at different concentrations, carvacrol can delay Campylobacter spp., colonization of chicken broilers, by inducing changes in gut microflora, and it demonstrates promise as an alternative to the use of antibiotics.

Effect of human isolated probiotic bacteria on preventing Campylobacter jejuni colonization of poultry.

This study was performed in order to determine whether human isolated probiotic bacteria can be effective in reducing Campylobacter jejuni infection of chicken intestinal cells, in vitro, and in decreasing its colonization abilities within the chicken gut. Our results show that the probiotic strains Lactobacillus paracasei J. R, L. rhamnosus 15b, L. lactis Y, and L. lactis FOa had a significant effect on C. jejuni invasion of chicken primary cells, with the strongest inhibitory effect detected when a combination of four was administered. In regard to the in vivo effect, using all four strains in one combination prevented mucus colonization in the duodenum and cecum. Moreover, the pathogen load in the lumen of these two compartments was significantly reduced. When probiotics were introduced during the early growth period, the presence of the pathogen in feces was increased (p>0.05), but when they were given during the last week of growth, there was no significant effect. In conclusion, our data indicate that these four new probiotic strains are able to cause modifications in the chicken intestinal mucosa and can reduce the ability of C. jejuni to invade, in vitro, and to colonize, in vivo. These probiotics are now proven to be effective even when introduced in broiler's feed 7 days before slaughter, which makes them cost-effective for the producers.