The aim of this study was to determine the influence of feed on the pharmacokinetics of flumequine (FLU) administered to broiler chickens as follows: directly into the crop (10 mg/kg of BW) of fasted (group I/control) and non-fasted chickens (group II), or administered continu- ously with drinking water (1 g/L for 72 h) and with unlimited access to feed (group III). Plasma concentration of FLU was determined by high-performance liquid chromatography with fluo- rescence detection. In group II, a significant decrease in the maximum concentration (Cmax = 2.13±0.7 μg/mL) and the area under the concentration curve from zero to infinity (AUC0→∞ = 7.47±2.41 μg·h/mL) was noted as compared to the control group (Cmax = 4.11±1.68 μg/mL and AUC0→∞ = 18.17±6.85 μg·h/mL, respectively). In group III, the decrease in AUC was signifi- cant only in the first 3 hours (AUC0→3 = 5.02±1.34 μg·h/mL) as compared to the control group (AUC0→3 = 7.79±3.29 μg·h/mL). The results indicate that feed reduced the bioavailability of FLU from the gastrointestinal tract by at least 50% after the administration of a single oral dose. However, continuous administration of FLU with drinking water could compensate for the feed-induced decrease in absorption after single oral dose.
The present study was conducted to characterize the infectious bursal disease virus (IBDV) circulating in clinically diseased broiler chicken flocks with previous vaccination history during 2015-2016 in Egypt. IBDVs were isolated from 48 out of 63 of the investigated bursae from 10 flocks onto embryonated chicken eggs (ECEs) and verified by reverse transcriptase-poly- merase chain reaction (RT-PCR). Histopathologically, bursae lesions revealed some lymphocytes depletion as well as the presence of vesicles in the lining epithelium. The hyper variable region (HVR) of VP2 and VP1 genes of the 10 isolates (1 isolate/flock) were partially sequenced and subjected to comparative alignment and phyologenetic analysis. Phylogenetically, IBDV isolates were clustered into two distinct genetic lineages: variants of classical virulent (cv) and very viru- lent (vv) IBDV strains based on VP1 and VP2 amino acid (aa) sequences. Alignment analysis of HVR-VP2 aa sequences has demonstrated that the vvIBDV isolates have the conserved residues of the vvIBDV pathotype (A222, I242, and I256), while, the cvIBDV isolates have the same aa sequences of the classical attenuated vaccine strain (D78). Expected single point mutation occurred at position 253 (H253N). All previously characterized isolates were re-subjected to molecular analysis with VP1 protein due to its correlation with virulence and pathogenicity of IBDVs. vvIBDV isolates have the conserved tripeptide (TDN), while, the cvIBDV isolates have aa substitutions at conserved tripeptide including NEG at 145-147 amino acid. The present study has demonstrated that variants of classical virulent and very virulent IBDV circulated among vaccinated flocks in Egypt during 2015-2016.
The aim of this study was to evaluate the effect of high doses of calcium bentonite on the blood parameters, anticoccidial activity and intestinal histology of broiler chickens. Three undred and sixty one-day old broilers were distributed into three treatments (T+VE, T-VE, TB )with three replicates. Amprolium was added to the feed of the positive control group, calcium bentonite powder was added to the TB group, and nothing was added to the feed of the T-VE group. Coccidiosis was induced on day 14, the birds were kept until day 49, measurements of the diffe- rent variables started from week 3, blood samples were collected via wing vein, and fecal oocysts were counted from the intestinal contents of each individual bird using the McMaster techni- que. A decrease in feed consumption, body weight gain and conversion ratio was noticed in the calcium bentonite group. Broilers in the calcium bentonite group (TB ) and negative control group (T-VE ) showed clinical signs of coccidiosis (blood in feces) and the number of oocysts in feces increased with time. Histopathological examinations of the affected caeca also demonstrated excessive tissue damage, hemorrhage, the presence of clusters of large schizonts and merozoites in the tissue, and coccidian oocysts in the lumen. Feed conversion was highest in the T+VE group.
The aim of this study was to determine to what extent the ions present in hard water (125 mg/L of MgCl2 and 500 mg/L of CaCl2) may intensify the feed-induced decrease in oxytetracycline (OTC) absorption rate in broiler chickens after single oral administration at a dose of 15 mg/kg. Drug concentrations in plasma were determined by liquid chromatography-tandem mass spectrometry and combined, compartmental and non-compartmental approach was used to assess OTC pharmacokinetics.
The administration of feed decreased the absolute bioavailability (F) of OTC from 12.70%±4.01 to 6.40%±1.08, and this effect was more pronounced after the combined administration of OTC with feed and hard water (5.31%±0.90). A decrease in the area under the concentration- time curve (AUC0-t), (from 10.18±3.24 μg·h/ml in control to 5.13 μg·h/ml±1.26 for feed and 4.26 μg·h/ml±1.10 for feed and hard water) and the maximum plasma concentration of OTC (Cmax) (from 1.22±0.18 μg/ml in control, to 1.01 μg/ml ±0.10 for hard water, 0.68 μg/ml±0.10 for feed and 0.61 μg/ml±0.10 for feed and hard water) was observed. The results of this study indicate that feed strongly decreases F, AUC0-t and Cmax of orally administered OTC. The ions present in hard water increase this inhibitory effect, which suggests that, therapy with OTC may require taking into account local water quality and dose modification, particularly when dealing with outbreaks caused by less sensitive microorganisms.
The welfare and healthy growth of poultry under intensive feeding conditions are closely related to their living environment. In spring, the air quality considerably decreases due to reduced ventilation and aeration in cage systems, which influences the meat quality and health of broilers during normal growth stages. In this study, we analyzed the airborne bacterial communities in PM2.5 and PM10 in cage broiler houses at different broiler growth stages under intensive rearing conditions based on the high-throughput 16S rDNA sequencing technique. Our results revealed that PM2.5, PM10 and airborne microbes gradually increased during the broiler growth cycle in poultry houses. Some potential or opportunistic pathogens, including Acinetobacter, Pseudomonas, Enterococcus, Microbacterium, etc., were found in the broiler houses at different growth stages. Our study evaluated variations in the microbial communities in PM2.5 and PM10 and potential opportunistic pathogens during the growth cycle of broilers in poultry houses in the spring. Our findings may provide a basis for developing technologies for air quality control in caged poultry houses.
The aim of this study was to investigate the effect of the addition of fungal solid-state fermented product (FP) enriched with gamma-linolenic acid (GLA) and β-carotene to feed on the haematological and immunological parameters of broiler chickens. Eighty 1-day-old COBB 500 broiler chickens were divided into two groups. The control group was fed with basic diets and chickens of the experimental group received 10% addition of FP, while the amount of basic diet was reduced. FP was produced during a solid-state fermentation (SSF) process using Umbellopsis isabellina CCF2412 as a producer of GLA and β-carotene. After 38 days of feeding, blood samples were collected and analyzed. Lower total and LDL-cholesterol values were measured in blood samples of the experimental animals (p<0.05). However, the triacylglycerol content was higher in the experimental group (p<0.05). Significantly higher levels of hematocrit and hemoglobin, and lower eosinophil and basophil content in the experimental group were recorded (p<0.05). The experimental group showed higher numbers of B lymphocytes and greater phagocytic capacity (p<0.05). The results indicate that a fermented product produced by SSF, using the fungal strain Umbellopsis isabellina, is a good source of GLA and β-carotene, which can influence the biochemical, hematological and immunological parameters of broiler chickens.