Ringworm in calves: risk factors, improved molecular diagnosis, and therapeutic efficacy of an Aloe vera gel extract.

BACKGROUND: Dermatophytosis in calves is a major public and veterinary health concern worldwide because of its zoonotic potential and associated economic losses in cattle farms. However, this condition has lacked adequate attention; thus, to develop effective control measures, we determined ringworm prevalence, risk factors, and the direct-sample nested PCR diagnostic indices compared with the conventional methods of dermatophytes identification. Moreover, the phenolic composition of an Aloe vera gel extract (AGE) and its in vitro and in vivo antidermatophytic activity were evaluated and compared with those of antifungal drugs. RESULTS: Of the 760 calves examined, 55.79% (424/760) showed ringworm lesions; 84.91% (360/424) were positive for fungal elements in direct-microscopy, and 79.72% (338/424) were positive in culture. Trichophyton verrucosum was the most frequently identified dermatophyte (90.24%). The risk of dermatophytosis was higher in 4-6-month-old vs. 1-month-old calves (60% vs. 41%), and in summer and winter compared with spring and autumn seasons (66 and 54% vs. 48%). Poor hygienic conditions, intensive breeding systems, animal raising for meat production, parasitic infestation, crossbreeding, and newly purchased animals were statistically significant risk factors for dermatophytosis. One-step PCR targeting the conserved regions of the 18S and 28S genes achieved unequivocal identification of T. verrucosum and T. mentagrophytes in hair samples. Nested-PCR exhibited an excellent performance in all tested diagnostic indices and increased the species-specific detection of dermatophytes by 20% compared with culture. Terbinafine and miconazole were the most active antifungal agents for dermatophytes. Gallic acid, caffeic acid, chlorogenic acid, cinnamic acid, aloe-Emodin, quercetin, and rutin were the major phenolic compounds of AGE, as assessed using high-performance liquid chromatography (HPLC). These compounds increased and synergized the antidermatophytic activity of AGE. The treated groups showed significantly lower clinical scores vs. the control group (P < 0.05). The calves were successfully treated with topical AGE (500 ppm), resulting in clinical and mycological cure within 14-28 days of the experiment; however, the recovery was achieved earlier in the topical miconazole 2% and AGE plus oral terbinafine groups. CONCLUSIONS: The nested PCR assay provided a rapid diagnostic tool for dermatophytosis and complemented the conventional methods for initiating targeted treatments for ringworm in calves. The recognized antidermatophytic potential of AGE is an advantageous addition to the therapeutic outcomes of commercial drugs.

Effects of graded levels of microbial fermented or enzymatically treated dried brewer's grains on growth, digestive and nutrient transporter genes expression and cost effectiveness in broiler chickens.

BACKGROUND: Poultry feed consists mainly of conventional grains and protein supplements, however, using treated unconventional agro-industrial by-products as replacements of corn soybean-based diet can minimize production costs and improve productivity. Therefore, in this study, the effects of fermented or enzymatically treated dried brewer grains (DBG) on growth, expression of digestive enzymes and nutrient transporters genes and the profitability of the rations were evaluated. A total of 1600 one-day-old Ross 308 broiler chicks were randomly distributed in 2 × 4 factorial arrangement (eight treatments with ten replicates, 20 birds/replicate). Experimental diets included two controls; negative control (basal corn-soybean diet; NC) and positive control (basal corn-soybean diet with exogenous enzymes; PC), and six diets in which basal diet was replaced by three levels of fermented DBG (FDBG; 5, 10 or 15%), or enzyme-treated DBG (DBG 5, 10 or 15%+Enz), for 38 days. RESULTS: The results described that feeding FDBG (three levels) or DBG5%+Enz improved (P < 0.05) BW gain and feed efficiency of broilers. Also, feeding FDBG10% yielded the best improvement in weight gain (10%), compared to NC group. Increasing the inclusion levels of DBG either fermented or enzymatically treated up-regulated (p < 0.01) expression of digestive-genes in proventriculus (PGC and PGA5, range 1.4-1.8 fold), pancreas (AMY2A, PNLIP, CELA1, and CCK; range 1.2-2.3 fold) and duodenum (CAT1, CAT2, GLUT1, GLUT2, LAT1, Pep1; range 1.3-3 fold) when compared to NC group. Feeding treated DBG significantly increased (p < 0.05, range 4.5-13.6%) gizzard relative weight compared to NC and PC groups. An additional benefit was lower (p < 0.01) cholesterol content from 66.9 mg/100 mg (NC) to 62.8 mg/100 mg (FDBG5 or 10%) in thigh meat. Furthermore, the least cost feed/kg body gain was achieved in FDBG10% and DBG5%+Enz groups, with approx. 16% reduction compared to NC cost, leading to increasing the income gross margin by 47% and 40% in FDBG10% and DBG5%+Enz groups, respectively. CONCLUSIONS: Substitution of corn-soybean based diet with 10% FDBG or 5% DBG+Enz resulted in better growth and higher economic efficiency of broilers chickens.