The purpose of this study was to evaluate the dietary use of novel silage that was created by combining three agro-industrial wastes produced in bulk, i.e., olive mill wastewater, grape pomace, and deproteinized feta cheese whey, in the diets of broiler chickens. A total of 216 one-day-old male Ross-308 chicks were randomly allocated to three treatment groups with six replications (12 chicks per pen). Three isocaloric and isonitrogenous diets were formulated to include the examined silage at 0%, 5%, or 10%. Commercial breeding and management procedures were employed throughout the trial. At the end of the trial (day 35), tissue samples were collected for analysis. Feeding 10% silage resulted in increased (p ≤ 0.001) final body weight (p ≤ 0.001) and feed intake. Jejunum and cecum microflora, as well as breast and thigh meat microflora, were modified (p ≤ 0.05) by the dietary inclusion. Thigh meat oxidative stability was improved (p < 0.01) by the silage supplementation. In addition, breast and thigh meat fatty acid profiles were different, respectively, (p < 0.05) in the supplemented treatments compared to the control. The examined silage was successfully tested in broiler diets with potential benefits for their performance and meat quality.
The procurement of adequate feed resources is one of the most important challenges for the animal industry worldwide. While the need for feeds rich in protein is constantly increasing, their production cannot readily keep up. Consequently, to overcome this challenge in a sustainable way, it is necessary to identify and develop new feeding strategies and feed ingredients, such as insect meals. In the present study, Tenebrio molitor larvae that were reared on two different substrates (standard and enriched with medicinal aromatic plant material) were used as feed ingredients for growing pigs. A total of 36 weaned pigs (34 days old) were randomly allocated to three treatment groups and fed either the control diet (A) or diets supplemented at 10% with one of the two insect meals (B and C). At the end of the trial (42 days), blood, feces, and meat samples were collected for analysis. The insect meal supplementation did not affect (p > 0.05) overall performance but significantly modified (p < 0.001) the fecal microflora balance and the blood cholesterol (p < 0.001), while the rest of the blood parameters tested were not affected. Moreover, this dietary supplementation significantly affected some microbial populations (p < 0.001), improved the total phenolic content (p < 0.05), and the fatty acid profile (p < 0.001) of the meat cuts, but did not affect (p > 0.05) meat color or proximate composition. Further research is needed to evaluate the different types and levels of inclusion of insect meals in pig nutrition.
Milk samples of ewes’ and goats’ unprocessed milk were collected from milk tanks from various farms in Epirus, Greece and classified in two groups according to the type of farming. Analyses of the samples included microbial inhibition assays to detect the presence of antibiotic residues, isolation of Staphylococcus aureus and Escherichia coli strains as microbiological indicators for susceptibility to antimicrobial medicines, Somatic Cells and Coagulase Negative Staphylococci (CNS) counts. These findings were correlated with each other as well as to the stage of the lactation period and to the type of the farming practices. Monitoring of bulk tank milk for residues of antibiotics should be performed after heating of the milk, on a regular basis, and should include at least two different tests. The results point out that the type of farming affects the CNS counts as well as the prevalence of residues in the milk. Furthermore, the inverse correlation between CNS counts and prevalence of residues of antibiotics suggests a possible protective role of CNS. Resistance of the bacterial indicators to antibiotics was random and relatively rare, perhaps acquired in past due to misuse of antibiotics, turning the indicator microorganisms to reservoir of resistance.
The demand for ovine milk and ovine dairy products is constantly increasing due to their exceptional sensorial characteristics and their health benefits for consumers. However, dairy fat content and composition are of particular concern for consumers as well as the medical community, as there are risk factors for coronary disease, diabetes mellitus, cancer, and other serious diseases. For this reason, attempts have been made to control/regulate the fat composition of ovine milk by modifying sheep dietary intake of polyunsaturated fatty acids. In this experimental trial, a group of sheep were fed for 30 days a diet enriched in flaxseeds and lupines, feed ingredients rich in omega-3 fatty acids, aiming to investigate the effects on fat composition and the microbiota of ovine milk. Chemical analysis of the collected milk showed that the omega-3 and omega-6 content was increased. On the opposite, the atherogenic and thrombogenic indexes decreased. Of importance was the semi-protective effect on the udder by the increased omega-3 dietary intake, as depicted by its impact on the biodiversity of the pathogenic microbiota. These findings suggest that ovine milk could be modified under specific conditions to be more appropriate for the consumption by people belonging to high-risk groups for various diseases.
Staphylococcus spp. is an important mastitis-inducing zoonotic pathogen in goats and is associated with antimicrobial resistance (AMR). The objectives of this study were to determine the prevalence and composition of staphylococci in individual mammary secretion (MS) samples of clinically healthy goats and to evaluate the phenotypic AMR pattern and the presence of methicillin resistance in the Staphylococcus spp. strains. Staphylococcus spp. isolates (n = 101) from the MS samples (n = 220) were identified to species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The antimicrobial susceptibility testing included a disk diffusion assay and the determination of the minimum inhibitory concentrations (MIC) of resistant strains (n = 46). Presumptive methicillin-resistant strains (n = 9) were assessed for the presence of mecA, mecC and SCCmec/orfx genes. Staphylococcus spp. isolates were recovered from 45.9% of the MS samples, of which, 72.3% was identified as coagulase-negative staphylococci (CoNS), with the remaining being Staphylococcus aureus. CoNS and S. aureus were most commonly resistant to ampicillin (56.2% and 57.1%, respectively), penicillin (26.0% and 39.3%, respectively), amoxicillin (26 % and 25 %, respectively) and cephalexin (12.3% and 25%, respectively) in the disk diffusion method. CoNS exhibited a broader AMR pattern and a higher percentage of resistant strains than S. aureus in the disk diffusion and MIC methods. Of the nine oxacillin- and cefoxitin-resistant strains, three S. aureus and five CoNS strains carried the mecA gene and, thus, were identified as methicillin-resistant. The mecC gene was not found in any of the studied strains. The presence of AMR and methicillin resistance in caprine S. aureus and CoNS poses a concern for animal and public health.
The Gram-negative bacterium Riemerella anatipestifer (RA) is known to cause clinical disease with severe economic impacts primarily in ducks and less frequently in geese and turkeys. RA was isolated and identified in broiler chickens, from a clinical case in a commercial broiler farm located in the southwest mainland of Greece. The morbidity and the mortality in the broiler house were estimated at 10% and 5% respectively. The observed clinical signs appeared at the age of 30 to 42 days with respiratory distress (dyspnea), white fluid feces and stunting. Post-mortem examinations displayed serositis, pericarditis, perihepatitis and airsacculitis. Edematous swelling around the tibio-tarsal joints was observed in some birds. Tissue samples from lesions were streaked on selective media. Three bacterial isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Moreover, an antibiogram analysis was performed for the three RA strains, using a pattern of 16 common antibiotics to advocate the most effective drugs for a proper treatment. All the RA isolates were sensitive to ceftiofur, sulphamethoxazole–trimethoprim and amoxicillin, whereas all were resistant to gentamicin, tylosin, tetracyclin, colistin sulphate, spectinomycin, lincomycin and oxytetracycline.
In this work, the production of a novel and sustainable silage was realized and optimized. Three agro-industrial wastes produced in bulk: olive mill wastewater (OMWW), grape pomace (GP) and de-proteinized feta cheese whey (DFCW) were mixed with coarsely ground maize grains, and the mixture was inoculated with commercial lactic bacteria starter culture and fermented for 30 days under anaerobic conditions to obtain silage. Sixty-seven recipes with varying compositions of the three agro-wastes were ensilaged, and four silage quality indices: pH value, % acidity as lactic acid, total lactobacillus count (cfu/g) and total yeast and mold count (cfu/g) were monitored throughout the ensilage process, and the obtained data were used to perform multicriteria optimization of the silage composition. The optimization target was to simultaneously maximize the pH drop, % total acidity as lactic acid and lactobacillus count while minimizing the count of undesirable yeasts and molds. Following this optimization strategy, it was found that the best composition of the mixture of all three tested agro-industrial wastes to obtain a high-quality silage was the one containing: 20% w/w GP, 60% w/w OMWW and 20% w/w feta cheese whey. Finally, the produced silage was tested in broilers’ nutrition and by 10% w/w inclusion in the feed, which led to the production of high added-value bioactive meat rich in ω-3 fatty acids and with high antioxidant capacity.
Screening natural products for bacteriocin-producing bacteria may be the equilibrium point between the consumer demand for mild processing and the industry's need for hazard control. Raw unprocessed honeycombs filled with oregano honey from the alpine mountainous territory of Epirus, Greece were screened for bacteriocinogenic lactic acid bacteria and Bifidobacterium spp., with inhibitory action towards some pathogens and spoilage microorganisms isolated from fresh fruits and vegetables (number and type of strains: three E. coli, two L. monocytogenes, two Salmonella spp., two B.cereus, two Erwinia spp., one Xanthomonas spp., L. innocua (ATCC 33090TM) and E. coli 0157:H7 (ATCC 69373)). Among the 101 collected isolates (73 Lactobacillus, 8 Lactococcus, 8 Leuconostoc and 12 Bifidobacterium species) from the oregano honeycombs (an original finding since there are no other reports on the microbial biodiversity of the flora of the oregano honey), 49 strains of lactic acid bacteria (LAB) and Bifidobacterium spp. were selected and tested for their bacteriocin-producing capacity (34 Lactobacillus, 6 Lactococcus, 5 Leuconostoc and 4 Bifidobacterium). The antibacterial activity exerted by the tested LAB and Bifidobacterium strains was not of the same potency. Our results suggest that the main molecules involved in the antimicrobial activity are probably bacteriocin-like substances (a conclusion based on reduced antibacterial activity after the proteolytic treatment of the cell-free supernatant of the cultures) and this antimicrobial activity is specific for the producing strains as well as for the target strains. The spoilage bacteria as well as the reference microorganisms showed increased resistance to the bacteriocin-like substances in comparison to the wild-type pathogens.
In the last three decades, modern extraction and processing methods have resulted in the isolation and identification of bioactive ingredients of several aromatic plants. These ingredients are mainly plant secondary metabolites, such as terpenes, phenolics, and nitrogen-containing compounds. These extracts are under examination as possible performance enhancers for farm animals, as well as alternatives to commonly used veterinary drugs, based on their promising antimicrobial, antiquorum sensing, antiparasitic, antioxidant, antiinflammatory, and immune promoting properties. This research interest is further supported by the modern eco-sensitive consumer's demands for more “natural” livestock farming methods with less environmental impact, animal products free from chemical residues and antibiotics. A comparison of research output is hindered by the use of different experimental disease models, with variable active components and infectious dosages. Accordingly, this review aims to provide a current overview of the health-promoting and performance enhancing effects of dietary aromatic plants and extracts in healthy and disease challenged farm animals.
Campylobacter is an important pathogen commonly found in chickens that can cause severe acute gastroenteritis in humans. Despite intensive efforts to inhibit food-borne transmission of Campylobacter no effective strategy exists to reduce Campylobacter loads in farmed broilers. This study examined the capacity of a novel feed additive to lower Campylobacter jejuni populations and to improve growth efficiency of broiler chickens. A total of 384 male one-day-old broiler chicks were used in a 42-day trial. Birds were randomly allocated into four treatments with six replicates of sixteen chicks per pen. Three groups were fed the basal diets further supplemented with TYPLEX (TM) chelate (ferric tyrosine) at various concentrations (0.02, 0.05 and 0.20 g/kg, groups T-2-T-4, respectively). Control group (T-1) was fed basal diets in mash form that did not contain added ferric tyrosine. Feed and water were provided ad libitum. At 20 days of age, broilers were exposed to natural C. jejuni challenge by introducing contaminated litter from a commercial farm. At day 25, pen litter samples analysed positive for C. jejuni, and the infection intensity was homogeneous among pens. At the end of the study C. jejuni counts in bird caeca were significantly reduced, by 2 log(10) in the T-4 group, compared to the T-1 Control and T-3 groups (p = 0.004). During this study, a natural infection with Eimeria tenella occurred at days 26-29. For animal welfare reasons all birds were treated with an anti-coccidial drug as recommended, for two consecutive days. At day 42, diarrhoea was observed on the litter in only 1 of 6 pens in the T-4 group, but in 5 of 6 pens in the T-1 Control group. In addition, autopsies showed that the T-4 group had the highest percentage of birds with normal intestinal tracts. The T-1 group had the lowest percentage of birds with infection-free tracts, and higher incidence of coccidiosis and bloody diarrhoea. At 42 days of age all birds were slaughtered and samples collected for further analysis. Birds in the T-4 group tended to exhibit improved weight gain and feed efficiency, a result that warrants further investigation. Collectively, our data suggest that addition of ferric tyrosine at 0.20 g/kg exerts a protective effect against C. jejuni and coccidiosis.
•Combined dietary use of additives improved growth performance of fattening pigs.•Combined dietary use of additives improved villus heights and villus to crypt ratio.•Enterococcus faecium use increased enterococci counts in jejunum and cecum.•In absence of challenge, pigs’ blood lymphocytes subpopulations were not affected.
In this study, the essential oil of oregano and salvia were used as a source of functional ingredients with antioxidant properties in chicken diet for 6 weeks; birds were fed a basal diet, or a basal diet supplemented with 500 or 1000 ppm extract that contained 5% oregano essential oil and 0,5% sage oil, respectively. Feed and water were offered to birds ad libitum. At the end of the trial, breast and thigh samples were taken for further analysis. Breast and thigh meat revealed no differences on moisture, fat and protein content among the three experimental groups. Results on oxidation showed that dietary oregano and sage oil at both supplementation levels improved antioxidant status compared to control diet, the effect being dose dependent. In conclusion, a combination of dietary oregano and sage exerted an antioxidant protective activity in both raw and cooked chicken breast and thigh meat.
Soybean meal is a widely available feed for farm animals, rich in protein (440-500 g kg -1 ). It has high biological value and digestibility, and considerable energy content. Unfortunately, in recent years, soybean meal has become so expensive that other vegetable feedstuffs are urgently sought after by nutritionists and feed industries. The dietary inclusion of other oil seed meals in order to reduce reliance on imported soybean meal, such as sunflower meal (240-440 g kg -1 crude protein) or rapeseed meal (310-370 g kg -1 crude protein) in pig diets can provide opportunities for diversifying the feedstuff matrix by using home-grown feedstuffs, which can result in the reduction of the feeding cost without negatively affecting the performance of the animals or the meat quality. Such alternative feeds may replace soybean meal partially or entirely in swine rations, especially in the growing and finishing periods. Moreover, there are other protein sources which could be used in swine nutrition, such as cottonseed meal, flaxseed meal, peas and faba beans. In addition, algae which have high quality proteins may be considered as a non-conventional source of proteins in pig diets, comparable to soybean meal. The above mentioned feedstuffs seem to be promising materials for pig nutrition, as well as the protection of the environment by lowering the carbon footprint production.
A study was conducted to examine the effect of dietary oregano essential oil supplementation on the performance of broiler chickens challenged with Eimeria acervulina and Eimeria maxima at 14 days of age. A total of 375 day-old Cobb-500 male chicks separated into 5 equal groups with three replicates each, were used in this study. Two of the groups, one challenged with 1 X 10(5) sporulated oocysts of E. acervulina along with 1 X 10(5) sporulated oocysts of E. maxima and the other not, were given a basal diet and served as controls. The other three groups also challenged with combined E. acervulina and E. maxima were administered diets supplemented with oregano essential oil by adding the product Orego- Stim (containing 5% oregano essential oil) at the levels of 300 or 600 mg/kg, and the last group the anticoccidial substance salinomycin at the dosage of 60 mg/kg. Following the challenge, survival rate, bloody diarrhea and oocysts excretion, as well as intestinal lesion score were all determined. Throughout the experimental period that lasted 35 days, body weight gain and feed intake were weekly recorded, and feed conversion ratios were calculated. The results showed that dietary oregano oil supplementation in both oregano supplemented groups, attained body weight gains and feed conversion ratios not differing (p>0.05) to those of the non-challenged group or the salinomycin group. The challenged control presented lower (p>0.05) performance than those of the other groups for the consecutive three weeks after the challenge. These performance parameters along with lesion scoring indicated that oregano essential oil exerted an anticoccidial effect against E. acervulina and E. maxima, comparable to salinomycin.