RESUMEN
Several medium chain fatty acids and different chemical forms of these acids were evaluated in vitro as treatments of aerobically-exposed corn silage against spoilage and pathogenic microbes and for effects on rumen fermentation. Treatments were control (no additive), myristate (MY), laurate (LA), monolaurin (MLA), methyl ester laurate (MELA), a blend of mono-, di- and triglycerides of laurate (BLA), and monocaprylate (MC). After 24 h of aerobic incubation (37°C), yeast and mold growth were not influenced (P > 0.05) by treatments, while the net growth of lactic acid bacteria was decreased, albeit slightly, compared to that by untreated controls (P < 0.01) by all treatments of the air-exposed corn silage. Compared with controls, wild-type enterococci were decreased (P < 0.01) in MLA, MELA, and BLA. Staphylococcus aureus was reduced (P < 0.01) with MLA, MELA, BLA, and MC. Total aerobes showed reductions (P < 0.01) with MLA, BLA, and MC. Listeria monocytogenes numbers were reduced (P < 0.01) with MELA. Anaerobic incubation (24 h; 39°C) of ruminal fluid (10 mL) with 0.2 g air-exposed and MCFA-treated corn silage revealed higher hydrogen accumulations (P < 0.01) with MLA and MC over the control treatment. Methane was decreased (P < 0.01) solely by MLA. There was an increase (P < 0.01) of acetate with MELA and MC; of propionate with MELA or by BLA; and of butyrate with MLA, MELA, BLA, and MC. Total VFA, hexose fermented, and ammonia were increased (P < 0.01) with MELA, BLA, and MC. The acetate:propionate ratio was increased (P < 0.01) with MC. The results showed that treatment of air-exposed corn silage with esterified MCFA had no effect on yeasts and molds but prevented propagation or reduced populations of some unwanted and potentially desirable bacteria. Modest methane reduction was seen during in vitro incubation of rumen fluid suspensions with MLA-treated silage and ammonia accumulations were increased in esterified MCFA-treated silage. Little, if any, other detrimental effects on beneficial ruminal fermentation characteristics were observed.
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Poultry litter is a valuable crude protein feedstuff for ruminants, but it must be treated to kill pathogens before feeding. Composting effectively kills pathogens, but it risks losing ammonia to volatilization or leaching during degradation of uric acid and urea. Hops bitter acids also exert antimicrobial activity against certain pathogenic and nitrogen-degrading microbes. Consequently, the present studies were conducted to test if adding bitter acid-rich hop preparations to simulated poultry litter composts may improve nitrogen retention while simultaneously improving pathogen killing. Results from an initial study, testing doses of Chinook or Galena hops preparations designed to each deliver 79 ppm hops ß-acid, revealed that, after nine days simulated composting of wood chip litter, ammonia concentrations were 14% lower (p < 0.05) in Chinook-treated composts than untreated composts (13.4 ± 1.06 µmol/g). Conversely, urea concentrations were 55% lower (p < 0.05) in Galena-treated than untreated composts (6.2 ± 1.72 µmol/g). Uric acid accumulations were unaffected by hops treatments in this study but were higher (p < 0.05) after three days than after zero, six, or nine days of composting. In follow-up studies, Chinook or Galena hops treatments (delivering 2042 or 6126 ppm of ß-acid, respectively) for simulated composts (14 days) of wood chip litter alone or mixed 3:1 with ground Bluestem hay (Andropogon gerardii) revealed that these higher dosages had little effect on ammonia, urea, or uric acid accumulations when compared to untreated composts. Volatile fatty acid accumulations measured in these later studies were affected by the hops treatments, with butyrate accumulations being lower after 14 days in hops-treated composts than in untreated compost. In all studies, beneficial effects of Galena or Chinook hops treatments were not observed on the antimicrobial activity of the simulated composts, with composting by itself decreasing (p < 0.05) counts of select microbial populations by more than 2.5 log10 colony forming units/g compost dry matter. Thus, while hops treatments had little effect on pathogen control or nitrogen retention within the composted litter, they did lessen accumulations of butyrate, which may prevent adverse effects of this fatty acid on palatability of litter fed to ruminants.
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Medium chain fatty acid (MCFA) treatment (0.75% C6, hexanoic; C8, octanoic; C10, decanoic; or equal proportion mixtures of C6:C8:C10:C12 or C8:C10/g; C12 = dodecanoic acid) of aerobically-exposed corn silage on spoilage and pathogenic microbes and rumen fermentation were evaluated in vitro. After 24 h aerobic incubation (37 °C), microbial enumeration revealed 3 log10 colony-forming units (CFU)/g fewer (P = 0.03) wild-type yeast and molds in C8:C10-treated silage than controls. Compared with controls, wild-type enterococci decreased (P < 0.01) in all treatments except the C6:C8:C10:C12 mixture; lactic acid bacteria were decreased (P < 0.01) in all treatments except C6 and the C6:C8:C10:C12 mixture. Total aerobes and inoculated Staphylococcus aureus or Listeria monocytogenes were unaffected by treatment (P > 0.05). Anaerobic incubation (24 h at 39 °C) of ruminal fluid (10 mL) with 0.02 g overnight air-exposed MCFA-treated corn silage revealed higher hydrogen accumulations (P = 0.03) with the C8:C10 mixture than controls. Methane, acetate, propionate, butyrate, or estimates of fermented hexose were unaffected. Acetate:propionate ratios were higher (P < 0.01) and fermentation efficiencies were marginally lower (P < 0.01) with C8- or C8:C10-treated silage than controls. Further research is warranted to optimize treatments to target unwanted microbes without adversely affecting beneficial microbes.
Asunto(s)
Rumen , Ensilaje , Animales , Ensilaje/análisis , Ensilaje/microbiología , Rumen/microbiología , Zea mays , Propionatos/metabolismo , Fermentación , Ácidos Grasos/metabolismo , DietaRESUMEN
Poultry litter is a good crude protein supplement for ruminants but must be treated to kill pathogens before feeding. Composting effectively kills pathogens but risks loss of ammonia due to uric acid degradation. The objectives of this study were to test the ability of tannins to reduce pathogens and preserve uric acid during poultry litter composting. In two experiments, poultry litter was mixed with phosphate buffer and distributed to 50-ml tubes (three tubes/treatment per sample day) amended with 1 ml buffer alone or buffer containing pine bark, quebracho, chestnut, or mimosa tannins. Treatments achieved 0.63% (wt/wt) quebracho, chestnut, or mimosa tannins in experiment 1, or 4.5% pine bark or 9% quebracho, chestnut, or mimosa tannins in experiment 2. Tubes were inoculated with a novobiocin- and nalidixic acid-resistant Salmonella typhimurium, closed with caps, and incubated at successive 3-day increments at 22, 37, and 42°C, respectively. In experiment 1, bacterial counts in contents collected on days 0, 6, and 9 revealed a treatment by day effect (p < 0.03), with the Salmonella challenge being 1.3 log10 CFU/g higher in quebracho-treated composts than in untreated controls after 6 days of composting. After 9 days of composting, Salmonella, wildtype Escherichia coli, and total aerobes in untreated and all tannin-treated composts were decreased by about 2.0 log10 CFU/g compared to day 0 numbers (3.06, 3.75, and 7.77 log10 CFU/g, respectively). Urea and ammonia concentrations tended (p < 0.10) to be increased in chestnut-treated composts compared to controls and concentrations of uric acid, urea, and ammonia were higher (p < 0.05) after 9 days of composting than on day 0. Despite higher tannin application in experiment 2, antibacterial effects of treatment or day of composting were not observed (p > 0.05). However, treatment by time of composting interactions was observed (p < 0.05), with quebracho- and chestnut-treated composts accumulating more uric acid after 24 h and 9 days of composting and chestnut-, mimosa- or quebracho-treated composts accumulating less ammonia than untreated composts. Results demonstrate that composting may effectively control pathogens and that tannin treatment can help preserve the crude protein quality of composting poultry litter.
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Oregano essential oils from Lippia berlandieri Schauer (Lb) and Poliomintha longiflora Gray (Pl) were tested against the antioxidant butylated hydroxytoluene (Bht) to evaluate effects on the shelf life of ground beef (GB) over 7 days of storage at 4°C. The treatments were GB1 = GB control, GB2 = GB +100 mg/kg of Bht, GB3 = GB +100 mg/kg of Lb, and GB4 = GB +100 mg/kg of Pl. Lightness, redness, hardness, and springiness showed differences (p < .05) between treatments and days interaction, which serve as indicators of ground beef preserved quality and consumer acceptance. Mesophilic, psychrophilic, and lactic acid bacteria numbers and antioxidant activity showed differences (p < .05) for treatments and days. Sensory attributes showed no differences between treatments. The oregano oils may provide extended shelf life for packaged meat products treated with these natural additives and hence may be used for ground beef preservation.
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Poultry litter is a potentially valuable crude protein feedstuff for ruminants but must be treated to kill pathogens before being fed. Composting kills pathogens but risks losses of nitrogen due to volatilization or leaching as ammonia. Treatment of poultry litter with ethyl nitroacetate, 3-nitro-1-propionate, ethyl 2-nitropropionate (at 27 µmol/g), decreased numbers of experimentally-inoculated Salmonella Typhimurium (>1.0 log10 compared to controls, 4.2 ± 0.2 log10 CFU/g) but not endogenous Escherichia coli early during simulated composting. By day 9 of simulated composting, Salmonella and E. coli were decreased to non-detectable levels regardless of treatment. Some nitro-treatments preserved uric acid and prevented ammonia accumulation, with 18% more uric acid remaining and 17-24% less ammonia accumulating in some nitro-treated litter than in untreated litter (18.1 ± 3.8 µmol/g and 3.4 ± 1.4 µmol/g, respectively). Results indicate that nitro-treatment may help preserve uric acid in composted litter while aiding Salmonella control.
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Compostaje , Animales , Escherichia coli , Estiércol , Nitrógeno , Aves de Corral , SalmonellaRESUMEN
The influence of sodium chlorate (SC), ferulic acid (FA), and essential oils (EO) was examined on the survivability of two porcine diarrhetic enterotoxigenic Escherichia coli (ETEC) strains (F18 and K88) and populations of porcine fecal bacteria. Fecal bacterial populations were examined by denaturing gradient gel electrophoresis (DGGE) and identification by 16S gene sequencing. The treatments were control (no additives), 10 mM SC, 2.5 mg FA /mL, a 1.5% vol/vol solution of an EO mixture as well as mixtures of EO + SC, EO + FA, and FA + SC at each of the aforementioned concentrations. EO were a commercial blend of oregano oil and cinnamon oil with water and citric acid. Freshly collected porcine feces in half-strength Mueller Hinton broth was inoculated with E. coli F18 (Trial 1) or E. coli K88 (Trial 2). The fecal-E. coli suspensions were transferred to crimp top tubes preloaded with the treatment compounds. Quantitative enumeration was at 0, 6, and 24 h. All treatments reduced (P < 0.05) the counts of E. coli F18 at 6 and 24 h. With the exception of similarity coefficient (%SC), all the other treatments reduced (P < 0.05) the K88 counts at 24 h. The most effective treatments to reduce the F18 and K88 CFU numbers were those containing EO. Results of DGGE revealed that Dice percentage similarity coefficients (%SC) of bacterial profiles among treatment groups varied from 81.3% to 100%SC. The results of gene sequencing showed that, except for SC at 24 h, all the other treatments reduced the counts of the family Enterobacteriaceae, while Lactobacillaceae and Ruminococcaceae increased and Clostridiaceae decreased in all treatments. In conclusion, all treatments were effective in reducing the ETEC, but EO mixture was the most effective. The porcine microbial communities may be influenced by the studied treatments.
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Bacterias/efectos de los fármacos , Cloratos/farmacología , Ácidos Cumáricos/farmacología , Heces/microbiología , Aceites Volátiles/farmacología , Porcinos , Animales , Bacterias/clasificación , Cinnamomum zeylanicum , Microbiota , Origanum , Aceites de Plantas/farmacologíaRESUMEN
This study reports the characterization of the microbial community composition, and the establishment and dynamics of a continuous-flow competitive exclusion culture (CFCEC) derived from gut microbiomes of Nile tilapia (Oreochromis niloticus) specimens reared on aquaculture farms in Colombia. 16S rRNA gene amplicon Illumina sequencing was used to identify taxonomical changes in the CFCEC microbial community over time. The CFCEC was developed from adult tilapia from two farms in Colombia, and CFCEC samples were collected over two months. The pH varied from 6.25 to 6.35 throughout culturing, while anaerobic and aerobic cell counts stabilized at day 9, at 109 CFU mL-1 and were maintained to day 68. A variation in the CFCEC bacterial composition was observed over time. Cetobacterium was the most abundant in the first two days and coincided with a higher CFCEC supernatant antimicrobial effect against the fish pathogen Streptococcus agalactiae. Antimicrobial activity against S. agalactiae disappeared by day 3. Changes in bacterial composition continued to day 33 with Lactococcus spp. becoming the most abundant member of the community. In conclusion, the study of the CFCEC from intestinal tract of Nile tilapia (Oreochromis niloticus) by 16S rRNA gene sequencing allowed identification of predominant bacterial genera in the continuous-flow competitive exclusion culture exhibiting antibacterial activity against the fish pathogen Streptococcus agalactiae.
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Bacterias/clasificación , Cíclidos/microbiología , Secuenciación de Nucleótidos de Alto Rendimiento/veterinaria , Streptococcus agalactiae/crecimiento & desarrollo , Animales , Bacterias/aislamiento & purificación , Carga Bacteriana , Técnicas Bacteriológicas , Colombia , Fusobacterias/aislamiento & purificación , Fusobacterias/fisiología , Microbioma Gastrointestinal , Lactococcus/aislamiento & purificación , Lactococcus/fisiología , Viabilidad Microbiana , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
The gut microbiota has an important effect on poultry health and production. The aim of this study was to evaluate the effect of Colombian oregano (COO), Lippia origanoides Kunth, essential oil supplementation on broiler chicken performance and their cecal bacterial microbiome by 16S-based sequencing. Essential oil was extracted by steam distillation and analyzed by Gas chromatography/mass spectrometry. Two COO levels in feed, 0 ppm control (C) and 100 ppm (O), were evaluated in 2 groups of broilers either unchallenged (U) or challenged (E) with a viable attenuated Eimeria (coccidia) oocyte vaccine. Four treatments, UC, UO, EC, and EO, were distributed among 720 one-day-old male Ross broilers randomly placed in 24 pens. Cecal contents DNA was extracted and pyrosequencing was performed following a standard procedure. Pyrosequencing data were processed, and sequence reads were phylogenetically classified. Similarity of membership and structure in the communities were calculated. At the end of the study, the greatest COO effect was found in coccidia-challenged broilers, with an OE body weight of 1,889 ± 52.4 g with respect to 1,799 ± 36.2 g for CE (P < 0.01). Broiler cecal samples were consistent in that phylum Firmicutes and class Clostridia were highly prevalent; COO had no effect on these taxa levels between the 4 treatments (P > 0.05). A positive correlation (P < 0.01) was observed between the Firmicutes:Bacteriodetes phyla ratio against body weight at 35 D of age. This study provided both positive and negative correlations between broiler body weight against some bacterial groups identified, offering perspectives regarding bacterial groups and their impact on host health and metabolism. Lippia origanoides Kunth high thymol content showed a beneficial effect on body weight and the feed conversion ratio in broilers under coccidia challenge.
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Pollos , Coccidiosis/veterinaria , Eimeria/fisiología , Microbioma Gastrointestinal/efectos de los fármacos , Lippia/química , Aceites Volátiles/farmacología , Enfermedades de las Aves de Corral/parasitología , Alimentación Animal/análisis , Animales , Ciego/microbiología , Coccidiosis/parasitología , Colombia , Dieta/veterinaria , Suplementos Dietéticos/análisis , Masculino , Distribución AleatoriaRESUMEN
The objective of this study was to evaluate the effects of 2 Mexican oregano essential oils (MOO), from Poliomintha longiflora Gray (PLG) and Lippia berlandieri Schauer (LBS), in drinking water (DWt) on the performance, slaughter variables, and meat quality of broilers over a 40 D period of growth. A total of 180 non-sexed Ross-308 broilers (1-day-old) were randomly assigned to 3 treatments with 6 replications each (10 birds per replicate): CON = DWt control (without MOO); PLG = DWt + 400 mg/L of PLG; and LBS = DWt + 400 mg/L of LBS. The CON, PLG, and LBS broilers body weights were similar (P > 0.05) at all times. Feed intake (FI) was different by treatment (P < 0.05) at 7 and 28 D, and water intake (WI) was different (P < 0.05) at day 28. The CON treatment was highest (P < 0.05) at 28 D for FI and WI, whereas LBS was lowest (P < 0.05). Weight gain (WG) for CON, PLG, and LBS broilers was similar (P > 0.05), although WG for CON was slightly higher. In CON broilers, slaughter weight was highest (P < 0.05), but thigh yield was lowest (P < 0.05). The CON and PLG treatments were lower (P < 0.05) in thigh and leg cooking losses. The PLG treatment presented the highest values (P < 0.05) for breast-meat redness, saturation index, shear force, odor, taste, and overall sensory acceptability. The LBS was higher (P < 0.05) for breast-meat shear force, cohesiveness and resilience, but lower (P < 0.05) for sensory attributes. Mexican oregano essential oils at 400 mg/L can serve as natural alternative additives in DWt to improve broiler production and meat quality.
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Lamiaceae , Lippia , Carne/análisis , Aceites Volátiles/farmacología , Animales , Pollos/crecimiento & desarrollo , Culinaria , Agua Potable/química , Femenino , Humanos , Masculino , Odorantes , Aceites Volátiles/administración & dosificación , Distribución Aleatoria , Gusto , Aumento de PesoRESUMEN
Two essential oils (EO), thymol and carvacrol, were used in six ratio (100:00, 80:20, 60:40, 40:60, 20:80 and 00:100) combinations of both EO and in a dose of 0.2 g L-1 in bovine ruminal culture medium, 24-h cultures, to evaluate effects on total gas production (TGP), methane production, in vitro dry matter digestibility (IVDMD) and in vitro culture population dynamics of methanogenic and total bacteria. Total DNA extracted from ruminal microorganisms was subjected to denaturing gradient gel electrophoresis (DGGE)-polymerase chain reaction (PCR) to examine effects on bacterial populations. The effect of EO on TGP and IVDMD were assessed by comparison to untreated control cultures. In general, methane production by the microbial populations appeared to be higher with treatments containing the highest concentration of thymol than with treatments containing more carvacrol resulting in a tendency for greater methane-inhibiting activity achieved as the thymol concentration in the thymol:carvacrol mixtures decreased linearly. The population of total bacteria with a 74.5% Dice similarity coefficient for comparison of DGGE band patterns indicating shifts in bacterial constituents as EO ratios changed. No effects on TGP, IVDMD while only slight shifts in the methanogenic populations were seen with an overall 91.5% Dice similarity coefficient.
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Microbioma Gastrointestinal/efectos de los fármacos , Metano/metabolismo , Monoterpenos/farmacología , Rumen/microbiología , Timol/farmacología , Animales , Técnicas Bacteriológicas , Bovinos , Cimenos , Electroforesis en Gel de Gradiente Desnaturalizante , Digestión , Fermentación , Microbioma Gastrointestinal/fisiología , Aceites Volátiles/farmacología , Reacción en Cadena de la PolimerasaRESUMEN
The aim of this study was to evaluate the effect of oregano essential oil (MOO) from Mexican oregano, Lippia berlandieri Schauer, as substitute for Mexican oregano powder (MOP) on pork chorizo physicochemical characteristics, texture, antioxidant capacity, aerobic bacteria colony counts, and sensory evaluation under storage conditions over 7 d. The treatments were T1 = chorizo + 0.1% MOP and T2 = chorizo + 0.1% MOO. The pH, redness (a*), yellowness (b*), Chroma, and browning index (BI) were affected by treatments and storage time. T2 presented lower pH (5.27) at d 1 than at d 7 (5.34), as well as a* (23.13 vs. 25.27), b* (14.85 vs. 17.45), Chroma (28.60 vs. 30.79), and BI (103.42 vs. 109.82) were higher at d 7. At d 1, hardness (1392.75 vs. 872.29 g), springiness (0.3675 vs. 0.3351 mm), gumminess (491.45 vs. 284.38 g), and chewiness (180.25 vs. 95.43 g mm) were higher in T1 than T2. Aerobic bacteria counts (T1-4.19 vs. 4.73 log CFU/g and T2-4.37 vs. 4.50 log CFU/g, respectively) increased within each treatment at d 7. Antioxidant capacity was not affected (26.48 and 27.42%). Oregano odor was different at 7 d with T2 having a stronger odor (5.70) than T1 with oregano powder (4.63). Mexican oregano essential oil in the pork chorizo formulation improved pH, color parameters, textural profile, and sensory characteristics.
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Sciaenops ocellatus has a long history in aquaculture and many difficulties associated with its commercial culture have been addressed and successfully resolved; nevertheless, further research in lipid nutrition could address more comprehensive questions on the way these nutrients are utilized. The purpose of this study was to evaluate S. ocellatus growth and lipase gene expression in response to increasing dietary lipid supplementation. Four experimental diets were formulated to provide 3, 10, 16, or 23% lipid using menhaden fish oil. Twenty juveniles (mean initial weight 2.3 ± 0.1 g) were stocked per aquaria in a recirculating system; each diet was assigned to three aquaria and fed to fish for 6 weeks. At the end of the study, fish fed 3% of dietary lipid were significantly (P < 0.0001) smaller and showed significantly lower feed efficiency, condition factor, hepatosomatic index, and intraperitoneal fat than fish fed the other diets, but no differences were observed among fish fed 10, 16, or 23% lipid. A straight broken-line regression model for thermal growth coefficient provided an estimated value of 9.4% of dietary lipid as the optimal inclusion level. The bile salt-dependent lipase (BSDL) of red drum was 80.3 kDa. Relative gene expression of BSDL was significantly higher (P = 0.0007) in fish fed 10% lipid, with no differences among the other dietary treatments. Results provided could help monitor the metabolic status of farmed fish and contribute to optimize diet formulations based on maximum gene expression of BSDL for supplementation of dietary lipid.
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Alimentación Animal/análisis , Dieta/veterinaria , Grasas de la Dieta/administración & dosificación , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Perciformes/crecimiento & desarrollo , Esterol Esterasa/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Suplementos Dietéticos , Aceites de Pescado/administración & dosificación , Aceites de Pescado/farmacología , Esterol Esterasa/genéticaRESUMEN
The current study was conducted to investigate the effects of Mexican oregano essential oil (MOO) extracts from Lippia berlandieri Schauer (LBS) and Poliomintha longiflora Gray (PLG) on performance, blood profiles, carcass variables, and meat composition of broilers at slaugther. A total of 360 one-day-old Ross broilers were randomly distributed into four dietary treatments with six replicate pens per treatment and 15 birds per pen. The dietary treatments were: a basal diet (control), control + 0.40 g of LBS/kg of feed, control + 0.40 g of PLG/kg, and control + 0.40 g of LBS/kg + 0.40 g of PLG/kg. Results showed that linear, quadratic, and cubic effects of days were significant in the performance variables of broilers. The treatments with LBS and PLG maintained the broiler body weight without increasing feed intake and water intake when compared with the control group. Broilers given LBS+PLG and PLG had increased blood leukocytes, lymphocytes, low-density lipoprotein, and hot carcass yields. In meat composition, treatments with PLG and LBS+PLG presented similar breast protein content compared with the control treatment. Supplementation with these two MOO exhibits positive effects on broiler performance, blood profiles, carcass traits, and meat composition. These two MOO may be promising feed supplements as growth promoters and enhancers of meat quality in broiler production.(AU)
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Animales , Pollos/fisiología , Origanum/efectos adversos , Carne/análisis , Fenómenos Fisiológicos SanguíneosRESUMEN
Ruminal methanogenesis is a digestive inefficiency resulting in the loss of dietary energy consumed by the host and contributing to environmental methane emission. Nitrate is being investigated as a feed supplement to reduce rumen methane emissions but safety and efficacy concerns persist. To assess potential synergies of co-administering sub-toxic amounts of nitrate and 3-nitro-1-propionate (NPA) on fermentation and Salmonella survivability with an alfalfa-based diet, ruminal microbes were cultured with additions of 8 or 16mM nitrate, 4 or 12mM NPA or their combinations. All treatments decreased methanogenesis compared to untreated controls but volatile fatty acid production and fermentation of hexose were also decreased. Nitrate was converted to nitrite, which accumulated to levels inhibitory to digestion. Salmonella populations were enriched in nitrate only-treated cultures but not in cultures co- or solely treated with NPA. These results reveal a need for dose optimization to safely reduce methane production with forage-based diets.
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Fermentación/efectos de los fármacos , Medicago sativa/química , Viabilidad Microbiana/efectos de los fármacos , Nitratos/farmacología , Nitrocompuestos/farmacología , Propionatos/farmacología , Rumen/microbiología , Salmonella/metabolismo , Alimentación Animal/análisis , Animales , Bovinos , Nitratos/metabolismo , Nitritos/metabolismo , Filogenia , Salmonella/efectos de los fármacos , Salmonella/crecimiento & desarrolloRESUMEN
The current study was conducted to assess the bactericidal effectiveness of several nitrocompounds against pathogens in layer hen manure and litter. Evidence from an initial study indicated that treatment of layer hen manure with 12 mM nitroethane decreased populations of generic E. coli and total coliforms by 0.7 and 2.2 log10 colony forming units (CFU) g-1, respectively, after 24 h aerobic incubation at ambient temperature when compared to untreated populations. Salmonella concentrations were unaffected by nitroethane in this study. In a follow-up experiment, treatment of 6-month-old layer hen litter (mixed with 0.4 mL water g-1) with 44 mM 2-nitroethanol, 2-nitropropanol or ethyl nitroacetate decreased an inoculated Salmonella typhimurium strain from its initial concentration (3 log10 CFU g-1) by 0.7 to 1.7 log10 CFU g-1 after 6 h incubation at 37°C in covered containers. After 24 h incubation, populations of the inoculated S. Typhmiurium in litter treated with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate or nitroethane were decreased more than 3.2 log10 CFU g-1 compared to populations in untreated control litter. Treatment of litter with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate decreased rates of ammonia accumulation more than 70% compared to untreated controls (0.167 µmol mL-1 h-1) and loses of uric acid (< 1 µmol mL-1) were observed only in litter treated with 44 mM 2-nitropropanol, indicating that some of these nitrocompounds may help prevent loss of nitrogen in treated litter. Results warrant further research to determine if these nitrocompounds can be developed into an environmentally sustainable and safe strategy to eliminate pathogens from poultry litter, while preserving its nitrogen content as a nutritionally valuable crude protein source for ruminants.
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Estiércol/microbiología , Nitrocompuestos/química , Administración de Residuos/métodos , Acetatos/química , Acetatos/farmacología , Amoníaco/química , Amoníaco/metabolismo , Animales , Antibacterianos/química , Antibacterianos/farmacología , Pollos , Recuento de Colonia Microbiana , Escherichia coli/efectos de los fármacos , Etano/análogos & derivados , Etano/química , Etano/farmacología , Femenino , Nitrocompuestos/farmacología , Nitrógeno/química , Nitroparafinas/química , Nitroparafinas/farmacología , Propanoles/química , Propanoles/farmacología , Salmonella/efectos de los fármacosRESUMEN
Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are pathogens of public health importance that are frequently isolated from poultry. As a step toward implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance, this study characterized molecular patterns of Salmonella Paratyphi B dT+ and Salmonella Heidelberg isolated from poultry farms, fecal samples, and retail chicken meat using pulsed-field gel electrophoresis (PFGE). The objective of this study was to determine the genetic relationship among isolates and to determine potential geographically predominant genotypes. Based on PFGE analysis, both serovars exhibited high heterogeneity: the chromosomal DNA fingerprints of 82 Salmonella Paratyphi B dT+ isolates revealed 42 PFGE patterns, whereas the 21 isolates of Salmonella Heidelberg revealed 10 patterns. Similar genotypes of both serovars were demonstrated to be present on farms and in retail outlets. For Salmonella Paratyphi B dT+, closely genetically related strains were found among isolates coming from different farms and different integrated poultry companies within two departments (Santander and Cundinamarca) and also from farms located in the two geographically distant departments. For Salmonella Heidelberg, there were fewer farms with genetically related isolates than for Salmonella Paratyphi B dT+. A possible dissemination of similar genotypes of both serovars along the poultry production chain is hypothesized, and some facilitating factors existing in Colombia are reviewed.
Asunto(s)
Carne/microbiología , Aves de Corral/microbiología , Salmonella enterica/genética , Salmonella paratyphi B/genética , Salmonella/genética , Animales , Pollos , Colombia/epidemiología , Dermatoglifia del ADN , ADN Bacteriano/análisis , Electroforesis en Gel de Campo Pulsado , Heces/microbiología , Genotipo , Salmonella enterica/clasificación , Salmonella enterica/aislamiento & purificación , Salmonella paratyphi B/clasificación , Salmonella paratyphi B/aislamiento & purificaciónRESUMEN
Essential oils have been proposed as alternatives to antibiotic use in food animal production. This study evaluated 3 chemotypes of the Origanum genus, containing varying amounts of secondary metabolites carvacrol, thymol, and sabinene, in the broiler chicken diet. Aerial parts of Origanum vulgare L. (OL), O. vulgare L. ssp. hirtum (OH), and O. majorana (OM) were collected from a greenhouse located in the high altitude Sabana de Bogotá (Savanna of Bogotá) and O. vulgare L. ssp. hirtum (OG) produced and ground in Greece. Oregano essential oils (OEO) from these plants were obtained by steam distillation and analyzed by gas chromatography coupled to a mass spectrometer. Six treatments were evaluated: 200 mg/kg of OEO from OH, OL, and OM, 50 mg/kg of OEO from OG, 500 mg/kg of chlortetracycline, and without additives. Broiler chicks were maintained at 2,600 m above sea level, placed in brooder cages under a completely randomized design. Template DNA was isolated from duodenal, jejunal, ileal, and cecal contents in each group and bacterial 16S rDNA patterns were analyzed by denaturing gradient gel electrophoresis. Dendrograms of denaturing gradient gel electrophoresis band patterns revealed 2 main clusters, OEO-treated chicks and nontreated control chicks, in each intestinal segment. Band patterns from different gut compartments revealed major bacterial population shifts in the foregut (duodenum, jejunum, and ileum) compared with the hindgut (cecum and colon) at all ages evaluated (P < 0.05). The OEO groups showed less shift (62.7% similarity coefficient) between these 2 compartments versus the control groups (53.7% similarity coefficient). A reduction of 59% in mortality from ascites was seen in additive-supplemented groups compared with the control group. This study represents the first work to evaluate the effects of the 3 main chemotypes of Origanum genus in broilers.
Asunto(s)
Pollos/microbiología , Intestinos/microbiología , Microbiota/efectos de los fármacos , Aceites Volátiles/farmacología , Origanum/química , Alimentación Animal/análisis , Animales , Antibacterianos/farmacología , Pollos/metabolismo , Colombia , Cimenos , Electroforesis en Gel de Gradiente Desnaturalizante/veterinaria , Dieta/veterinaria , Suplementos Dietéticos/análisis , Grecia , Incidencia , Masculino , Monoterpenos/farmacología , Origanum/genética , Distribución Aleatoria , Timol/farmacologíaRESUMEN
The objective of this study was to determine Salmonella counts, serovars, and antimicrobial-resistant phenotypes on retail raw chicken carcasses in Colombia. A total of 301 chicken carcasses were collected from six departments (one city per department) in Colombia. Samples were analyzed for Salmonella counts using the most-probable-number method as recommended by the U.S. Department of Agriculture, Food Safety Inspection Service protocol. A total of 378 isolates (268 from our previous study) were serotyped and tested for antimicrobial susceptibility. The overall Salmonella count (mean log most probable number per carcass ± 95% confidence interval) and prevalence were 2.1 (2.0 to 2.3) and 37%, respectively. There were significant differences (P < 0.05) by Salmonella levels (i.e., counts and prevalence) by storage temperature (i.e., frozen, chilled, or ambient), retail store type (wet markets, supermarkets, and independent markets), and poultry company (chicken produced by integrated or nonintegrated company). Frozen chicken had the lowest Salmonella levels compared with chicken stored at other temperatures, chickens from wet markets had higher levels than those from other retail store types, and chicken produced by integrated companies had lower levels than nonintegrated companies. Thirty-one Salmonella serovars were identified among 378 isolates, with Salmonella Paratyphi B tartrate-positive (i.e., Salmonella Paratyphi B dT+) the most prevalent (44.7%), followed by Heidelberg (19%), Enteritidis (17.7%), Typhimurium (5.3%), and Anatum (2.1%). Of all the Salmonella isolates, 35.2% were resistant to 1 to 5 antimicrobial agents, 24.6% to 6 to 10, and 33.9% to 11 to 15. Among all the serovars obtained, Salmonella Paratyphi B dT+ and Salmonella Heidelberg were the most antimicrobial resistant. Salmonella prevalence was determined to be high, whereas cell numbers were relatively low. These data can be used in developing risk assessment models for preventing the transmission of Salmonella from chicken to humans in Colombia.
Asunto(s)
Comercio/estadística & datos numéricos , Farmacorresistencia Bacteriana , Contaminación de Alimentos/análisis , Carne/microbiología , Salmonella/aislamiento & purificación , Animales , Antibacterianos/farmacología , Pollos , Colombia/epidemiología , Recuento de Colonia Microbiana , Farmacorresistencia Bacteriana Múltiple , Contaminación de Alimentos/estadística & datos numéricos , Manipulación de Alimentos/métodos , Alimentos Congelados/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Fenotipo , Prevalencia , Salmonella/clasificación , Salmonella/efectos de los fármacos , Estados UnidosRESUMEN
A cross-sectional study was performed to estimate the prevalence of Salmonella on retail market chicken carcasses in Colombia. A total of 1,003 broiler chicken carcasses from 23 departments (one city per department) were collected via a stratified sampling method. Carcass rinses were tested for the presence of Salmonella by conventional culture methods. Salmonella strains were isolated from 27 % of the carcasses sampled. Logistic regression analysis was used to determine potential risk factors for Salmonella contamination associated with the chicken production system (conventional versus free-range), storage condition (chilled versus frozen), retail store type (supermarket, independent, and wet market), poultry company (integrated company versus nonintegrated company), and socioeconomic stratum. Chickens from a nonintegrated poultry company were associated with a significantly (P < 0.05) greater risk of Salmonella contamination (odds ratio, 2.0) than were chickens from an integrated company. Chilled chickens had a significantly (P < 0.05) higher risk of Salmonella contamination (odds ratio, 4.3) than did frozen chicken carcasses.