1. This study determined the antimicrobial resistance profile and the biofilm-forming ability of Salmonella enterica strains isolated from commercial broiler houses over a three-year period in ...southern Brazil.
2. Of the 720 drag swabs analysed, 37 (5%) tested positive for non-typhoidal Salmonella spp. and S. Heidelberg was the most frequent serovar.
3. Among the antimicrobial resistant strains (83.8%; 31/37), resistance was most common to tetracycline, ampicillin and nalidixic acid. Multidrug resistance was found in 65% (24/37) of the isolates, with a large proportion of multidrug resistant S. Heidelberg strains (81%; 13/16).
4. In total, 65% (24/37) of the isolates showed the ability to produce biofilm and multiple antimicrobial resistance was negatively correlated with biofilm formation.
5. Strains susceptible to all tested antimicrobials tended to form stronger biofilms than multidrug resistant ones. This suggested that Salmonella spp. with less antimicrobial resistance depend more on the protection provided by biofilm to survive in the farm environment.
Two experiments were undertaken to evaluate the bacterial load in recycled litter between broiler flocks following addition of quicklime (T1), windrowing (T2), shallow fermentation (T3), and control ...(no intervention, T4). The first experiment was developed in field conditions in which the broiler houses were accompanied by 6 consecutive flocks and the effect of the treatments was assessed on enterobacteria and aerobic mesophiles. The second experiment was conducted in an experimental broiler house with recycled litter for assessment of Salmonella Enteritidis phage type 4 (SE PT4). In the field study, T3 presented the best results in reducing enterobacteria in broiler litter in relation to the other treatments, with the highest reduction occurring in the first 3 flocks, tending to stabilization from the fourth flock onward for all the treatments assessed. From the third to sixth flocks, enterobacteria level at the end of the treatments (d 12) was lower than the average in the fresh litter, except in T4. All treatments reduced aerobic mesophiles throughout the flocks, where T2 showed the highest reduction. The percentage of dry matter in the broiler litter diminished in T4 and increased in T3 over the course of the flocks. In the second experiment, the drop in the SE PT4 level in the broiler litter first occurred in T2 and T3. However, all the treatments except for T4 eliminated SE PT4 within 12 d. The temperature of the broiler litter in T2 was higher in relation to the other treatments. The results show that litter treatment prior to reutilization by the successive broiler flock is required to reduce the level of residual bacteria. The fermentative treatments (T2 and T3) were found to be superior to the others in terms of reducing the bacterial load, with shallow fermentation standing out with the highest reduction of enterobacteria and equivalent SE PT4 elimination when compared to windrowing.
► Lagoon and compact treatment system reduce chemical and microbial from swine manure. ► Chemical and microbial reduction was better after lagoons treatment due to high HRT. ► Adenovirus showed to be ...a good environmental contamination marker.
Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid–liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen – TKN – and NH3), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required.
Three experiments were conducted with the aim of developing and validating an equation to predict the ME of corn for pigs from its chemical composition, physical characteristics and particle size. ...Exp. 1: Eight lots of corn were ground in a hammer mill, using 5 sieves with different screen opening sizes, generating 40 batches of ground corn. The chemical composition (DM, CP, ether extract, crude fiber, ADF, NDF, and ash) and physical characteristics (bulk density- BD and 1,000-kernel weight- TKW) were determined in the 8 lots and geometric mean diameter (GMD) and N-corrected ME (AMEn) were determined in the 40 batches of corn. The AMEn values were determined in 16 metabolism assays with pigs. Mathematical models were adjusted by regression analysis, based on the Akaike Information Criterion. Based on statistical parameters (R^sup 2^ = 0.76 and prediction error = 1.05%), number of predictor variables, and easiness of measurements, an equation with 2 segments was chosen: y = 2845.41 + 0.9385 x BD - 20.8784 x CP, if GMD ≤ 522.98 and y = 3105.75 - 0.4978 x GMD + 0.9385 ... BD - 20.8784 x CP, if GMD > 522.98. Exp. 2 and 3: Sixty four gilts (Exp. 1; 29.5 ± 3.8 kg) and 64 barrows (Exp. 2; 29.3 ± 3.6 kg), 1 lot of corn, and 3 particle sizes (GMD = 483, 632, and 904 μm) were used in a 3 x 2 factorial arrangement with 2 methods of diet formulation, differing in ME value of corn: "FIX" (value from nutrient composition table) vs. "ESTIMATED" (estimated for each particle size using the equation developed in Exp. 1). In Exp. 2, ADFI was greater (P < 0.05) and feed efficiency was lower (P < 0.05) in the diet with GMD of 904 μm compared to the diets with GMD of 632 or 483 μm, but only for diet formulation by the FIX method. In the treatments with GMD of 483 ...m, gilts fed with the diet formulated by the ESTIMATED method had greater (P < 0.10) ADFI, backfat, fat area, and fat:meat ratio than gilts fed the diet formulated by the FIX method. In Exp. 3, particle size and formulation method did not affect (P > 0.10) growth performance and carcass traits of barrows. The equation developed was effective to adjust the ME value of corn, considering particle size variation. However, improvement to the proposed equation is necessary to achieve greater precision for predicting corn ME. Validation of the equation with more lots of corn of different chemical compositions and densities appears necessary to assess the efficacy of the equation regarding the variation of the other predicting variables.
Abstract
Three experiments were conducted with the aim of developing and validating an equation to predict the ME of corn for pigs from its chemical composition, physical characteristics and particle ...size. Exp. 1: Eight lots of corn were ground in a hammer mill, using 5 sieves with different screen opening sizes, generating 40 batches of ground corn. The chemical composition (DM, CP, ether extract, crude fiber, ADF, NDF, and ash) and physical characteristics (bulk density– BD and 1,000-kernel weight- TKW) were determined in the 8 lots and geometric mean diameter (GMD) and N-corrected ME (AMEn) were determined in the 40 batches of corn. The AMEn values were determined in 16 metabolism assays with pigs. Mathematical models were adjusted by regression analysis, based on the Akaike Information Criterion. Based on statistical parameters (R2 = 0.76 and prediction error = 1.05%), number of predictor variables, and easiness of measurements, an equation with 2 segments was chosen: y = 2845.41 + 0.9385 × BD – 20.8784 × CP, if GMD ≤ 522.98 and y = 3105.75 – 0.4978 × GMD + 0.9385 × BD – 20.8784 × CP, if GMD > 522.98. Exp. 2 and 3: Sixty four gilts (Exp. 1; 29.5 ± 3.8 kg) and 64 barrows (Exp. 2; 29.3 ± 3.6 kg), 1 lot of corn, and 3 particle sizes (GMD = 483, 632, and 904 µm) were used in a 3 × 2 factorial arrangement with 2 methods of diet formulation, differing in ME value of corn: “FIX” (value from nutrient composition table) vs. “ESTIMATED” (estimated for each particle size using the equation developed in Exp. 1). In Exp. 2, ADFI was greater (P < 0.05) and feed efficiency was lower (P < 0.05) in the diet with GMD of 904 µm compared to the diets with GMD of 632 or 483 µm, but only for diet formulation by the FIX method. In the treatments with GMD of 483 µm, gilts fed with the diet formulated by the ESTIMATED method had greater (P < 0.10) ADFI, backfat, fat area, and fat:meat ratio than gilts fed the diet formulated by the FIX method. In Exp. 3, particle size and formulation method did not affect (P > 0.10) growth performance and carcass traits of barrows. The equation developed was effective to adjust the ME value of corn, considering particle size variation. However, improvement to the proposed equation is necessary to achieve greater precision for predicting corn ME. Validation of the equation with more lots of corn of different chemical compositions and densities appears necessary to assess the efficacy of the equation regarding the variation of the other predicting variables.
ABSTRACT The aim of this study was to evaluate the variations in the stability and nutrient concentration in concentrates for piglet feeding. Five treatments were established: T1 - Control, standard ...concentrate formulation (SCF); T2 - PXMore5, SCF with more 5% vitamin-mineral premix (VMP); T3 - PXLess5, SCF with less 5% VMP. All these three treatments used 400kg batches in an INTECNIAL mixer; T4 - FeedMixer, SCF using a 4,000kg batch in an IMOTO mixer; T5 - PremixMixer, SCF using a 1,200kg batch in an MUYANG mixer. For each treatment, bags of 20kg were stored in three storage places for four months where room temperature and relative humidity was recorded daily. The concentration of nutrients was evaluated through centesimal and mineral analysis. The water activity of concentrate was affected by temperature and relative air humidity in different storage places. The greatest variation in concentration of crude protein, mineral residue, copper, zinc, and selenium was due to the PremixMixer treatment. Regarding the guaranteed levels, the critical value was verified only for the chrome concentration.
RESUMO O objetivo deste estudo foi avaliar as variações na estabilidade e na concentração de nutrientes em concentrados para alimentação de leitões. Foram estabelecidos cinco tratamentos: T1 - controle, concentrado com formulação padrão (CFP); T2 - PXMais5, CFP com 5% a mais de vitaminas e minerais da pré-mistura (PVM); T3 - PXMenos5, CFP com 5% a menos de PVM (todos os três tratamentos utilizaram lotes de 400kg em um misturador INTECNIAL); T4 - FeedMixer, CFP usando um lote de 4.000kg em um misturador IMOTO; T5 - PremixMixer, CFP usando um lote de 1.200kg em um misturador MUYANG. Para cada tratamento, sacos de 20kg foram armazenados em três ambientes distintos por quatro meses, onde a temperatura ambiente e a umidade relativa do ar foram registradas diariamente. A concentração de nutrientes foi avaliada por meio de análises centesimal e mineral. A atividade de água do concentrado foi afetada pela temperatura e a umidade relativa do ar nos diferentes locais de armazenamento. A maior variação na concentração de proteína bruta, resíduo mineral, cobre, zinco e selênio foi devido ao tratamento “MistPremix”. Em relação aos níveis de garantia, foi verificado valor crítico apenas para a concentração de cromo.
ABSTRACT The aim of this study was to evaluate the reasons of quality deviation of a concentrate from a predefined standard. Five treatments were established: T1 - Control, standard concentrate ...formulation (SCF); T2 - PXMore5, SCF with more 5% vitamin-mineral premix (VMP); T3 - PXLess5, SCF with less 5% VMP. All three treatments used a 400kg batches in an INTECNIAL mixer; T4 - FeedMixer, SCF using a 4,000kg batch in an IMOTO mixer; T5 - PremixMixer, SCF using a 1,200kg batch in an MUYANG mixer. For each treatment, bags of 20 kg were stored in three storage places for four months. Water activity of concentrate was affected by temperature and air relative humidity in different storage places. Regarding the kind of mixer, the greatest variation in concentration of crude protein, mineral residue, copper, zinc, and selenium was observed in the PremixMixer. Adjustments are imperative in the handling and use procedures of this kind of mixer to meet the quality requirements required in the concentrate production. Analyzing the effect of the mineral-vitamin premix level, no difference could be defined with the evaluated parameters.
RESUMO O objetivo deste estudo foi avaliar as razões do desvio de qualidade de um concentrado de um padrão predefinido. Foram estabelecidos cinco tratamentos: T1 - controle, concentrado com formulação padrão (CFP); T2 - PXMais5, CFP com 5% a mais de vitaminas e minerais da pré-mistura (PVM); T3 - PXMenos5, CFP com 5% a menos de PVM. Todos esses três tratamentos utilizaram lotes de 400kg em um misturador INTECNIAL; T4 - FeedMixer, CFP usando um lote de 4.000kg em um misturador IMOTO; T5 - PremixMixer, CFP usando um lote de 1.200kg em um misturador MUYANG. Para cada tratamento, sacos de 20kg foram armazenados em três ambientes distintos por quatro meses. A atividade de água do concentrado foi afetada pela temperatura e umidade relativa do ar em diferentes locais de armazenamento. Em relação ao tipo de misturador, a maior variação na concentração de proteína bruta, resíduo mineral, cobre, zinco e selênio foi devido ao PremixMixer. Ajustes são imperativos nos procedimentos de manuseio e uso desse tipo de misturador para atender aos requisitos de qualidade exigidos na produção de concentrado. Ao se analisar o efeito do nível da pré-mistura de vitaminas e minerais, nenhuma diferença pôde ser definida com os parâmetros avaliados.
Conventional culturing methods enable the detection of Campylobacter in broiler flocks. However, laboratory culture of Campylobacter is laborious because of its fastidious behavior and the presence ...of competing nontarget bacteria. This study evaluated different protocols to isolate Campylobacter from broiler litter, feces, and cloacal and drag swabs. Samples taken from commercial Brazilian broiler flocks were directly streaked onto Preston agar (PA), Campy-Line agar (CLA), and modified charcoal cefoperazone deoxycholate agar (mCCDA) and also enriched in blood-free Bolton broth (bfBB) for 24 and 48 h followed by plating onto the different selective media. Higher numbers of Campylobacter-positive cloacal and drag swab samples were observed using either direct plating or enrichment for 24 h before plating onto PA, compared with enrichment for 48 h (P < 0.05). Furthermore, direct plating was a more sensitive method to detect Campylobacter in broiler litter and feces samples. Analysis of directly plated samples revealed that higher Campylobacter levels were detected in feces streaked onto PA (88.8%), cloacal swabs plated onto mCCDA (72.2%), drag swabs streaked onto CLA or mCCDA (69.4%), and litter samples inoculated onto PA (63.8%). Preston agar was the best agar to isolate Campylobacter from directly plated litter samples (P < 0.05), but there was no difference in the efficacies of PA, mCCDA, and CLA in detecting Campylobacter in other samples. The isolated Campylobacter strains were phenotypically identified as Campylobacter jejuni or Campylobacter coli. The predominant contaminant observed in the Campylobacter cultures was Proteus mirabilis, which was resistant to the majority of antimicrobial agents in selective media. Together, these data showed that direct plating onto PA and onto either CLA or mCCDA as the second selective agar enabled the reliable isolation of thermophilic Campylobacter species from broiler samples. Finally, Campylobacter was detected in all broiler flocks sampled.
The objective of this study was to determine the equation parameters of carbon (i.e., C) flow curves and to estimate C flow and carbon dioxide (i.e., CO2) emissions from the production of 1- to ...49-day-old broilers from different genetic strains. In total, 384 1-day-old chicks were used, distributed into 4 groups: high-performance males (Cobb-M) and females (Cobb-F), and intermediate-performance males (C44-M) and females (C44-F), with 6 replicates/treatment according to a completely randomized study design. Carbon intake and retention were calculated based on diet and body C composition, and expired C was stoichiometrically estimated as digestible C intake − C retention − C in the urine. Litter C emission was estimated as initial litter C + C in the excreta − final litter C. Carbon flow curves were determined fitting data by nonlinear regression using the Gompertz function. Expired CO2 was calculated based on expired C. The applied nonlinear model presented goodness-of-fit for all responses (R2 > 0.99). Carbon dioxide production was highly correlated with growth rate. At 42 d age, CO2 expiration (g/bird) was 3,384.4 for Cobb-M, 2,947.9 for Cobb-F, 2,512.5 for C44-M, and 2185.1 for C44-F. Age also significantly affected CO2 production: to achieve 2.0 kg BW, CO2 expiration (g/bird) was 1,794.3 for Cobb-M, 2,016.5 for Cobb-F, 2617.7 for C44-M, and 3,092.3 for C44-F. The obtained equations present high predictability to estimate individual CO2 emissions in strains of Cobb and C44 broilers of any weight, or age, reared between 1 and 49 d age.
Meat quality and cut yield of pigs slaughtered between 100 and 150kg live weight were evaluated. Pigs (417 Agroceres PIC barrows and gilts) were fed a daily allowance of 2.8kg per head from 80kg ...until 100.71±0.85, 118.58±0.99, 134.07±1.18 or 143.90±1.24kg live weight. Seventy-one pigs were used for the evaluation of primal and subprimal cuts. There was no interaction between sex and slaughter weight for any of the evaluated parameters. Ham, shoulder, and loin weights linearly increased (P<0.01; R2: 84.3-93.2%) with increasing slaughter weight, which, however, had little effect on primal cuts meat yield. Increasing slaughter weight promoted a linear (P<0.05) and a quadratic (P<0.01) increase of red/green coordinate (a* value) of the loin and ham, respectively. Shear force showed a quadratic response (P<0.05), with minimum value estimated at 122kg slaughter weight. It was concluded that, under the applied management, increasing slaughter weight increased the volume of meat, but had little effect on meat yield. The meat of pigs slaughtered at heavier weights showed more intense red color and the same intramuscular fat content as lighter pigs, while tenderness was slightly affected.
Foi avaliada a qualidade da carne e os cortes de suínos abatidos entre 100 e 145kg de peso vivo. Os suínos (417 machos castrados e fêmeas, linhagem Agroceres PIC) foram mantidos sob fornecimento programado de 2,8kg de ração por animal por dia a partir de 80kg até o abate aos: 100,71±0,85, 118,58±0,99, 134,07±1,18 ou 143,90±1,24kg de peso vivo. Destes, 71 suínos foram usados para avaliação dos cortes primários e secundários. Não foi observada interação entre sexo e peso de abate em nenhuma das variáveis avaliadas. Os pesos do pernil, da paleta e do carré aumentaram linearmente (P<0,01; R2entre 84,3 e 93,2%) com o peso de abate, com pouco efeito sobre o rendimento da carne. A coordenada vermelho/verde (valor de a*) aumentou linearmente (P<0,05) no lombo e de forma quadrática (P<0,01) no pernil com o aumento do peso de abate. A força de cisalhamento apresentou resposta quadrática (P<0,05), com redução até o valor mínimo estimado para os 122kg de peso vivo. Conclui-se que, com o manejo utilizado neste estudo, a elevação do peso de abate resulta em aumento na quantidade de carne produzida, com pouco efeito sobre o rendimento de carne. A carne de suínos abatidos em pesos elevados apresenta cor vermelha mais intensa e mesmo nível de gordura intramuscular que a carne de suínos mais leves, enquanto a maciez é alterada apenas de maneira discreta.
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