Evaluation of IFA, MAT, ELISAs and immunoblotting for the detection of anti-Toxoplasma gondii antibodies in paired serum and aqueous humour samples from experimentally infected pigs

The study evaluated the efficiency of diagnostic laboratory methods to detect anti-Toxoplasma gondii antibodies in paired serum and aqueous humour samples from experimentally infected pigs. 18-mixed breed pigs were used during the experiment; these were divided into two groups, G1 (infected group, n = 10) and G2 (uninfected group, n = 8). Infection was performed with 4 × 10 4 VEG strain oocysts at day 0 by the oral route in G1 animals. All pigs were euthanized at day 60, when retina, aqueous humour, and blood samples were collected. Anti-T. gondii antibody levels were assessed in serum (s) and aqueous humour (ah) by indirect immunofluorescence assay (IFA), modified agglutination test (MAT), m-ELISA (using crude membranes from T. gondii tachyzoites as antigen) and r-ELISA (using rhoptries from T. gondii tachyzoites as antigen). Polymerase chain reactions (PCR) of samples from the retina were performed by using Tox4 and Tox5 primers. Antibody titers of G1 animals ranged from 128 to 1024 and from 16 to 256 in serum and aqueous humour, respectively. There were differences in the correlation coefficients between IFA(s) × IFA (ah) (r = 0.62, P = 0.05), MAT(s) × MAT (ah) (r = 0.97, P < 0.0001); however, there was no significant difference between r-ELISA(s) × r-ELISA (ah) (r = 0.14, P = 0.7). Antibodies present in serum and aqueous humour recognized similar antigens. Samples of retina were positive by PCR in 30% (3/10) of infected pigs. G2 animals remained without antibody levels and were PCR negative throughout the experiment. These results suggest that the use of a combination of tests and immunoblotting for paired aqueous humour and serum samples could improve the sensitivity and specificity for the diagnosis of ocular toxoplasmosis. © 2007 Elsevier Ltd. All rights reserved.

Influence of environmental temperature, dietary energy level and sex on performance and carcass characteristics of pigs

Pigs are quite sensitive to high environmental temperatures and the thermoregulation mechanisms represent great expenses in energy for heating loss, reducing animal well-being and production performance, and altering carcass quality. The aim of this study was to assess the effects of sex and dietary energy level in growing-finishing pigs submitted to characteristic seasonal variation of temperature in subtropical humid climate, and to propose a mathematical model to predict growth performance and carcass characteristics. Twenty-eight crossbred growing-finishing pigs were randomly allotted to twelve treatments, in a 2x2x3 factorial trial (2 sex; 2 environmental conditions, and 3 energy levels). Heat stress condition (climatic chamber) showed temperatures of 31 oC at 7:00 and 22 oC at 17:00 (maximum of 33 °C) and thermal comfort condition (stall) showed temperatures of 18 °C at 7:00 and 24 °C (maximum of 27 °C). Pigs were fed ad libitum with diets containing 12.2 (low), 13.6 (medium) and 15.0 (high) MJ ME/ kg DM. Voluntary feed intake, daily weight gain, and final body weight were higher (P<0.01) at thermal comfort condition and were influenced by sex (P<0.01) in growing pigs. Feed to gain ratio decreased as the energy level increased (P<0.01), with values of 2.67, 2.59, and 2.32 (12.2, 13.6, and 15.0 MJ ME/kg DM, respectively). There was energy level and sex interaction only for daily weight gain. Regarding finishing pigs, environmental conditions also showed effects (P<0.01) on voluntary feed intake, daily weight gain, and final body weight. Performance of pigs was better at thermal comfort condition. Feed to gain ratio values were 3.55, 3.42, and 2.95 for low, medium, and high energy level, respectively. Interactions between energy level and sex were observed for voluntary feed intake, daily weight gain, and final body weight (P<0.05). Carcass yield and quality were affected by environmental condition and dietary energy level. Both hot and cold carcass weight increased as energy of ration increased. Cold carcass weight increased by 1.142 kg/MJ EM whereas backfat thickness was up to 252 mm/MJ EM. Longissimus thoracis muscle thickness was around 16 mm smaller in pigs under heat stress, but lean content was 2.68% higher in those animals. Regression equations were proposed to predict the performance values in the different situations studied.

Role of nitric oxide in the remodelling of extracellular matrix in myxomatous mitral valve degeneration of dogs and pigs

Myxomatous mitral valve degeneration (MMVD) or endocardiosis is a heart valve disease that occurs in many mammalian species, especially in humans, dogs and pigs. Nitric oxide (NO) plays an important role in the MMVD development. NO can be indirectly evaluated by the nitric-oxide synthase (NOS) expression and by the histochemical reaction of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d). The aim of this study was to evaluate NOS activity, by NADPH-d reaction, in the anterior leaflet of dogs with regular mitral valves and in those with MMVD, as well as in young swine and old females, comparing the reaction level with the degree of endocardiosis disease and also the histological alterations. Twelve mitral valves of dogs and 22 of swine were used for the research. All the valves were macroscopically analyzed for the occurrence or not of endocardiosis. They were fixed in a 4% paraformaldehyde, exposed to NADPH-d reaction, routinely processed and microscopically evaluated for the detection of mucopolysaccharides (MPS) deposition, collagen degeneration, fibrosis and level of endocardiosis. In dogs, relation was observed between higher intensity of the NADPH-d reaction, higher endocardiosis degree, MPS deposition as well as the collagen degeneration. No alteration in color was observed in pigs ́ valves during NADPH-d reaction. In conclusion, NO works in canine mitral valve remodeling extracellular matrix and plays an important role in endocardiosis disease. In swine, the lack of reaction reinforces the absence of macroscopical endocardiosis lesions, suggesting restrict NO action or major differences in the structures of swine valves.

Development of sustainable precision farming systems for swine: Estimating realtime individual amino acid requirements in growing-finishing pigs

The objective of this study was to develop and evaluate a mathematical model used to estimate the daily amino acid requirements of individual growing-finishing pigs. The model includes empirical and mechanistic model components. The empirical component estimates daily feed intake (DFI), BW, and daily gain (DG) based on individual pig information collected in real time. Based on DFI, BW, and DG estimates, the mechanistic component uses classic factorial equations to estimate the optimal concentration of amino acids that must be offered to each pig to meet its requirements. The model was evaluated with data from a study that investigated the effect of feeding pigs with a 3-phase or daily multiphase system. The DFI and BW values measured in this study were compared with those estimated by the empirical component of the model. The coherence of the values estimated by the mechanistic component was evaluated by analyzing if it followed a normal pattern of requirements. Lastly, the proposed model was evaluated by comparing its estimates with those generated by the existing growth model (InraPorc). The precision of the proposed model and InraPorc in estimating DFI and BW was evaluated through the mean absolute error. The empirical component results indicated that the DFI and BW trajectories of individual pigs fed ad libitum could be predicted 1 d (DFI) or 7 d (BW) ahead with the average mean absolute error of 12.45 and 1.85%, respectively. The average mean absolute error obtained with the InraPorc for the average individual of the population was 14.72% for DFI and 5.38% for BW. Major differences were observed when estimates from InraPorc were compared with individual observations. The proposed model, however, was effective in tracking the change in DFI and BW for each individual pig. The mechanistic model component estimated the optimal standardized ileal digestible Lys to NE ratio with reasonable between animal (average CV = 7%) and overtime (average CV = 14%) variation. Thus, the amino acid requirements estimated by model are animal- and time-dependent and follow, in real time, the individual DFI and BW growth patterns. The proposed model can follow the average feed intake and feed weight trajectory of each individual pig in real time with good accuracy. Based on these trajectories and using classical factorial equations, the model makes it possible to estimate dynamically the AA requirements of each animal, taking into account the intake and growth changes of the animal. © 2012 American Society of Animal Science. All rights reserved.

Stress susceptibility in pigs supplemented with ractopamine

Ractopamine is a β-adrenergic agonist used as an energy repartitioning agent in the diets of finishing pigs. Most ractopamine studies are limited to evaluations of growth performance and meat quality, and there is little information on the effects of this additive on the behavior and welfare of pigs. Therefore, the objective of this study was to evaluate various indicators of stress caused by feeding diets containing ractopamine. One hundred seventy barrows and 170 gilts weighing 107.3 kg were allocated to 30 pens with 10 to 12 barrows or gilts per pen. Pigs were offered 1 of the 3 dietary treatments (0, 5, or 10 mg ractopamine/kg) for 28 d with 5 barrow pens and 5 gilt pens per treatment. Pigs were evaluated for behavior 3 d per week 1 wk before the initiation of the experiment and throughout the experiment. Each pig was classified into 1 of the 13 activities (drinking water, lying alone, lying in clusters, standing, nosing pig, sitting, feeding, biting pig, walking, exploring, running away, playing, and mounting pen mates) and also grouped into 1 of the 3 categories (calm, moving, and feeding themselves) based on those activities. At the end of the experiment, 3 pigs from each pen were slaughtered, and blood samples were collected during exsanguination to determine physiological indicators of stress (cortisol, lactate, and creatine-kinase enzymes). The incidence of skin and carcass lesions was determined at shoulder, loin, and ham. Ractopamine had no effect (P > 0.05) on pig behavior, total number of skin and carcass lesions, or blood concentrations of cortisol or lactate. However, there was an increase (P < 0.05) of creatine kinase concentrations in pigs receiving ractopaminesupplemented feed. This finding is consistent with the concept that ractopamine may cause muscular disorders, and this warrants further investigation. © 2013 American Society of Animal Science. All rights reserved.

Citrus pulp and enzyme complex for growing and finishing pigs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Implicações da União Econômica e Monetária Europeia sobre a política econômica dos PIGS: uma análise sobre a crise das dívidas soberanas

The present work intends to analyze the impacts of the European Economic and Monetary Union in the economic policies of the countries named PIGS, with an analysis about the sovereign debt crisis, in view of the autonomy loss to adopt own monetary and exchange rate policies of countries with different levels of development

Outcome of pigs with short gut syndrome submitted to orthotopic intestinal transplantation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anthelmintic efficacy of ivermectin and abamectin, administered orally for seven consecutive days (100 mu g/kg/day), against nematodes in naturally infected pigs

The present study aimed to evaluate ivermectin and abamectin, both administered orally in naturally infected domestic swine, as well as analysing if the EPG (eggs per gram of faeces) values were equivalent with the ivermectin and abamectin efficacy obtained by 'parasitological necropsies. The animals were randomly selected based on the average of three consecutive EPG counts of Strongylida, Ascaris suum and Trichuris for experiment I, and of Strongylida and Trichuris for experiment II. After the random draw, eight animals were treated, orally, during seven consecutive days with 100 mu g/kg/day ivermectin (Ivermectina (R) premix, Ouro Fino Agronegocios), eight other animals were treated, orally, during seven consecutive days with 100 mu g/kg/clay abamectin (Virbamax (R) premix - Virbac do Brasil Industria e Comercio Ltda.), and eight pigs were kept as controls. EPG counts were performed for each individual animal at 14th day post-treatment (DPT). All animals (control and treatment) were necropsied at the 14th DPT. The results from both experiments demonstrate that both ivermectin and abamectin, administered orally for a continuous period of seven days, at a daily dosage of 100 mu g/kg, were highly effective (>95%) against Hyostrongylus rubidus, Strongyloides ransomi, Ascaris suum and Metastrongylus salmi. Against Oesophagostomum dentatum, abamectin presented over 95% efficacy against both evaluated strains, while ivermectin reached other strain as resistant. Regarding T. suis, both ivermectin and abamectin were effective (efficacies >90%) against one of the tested strains, while the other one was classified as resistant. Furthermore, the EPG values were equivalent with the ivermectin and abamectin efficacy obtained by parasitological necropsies. (C) 2014 Elsevier Ltd. All rights reserved.

VapB type 8 plasmids in Rhodococcus equi isolated from the small intestine of pigs and comparison of selective culture media

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of femur of orchiectomized guinea pigs by bone densitometry using dual-energy x-ray absortiometry (DXA) and mechanical testing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of the starting time of preslaughter feed withdrawal on welfare of pigs and pork quality

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dunging gutters filled with fresh water in finishing barns had no effect on the prevalence of Salmonella enterica on Brazilian swine farms

Our aim was to assess the importance of dunging gutters filled with water in finishing barns for the prevalence of pigs shedding Salmonella enterica. Some finishing barns in Brazil are provided with a dunging-gutter system which consists of a continuous water flow at the back of solid-floored adjacent pens. Because there is transfer of faecal material between adjacent pens by water in this system and the faecal-oral route of transmission is so important for enteric pathogens, we tested the hypothesis that the presence of this kind of dunging-gutter system in finishing barns affects the prevalence of slaughter-age pigs shedding salmonella organisms in their faeces. The cross-sectional study was conducted on six farms each having barns with and barns without a dunging-gutter system. Breeding, management, nutritional and seasonal factors were similar in both barns on each farm. The two systems did not differ in prevalence of pigs shedding salmonella organisms. Five S. enterica scrotypes were isolated: S. Agona, S. Javiana, S. Rissen, S. Sandiego and S. Senftenberg. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Prevalence of Methicillin-Resistant Staphylococci on a Farm: Staff can Harbour MRS When Animals do Not

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brucellosis due to Brucella suis in a swine herd associated with a human clinical case in the State of São Paulo, Brazil

Brucella suis has been recognized as the major etiological agent of human brucellosis in areas free from Brucella melitensis infection. However, with changes in swine management, the occurrence of swine brucellosis has decreased as has the human incidence of B. suis infection. A swine brucellosis outbreak within a herd from Jaboticabal (So Paulo, Brazil) was detected in July 2006. The herd comprised approximately 300 sows and 1,500 finishing animals. Many sows within this herd experienced abortions, while others exhibited vaginal discharge; three sows suffered posterior paralysis. Among 271 sows, 254 (93.7%) tested positive for brucellosis by complement fixation, and among 62 randomly bled finishing animals, 17 (27.4%) also tested positive. The B. suis biovar 1 was cultured from 14 aborted fetuses and six sows. Brucella was identified using routine methods. Fourteen farm workers were tested using agglutination tests, with three workers showing evidence of Brucella antibody titers. A 39-year-old woman, who worked with maternal pigs and had direct contact with aborted fetuses, presented an agglutinating titer of 480 IU/mL and displayed clinical signs of infection. Our findings suggest that despite a reduction of swine brucellosis throughout Brazil, B. suis infection still occurs, thereby posing a zoonotic risk.