Frequency of Sarcocystis in pigs in Ohio and attempted transmission to cats and dogs.

Tissues of 236 sows, obtained at slaughter in Xenia, Ohio, were examined microscopically after trypsin digestion. Sarcocystis bradyzoites were found in eight of 236 (3.4%) pigs (in 8 diaphragms, 7 esophagi, and 1 heart) and in three of 101 tongues. After these infected porcine tissues were fed to three dogs and three cats, none of the animals shed Sarcocystis sporocysts in their feces.     

Experimental aerosol transmission of Actinobacillus pleuropneumoniae to pigs.

In order to demonstrate the possible role of aerosol in the transmission of Actinobacillus pleuropneumoniae, an experiment including 18 specific pathogen-free (SPF), 10-week-old piglets, randomly distributed into 2 adjacent units, was carried out. In these facilities, air was forced through absolute filters to prevent any contact with infectious agents. During the first 6 d post inoculation, the 2 units were connected by a rectangular opening and the air circulation was forced by the ventilation system from unit A (inoculated pigs) to unit B (non-inoculated pigs). The A. pleuropneumoniae strain (biovar 1 serovar 9) was isolated in France from an outbreak of porcine pleuropneumonia. Two different infecting doses, 10(7) cfu/animal and 10(8) cfu/animal, were inoculated by intranasal route in 6 pigs of unit A. The infection spread quickly from the inoculated pigs to the non-inoculated pigs. Clinical signs were acute during the 4 d post inoculation: hyperthermia, respiratory distress and, sometimes, death (6 pigs of the unit A and 2 pigs of the unit B). All pigs seroconverted against A. pleuropneumoniae serovar 9 within 2 weeks. Lung lesions were severe: fibrinous pleurisy and lung hemorrhages in the acute stage, pleural adherences and focal pulmonary necrosis in the chronic stage. Actinobacillus pleuropneumoniae was isolated from the tonsils and/or lungs in 16 animals. It could be also isolated from the air of the experimental unit. This study showed that A. pleuropneumoniae was readily transmitted through aerosol over a distance of at least 2.5 m.     

Experimental infection of specific pathogen-free pigs with Campylobacter: excretion in faeces and transmission to non-inoculated pigs

Campylobacter species are leading agents of human bacterial gastroenteritis and consumption of food of animal origin is a major source of infection. Although pigs are known to frequently exhibit high counts of Campylobacter in their faeces, more information is needed about the dynamics of this excretion. An experimental trial was conducted to evaluate the faecal excretion of Campylobacter by 7-week-old specific pathogen-free piglets inoculated per os with three Campylobacter strains (one C. coli isolated from a pig, one C. coli and one C. jejuni from chickens) alone or simultaneously (5x10(7)CFU/strain). Non-inoculated pigs were housed in adjacent pens. Pigs were monitored for 80 days for clinical signs and by bacteriological analysis of faeces. Pigs inoculated with porcine C. coli or with a mix of the three strains excreted from 10(3) to 10(6)CFU/g of faeces with a slight decrease at the end of the trial. Animals inoculated with poultry C. coli or C. jejuni strain excreted a lower quantity and some of them stopped excreting. At the end of the trial, only C. coli was detected in the faeces of pigs inoculated simultaneously with the three bacteria. Moreover, the transmission of Campylobacter was noticed between pens for the two C. coli strains and all the neighbouring animals became shedders with a level of excretion similar to the inoculated pigs. Intermittence in the Campylobacter excretion was also observed. Finally, our study highlighted a host preference of Campylobacter, namely C. coli seems to have a higher colonization potential for pigs than C. jejuni.     

Experimental Aujeszky's disease in pigs: excretion, survival and transmission of the virus

Airborne Aujeszky's disease virus was recovered from looseboxes containing groups of pigs infected with virus strains from England, Northern Ireland and Denmark from days 1 to 7 after infection. Pigs sampled individually excreted most airborne virus on days 2 and 3 after infection. On a 24 hour basis the maximum amount of airborne virus excreted per pig was log10 5.3 TCID50. Subclinical infection was transmitted from a clinically affected group of pigs to a seronegative group held in separate looseboxes when air was drawn through ducting connecting one box with the other. Tissues taken from pigs killed at varying times after infection showed that the main sites of virus replication were in the head and neck region. Aujeszky's disease virus was detected for up to 40 days in a range of tissues taken from pigs at the acute stage of disease and stored at -20 degrees C.     

Resistance to fecal shedding of salmonellae in pigs and chickens vaccinated with an aromatic-dependent mutant of Salmonella typhimurium.

The purpose of this study was to evaluate the effectiveness of an aromatic-dependent mutant of Salmonella typhimurium as a parenteral vaccine for prevention of fecal shedding of Salmonella spp. Pigs and chickens were vaccinated IM, with 1 x 10(9) and 1 x 10(8) organisms, respectively, followed by a second identical vaccination 2 weeks later. Salmonella organisms were not detected by analysis of fecal or cloacal swab specimens from any animal after vaccination. Deleterious side effects were not noticed after vaccination. Pigs were challenge-inoculated PO with 1 x 10(12) virulent S typhimurium 1 week after the second vaccination. Chickens were challenge-inoculated PO with 3 x 10(8) organisms of either S enteritidis or the virulent parent strain of S typhimurium 3 weeks after the second vaccination. Vaccinated pigs shed Salmonella spp significantly less frequently than did nonvaccinated pigs. Vaccinated chickens challenge-inoculated with either S enteritidis or S typhimurium also shed Salmonella less frequently than the corresponding nonvaccinated control birds; however, the difference was not significant.     

The reduction of CSFV transmission to untreated pigs by the pestivirus inhibitor BPIP: A proof of concept

5-[(4-Bromophenyl)methyl]-2-phenyl-5H-imidazo[4,5-c]pyridine (BPIP) is a representative molecule of a novel class of highly active in vitro inhibitors of the replication of Classical swine fever virus (CSFV). We recently demonstrated in a proof of concept study that the molecule has a marked effect on viral replication in CSFV-infected pigs. Here, the effect of antiviral treatment on virus transmission to untreated sentinel pigs was studied. Therefore, BPIP-treated pigs (n = 4), intra-muscularly infected with CSFV, were placed into contact with untreated sentinel pigs (n = 4). Efficient transmission of CSFV from four untreated seeder pigs to four untreated sentinels was observed. In contrast, only two out of four sentinel animals in contact with BPIP-treated seeder animals developed a short transient infection, of which one was likely the result of sentinel to sentinel transmission. A significant lower viral genome load was measured in tonsils of sentinels in contact with BPIP-treated seeder animals compared to the positive control group (p = 0.015). Although no significant difference (p = 0.126) in the time of onset of viraemia could be detected between the groups of contact animals, a tendency towards the reduction of virus transmission was observed. Since sentinel animals were left untreated in this exploratory trial, the study can be regarded as a worst case scenario and gives therefore an underestimation of the potential efficacy of the activity of BPIP on virus transmission.     

Sarcocystis infection in pigs of Hissar, Haryana, India and its transmission to dogs

Sarcocystis zoites were found in pepsin digests of 68.8% of 157 pigs from Hissar, Haryana. Sarcocystis-infected meat was fed to 4 young dogs and 2 cats. The dogs shed Sarcocystis sporocysts in their faeces 12 days after eating infected meat whereas cats did not shed sporocysts.     

Integrated adrenal, somatotropic, and immune responses of growing pigs to treatment with lipopolysaccharide

The objective of this research was to provide an integrated look at systemic adrenal, somatotropic, and immune responses of growing pigs to challenge with lipopolysaccharide (LPS). Weaned pigs were challenged intraperitoneally with 100 microg/kg BW of LPS or sterile saline, and rectal temperature and blood data were collected for 72 h. Daily feed intake also was monitored. Plasma was analyzed for concentrations of cortisol, tumor necrosis factor alpha (TNFalpha), the acute phase protein haptoglobin, growth hormone (GH), insulin-like growth factor I (IGF-I), and prostaglandin E2 (PGE2). As expected, LPS decreased feed intake, stimulated a febrile response, and activated the hypothalamic-pituitary-adrenal (HPA) axis as demonstrated by increased cortisol levels. Cortisol reached maximum elevation 2 h after treatment (P < .001) and remained elevated through 12 h (P < .001). Circulating TNFalpha was increased by LPS at 2 and 4 h after treatment (P < .001), and an apparent (not statistically significant) increase in haptoglobin also occurred in challenged animals. The LPS injection suppressed IGF-I by 2 h following treatment (P < .01), and circulating IGF-I remained reduced relative to controls through 44 h. Overall, GH was increased in LPS-treated pigs (P < .05), although the treatment x time interaction was not significant. Plasma PGE2 was increased transiently at 2 h (P < .05) and then subsequently suppressed at 4, 8, and 12 h following LPS (P < .05). This study provides a comprehensive view of systemic effects of LPS on components of the HPA, growth, and immune axes. In addition, these are the first data to document changes in circulating PGE2 in unrestrained animals during the early hours of the acute phase response to LPS.     

Experimental infection of cattle, sheep and pigs with 'Hobi'-like pestivirus

To date, limited information is available on the ability of 'Hobi'-like pestiviruses (putative bovine viral diarrhoea 3) to infect and cause disease in animal species traditionally affected by pestiviruses. In order to obtain new insights into host range and pathogenic potential of this atypical pestivirus, BVDV-seronegative calves (n=5), lambs (n=5) and piglets (n=5) were experimentally infected with the European 'Hobi'-like strain Italy-1/10-1, whereas two animals per species served as uninfected controls. Appearance of clinical signs, leukopenia, viremia, viral shedding and seroconversion were monitored for 28 days post-infection. Calves and lambs were successfully infected, displaying respiratory signs (nasal discharge), moderate hyperthermia and leukopenia, viremia and viral shedding through the nasal and faecal routes. Antibody responses were observed in both animal species by ELISA and virus neutralisation assays. In contrast, inoculated piglets did not display any clinical signs nor leukopenia and viral RNA was not detected in any biological samples. Nevertheless, the presence of detectable antibodies by virus neutralisation accounted for a successful, albeit limited infection of these animals.     

Experimental transmission of a goat strain of Sarcoptes scabiei to desert sheep and its treatment with ivermectin

Desert sheep were experimentally infected with a goat strain of Sarcoptes scabiei, proving that this mite is not completely host specific. More severe lesions were produced on sheep when the mites were applied to lacerated than when applied to scarified or non-scarified areas. Lesions were more pronounced on moistened areas than dry areas and lesions produced on dry scarified areas resembled those produced on non-scarified moistened ones. Skin scrapings from the experimental lesions in the sheep contained numerous mites of all stages, proving the goat mites had become well established and were reproducing actively in the experimental lesions. Severe histopathological changes were observed in skin sections, comprising mainly thick crust formation, mites beneath the keratin and severe degenerative and necrotic changes. Treatment of sheep with ivermectin at a dose rate of 200 micrograms kg-1 body weight produced rapid and excellent cure.     

Procedures for preventing the transmission of foot-and-mouth disease virus to pigs and sheep by personnel in contact with infected pigs

The most effective method of containing an outbreak of foot-and-mouth disease (FMD) is by the culling of livestock. However, qualified people must diagnose the disease before the culling can begin, and they must avoid susceptible animals after having been in contact with infected premises, to prevent them from transmitting the virus. To test the effectiveness of biosecurity procedures in preventing the transmission of FMD virus (O/UK/35/2001) investigators contacted and sampled pigs inoculated with FMD virus for approximately 45 minutes and then contacted and sampled sentinel pigs and sheep after either using no biosecurity procedures, or washing their hands and donning clean outerwear, or showering and donning clean outerwear. The virus was detected in the nasal secretions of one investigator immediately after the postmortem investigation of the inoculated pigs but was not detected in samples collected between approximately 12 and 84 hours later. After the contaminated personnel had showered and changed into clean outerwear they did not transmit the strain of FMD virus to susceptible pigs and sheep.     

Competitive exclusion treatment reduces the mortality and fecal shedding associated with enterotoxigenic Escherichia coli infection in nursery-raised neonatal pigs.

We have previously reported that the administration of a competitive exclusion culture (PCF-1), derived from the cecal microflora of a young, healthy pig and maintained in a continuous flow fermentation system to neonatal pigs resulted in a decrease in the incidence of fecal shedding and cecal colonization by Salmonella choleraesuis in pigs at weaning. In the present experiment, we describe the effects of the administration of a derivative of the PCF-1 culture, RPCF, against an enterotoxigenic E. coli infection in neonatal pigs raised off-sow. The administration of RPCF at 12 and 24 hours after birth resulted in significant (P < 0.05) reductions in mortality, incidence of fecal shedding, and in gut colonization by E. coli when compared to control values. The RPCF reduced mortality from 17.5%, observed in untreated pigs, to 4.4% in RPCF-treated pigs. Fecal shedding of E. coli was reduced significantly (P < 0.05) in RPCF-treated pigs between Days 1 and 3 post-challenge. These results indicate that the RPCF culture is effective against one of the most important causes of neonatal scours (E. coli infections) in piglets.     

Experimental infection of slaughter pigs with classical swine fever virus: transmission of the virus, course of the disease and antibody response.

The spread of classical swine fever virus was investigated in an isolation unit containing four pens, each containing six slaughter pigs. One pig in the middle pen of three adjacent pens was inoculated intramuscularly and intranasally with the virus. The fourth pen was located in a separate compartment. The pens were visited in a strict order to study, first, the effect of indirect contact via contaminated clothing and footwear on the spread of the virus to adjacent pens and, secondly, the airborne transmission of the virus between compartments. The pigs were examined and blood samples were taken every other day for 62 days for virological and serological analyses. The virus was highly contagious for the five pigs that were in direct contact with the inoculated pig, but spread to the other pens only after all the pigs in the originally infected pen had become viraemic. The spread of the virus was promoted by contaminated clothing and footwear, but airborne transmission contributed considerably to the spread of the virus within the pighouse. The first clinical signs observed after the virus was introduced into a pen were decreased feed intake, increased mean rectal temperature and apathy. Neither the clinical course of the infection, nor the pattern of seroconversion observed over time, was affected by the differences in the intensity of contact with the virus between the pigs in the different pens.     

Growth performance,nutrient digestibility,and fecal microbial composition of weaned pigs fed multi-enzyme supplemented diets

A study determined the effects of supplementing corn-based diets for weaned pigs with multi-enzymes on growth performance, apparent total tract digestibility (ATTD) of nutrients, fecal score, and fecal microbial composition. A total of 132 pigs (initial body weight = 7.23 kg) that had been weaned at 21 d of age and fed a drug-free nursery diet for 7 d were housed in 33 pens of 4 barrows or gilts, blocked by body weight and gender, and fed 3 experimental diets at 11 pens per diet. The diets were corn-based diet without or with multi-enzyme A or B. Multi-enzyme A supplied 4,000 U of xylanase, 150 U of β-glucanase, 3,500 U of protease, and 1,500 U of amylase per kilogram of diet. Multi-enzyme B was the same as multi-enzyme A except that it supplied amylase at 150 U/kg, and that its source of amylase was different from that of multi-enzyme A. All diets contained phytase at 1,000 U/kg. The diets were fed for 35 d in 2 phases; phase 1 for the first 14 d and phase 2 for the last 21 d of the trial. Fecal score was determined daily during the first 7 d of the trial. Fecal samples were collected from rectum of 1 pig per pen on days 2, 7, 14, and 35 of the trial for determining bacterial composition. Also, fresh fecal samples were collected from each pen on days 41 and 42 to determine ATTD of nutrients. Multi-enzyme B increased (P < 0.05) average daily gain (ADG) for phases 1 and 2. For the overall study period, multi-enzyme B increased (P < 0.05) ADG from 262 to 313 g, and average daily feed intake (ADFI) from 419 to 504 g. Multi-enzyme A increased (P < 0.05) overall ADG from 262 to 290 g, but did not affect ADFI. Multi-enzyme A or B did not affect ATTD of gross energy, but increased (P < 0.05) the ATTD of ether extract from 30% to 36% or 37%, respectively. Multi-enzyme A did not affect fecal score; however, multi-enzyme B tended to decrease (P = 0.09) fecal score, implying that it tended to decrease diarrhea. Firmicutes were the most abundant phylum of fecal bacteria (its relative abundance ranged from 58% to 72%). Bacteroidetes and Actinobacteria were the 2nd and 3rd most abundant phyla of fecal bacteria. Neither multi-enzyme affected fecal bacterial composition. In conclusion, the addition of multi-enzyme A or B to phytase-supplemented corn-based diet for weaned pigs can improve their growth performance and fat digestibility. However, multi-enzyme B was more effective than multi-enzyme A in terms of improving the growth performance of weaned pigs fed corn-based diet.     

The effect of diet on fecal moisture, osmolarity of fecal extracts, products of bacterial fermentation and loss of minerals in feces of weaned pigs

Litters of pigs were allotted to one of three dietary treatments. Treatment 1 (T1) consisted of a corn-soybean meal starter diet. Pigs fed treatment 2 (T2) received a steamed, rolled oat groats-casein diet and pigs in treatment 3 (T3) remained with the sow. Four pigs/treatment were used to investigate the difference in performance and the cause of post-weaning diarrhea associated with early weaning of pigs at 4 wk of age to a starter diet. Fecal moisture, osmolarity, acetic acid, lactic acid and glucose contents were all good indicators of dietary differences because of treatment X age interactions. These variables increased faster in fecal extracts from pigs fed the corn-soybean meal diet. Lactic acid, volatile fatty acid (VFA) levels, glucose and pH values were indicative of a more active bacterial fermentation in pigs receiving T1 than in those receiving T2 or pigs remaining with the sow (T3). Excess minerals appear to contribute significantly to the osmolarity of fecal material. Of the anions, lactate was the main contributor to the osmolarity of feces of T1 pigs, followed by P, VFA, of which acetic acid contributed 70%, and Cl. The main cations were K, Na and Ca. In T2, P was the main anion, followed by lactate, VFA and Cl, while the main cations were Na, K and Ca. Minerals seemed to be the major osmotic particles in fecal extracts of pigs remaining with the sow. Phosphorus was the major anionic contributor to osmolarity, followed by VFA, Cl and lactic acid. Potassium was the major cation, followed by Na and Ca.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary supplementation of modified zinc oxide on growth performance,nutrient digestibility,blood profiles,fecal microbial shedding and fecal score in weanling pigs

One hundred and forty piglets ((Landrace × Yorkshire) × Duroc, 21 day of age) with an initial weight of 6.50 ± 0.71 kg, were randomly allotted into four treatments to determine the effects of a modified form of zinc oxide (ZnO) on growth performance, nutrient digestibility, blood profiles, fecal microbial shedding and fecal score in weanling pigs. Dietary treatments were: (i) NC, negative control, basal diet containing zinc (Zn) from the premix; (ii) PC, positive control, basal diet containing Zn‐free premix + 3000 ppm ZnO; (iii) H1, basal diet containing Zn‐free premix + 3000 ppm ZnO (phase 1, days 1 to 14)/200 ppm modified ZnO (phase 2, days 15 to 42); (iv) H2, basal diet containing Zn‐free premix + 300 ppm modified ZnO (phase 1)/200 ppm modified ZnO (phase 2). During days 1 to 14, average daily gains (ADG) were higher (P = 0.04) in PC, H1 and H2 groups than that in NC group. Overall, H1 treatment increased the ADG compared with NC (P = 0.05). On day 14, the alkaline phosphatase and plasma Zn concentration were increased (P = 0.01 and 0.04, respectively) in PC, H1 and H2 treatments compared with NC treatment. On days 14 and 42, the fecal Lactobacillus counts in NC group were lowest (P = 0.01, P = 0.04 respectively) among treatments. All supplemented groups showed lower (P = 0.03) fecal score than NC treatment on days 21 and 28. In conclusion, dietary supplementation with modified ZnO increased growth rates and reduced fecal scores in weanling pig. Modified ZnO could be used as a substitute to ZnO as a growth promoter and reduce Zn excretion to the environment because of the lower dosage. [Correction added on 3 February 2015, after first online publication: the initial weight of ‘6.50 ± 1.11 kg’ has been replaced with ‘6.50 ± 0.71 kg’ in the abstract.]     

Effects of lactose and yeast-dried milk on growth performance, fecal microbiota, and immune parameters of nursery pigs

An experiment was conducted to evaluate the effects of dietary lactose alone or in combination with a yeast-dried milk product (50% dried near-dated milk and 50% dried yeast) on growth performance, fecal microbiota, and immune status in nursery pigs (Sus scrofa). A total of 108 pigs (age, 20 ± 1 d; initial BW, 6.07 ± 0.03 kg) were randomly allotted to 18 pens (6 pigs/pen; 6 pens/treatment). Dietary treatments were: 1) control, 2) control + lactose, and 3) control + lactose + 5% yeast-dried milk. Except for the control diet, diets in Phase 1 (wk 1 and 2), 2 (wk 3 and 4), and 3 (wk 5) contained 20, 15, and 5% total lactose, respectively. Blood samples were collected from all pigs at d 0, 14, 28, and 35 to determine circulating IgG, IgA, and tumor necrosis factor (TNF)-α concentrations. At d 0, 7, and 14, fecal samples were collected (n = 18; 6 pigs/treatment) to evaluate fecal microbiota using PCR-denaturing gradient gel electrophoresis. Compared with pigs fed the control diet, pigs fed lactose and lactose with yeast-dried milk had greater (P < 0.05) ADG and tended (P = 0.07) to have greater BW and ADFI during Phase 1. There were no differences for BW, ADG, or ADFI during Phase 2, 3, or the overall experimental period. A main effect of treatment was observed for circulating IgA where control pigs had greater (P < 0.01) IgA compared with pigs fed lactose with or without yeast-dried milk; however, no effects of treatment were observed (P > 0.10) for circulating IgG or TNF-α. No differences (P > 0.10) in microbial diversity indices were observed on d 7 or 14 among treatments. However, a shift in microbial composition was observed on d 7, with lactose-fed pigs having greater (P < 0.05) putative L. johnsonii staining intensity compared with control pigs and pigs fed lactose plus yeast-dried milk. On d 14, L. delbrueckii was eliminated (P < 0.04) by feeding lactose with or without yeast-dried milk. This research indicates that growth performance, immune status, and fecal microbiota are affected by dietary inclusion of lactose alone, or in combination with yeast-dried milk.