Oral fluid replacement by a glucose glycine electrolyte formulation in E coli and rotavirus diarrhoea in pigs

A glucose glycine electrolyte solution (GGES) was investigated to determine its suitability for oral rehydration in diarrhoea in pigs. Piglets with diarrhoea following experimental infection with eneteropathogenic Escherichia coli were given access in cube drinkers to either GGES or water. The mortality in the GGES group (11.6 per cent) was significantly (P less than 0.05) less than in the controls (24.0 per cent), and weight gain in severely diarrhoeic piglets was greater in the GGES group. Gnotobiotic piglets were challenged with pig rotavirus and either given access to GGES or milk. The GGES was either in restricted volume or ad lib. Restricted access to GGES prevented much of the weight loss due to the diarrhoea and ad lib access to GGES allowed relatively uninterrupted weight gain in comparison with controls. In naturally occurring cases of diarrhoea on farms, access to GGES reduced mortality to weaning from 19.7 per cent to 7.2 per cent (P less than 0.05). Weight gain per day was also greater in piglets which scoured for three days or more, indicating the rehydrating effect in reducing net fluid loss. Thus GGES treatment was of value in treatment e&ects of diarrhoea due to either E. coli or rotavirus.     

IgG1 antibody in milk protects lambs against rotavirus diarrhoea

Newborn gnotobiotic lambs were fed a diet of diluted evaporated milk supplemented either with normal ewes' milk or with milk obtained from ewes injected parenterally during gestation with rotavirus. Lambs fed 150 ml per day of milk collected 5 days after lambing from normal ewes were susceptible to rotavirus infection and diarrhoea, while lambs fed milk from vaccinated ewes collected either 5 or 12 days after lambing were protected. Analysis of the milk by column chromatography showed the anti-rotavirus activity to be in the fractions containing IgG1.     

The effect of dietary spray-dried porcine plasma on clinical response in weaned piglets challenged with a pathogenic Escherichia coli.

Weaned piglets were used to determine the effect of dietary spray-dried porcine plasma (SDPP) on the clinical response to an infection with a pathogenic Escherichia coli (E. coli) O139:K82 LT(-). The piglets were divided into two groups of 10 animals each. One group was fed the control diet containing soybean(meal) plus whey powder. The test piglets were fed a diet with 8% SDPP. Piglets were orally infected with the challenge strain on days 6 and 7 after weaning. The experimental period lasted 14 days after which the piglets were euthanised and necropsied. Faecal samples were collected daily for bacteriological analysis. Segments of jejunum, caecum and rectum were removed for bacteriological analysis post mortem. Feed intake and weight gain, faecal and condition scores and body temperature were measured daily. In the control and SDPP groups, 6 and 7 piglets died from diarrhoea. The average daily feed intake (ADFI) and average daily gain (ADG) were substantially higher in the SDPP group than in the control group. SDPP-fed piglets generally had a more favourable faecal score and a healthier appearance than did the control piglets. The faecal excretion of E. coli O139:K82 was similar for control and test piglets. There were no diet effects on the E. coli O139:K82 counts at different sites of the intestine. In this experiment, the inclusion of SDPP at an economically acceptable percentage in the diet could not prevent piglet losses due to challenge with a pathogenic E. coli, but improvements of ADG, ADFI and faecal and condition scores were achieved.     

Diarrhoea in dairy calves reduced by feeding colostrum from cows vaccinated with rotavirus

Forty-two dairy calves remained with their dams for two days after birth, and then were removed to a calf rearing shed. Calves were allocated to three groups for the next 14 days, and received twice daily either whole milk, whole milk with a 10 per cent supplement of pooled normal bovine colostrum or whole milk with 10 per cent supplement of colostrum from cows vaccinated with rotavirus. A natural outbreak of diarrhoea occurred, affecting 28 of the 42 calves. Feeding immune colostrum delayed the onset of diarrhoea, and reduced its incidence, duration and severity. Live weight gains were consequently improved. The group fed normal colostrum had diarrhoea intermediate in severity between that of control calves and those fed immune colostrum. The aetiology of the diarrhoea was complex, with calves excreting rotavirus, enteropathogenic Escherichia coli and cryptosporidia.     

DIARRHOEA IN PIGLETS INOCULATED WITH ROTAVIRUS

A rotavirus isolated from a field outbreak of diarrhoea in artificially reared piglets was purified, filtered and administered orally to gnotobiotic and conventional piglets. Four successive passages of the virus in gnotobiotic piglets produced severe diarrhoea within 20 to 24 hours of administration. The diarrhoea lasted several days causing dehydration, emaciation, loss of body weight and some deaths. Virus was demonstrated in the faeces of the infected piglets by electron microscopy. Conventionally reared piglets developed little or no diarrhoea when given virus, whereas artificially reared piglets developed moderate to severe diarrhoea which lasted from 3 to 8 days with some deaths. No clinical disease was obvious in surviving piglets following challenge with the virus 10 or 17 days after initial infections.     

FACTORS CONTRIBUTING TO POSTWEANING DIARRHOEA IN A LARGE INTENSIVE PIGGERY

Some aspects of postweaning diarrhoea (PWD) in a piggery during the first week after early weaning were investigated. A haemolytic enterotoxigenic strain of E. coli (0149: K88: H10) was regularly recovered from piglets with PWD while rotavirus was demonstrated on a number of occasions. Prior to weaning piglets were either free of, or shed very few, haemolytic E. coli in their faeces. However, all piglets were excreting haemolytic E. coli between 5 and 7 days after weaning. The role of rotavirus in PWD was unclear. There appeared to be a direct relationship between serum antibodies to rotavirus in the sow at farrowing and those of the piglets soon after birth. The decline of maternal neutralising antibody to rotavirus coincided with the immediate postweaning period (3 to 5 weeks after birth). This was followed by an increase in antibody levels, 5 to 8 weeks after birth. There was no significant difference in the growth rate between affected and unaffected piglets over a period of 120 days. Medication of water during the first week after weaning had no significant effect on the incidence of PWD in the herd. A change in both the weaner diet and the weaning procedure reduced piglet mortality associated with PWD by more than half.     

Escherichia coli post-weaning diarrhoea occurrence in piglets with monitored exposure to creep feed

The objective of the study was to investigate the effect of offering supplementary creep feed to piglets during the suckling period on the faecal shedding of haemolytic Escherichia coli bacteria and occurrence of spontaneous post-weaning diarrhoea 0-5 days after weaning. Supplementary creep feed was offered to half of the piglets in 12 litters, from 2 weeks of age until weaning at 4 weeks, and the individual feed contact was recorded by direct observations. It was found that diarrhoea occurrence was associated with faecal shedding of haemolytic E. coli bacteria (p=0.003), specifically E. coli O149 (p=0.004). Occurrence of diarrhoea and faecal shedding of haemolytic E. coli was not associated with creep feeding per se. However, the faecal E. coli O149 shedding occurred significantly less often in piglets that were offered creep feed in the suckling period but only showed limited interest in the feed (i.e. contacted the feed less than or equal to the median level of contact) compared to piglets that had frequent creep feed contact or piglets that had not had access to creep feed at all (p=0.015). Correspondingly, the diarrhoea occurrence tended to be lower in these piglets (p=0.081). Piglets with low creep feed contact during the suckling period ate the same total amount of feed during the 5 days after weaning, however, they ate less feed on days 0-2 after weaning compared to the piglets with frequent creep feed contact and non-creep fed piglets. It is suggested that intestinal function associated with a voluntary low creep feed contact during the suckling period leads to decreased feed intake just after weaning, and thus reduces the intestinal proliferation of E. coli O149 in these piglets.     

Plasma enteroglucagon and neurotensin levels in gnotobiotic calves infected with enteropathogenic and non-enteropathogenic viruses

Five gnotobiotic calves were each infected with five viruses. Each calf was inoculated with coronavirus at seven days old, followed by astrovirus, Newbury agent, parainfluenzavirus type 3 and rotavirus at intervals of two weeks. Three of the viruses were enteropathogenic (bovine coronavirus, bovine calici-like virus and bovine rotavirus) and two were not (bovine astrovirus and parainfluenzavirus type 3). Plasma levels of the peptide hormones enteroglucagon and neurotensin and faecal output were measured daily and xylose absorption was studied before and after each infection. A close correlation was found between a rise in plasma enteroglucagon and neurotensin and infection with enteropathogenic viruses. The three enteropathogenic viruses caused increased daily faecal output, and elevated plasma levels of enteroglucagon and neurotensin, while the non-enteropathogens did not. The calici-like virus and rotavirus but not the coronavirus caused xylose malabsorption.     

Field study of coccidial and rotaviral diarrhoea in unweaned piglets

A study of diarrhoea in unweaned piglets was carried out in nine herds, with special reference to the enteropathogenic agents which could be demonstrated. Coccidial (Isospora suis) and rotaviral infections were both identified, either singly or in combination. More extensive studies of I suis infection were undertaken in two of the herds and it was found that diarrhoea occurred most commonly in five- to 14-day-old piglets. Piglets with I suis infection were not necessarily diarrhoeic but grew poorly compared to uninfected piglets. I suis infection in litters correlated with oocyst excretion in sows. In herds with I suis infection, amprolium and monensin were used in the sow ration to achieve control, and in one herd oral dosing of piglets with amprolium in the first three or four days of life was carried out.     

Black tea reduces diarrhoea prevalence but decreases growth performance in enterotoxigenic Escherichia coli-infected post-weaning piglets

Enterotoxigenic Escherichia coli (ETEC) is a main cause of diarrhoea in humans and piglets. In vitro, black tea extract (BTE) has anti-pathogenic properties. Anti-diarrhoeal properties of BTE were assessed in a pig model of gastrointestinal infection. At weaning (day 0), piglets (n = 96) were randomly assigned to a diet containing 0% (control), 0.4% or 0.8% (wt/wt) BTE during 27 days. Piglets were orally infected with 6.4 × 10(6) cfu of ETEC on day 6. Faecal consistency, feed intake and body weight were measured. In a sub-study (n = 30 piglets), the effect of BTE palatability on feed intake was assessed. Additionally, the effect of BTE on ETEC growth in the presence or absence of iron was studied in vitro. The 0.8% BTE diet reduced diarrhoea prevalence by 20% but also decreased feed intake by 16% and feed efficiency by 12% over the total period. The 0.4% BTE diet decreased feed efficiency and weight gain from day 13 onwards. The palatability study demonstrated that piglets preferred the control to the BTE diets. In vitro, BTE delayed ETEC exponential growth, which was reversed by iron addition. Although BTE had anti-diarrhoeal properties, this effect was accompanied by impaired performance. The absence of a correlation between diarrhoea prevalence and feed intake suggests that reduced diarrhoea directly results from BTE rather than from reduced feed intake caused by BTE astringency.     

The aetiology of diarrhoea in pigs weaned at two days of age.

When pigs are weaned at two days of age large numbers of Excherichia coli appear in the anterior gut and the incidence of diarrhoea rises. The two phenomena do not appear to be directly related because the strains of E coli isolated are not serotypes previously found to be associated with neonatal pig scouring. Representative strains of the non-enteropathogenic serotypes did not produce enterotoxin and did not adhere to small intestine brush borders. Moreover when antibiotics were fed to eliminate E coli from the gut, the pigs still scoured. Rotavirus was detected in the gut contents and gut epithelium of scouring pigs and a bacteria-free filtrate of gut contents produced diarrhoea when administered to germ-free pigs. It is suggested that rotavirus may be one of the causes of the scouring seen shortly after weaning pigs at two days of age.     

Interaction with pig ileal explants of Escherichia coli O45 isolates from swine with postweaning diarrhea.

We have previously observed that Escherichia coli O45 isolates from swine postweaning diarrhea (PWD) induced attaching-effacing (A/E) lesions in experimentally inoculated gnotobiotic piglets. In the present work, ileal explant culture has been used as an in vitro model for the study of the development of A/E lesions due to these isolates. The characteristic intimate bacterial attachment and microvilli effacement with cupping and pedestal formation, identical to that observed in gnotobiotic piglets, was demonstrated in pig ileal explants inoculated with O45 E. coli isolates. The initial attachment of bacteria to the enterocytes was observed from 2 to 4 h postinoculation (PI) and full development of A/E lesions was observed within 8 h PI. In this model, we observed that 22 of 25 eaeA-positive O45 isolates induced A/E lesions. However, A/E lesions were not observed for any of 7 eaeA-negative O45 isolates. Thus, we describe a useful in vitro model for the study of A/E capacity of porcine E. coli. Use of this model has enabled us to demonstrate the relatedness of the eaeA gene to A/E capability among porcine O45 E. coli from PWD.     

Effects of microbial and host variables on the interaction of rotavirus and Escherichia coli infections in gnotobiotic calves

Naturally occurring mixed infections with Escherichia coli and rotavirus have been associated with fatal diarrhea of calves about 1 week old. Experiments were designed to reproduce this syndrome in gnotobiotic calves. Clinical, microbiological, and pathologic data were used to assess severity of disease and mechanisms of the interaction between the 2 infections. An initial study involved 5- to 8-day-old gnotobiotic calves inoculated with a strain of enterotoxigenic E coli (ETEC) and a strain of rotavirus. Calves were observed for 2 days after they were inoculated; fatal diarrhea was not produced. In later studies, variables were tested to identify those that might contribute to fatal diarrhea. Variables which did not result in fatal or severe diarrhea or which did not cause disease that was more severe in dually inoculated calves than that in monoinoculated calves were increasing feed to 2 times base line, increasing dose of ETEC to 10 times base line, inoculating calves when they were 2 days old, using a strain of E coli that causes colisepticemia, and using a different strain of rotavirus. When the observation period was extended from 2 days to 6 days after calves were inoculated, severe, watery, fatal diarrhea occurred in 6 of 12 calves by 32 to 72 hours after dual inoculation was given. Fatal diarrhea was associated with intensive colonization by the ETEC in the caudal half of the small intestine. Microscopic lesions were similar between dually inoculated and rotavirus-monoinoculated calves, except there was more severe atrophy of ileal villi of dually inoculated calves.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidemiological studies of piglet diarrhoea in intensively managed Danish sow herds. IV. Pathogenicity of porcine rotavirus

Colostrum-deprived piglets inoculated with rotavirus 24 h after birth developed a profuse diarrhoea that spread to non-inoculated, colostrum-deprived litter mates and, occassionally, to colostrum-fed piglets. Case fatality rates in these 3 categories of piglets were 63.2%, 35.7% and 8.3%, respectively. Surviving piglets recovered in 1-2 weeks, but shedded virus via the faeces for up to 3 weeks p.i. The D-xylose test revealed severe malabsorption, with extremely flat absorption curves for up to 3-4 weeks p.i. Malabsorption was more marked in piglets with a long-lasting faecal virus excretion than in piglets where virus disappeared from the faeces within 10 days p.i. Infected piglets (colostrum-fed and colostrum-deprived) had decreased weight gains and were 5 days older at a bodyweight of 25 kg than non-inoculated controls. It is concluded that rotavirus is probably of significance in diarrhoeal syndromes in suckling piglets, alone or in combination with E. coli or other pathogens.     

Effect of diet composition on postweaning colibacillosis in piglets

The weaning of piglets is often associated with digestive disorders, particularly diarrhea--postweaning colibacillosis (PWC)--which is caused by infection with enterotoxigenic strains of Escherichia coli. It has been shown previously that a diet for newly weaned pigs based on cooked white rice and animal protein decreases the occurrence of PWC, whereas the addition of carboxymethylcellulose (CMC) to this diet enhances PWC. The aims of the current work were to 1) determine whether substitution of animal protein with plant proteins in the cooked-white-rice diet influenced its protective effects on PWC and 2) confirm that an increase in viscosity of the digesta by adding CMC to the diet favors the development of PWC--with (Exp. 1) or without (Exp. 2) experimental infection of piglets with E. coli. The diets were 1) cooked white rice and animal protein sources (RAP), 2) RAP + CMC added at 40 g of CMC/kg (air-dry basis) of diet, 3) cooked white rice and plant protein sources (RPP), and 4) wheat and plant protein sources (WPP). Experiments 1 and 2 were conducted using 32 and 24 piglets (eight and six per treatment), respectively. Piglets were weaned at 21 d (d 1), and fed ad libitum until slaughter on d 9. In Exp. 1, piglets were orally infected with enterotoxigenic E. coli on d 4, 5, 6, and 7. On d 8 of Exp. 1, the E. coli scores in feces of pigs fed RAP + CMC were higher than with RAP (P < 0.01). On d 9 after weaning, feces from pigs fed diet RAP were normal or moist, whereas feces from pigs fed RAP + CMC were wet to diarrheic. On d 7 of Exp. 2, pigs fed diets RAP + CMC and WPP had wetter feces than pigs fed diets RAP or RPP (P < 0.05). On d 8, the E. coli scores in feces were higher (P < 0.01) with pigs fed RAP + CMC than with all other diets. The E. coli scores in the digesta were also higher with pigs fed RAP + CMC, and to a lesser extent with diet WPP, than with pigs fed RAP or RPP (P < 0.01). The large intestine was heavier in pigs fed diets RPP and WPP, and the digesta were more acidic (P < 0.05). This study confirmed that diet RAP was protective against PWC, and that substitution of animal proteins with plant protein in a rice-based diet did not diminish its protective effects. The addition of CMC to cooked white rice increased digesta viscosity and enhanced PWC. Consequently, this diet represents a useful model for studying this condition.     

Development of post-weaning diarrhoea in piglets. Relation to presence of Escherichia coli strains and rotavirus

Weaning of piglets complicated with an exposure to pathogenic strains of Escherichia coli was scrutinized in two sets. The first set comprised 20 animals representing two litters and the second set included 30 animals from five litters. The piglets were either left as controls or exposed to one or three pathogenic strains of E. coli. Aiming to simulate a natural exposure the challenge strains were spread on the floor of the pens at weaning. In addition the pigs experienced several non-infectious stress factors commonly occurring at that occasion. Some groups were given adrenocorticotropic hormone (ACTH), aiming to simulate a stressful weaning. The balance and the composition of the faecal coliform populations, measured by a metabolic fingerprinting method, was disturbed among all animals following weaning. This disturbance was more pronounced and lasted longer among piglets exposed to pathogenic strains of E. coli. All piglets exposed to pathogenic E. coli shed these strains in faeces. Diarrhoea was induced in the groups exposed to E. coli, but not among the control animals. Pigs not treated with ACTH and subjected to a single pathogenic strain of E. coli became infected but did not develop diarrhoea unless if coinciding with shed of rotavirus. Control pigs excreting rotavirus had no diarrhoea. Diarrhoea was most frequent in the groups exposed to three pathogenic strains of E. coli, and in these groups diarrhoea was seen in the absence of rotavirus. ACTH administration amplified the clinical signs. The litter of origin influenced the development of post-weaning diarrhoea.     

Differences in the development of the small intestine between gnotobiotic and conventionally bred piglets

The effects of age, weaning and breeding conditions on the small intestinal morphology and the distribution of immunocompetent cells were investigated. The villus height and numbers of CD3+ T-lymphocytes, measured in the duodenum, jejunum and ileum, were determined in both the gnotobiotic and conventionally bred piglets. The diet of gnotobiotic piglets was composed of milk-replacement and feed mixtures. The application of milk replacement was finished on day 28. Conventional piglets were fed on sow's milk and feed mixtures. The animals were weaned on day 28. Small intestines were collected from 12 conventional and 12 gnotobiotic piglets slaughtered at the age of 2, 7, 14, 21, 28 and 35 days. The morphology results demonstrated that duodenal and ileal villi were significantly higher (p < 0.001) in gnotobiotic piglets during the entire period of the experiment. However, the weight of conventional piglets was higher during the experiment, in some cases significantly (p < 0.05). A marked reduction, in some cases significant (p < 0.001, p < 0.01 respectively), of the villi height on day 7 after the diet change for both groups of animals was recorded. The results demonstrate the differences in the gut development between both groups and their relationship to the breeding conditions. Nevertheless, the effect of crucial diet changes was observed independently of them. The immunohistochemistry results showed significantly (p < 0.001, p < 0.01 respectively) higher numbers of CD3+ T-lymphocytes in the jejunal villi of conventionally bred piglets. Similar results, in some cases significant (p < 0.001, p < 0.01 respectively), were also obtained from the other parts of the small intestine. These observations confirm reduced microorganism exposure under the gnotobiotic conditions.     

Effect of vaccination of the dam on rotavirus infection in young calves

Vaccination of cows with a combined, inactivated, adjuvanted rotavirus and Escherichia coli vaccine resulted in increased neutralising antibody titres to rotavirus in serum and colostral whey. Evidence was obtained that vaccination resulted in a decreased incidence of rotavirus shedding and of abnormal faeces or diarrhoea in young calves fed colostrum and milk from the vaccinated dams. The E coli component of the vaccine was not evaluated because no natural challenge was evident.     

Immunity to Escherichia coli in Pigs. The Role of Milk in Protective Immunity to E. coli Enteritis

Milk whey from immunized sows increased the survival time of gnotobiotic piglets infected with Escherichia coli. The survival time of infected piglets fed milk whey from non-vaccinated sow's was the same as that of similar pigs fed condensed cow milk.

The significance of milk antibodies in immune protection against E. coli enteritis is discussed and compared with that of absorbed colostral antibodies. From calculations presented it would appear that seven day old piglets receive approximately 1 g of gamma globulin daily from milk and that this is equal to the piglets total serum gamma globulin content. After seven days of age the gamma globulin content of piglet serum falls, whereas that of milk remains constant; milk is, therefore, potentially a major source of immunoglobulins with protective activity against E. coli associated enteritides.

     

Concurrent porcine rotaviral and transmissible gastroenteritis viral infections in a three-day-old conventional pig.

A 3-day-old suckling pig with diarrhea was necropsied, and immunofluorescent microscopic examination of the small intestinal mucosa, together with immune electron microscopic examination of the large intestinal contents, provided a presumptive diagnosis of a concurrent infection with transmissible gastroenteritis (TGE) virus and porcine rotavirus. Immunofluorescent microscopic, immune electron microscopic, and serologic data obtained from gnotobiotic pigs experimentally inoculated with the large intestinal contents of the suckling pig confirmed this diagnosis. Two gnotobiotic pigs, convalescent from previous TGE viral infections, became infected with porcine rotavirus only. However, another gnotobiotic pig, convalescent from a previous porcine rotaviral infection, became infected with TGE virus only, following inoculation with the large intestinal contents of the suckling pig.