The effect of avilamycin in the control of stress-induced post-weaning diarrhoea in piglets

Avilamycin, an oligosaccharide antibiotic with growth-promoting properties in pigs, has proved to be effective in controlling stress-induced post-weaning diarrhoea in piglets, caused mainly by Escherichia coli. The present study includes two trials, in which 400 newly-weaned piglets were used (200/trial). The following five different treatments were tested; 0, 40 and 80 p.p.m. avilamycin, 50 p.p.m. olaquindox and 100 p.p.m. apramycin. In each trial there were four pens (each with five females and five males) per treatment. Avilamycin when given at 80 p.p.m. reduced average daily diarrhoea score (ADDS) and mortality, and improved liveweight gain and feed conversion ratio (FCR), compared with the untreated controls, the 40 p.p.m. avilamycin and the 50 p.p.m. olaquindox (P less than 0.05) treatments. The overall performance of 40 p.p.m. avilamycin and 50 p.p.m. olaquindox was similar. The results indicate that avilamycin at the dose level of 80 p.p.m. in the starter feed can control post-weaning diarrhoea of piglets and prevent loss of productivity. Nevertheless, the antibiotic apramycin, whose spectrum of activity is mainly against the Gram-negative bacteria, given at the therapeutic level of 100 p.p.m., was more effective than any other experimental treatment (P less than 0.05), except for ADDS and FCR which were not significantly different from that of avilamycin 80 p.p.m.     

The effect of organic acids on the control of porcine post-weaning diarrhoea

Post-weaning diarrhoea syndrome (PWDS) of piglets is caused mainly by Enterotoxigenic Escherichia coli (ETEC) strains. Six organic acids were tested for their efficacy in the control of PWDS, using a total of 384 weaned piglets, in eight groups, during a 28-day period. One group (negative control) was offered a diet free of antimicrobials, one group (positive control) was offered the same diet medicated with 44 p.p.m. of lincomycin and 44 p.p.m. spectinomycin (Lincospectin 22 premix, Upjohn), and six groups were offered feed supplemented with either 1.0 per cent propionic acid, 1.6 per cent lactic acid, 1.2 per cent formic acid, 1.2 per cent malic acid, 1.5 per cent citric acid or 1.5 per cent fumaric acid. Groups were compared with regard to the appearance of clinical signs, mortality, weight gain and feed conversion. All groups supplemented with organic acids had reduced incidence and severity of diarrhoea, and performed significantly better than the negative control group (P<0.05). At the end of the trial, ETEC strains were detected in the control group not receiving antibiotics but not in the treated group. Organic acids and especially lactic acid are a useful tool in controlling PWDS.     

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.     

The pathogenesis of the post-weaning syndrome in weaned piglets: a review.

This review deals with the pathogenesis of the post-weaning syndrome. This syndrome includes post-weaning diarrhoea (PWD), oedema disease (OD) and endotoxin shock (ES). The role of different enteropathogenic Escherichia coli bacteria and some other predisposing factors relating to this post-weaning syndrome (PWS) are discussed. Based on intestinal pathophysiological mechanisms, some suggestions for the prevention of PWS and prospects for future research are given.     

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.     

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.     

Research of the application of a water-in-oil emulsion for the prevention of post-weaning diarrhoea and oedema disease in piglets

A stable water-in-oil emulsion was injected intraperitoneally (i.p.) in piglets about 5 days before weaning to prevent post-weaning diarrhoea (PWD) and oedema disease (OD). So far more than 200,000 piglets have been treated with this adjuvant on a number of farms. On these farms the mortality rate due to PWD and OD decreased, whereas the need for antibiotic treatment declined. Experiments involving alternate application of adjuvant and physiological saline, or adjuvant treatment and no treatment at all, showed a statistically significant positive effect of adjuvant application. The effect of i.p. adjuvant application on specific and non-specific defence mechanisms were examined in well defined rat- and mouse-models, to throw light upon the mechanisms behind the observed adjuvant effect in piglets.     

Intraperitoneal injection of an adjuvant for the prevention of post-weaning diarrhoea and oedema disease in piglets: A field study

Shortly before weaning, piglets were intraperitoneally injected with a stable water-in-oil emulsion serving as an adjuvant without any added antigens. The aim of this treatment was to potentiate the immune response to naturally occurring antigens of pathogenic organisms in the gut, and thereby to prevent post-weaning diarrhoea and oedema disease. Experiments were done on seven farms and comprised more than 7,000 piglets. Results indicate a positive effect of the intraperitoneal adjuvant injection on mortality rates, viz. average mortality rate after weaning decreased from circa 12% to 2%. Moreover, the need for antibiotic treatment declined sharply. A statistically significant positive effect of adjuvant treatment was shown by adopting experimental schemes involving alternate treatment with adjuvant and physiological saline, or adjuvant treatment andno treatment at all. Possible side effects and prospects for the future of this alternative vaccination principle are discussed.     

复合益生菌乳膏剂的制备和对断奶仔猪生长性能的影响

益生菌已经在畜禽养殖中广泛应用于动物保健。当前益生菌制剂仍存在需低温保存且有效期短的问题。此研究开发了一种由干酪乳杆菌、屎肠球菌和约氏乳杆菌组合而成的新型复合益生菌乳膏剂,在室温下贮存56 d后仍可维持较高活菌数(>108 cfu/g)。在断奶仔猪日粮中添加该复合益生菌乳膏剂可提高断奶仔猪平均日增重和末均重(P<0.05)、降低饲料增重比,而不影响平均日采食量。研究结果表明,所制备和优化的复合益生菌乳膏剂具有良好室温保存稳定性,在断奶仔猪中使用可有效促进饲料营养吸收,从而提高生长性能。     

Effects of a probiotic Enterococcus faecium strain supplemented from birth to weaning on diarrhoea patterns and performance of piglets

This placebo-controlled double-blind study was conducted to evaluate effects of Enterococcus faecium DSM 10663 NCIMB 10415 (EcF) orally given from birth to weaning on diarrhoea and performance of piglets. At the first 3 days postnatum (p.n.), piglets from 54 [verum group (VG)] and 60 [placebo group (PG)] sows got 1 g of a gel directly per mouth by a dosing device. Gel for the VG contained 2.8 x 10(9) colony forming units (CFU) EcF/g. From day 4 p.n. until weaning (24 +/- 3.2 days p.n.) a liquid additive was given that administered twice a day 1.26 x 10(9) CFU EcF to each VG piglet. In case of diarrhoea, an electrolyte solution was used which provided daily 2.9 and 5.8 (week 1 and >or= 2, respectively) x 10(8) CFU EcF per VG piglet. Diarrhoea scores were defined as follows: (i) no diarrhoea; (ii) piglets developed diarrhoea, but were vital and (iii) piglets suffered from diarrhoea and additionally looked pale, developed rough coat, showed slackening of the flank and lethargy. Counts of viable born, stillborn and weaned piglets were normal and not different between groups (p > 0.05). Placebo group vs. VG piglets suffered more frequently from diarrhoea (40.0 vs. 14.8%, p < 0.05). Duration of diarrhoea was not affected by feeding EcF (2.2 +/- 0.81 days, p > 0.05). Diarrhoea score was lower in VG vs. PG (1.2 vs. 1.5 +/- 0.54, p < 0.05) and the daily weight gain (DWG) was higher by 17 g/day (p < 0.05). Results suggest that the daily oral supplementation of EcF from birth to weaning reduces the portion of piglets suffering from diarrhoea. This may improve performance, as the higher DWG indicates. In contrast, no obvious benefit seems to result from an additional supply of EcF via electrolyte solution when diarrhoea is always present.     

Risk factors for post-weaning diarrhoea on piglet producing farms in Finland

Background

Post-weaning diarrhoea (PWD) is a significant gastrointestinal disease in pigs. It is considered a multifactorial disease associated with proliferation of enterotoxigenic Escherichia coli in the intestinal tract of affected pigs. The aim of this study was to analyse risk factors related to the occurrence of PWD on Finnish piglet producing farms.

Methods

The data of a follow-up study of 73 conventional piglet producing farms was used in the case-control study. The selection of the 41 PWD case and 28 control farms was based on the use of antimicrobials for treating diarrhoea in weaned pigs and the answers related to the occurrence of diarrhoea after weaning in the questionnaire. Four intermediate farms were excluded from the statistical analysis.Altogether 39 factors related to herd characteristics, weaner pig management and pig health were studied. The median number of sows was 59.0 (IQR = 44.0; 74.5) and 52.5 (IQR = 36.8; 61.5) on the case and the control farms, respectively.The significances of the univariable associations between the explanatory variables and the outcome variable were tested, and in the multivariate analysis quasibinomial generalized linear models were applied.

Results

An increased risk of PWD was associated with the regimen of twice a day feeding and feed restriction after weaning (P = 0.02; compared to feeding three or more meals a day or the use of ad libitum feeding) and with a higher number of sows on the farm (P = 0.02; risk increasing with increasing number of sows). Automatic temperature control was associated with a decreased risk of PWD (P = 0.03; compared to manual temperature control).

Conclusion

Twice a day feeding of newly-weaned pigs should be avoided if the amount of feed given is restricted. Variation in ambient temperature should be minimized in housing of newly-weaned pigs and this can be achieved by using automatic temperature control. With increasing number of sows in the herds the risk of PWD increases and more attention should be paid to prevention of post-weaning diarrhoea.     

珠蛋白肽对断奶后期仔猪生长性能和免疫影响的研究

96头52日龄的长×大二元去势公猪随机分成对照组和试验组,对照组饲喂基础日粮,试验组饲喂基础日粮+1%珠蛋白肽,试验期21d。结果表明:试验组和对照组生产性能指标无显著差异(P>0.05)。与对照组相比,试验组血清中IgG的含量提高了33%(P<0.05);免疫器官指数和消化器官指数都有所提高,腹泻率有所降低。     

Experimental models of porcine post-weaning colibacillosis and their relationship to post-weaning diarrhoea and digestive disorders as encountered in the field

The aim of this study was to develop a reliable model system of porcine post-weaning colibacillosis, and in doing so to assess the primary relationship of enterotoxigenic Escherichia coli to post-weaning diarrhoea and digestive disorders as encountered in the field. Six sequential experiments were carried out using 168 SPF piglets weaned into an optimal controlled environment at 28 days of age. The piglets were allocated to 23 treatment groups, 17 of which were inoculated either orally or intragastrically with enterotoxigenic strains of E. coli (LT+, STI+, STII+) possessing adhesive factors including K88 (F4). The piglets were challenged either once (Day 4 post-weaning) or on several days post-weaning, with the challenge load for each inoculation varying from 10(8) to 10(12) CFU.Overall 14.5% of inoculated pigs developed severe illness and died: these had lesions in their digestive tracts typical of colibacillosis. Diarrhoea occurred on at least 1 day in 50% of inoculated pigs, but was transient (1.7 days on average), appeared very soon after challenge (sometimes within half a day), and was accompanied by signs of depression and low weight gain. Generally a prompt recovery then occurred. In the second 2 weeks post-inoculation daily weight gain reached the same level in most inoculated groups of pigs as in the uninoculated controls. Only a small number of pigs developed a chronic enteritis lasting several days, as is typically observed in field cases. Diarrhoea was more common in the piglets that were tested adhesive positive to the K88 fimbriae receptor, but the disorders were no more severe in these animals. The response of all pigs depended primarily on the inoculum used, and especially on the challenge load. Although enterotoxigenic E. coli are clearly important in the aetiology of post-weaning diarrhoea, other factors are also required for the production of the chronic post-weaning digestive disorders and ill-thrift that are commonly encountered in commercial piggeries.     

早期断奶仔猪腹泻的发生原因及其预防措施

栏舍利用率,在现代专业化、集约化养猪生产中,目前国内外已广泛实行仔猪3～4周龄断奶,即早期断奶。但早期断奶仔猪最常见、危害性最大的是断奶后腹泻。据报道,断奶后头7d腹泻率为0.6%,8～13d增到32%,14～17d增到41.4%,22～28d降到8.4%,断奶后死亡率高达20%～30%,存活下来的仔猪大多生长发育不良,总增重下降约33%,给养猪业带来了巨大的经济损失。如何降低早期断奶仔猪腹泻的发生仍是当前养猪业迫切需要解决的问题。本文就早期断奶仔猪腹泻的发生原因及其预防措施加以介绍,以供参考。1早期断奶仔猪腹泻的发生原因1.1早期断奶仔猪的消化生理特…     

An evaluation of the efficacy of cordial for preventing post-weaning diarrhoea in pigs

An evaluation of the efficacy of a commercial crystalline cordial concentrate for preventing post-weaning diarrhoea (PWD) and improving weight gains in pigs following weaning, was carried out in 3 herds using 861 pigs. The incidence of PWD in pigs drinking the cordial was reduced in 2 herds and its severity was reduced in one of these. There was no effect on either incidence or severity in the other herd. The pigs given cordial consumed considerably more water per day and less feed per day than pigs drinking plain water during the 10-day supplementation period. There was no improvement in average daily gain or feed conversion ratio attributable to adding cordial to drinking water in any of the herds. In one herd the growth rate of pigs receiving cordial was actually depressed during the supplementation period. There was no reduction in mortality or in number of treatments given for diarrhoea in pigs receiving cordial.     

Effect of creep feeding on the incidence, duration and severity of post-weaning diarrhoea in pigs

The effect of creep feeding on the response of pigs weaned at two or three weeks old to infection with an enteropathogenic strain of Escherichia coli (O149; K91[B], K88 a, c [L]) was studied in two separate experiments. Gastric intubation was adopted to regulate the intake of creep feed during the sucking period. Animals were given the enteropathogenic strain either before weaning or at weaning and the course and outcome of the infection followed bacteriologically and clinically. The response of the animals to the infection varied considerably in accord with recent reports of multiple phenotypes (to K88 +ve organisms) among pigs but consumption of creep feed before weaning did not significantly affect the prevalence, duration or severity of the diarrhoea induced experimentally by the organism. Hence reputed immunological responses mounted against dietary antigens did not predispose to or protect against this infection.     

The effect of josamycine on the control of ileitis in weaned piglets under field conditions

The aim of this trial was to evaluate the effect of in-feed josamycine on the control of ileitis in weaned piglets. On a farm with a previous history of ileitis outbreaks, 288 piglets at weaning age (25 +/- 2 days old) were allocated into three experimental groups, each group comprising of four pens with 24 piglets in each pen. Group one (T1) served the trial as negative control group (unmedicated), group T2 was administered josamycine at 36 mg/kg of feed and group T3 was administered josamycine at 50 mg/kg of feed. Treatments lasted for 14 days followed by an observation period of 28 days. Administration of josamycine at both inclusion levels tested had a beneficial effect compared with the negative control group, by the reduction of prevalence of diarrhoea, the enhancement of growth performance and the reduction of prevalence of Lawsonia intracellularis in the intestine, as determined either by the PCR method or by specific histopathological examinations. The beneficial effect of josamycine was more pronounced at the inclusion level of 50 mg/kg of feed.     

特异性IgY抗仔猪断奶腹泻机理的研究概况

针对仔猪断奶腹泻（Post—weaning Escherichia coli diarrhea，PWECD）这一仔猪断奶后的常见病和多发病的病原特异性，阐述了利用K88和F18等特异性菌毛作为抗原免疫产蛋母鸡制备的抗PWECD特异性卵黄抗体对大肠埃希氏菌引起的断奶仔猪腹泻的作用机理。认为，特异性IgY用于防治PWECD，具有安全、高效、成本低、产率高、稳定性好，无药物残留，不会产生耐药性，符合现代动物管理理念等诸多优点，是一种能有效防治PWECD的绿色生物制剂，应用前景广阔。     

Effect of an inactivated Parapoxvirus based immunomodulator (Baypamun) on post weaning diarrhoea syndrome and wasting pig syndrome of piglets

Post weaning diarrhoea syndrome (PWDS) and wasting pig syndrome (WPS) are two entities of the pig industry induced by stress factors occurring at the early weaning and further complicated by opportunistic pathogens. In the present paper we examine - through one pilot and one final trial - whether prevention of these two syndromes can be achieved in the field by immunomodulation of the pig e.g., by improving its non-specific immunological response. In both trials two groups of early weaned piglets were submitted to the treatments. In the pilot trial the first group received no treatment and served as controls and the animals of the second group were injected twice with an inactivated Parapoxvirus based immunomodulator (Baypamun, Bayer, Germany). In the final trial the first group of piglets received no treatment and served as a control group. The animals of the second group were injected twice with a freeze-dried immunomodulator (Baypamun). Piglets were compared with regard to the severity of PWS, mortality, growth performance parameters, and for the presence of pathogens in their faeces. The results have shown that Baypamun treated piglets performed significantly better than negative control piglets in all the parameters examined. It was concluded that stimulation of the non-specific immunity of piglets may be helpful in preventing the appearance of PWDS and WPs in the field.