首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
Four dietary factors (ad libitum versus feed restriction, control versus protein restriction at ad libitum feeding, control versus inclusion of lupin as a protein source at ad libitum feeding, and control versus extra vitamin E at ad libitum feeding) were tested in four separate experiments for the effect on diarrhoea. To introduce a diarrhoea-like condition, half of the piglets were challenged with an E. coli O 149 dose of 1 × 108 colony forming units on days one and two after weaning (day of weaning = day zero). All piglets were susceptible since the dams were tested mono-zygotic susceptible to the attachment site of E. coli O 149 in the intestines. Each of the four experiments included 32 piglets from 4 sows. The design was a 2 × 2 factorial with dietary factor and E. coli O 149 challenge as the two factors, each at two levels. The piglets were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. The daily recordings included feed intake, weight and faecal score (from 1 = solid and cloddy to 6 = watery and yellow). Faeces from days 1 to 4 were tested for E. coli strains. In addition, blood was sampled and serum was analysed for antibodies to E. coli, IgG and IgM. Generally the E. coli challenge had no effect on growth and feed intake whereas faecal score and number of faecal haemolytic bacteria increased and faecal dry matter decreased. Feed restriction decreased the weight gain while faecal characteristics were unaffected. An analysis including all four experiments revealed that a feed intake of less than 200 g during the first day after weaning seems to be associated with a relatively high incidence of a post-weaning diarrhoea-like condition. Protein restriction decreased faecal score and increased faecal dry matter while weight gain tended to decrease. Inclusion of lupin affected neither weight gain nor faecal characteristics. Extra vitamin E did not affect weight gain while faecal dry matter decreased, and faecal score and number of faecal haemolytic bacteria increased. The dietary treatments had no effect on the measured immunoglobulins. In conclusion, the studied dietary factors could not alleviate a diarrhoea-like condition and at the same time maintain the growth rate. Furthermore, the results indicate that performance can be improved if piglets achieve a daily feed intake of at least 200 g during the first day after weaning.  相似文献   

2.
The ability of feed related measures to prevent or reduce post weaning diarrhoea (PWD) was examined in a split litter study including 30 pigs from 6 litters allotted into 5 groups. Four groups were exposed to 3 pathogenic strains of E. coli via the environment at weaning. Three of them were given zinc oxide, lactose+fibres or non-pathogenic strains of E. coil as probiotics. The challenged and the unchallenged control groups were given a standard creep feed. Diarrhoea was observed in all challenged groups but not among uninfected animals, and the incidence of diarrhoea was lower in the group given nonpathogenic E. coli compared to all other challenged groups. The severity of PWD also differed between litters. When corrected for mortality due to PWD, a decreased incidence of diarrhoea was also seen in the groups given zinc oxide or lactose+fibres. The dominating serotype of E. coil within faecal samples varied from day to day, also among diarrhoeic pigs, indicating that diarrhoea was not induced by one single serotype alone. The diversity of the faecal coliform populations decreased in all piglets during the first week post weaning, coinciding with an increased similarity between these populations among pigs in the challenged groups. This indicated an influence of the challenge strains, which ceased during the second week. The group given lactose+fibres was least affected with respect to these parameters. In conclusion feed related measures may alleviate symptoms of PWD.  相似文献   

3.
FACTORS CONTRIBUTING TO POSTWEANING DIARRHOEA IN A LARGE INTENSIVE PIGGERY   总被引：4，自引：0，他引：4  
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
Little is known about the sources and kinetics of enterotoxigenic Escherichia coli colonization in pigs during the pre-and post-weaning period. In this study, farrowing pens, sows, and piglets were tested for the presence of E. coli O149 by real-time polymerase chain reaction (PCR) after bacterial culture pre-enrichment on 2 farms, one with a history of post-weaning diarrhea (problem farm - PF) and the other without such a history (non-problem farm - NPF). Unlike those on the PF, the sows from the NPF did not carry E. coli O149 before parturition, although they were colonized to frequencies similar to animals on the PF soon afterwards. Most piglets from the NPF were colonized within a week after birth, whereas only a small proportion of those on the PF were colonized during that period. No difference was observed in the frequency of piglet colonization at the 2 farms either at weaning or during the following week. Post-weaning diarrhea (PWD), which is caused by enterotoxigenic E. coli (ETEC), is a multifactorial disease. The presence of ETEC alone is not always sufficient for the disease to develop. Many other factors are considered to be associated with the occurrence of PWD, including feed type (1,2), feeding regimen (1,3,4), the presence of other infectious agents (3,5), weaning age, and weight (6). Weaning, which is considered to be a major physiological and psychological stress factor, is critical for the disease to occur (7). Although piglets are already colonized with ETEC before weaning (4,8), on many farms, clinical disease occurs only after weaning (1). Both sows (9,10) and the environment (6) could be possible sources of infection for piglets, but results from previous studies have not resolved this issue because of the low sensitivity of ETEC detection methods. This study provides preliminary data based on a sensitive detection method for E. coli O149 in pigs and their environment. The results demonstrate the potential of real-time PCR for future studies on this topic.  相似文献   

7.
Duplex real-time PCR assays were used as modules to cover partially automated detection of 12 genes encoding adhesins, enterotoxins and Shiga toxins in faecal E. coli isolates. For this a total of 194 E. coli isolates from pigs suffering from post-weaning diarrhoea (PWD), including 65 isolates with haemolytic activity, and 83 isolates from calves with diarrhoea were examined. Data obtained by PCR were compared with O-typing and with haemolytic activity as indirect virulence markers. E. coli O-types O139:K82, O141:K85, and O149:K91 accounted for 43.8% (n = 85) of all porcine strains and for 55.4% (n = 36) of the porcine strains, which exhibited haemolytic activity. These strains carried virulence genes by 65.9% (n = 56) and 80.6% (haemolytic E. coli, n = 29), respectively. The E. coli O-types O139:K82 and O141:K85 were significantly associated with the adhesin gene F18, and O149:K81 with the F4 gene. In this context, detection of the gene encoding F18 was coupled predominantly with the genes responsible for the production of the toxins ST-I, ST-II and Stx2, and the F4 gene with those of the enterotoxins ST-I, ST-II and LT. Both virulence patterns were detected more pronounced in E. coli strains with haemolytic activity. Fifty-six of a total of 83 E. coli isolates originating from calves were O-typed as O101 (O101:K28, O101:K30, O101:K32; n = 29), O78:K80 (n = 23), and O9:K35 (n = 4). Most of the E. coli O78:K80 strains carried the F17 gene (69.6%, n = 16). Virulence genes encoding for F4, F5 or ST-I were detected only in single cases. Intimin and Shiga toxin genes that are present in enterohaemorrhagic E. coli (EHEC) were not detected.  相似文献   

8.
The aim of the study was to measure the effect of creep feeding during lactation on net absorption in the small intestine at 4 days after weaning. Intermittent suckling was used to increase creep feed intake during lactation. Creep feed containing chromic oxide was provided. Based on the colour of the faeces, piglets were classified as ‘eaters’ or ‘non-eaters’, respectively. At day 4 after weaning, an in vivo small intestine segment perfusion test was performed at 5 sites along the small intestine in 24 piglets (12 eaters and 12 non-eaters). At both sides of each intestinal segment a tube was fitted to perfuse and drain fluid in order to assess net absorption. Net absorption was higher in eaters than in non-eaters (P < 0.001). Net absorption varied greatly between and within piglets and was highest in the caudal segments of the small intestine (P < 0.001). These data suggest that creep feeding could be a useful tool in the prevention of post-weaning diarrhoea.  相似文献   

9.
To assess the effects of creep feed consumption on individual feed intake characteristics and performance of group-housed weaned pigs, 16 litters (149 piglets) were fed a commercial creep feed (3,040 kcal NE/kg, 15.2 g lysine/kg) supplemented with 1% chromic oxide. Another five litters (48 piglets) were not given access to creep feed (no-feed). Piglets were weaned at 28 d after birth. On d 18, 22, and 27 of age, fecal samples from all the piglets were taken using fecal loops. A green color of the feces indicated that the piglet had eaten creep feed. Piglets that had green-colored feces three times were considered as eaters. Piglets that never showed green-colored feces were considered as non-eaters. At weaning 22 piglets of each type (no-feed, non-eaters, and eaters) were selected based on BW, litter origin, and sex. These 66 pigs were assigned to six pens equipped with computerized feeding stations. Eaters, non-eaters, and no-feed pigs were equally divided over all six pens. After weaning a prestarter (d 0 to 13) and a starter diet (d 14 to 34) were offered for ad libitum consumption. The individual feed intake characteristics of latency time (interval between weaning and first feed intake) and initial feed intake (intake during the first 24 h following first feed intake) and performance traits were determined for all piglets. The pigs that were designated as eaters needed less time between weaning and first feed intake than the pigs that were designated as non-eaters and no-feed pigs (P = 0.04 and P = 0.06, respectively). Initial feed intake was not affected (P > 0.1) by feed intake prior to weaning. However, during d 0 to 8 the eaters had more visits per day during which feed was consumed than both the non-eaters and no-feed pigs. Averaged over the first 8 d after weaning, the ADFI and ADG of the eaters were higher than that of the non-eaters and no-feed pigs (P < 0.05). Averaged over the total 34-d period the effect of creep feed intake on postweaning ADFI was much less pronounced (P = 0.20), whereas ADG of the eaters was the highest (P < 0.05). Creep feed intake during the sucking period stimulates early postweaning feed intake as well as postweaning performance.  相似文献   

10.
To investigate the association of pathogenic Escherichia coli fimbrial adhesins with the development of diarrhoea in piglets of different age groups and to test their relative competitiveness, piglets were orally inoculated with a mixture of E. coli strains harbouring F4, F5, F6, F18 and F41 fimbrial genes. A total of 537 E. coli strains with haemolytic activity were isolated from 36 diarrhoeic piglets. The F4 fimbrial gene was observed in 98.5%, 97.6% and 80.6% strains carrying fimbrial genes isolated from diarrhoeic piglets that were infected at 1, 3 and 5 weeks of age, respectively. These data demonstrate that F4 fimbriae are highly associated with diarrhoea in piglets of all age groups. Interestingly, the F18 fimbrial gene was observed in 2.4% and 25.4% strains carrying fimbrial genes isolated from the 3- and 5-week-old groups, respectively, which confirms that F18 fimbriae are associated with diarrhoea in piglets from late stages of suckling to post-weaning, and are more related to diarrhoea in weaned than in unweaned piglets.  相似文献   

11.
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.  相似文献   

12.
采用大肠杆菌C83549(O149:K88ac)、C83644(O68:K99)、C83710(O9:987P)菌株制备抗原,以蜂胶为佐剂,研制仔猪大肠杆菌病三价蜂胶灭活疫苗,疫苗成品检验均符合相关要求。将疫苗免疫妊娠母猪并用凝集试验测定其所产仔猪的抗体消长规律,并研究疫苗免疫保护相关性。结果表明:妊娠母猪产前40d和15d各免疫1次所产仔猪母源抗体效价较高,仔猪在整个哺乳期都可以得到保护。同时也可运用产前30d和10d进行免疫接种方法。  相似文献   

13.
Milk from sows whose progeny developed post weaning E. coli diarrhoea (PWD milk) and from sows which were immunized by intramuscular vaccination using a homologous strain of E. coli (immune milk) were tested in ligated segments of pig intestine. The results showed that PWD milk neutralized the enterotoxigenic, fluid accumulating capacity of the lysate of the disease-causing E. coli pathogen. A similar effect was seen by using immune milk (Table I). Neither PWD milk nor immune milk contained sufficient antibacterial activity to neutralize the fluid accumulating capacity of live cultures of E. coli O149:K91, while such activity was contained in immune serum. It is concluded that milk from sows whose progeny developed PWD contains antibodies capable of neutralizing the enterotoxigenic effects of the homologous E. coli organisms. It is suggested that the presence in milk from these sows of antibody-mediated activity against enteropathogenic E. coli organisms may be instrumental in preventing the disease in the progeny during the suckling period and consequently, when this protective milk supply stops at weaning, the disease may develop in susceptible animals, mainly because their own production of specific E. coli antibodies is insufficient to prevent PWD.  相似文献   

14.
An experiment was conducted to determine if the improved creep feed intake observed during intermittent suckling (IS) is important for postweaning performance. Therefore, creep feed intake of litters was assessed, and within litters, eaters and noneaters were distinguished using chromic oxide as an indigestible marker. Batches of sows were suckled intermittently (IS, 7 batches; n = 31) or continuously (control, 7 batches; n = 31). In the IS group, litters were separated from the sow for a period of 12 h/d (0930 to 2130), beginning 11 d before weaning. Litters were weaned at 4 wk of age. Litters had free access to creep feed from 1 wk of age onward. Five days after weaning, the piglets were moved as a litter to weanling pens. At 8 wk of age, 2 barrows and 2 gilts were randomly chosen from each litter and moved to a finishing facility. Feed intake was improved by IS during the last 11 d of lactation (IS, 284 +/- 27 vs. control, 83 +/- 28 g/piglet; P < 0.001) and after weaning during the first (IS, 201 +/- 24 vs. control, 157 +/- 25 g x piglet(-1) x d(-1); P < 0.05) and second (IS, 667 +/- 33 vs. control, 570 +/- 35 g x piglet(-1) x d(-1); P < 0.05) wk. Thereafter, no differences were found to slaughter. Weaning BW was lower in IS litters (IS, 7.1 +/- 0.01 vs. control, 8.1 +/- 0.01 kg/piglet; P < 0.05), but 7 d after weaning BW was similar (IS, 8.5 +/- 0.2 vs. control, 8.7 +/- 0.2 kg/piglet; P = 0.18), and no differences were found to slaughter. The percentage of eaters within a litter was not increased by IS during lactation (IS, 23 +/- 4.5% vs. control, 19 +/- 4.1%; P = 0.15). Weaning BW did not differ between eaters and noneaters (eater, 7.7 +/- 0.1 vs. noneater, 7.5 +/- 0.08 kg/piglet; P = 0.63). From 1 until 4 wk after weaning, piglets that were eaters during lactation had heavier BW than noneaters (eater, 20.3 +/- 0.3 kg vs. noneater, 18.2 +/- 0.2 kg; P < 0.05). The influence of eating creep feed during lactation on BW and ADG and the influence of suckling treatment never showed an interaction. We conclude that IS increases ADFI during lactation on a litter level and improves ADG in the first week and ADFI in the first and second weeks after weaning. No long-term effects on ADFI or ADG were observed throughout the finishing period. In the current experiment, in which creep feed intake was low, the percentage of eaters within a litter was not increased, suggesting that creep feed intake of piglets that were already eating was stimulated by IS. Further, piglets that were eaters during lactation had heavier BW up to 4 wk after weaning.  相似文献   

15.
Faecal samples from suckling (n = 205) and weaned piglets (n = 82) with diarrhoea from 24 farms in Southern Germany were examined for shedding of important metazoic parasitic, viral and bacterial pathogens using culture, microscopic and electronmicroscopic methods. Escherichia coli isolates were tested further for the enterotoxin genes est-Ia and elt-I by colony blot hybridization. Isospora suis was diagnosed in 26.9% and Cryptosporidium parvum in 1.4% of the piglets investigated. The proportion of coronavirus-positive animals was 13.4% and 4% were positive for rotavirus. It was found that 17.6% of the animals were infected with enterotoxigenic E. coli (ETEC; 10.1% ETEC-ST-Ia and 8.6% ETEC-LT-I, respectively). The occurrence of the pathogens was significantly associated with the age of the animals examined (P < 0.001). Isospora suis was predominantly isolated from suckling piglets (in the second and third week of life), while in weaned piglets (fourth week of life) rotavirus and ETEC were most prevalent. On 22 of the 24 piglet production farms examined at least one of the investigated pathogens was detected. Coronavirus was diagnosed in 66.7%, I. suis in 62.5%, rotavirus in 20.8% and C. parvum in 8.3% of the farms. These results underline the fact that despite the hygienic, technical and immune preventive efforts during the last years, enteropathogens are still common in German piglet production units.  相似文献   

16.
选用二元杂交仔猪10窝,随机分为对照组和试验组,8日龄时开始补饲,对照组自由采食,试验组在自由采食基础上,增加强制补饲至21日龄.结果表明,强制补饲可明显增加28日龄断奶仔猪断奶前的饲粮采食量:试验组(600.6±29.97)g,对照组(202.6±16.59)g(P<0.01);断奶前后日增重显著提高(P<0.01);断奶后仔猪腹泻频率显著降低:试验组(14.78±2.13)%,对照组(45.75±6.26)%(P<0.01);28日龄胃内pH值低于4,显著低于对照组(P<0.05);肠道内大肠杆菌数量显著低于对照组(P<0.01);35日龄时,试验组胃质量显著大于对照组(P<0.05),胃和十二指肠黏膜绒毛显著高于对照组(P<0.05).  相似文献   

17.
Human illness due to infections with Escherichia coli O157 is a serious health concern. Infection occurs through direct contact with infected animals or their faeces, through contaminated food or water and/or through person‐to‐person transmission. A reduction in faecal E. coli O157 shedding in cattle might reduce the burden of human infections. We used systematic review and meta‐analysis to assess the efficacy of direct‐fed microbials (DFM), compared with placebo or no treatment, fed during the pre‐harvest stage of production in reducing faecal E. coli O157 shedding in beef cattle during field trials. Four electronic databases, Nebraska Beef Reports and review article reference lists were searched. A total of 16 publications assessing faecal shedding at the end of the trial and/or throughout the trial period were included. The majority of publicly disseminated trials evaluated the prevalence of E. coli O157 faecal shedding; only two evaluated the concentration of organisms in faeces. The prevalence of faecal E. coli O157 shedding in cattle is significantly reduced by DFM treatments (summary effect size for all DFM – OR = 0.46; CI = 0.36–0.60). The DFM combination Lactobacillus acidophilus (NP51) and Propionibacterium freudenreichii (NP24) was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period compared with the group of other DFM, although this difference was not statistically significant. Furthermore, we found that the combination [NP51 and NP24] treatment was more efficacious in reducing the prevalence of faecal E. coli O157 shedding at the time of harvest and throughout the trial period when fed at the dose of 109 CFU/animal/day than any lesser amount, although this difference was not statistically significant. Feeding beef cattle DFM during the pre‐harvest stage of production reduces the prevalence of E. coli O157 faecal shedding and might effectively reduce human infections.  相似文献   

18.
The objective of this study was to determine whether intermittent suckling (IS) combined with an extended lactation can reduce postweaning growth check in pigs. Three weaning regimens [conventional weaning (CW), IS with 6-h separation intervals (IS6), and IS with 12-h separation intervals (IS12)] were compared. In CW (n = 17 litters), litters had continuous access to the sow until weaning (d 21, d 0 = farrowing). In IS6 and IS12, litters were separated from the sow for 12 h/d, beginning at d 14 and lasting until weaning (d 41 to 45). Litters were with the sow from 1400 to 2000 and from 0200 to 0800 (IS6, n = 14) or between 2000 and 0800 (IS12, n = 14). Litter size was standardized within 2 d after farrowing by crossfostering, resulting in an average litter size of 10.9 +/- 1.8 piglets. Piglets had ad libitum access to creep feed from d 7 onward. One week after the onset of IS (d 20), creep feed intake was increased in litters from both IS groups compared with CW litters (P < 0.05). Both IS groups consumed considerable amounts of creep feed before weaning (d 41 to 45). Total feed intake before weaning was greater (P = 0.004) in IS12 (3,808 +/- 469 g/piglet) than in IS6 (2,717 +/- 404 g/piglet). In comparison, CW litters consumed 18 +/- 9 g/piglet before weaning (d 21). Irrespective of weaning regimen, total feed intake of litters before weaning was highly correlated with post-weaning feed intake (P < 0.001). Furthermore, in all treatment groups, total preweaning feed intake was correlated with postweaning growth (P < 0.10). Irrespective of treatment, piglets suckling anterior teats grew faster than piglets suckling middle or posterior teats during the first 2 wk of lactation. Body weights at the end of the experiment (d 55) were similar among weaning regimens. Onset of IS induced a growth check in both IS groups (34% for IS12 and 22% for IS6). Only a mild growth check was observed after weaning of IS litters (14% for both IS groups). However, a serious growth check (98%) was observed after weaning of CW litters. Results of the current study indicate that IS stimulated feed intake during lactation, providing a more gradual transition to weaning. Because the IS6 regimen did not prevent the growth check after the onset of IS and is rather laborious, we suggest that IS12 might be preferable for a practical implementation of IS.  相似文献   

19.
To prevent enterotoxigenic Escherichia coli (ETEC) induced postweaning diarrhoea, the piglet needs an active mucosal immunity at the moment of weaning. In the present study, the feasibility of oral vaccination of suckling piglets against F4+ETEC infection with F4 fimbriae was studied. Furthermore, oral vaccination with enteric-coated pellets of F4 fimbriae was compared to vaccination with F4 fimbriae in solution. Therefore, piglets were orally administered 1mg F4 fimbriae in pellets or in solution during three successive days at the age of 7 and 21 days, whereas control piglets were not vaccinated. Five days postweaning (33 days of age), all animals were orally challenged with F4+ETEC. Despite the induction of an immune response upon oral administration of both F4 fimbriae in pellets as in solution, the colonisation of the small intestine by F4+ETEC upon oral challenge could not be prevented. However, a marginal but significant reduction in F4+ E. coli faecal excretion was found in the piglets vaccinated with F4 fimbriae in pellets, indicating that the use of an enteric-coat which protects the F4 fimbriae against inactivation by milk factors and degradation by enzymes and bile improves vaccination.  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号