Impact of general injection anaesthesia and analgesia on post-castration behaviour and teat order of piglets

Injection anaesthesia with a combination of ketamine and azaperone (K/A) is discussed as a painless alternative to commonly used non-anaesthetized castration. To protect anaesthetized piglets from being crushed, they have to be separated from the sow for 3 h following castration. The aim of this study was to test if this separation and the different treatments would affect short-term behaviour after castration (3 to 6 h after castration) as well as weight gain. Piglets were 5 to 7 days old. Treatment Group 1 received a combination of anaesthesia and analgesia (n = 29, ketamine: 25 mg/kg BW; azaperone: 2 mg/kg BW; meloxicam: 0.4 mg/kg BW), Group 2 received only analgesia (n = 24) and Group 3 received no medication (n = 29). Behaviour and suckling order were compared for a 3 h period the day before castration and after castration. A significantly higher number of teats used by anaesthetized piglets (P = 0.004) suggests a decrease in suckling order stability. There were significant treatment effects between all three groups in the time spent at the sow's teat, with an increase in Group 2 (+69%), decrease in Group 1 (−28%), whereas the control Group 3 (+2%) almost remained unchanged. The anaesthetized piglets showed an increase in the time spent active away from the sow after castration of almost 200% (Groups 2 and 3: ∼50%, P < 0.001). However, no significant treatment effect was seen for weight gain. The results suggest that analgesia has an effect on behaviour, perhaps due to less post-castration pain. This advantage is not apparent for animals receiving additional anaesthesia, probably because of impaired coordination. Although the behavioural changes did not affect weight gain significantly, a decrease in suckling order stability indicates a certain degree of stress due to fighting over teat positions as a consequence of separation. Thus, post-castration behaviour must be taken into account when evaluating alternative castration methods.     

Effect of fermented liquid diet prepared with Lactobacillus plantarum LQ80 on the immune response in weaning pigs

Probiotics such as lactic acid bacteria directly influence the host's health and have beneficial effects such as decreasing the number of enteric pathogens, regulating intestinal immune responses and preventing diseases. Among domestic animals, probiotics have been expected to be an alternative to antibiotics added in the diet; and fermented liquid diet (FLD) containing probiotics has great potential as a diet for reducing the use of antibiotics. In this study, we evaluated the immunomodulatory effects of FLD, prepared using Lactobacillus plantarum LQ80 (LQ80), on the immune response of weaning pigs. Ten weaning piglets were divided into two groups and were fed the FLD (n = 5) or a non-fermented liquid diet (NFLD) (n = 5) for 28 days. At the end of the experiment, the total immunoglobulin M (IgM) and immunoglobulin G (IgG) levels in the sera of the FLD-fed piglets were significantly higher than those of the NFLD-fed piglets (P < 0.05). In contrast, the total immunoglobulin A (IgA) levels in the feces and saliva were not significantly affected by FLD feeding. However, the mean fecal IgA levels of FLD-fed piglets at day 28 were higher than those at 14 and 21 days (P < 0.05). Blood cells from the FLD-fed piglets showed a low level of interferon-γ secretion and mitogen-induced proliferation compared to that of the NFLD-fed piglets. Furthermore, the levels of interluekin-8 and tumor necrosis factor-α, which are proinflammatory cytokines, in the blood cells of the FLD-fed piglets were lower than those of the NFLD-fed piglets (P < 0.05). In conclusion, the FLD used in this study could alter the immune responses of weaning piglets by stimulation of the systemic or mucosal antibody response, without unnecessary inflammatory reactions. This indicates, that the FLD feed prepared with the use of LQ80 may be a candidate feed, with regard to enhancing immune responses and preventing diseases in weaning piglets.     

Shivering thermogenesis in the neonatal pig

(I) Shivering intensity and metabolic rate were determined in Large White pigs aged 2, 24, 48 h and 5 d, at temperatures ranging from thermoneutrality (36°C) to cold (20°C). (2) Shivering is the main heat producing mechanism, the absence of nonshivering thermogenesis being implied by both the absence of delay between the onset of shivering (S_tt) and the increase in metabolic rate (L_ct) and by the linearity of the relationship between metabolic rate and shivering intensity in the cold. (3) For a comparable thermal demand, shivering intensity decreased with age whereas cold induced heat production remained constant, which suggests that the thermogenic efficiency of shivering is improved during the first 5 days of life.     

断奶仔猪肠道菌群的研究

研究断奶仔猪在不同生理状况下的肠道菌群,结果表明：健康仔猪肠道内容物中,从十二指肠到结肠,所测定的８种细胞数量都随肠段后移而逐渐增加,４３日龄仔猪肠道内容物中以乳杆菌、肠球菌和梭菌占绝对优势,双歧杆菌次之;与健康仔猪相比,下痢仔猪肠道中肠球菌、梭菌和乳杆菌等优势菌群的数量明显低于对照组;饲喂了含肠球菌的活菌制剂的仔猪肠道中双歧杆菌和类杆菌的数量比对照组明显增加,但肠球菌数量却无显著改变。     

Physicochemical properties and nutritional quality of raw cereals for newly weaned piglets

The digestibility of the starch component of raw cereals in newly weaned piglets is highly variable. Reasons for this must be elucidated if the most suitable cereals are to be used. A novel approach was employed, which consisted of assessing the physicochemical properties (rapid visco analysis, water absorption and solubility indices, particle size distribution and in vitro amylolytic digestion) of eight raw cereals contained within piglet diets and subsequently relating this in vitro data to the biological responses of weaned piglets. Trial 1 examined soft and hard wheat, trial 2 - soft wheat, barley, rye and triticale, and trial 3 - soft wheat, naked oats, whole oats and maize. The initial observation was that in vitro testing prior to animal trials is recommended in nutritional evaluation since it indicated fundamental differences between raw cereals, such as for example the levels of endogenous amylase in wheat. Starch and nitrogen digestibility differed between cereals (apparent digestibility coefficients at the 0.5 site of the small intestine ranged from 0.10 to 0.69 for starch and from 0.17 to 0.68 for nitrogen). There is also a probable relationship between the coefficients of ileal apparent starch digestibility, at approximately halfway from the gastric pylorus to the ileocaecal valve, and the presence of endogenous amylase (mean values of 0.53 and 0.62 in trials 2 and 3, respectively, for the higher amylase wheat; 0.38 for the low-amylase wheat used in trial 1). This additional variable (i.e. the unforeseen presence of endogenous amylase) in wheat made it more difficult to draw a firm conclusion about the nutritional suitability of the different cereals. All raw-cereal diets caused atrophy of the villi during the initial week following weaning, but the soft wheat was associated with the highest comparative villi height and might therefore be considered the best of all raw cereals in minimising the post-weaning growth check. For wheat, this might also suggest a possible interaction between villus architecture and endosperm texture in the immediate post-weaning period.     

猪源大肠杆菌(ETEC、STEC、AEEC)毒力基因及其与O抗原型的关系

[目的]揭示从我国部分地区仔猪腹泻或水肿病病猪体内分离到的300个大肠杆菌分离株所属病原型(pathotype)、毒力基因及其与O血清型的关系.[方法]O血清型采用常规的凝集试验进行测定,毒力基因采用PCR方法检测.[结果]通过对这300个分离株的O血清型及其毒素、紧密素和黏附素基因进行鉴定,结果显示除50株未定型、17株自凝外,测定出233个分离株的血清型,这些分离株覆盖了45个血清型,其中以0149、0107、0139、093和091为主,共133株,占定型菌株的57.1%;拥有est Ⅰ、estⅡ、elt、stx2e和eae A基因的菌株分别为102(34.0%)、190(63.3%)、81(27.0%)、57(19.0%)和54(18.0%)株;分离株中有51株K88基因阳性(其中菌毛表达率为100%),75株F18基因阳性(其中菌毛表达率为50.7%),在K88菌株中,0149血清型与est Ⅰ或estⅡ elt密切相关,在F18菌株中,0107血清型与est Ⅰ或estⅡ、0139血清型与stx2e紧密相关.依其毒力特征可将这些分离株分为以下6种类型:ETEC、STEC、AEEC、ETEC/STEC、AEEC/ETEC和AEEC/ETEC/STEC,分别拥有190、24、36、32、17和1个菌株,占分离株的63.3%、8.0%、12.0%、10.7%、5.7%和0.3%.通过分析这些分离株的O血清型、毒素类型和黏附素型之间的相关性:猪源ETEC以0149、0107、093和098等血清型为主,0149:K88菌株主要与estⅡ或estⅡ elt肠毒素相关,0107:F18菌株主要与estⅡ相关,093和098血清型菌株主要与estⅡ肠毒素相关;STEC菌株以0139:F18血清型为主,拥有stx2e;AEEC菌株拥有紧密素,无明显优势血清型;ETEC/STEC菌株以0107:F18和0116:F18血清型为主,主要与est Ⅰ stx2e或estⅡ stx2e密切相关,ETEC/AEEC菌株以091和0107血清型为主,全部拥有肠毒素est Ⅰ和紧密素基因.[结论]我国至少存在6种病原型的猪肠道致病性大肠杆菌,其中ETEC为我国部分地区猪大肠杆菌病的主要病原,同时其病原型日益复杂.     

Glycosylated F4 (K88) Fimbrial Adhesin FaeG Expressed in Barley Endosperm Induces ETEC-neutralizing Antibodies in Mice

The F4-positive enterotoxigenic Escherichia coli (ETEC) strains are a frequent cause of porcine post-weaning diarrhea. Orally administered F4 fimbriae or FaeG, the major subunit and adhesin of F4, induce a protective mucosal immune response in F4 receptor-positive piglets. Feed plants carrying immunogenic subunit proteins can offer great advantages for oral vaccination of domestic animals. Here, we describe high-level endosperm-specific production (1% of total soluble proteins) of FaeG in the crop plant barley. The endoplasmic reticulum-targeted recombinant endospermic FaeG (erFaeG) was shown to be heterogeneously glycosylated. The erFaeG showed resistance at digestive conditions simulating piglet gastric fluid. Glycosylation did not abolish the immunogenic character of the FaeG protein, since erFaeG was able to induce F4 fimbria-specific antibodies in mice. Biological activity of these anti-F4 antibodies was demonstrated in vitro by blocking the attachment of the F4⁺ ETEC to the F4 receptors present on porcine intestinal enterocytes.     

PEGylated porcine glucagon-like peptide-2 improved the intestinal digestive function and prevented inflammation of weaning piglets challenged with LPS

This study was conducted to determine the effects on intestinal function, anti-inflammatory role and possible mechanism of polyethylene glycosylated (PEGylated) porcine glucagon-like peptide-2 (pGLP-2), a long-acting form of pGLP-2, in weaning piglets challenged with Escherichia coli lipopolysaccharide (LPS). We divided 18 weaned piglets on day 21 into three groups (control, LPS and LPS+PEG-pGLP-2; n=6). The piglets from the LPS+PEG-pGLP-2 group were injected with PEG-pGLP-2 at 10 nmol/kg BW from 5 to 7 days of the trials daily. On 8^th day, the piglets in the LPS and LPS+PEG-pGLP-2 groups were intraperitoneally administered with 100 µg LPS/kg. The control group was administered with the same volume of saline solution. The piglets were then sacrificed on day 28. Afterwards, serum, duodenum, jejunum and ileum samples were collected for analysis of structural and functional endpoints. LPS+PEG-pGLP-2 treatment increased (P<0.05) lactase activities in the duodenum and the jejunum compared with LPS treatment. LPS+PEG-pGLP-2 treatment also significantly increased sucrase activity in the jejunum compared with LPS treatment. Furthermore, LPS treatment increased (P<0.05) the mRNA expression levels of interleukin (IL)-8, tumour necrosis factor-α (TNF-α) and IL-10 in the ileum compared with the control treatment. By contrast, LPS+PEG-pGLP-2 treatment decreased (P<0.05) the mRNA expression levels of IL-8, IL-10 and TNF-α in the ileum compared with the LPS treatment. LPS treatment also increased (P<0.05) the mRNA expression level of GLP-2 receptor (GLP-2R) and the percentage of GLP-2R-positive cells in the ileum; by comparison, these results were (P<0.05) reduced by LPS+PEG-pGLP-2 treatment. Moreover, LPS+PEG-pGLP-2 treatment increased (P<0.05) the content of serum keratinocyte growth factor compared with the control group and the LPS group. The protective effects of PEG-pGLP-2 on intestinal digestive function were associated with the release of GLP-2R mediator (keratinocyte growth factor) and the decrease in the expressions of intestinal pro-inflammatory cytokines.