Marianne Jensen-Waern

Dietary zinc oxide in weaned pigs — effects on performance, tissue concentrations, morphology, neutrophil functions and faecal microflora

The uptake and distribution of zinc in tissues and the effects of 2500 ppm dietary zinc oxide on health, faecal microflora, and the functions of circulating neutrophils were evaluated in weaned pigs. One group was fed a zinc supplement diet and another group was used as a control. All pigs remained healthy throughout the study, but the supplemented animals showed better performance than the controls. The serum zinc values rose rapidly. At autopsy, carried out at the age of 63 days, the zinc concentrations in liver tissue were 4.5 times higher, and in renal tissue two times higher in the supplemented group than in controls (P<0.001). Microscopic examination showed increased lipid accumulation in hepatocytes from supplemented pigs. No effect on the number of excreted Escherichia coli and enterococci per gram faeces or on the functions of circulating neutrophils was observed. Dietary supplementation with 2500 ppm ZnO for up to two weeks after weaning appears to be potentially beneficial in the prevention of postweaning diarrhoea in pigs.

Diarrhoea in the growing pig - a comparison of clinical, morphological and microbial findings between animals from good and poor performance herds.

Abstract Diarrhoea among growing pigs (8–13 weeks old) is a significant problem in many herds. Nine herds with poor performance and diarrhoea among growing pigs were selected on the basis of their piglet mean age at a body weight of 25kg, compared to the overall mean age in Swedish herds. In addition, four herds with good average performance and no problems with diarrhoea were selected. Pigs were necropsied and samples for histology and microbiology were collected. Based on the necropsy findings, the pigs from the good performing herds were all judged to be healthy. The presence of Brachyspira pilosicoli and Lawsonia intracellularis was significantly correlated to poor performing herds and the results indicate that these microbes are main pathogens involved in enteric diseases among Swedish grower pigs. In addition, concomitant infections with other presumptive pathogens were commonly found.

Porcine proliferative enteropathy: an important disease with questions remaining to be solved.

Proliferative enteropathy caused by the intracellular bacterium Lawsonia intracellularis is an endemic disease with high herd prevalences reported worldwide. The infection has a considerable impact on pig production and herd economics and, with the development of new diagnostic techniques, L. intracellularis is being identified in an increasing number of pig herds and a wider range of species. This paper reviews current knowledge of the disease, with a focus on the epidemiology in pigs. The prevalence of infection, transmission, predisposing factors, microbial features, pathogenesis, clinical signs, diagnosis, treatment and control are discussed. The disease is mainly controlled by antibiotic treatment and vaccination at herd level. In the development of effective measures to prevent the spread of the infection, increased knowledge of the transmission and persistence of the microorganism are crucial.

Development of selected faecal microfloras and of phagocytic and killing capacity of neutrophils in young pigs

Nine healthy piglets, weaned at the age of 35 days and emanating from two litters, were studied from 7 to 63 days of age. The development of their faecal flora was analysed by bacteriological quantification of coliforms, E. coli, enterococci and Clostridium perfringens. The numbers of coliforms, E. coli and enterococci decreased from about 10(8) CFU/g faeces on day 7 to about 10(5) at the end of the study. Clostridium perfringens, with an initial value of 10(4) CFU/g faeces, was not found in any faecal sample from day 21 onwards. At each sampling occasion the similarity between the floras of different pigs were investigated by biochemical fingerprinting and calculated as correlation coefficients between metabolic fingerprints. This was performed for the coliform and the enterococcal floras. Initially, the coliform floras had a low homogeneity (rmean = 0.6), indicating large initial differences between the piglets. From day 14 post-partum until weaning the homogeneity was stable at a high level (rmean = 0.9). On day 3 post-weaning a marked decrease of the homogeneity was seen (rmean = 0.5), which later returned to the level before weaning. The enterococcal floras had a high homogeneity (rmean = 0.8-0.9) through the study and was only slightly affected by weaning. The function and development of the phagocytic and killing capacity of neutrophil granulocytes was monitored by flow cytometry and chemiluminescence. No changes in these functions were seen over time or between litters.

Neutrophil functions and serum IgG in growing foals

The aim of this study was to investigate the phagocytic and killing capacities as well as expression of CD18 of neutrophils obtained from healthy foals from birth to age 8 months. Blood was taken from 6 Standardbred foals at 7 time-points between ages 2-56 days and thereafter once a month. For comparison, cells from 16 mature horses were evaluated. Neutrophil phagocytosis of yeast cells was assessed by flow cytometry after opsonisation with mature pooled serum, autologous serum or anti-yeast IgG. The killing capacity of the neutrophils, as indicated by the oxidative burst, was monitored by chemiluminescence. Serum IgG concentration was measured by radial immunodiffusion. In addition to clinical examination, the amount of serum amyloid A and the total leucocyte count were used as markers for infection. The phagocytic ability was impaired until age 3 weeks, when autologous serum was used as opsonin. Killing capacity was also low initially but, from 3 months onwards, chemiluminescence values were equal to or higher than in mature horses. Serum IgG decreased from 10 g/l at 2 days to 5 g/l at 2 months and then increased gradually to 10 g/l at the end of the study. These findings may in part explain the increased susceptibility to bacterial infections in young horses.

Effects of epidural morphine and transdermal fentanyl analgesia on physiology and behaviour after abdominal surgery in pigs.

The objective of this work was to evaluate the physiological and behavioural effects of opioid analgesic treatment in pigs subjected to abdominal surgery. Ten Swedish Landrace × Yorkshire pigs (20 ± 4 kg b.w.) were submitted for intestinal cannulation. The pigs were allocated into two groups during one preoperative, one surgical and two postoperative days. All pigs were anaesthetized with medetomidine, tiletamine and zolazepam. One group was treated with epidural morphine (0.1 mg/kg) preoperatively, and transdermal fentanyl patches (50 μg/kg/h) were applied behind the ear immediately after surgery. The other group received epidural saline (equivalent volume) and placebo patches. All pigs were regularly weighed and clinically examined and repeated blood samples were analysed for serum concentrations of cortisol, β-endorphin and fentanyl. Pre- and postoperative behaviours were evaluated by a swine specialist blinded to the treatment, three times a day, and were also videotape recorded for a total of 84 h per pig. No differences in behaviour were noted by the observer. During the first postoperative 12 h, treated pigs did not differ in activity compared with preoperative recordings, while untreated pigs were found to be less active. The treated group started to show interest in eating immediately after anaesthesia recovery, whereas the placebo group did not. During the 12–60 h postoperative period, the treated group had lower activity levels compared with the preoperative levels, which were similar to those in the placebo group. Treated pigs gained 0.5 ± 0.2 kg during the subsequent two postoperative days, whereas the untreated pigs lost weight throughout the experiment. Cortisol concentration differed immediately after the surgery: Group P had 325 ± 120 nmol/L and Group M 159 ± 49 nmol/L. β-endorphin concentration did not differ between groups. The highest serum fentanyl concentration (0.37 ± 0.3 ng/mL) was measured 24 h postoperatively. Preoperative epidural morphine in combination with postoperative transdermal fentanyl resulted in earlier return to normal activity levels and an immediate weight gain after surgery.

In situ cross-linkable hyaluronan hydrogel enhances chondrogenesis

The present work describes the feasibility of a cross‐linkable injectable hyaluronan hydrogel for cartilage repair. The hydrogel used is a two‐component system based on aldehyde‐modified hyaluronan and hydrazide‐modified polyvinyl alcohol, which are rapidly cross‐linked in situ upon mixing. The in vitro study showed that chondrocytes and mesenchymal cells cultured in the gel form cartilage‐like tissue, rich in glycosaminoglycans, collagen type II and aggrecan. In a rabbit animal model the injection of the hydrogel improved the healing of a full‐thickness cartilage defect created in the knee as compared to non‐treated controls. This rabbit study showed that the regenerated cartilage defects stained more intensely for type II collagen upon treatment with the hydrogel. The hyaluronan‐based hydrogel may be used as a delivery vehicle for both growth factors and/or cells for cartilage repair. The in vivo study also indicated that the hydrogel alone has a beneficial effect on cartilage regeneration. Copyright

Opsonic capacity of foal serum for the two neonatal pathogens Escherichia coli and Actinobacillus equuli

Two of the most commonly isolated foal pathogens are Escherichia coli and Actinobacillus equuli. The hypothesis tested in this study was that young foals carry a lower opsonic capacity for these bacteria compared to adult horses. A flow-cytometric method for the phagocytosis of these by equine neutrophils was established. The opsonic capacity of serum from healthy foals from birth to age 6 weeks was evaluated and related to the concentrations of IgGa and IgGb. Phagocytosis of yeast was used as a control. Serum was required for phagocytosis, with higher concentrations for E. coli than for A. equuli. Ingestion of colostrum led to a significantly higher serum opsonic capacity. After that, there was no consistent age-related trend for opsonic capacity for the different microbes. Foal serum showed similar or higher opsonisation of E. coli and A. equuli compared to serum from mature individuals. During the studied period, the predominance among IgG subisotypes switched from IgGb to IgGa. Although the overall correlation between concentrations of IgG subisotypes and serum opsonic capacity was poor, sera with IgGb levels below 1.9 mg/ml induced lower opsonisation of E. coli and yeast, but not of A. equuli. Complement activation was important for opsonisation of all tested microbes. The results of this study are significant to the understanding of a key immunological facet in the pathophysiology of equine neonatal septicaemia in clinical practice.

Simultaneous detection of porcine proinflammatory cytokines using multiplex flow cytometry by the xMAP™ technology

Multiplex flow cytometry is in widespread use for detection of cytokines in human samples. However, no report on the measurement of porcine cytokines using this method has previously been published. We report on the detection of the porcine proinflammatory cytokines TNF‐α, IL‐8, and IL‐1β by the xMap‐assay for multiplex flow cytometry.

Postmortem changes in pork muscle protein phosphorylation in relation to the RN-genotype

Postmortem changes in pork muscle protein phosphorylation in relation to the RN(-) genotype were investigated using one-dimensional gel electrophoresis and a phosphor specific staining. The phosphorylation levels of several protein bands were found to be affected by the RN(-) genotype and to change during postmortem development. Glycogen phosphorylase, phosphofructokinase, and pyruvate kinase were found in protein bands affected by the RN(-) genotype, and the phosphorylation profile indicates that part of the increased rate and extended pH decline of the RN(-) genotype could be a consequence of phosphorylation of these key enzymes during the postmortem metabolism. The results illustrate that the protein phosphorylation level of the muscle proteins could be interpreted as a global metabolic fingerprint containing information about the activity status of the enzymes in the postmortem metabolism.