Articles 11-20

Effect of oligosaccharide supplementation on an ETEC infection in piglets

S. Vancaeneghem 1 , Y. Van der Stede 1 , T. Verfaillie 1 , F. Verdonck 1 , S. Arnouts 3 , P. Deprez 4 , E. Cox 1 , B.M. Goddeeris 1+2 .

1 Laboratory of Veterinary Immunology, Ghent University, Faculty of Veterinary Medicine, Merelbeke, Belgium.
2 Laboratory of Physiology and Immunology of Domestic Animals, Faculty of Agricultural and Applied Biological Sciences, University Of Leuven, Leuven, Belgium.
3 INVE Technologies NV, Baasrode, Belgium
4 Internal Medicine and Clinical Biology of Domestic Animals,Ghent University, Faculty of Veterinary Medicine, Merelbeke, Belgium

Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) is one of the major problems just after weaning. Antibiotics are the treatment of choice, since no vaccine is available. However, due to the risk for development of resistant bacteria, there is a search for alternatives. Oligosaccharides are known immunostimulants that activate the innate immune system, thereby enhancing protection against infections (Raa, 1996). In the present study 6 particulate oligosaccharides, differing in origin and/or extraction procedure, were tested for their protective effects against an ETEC infection. After weaning, six groups of piglets (n = 4 to 5) were fed different oligosaccharide food supplements during 14 days and whereas no supplement was given to the control group (n = 4). Three days after treatment, all pigs were inoculated with the F4 + ETEC strain GIS26. All piglets excreted F4 + ETEC in the faeces, but there was a statistically insignificant reduction in the ETEC excretion in the oligosaccharide-supplemented pigs. The two best oligosaccharides were from yeast (oligo 1) and fungi origin (oligo 6). An effect of both oligosaccharides was seen on the antibody response in serum and on the number of F4-specific antibody secreting cells (ASC) in spleen and Peyer’s patches. The F4-specific IgA and IgM serum antibody response was lower in oligosaccharide fed pigs in comparison with the control pigs. The number of F4-specific ASC per 10 7 mononuclear cells in the spleen was highest in the control pig (302 IgM ASC-14 IgA ASC) followed by the oligo1-supplemented pig (126 IgM ASC-2 IgA ASC) and the oligo6-supplemented pig (22 IgM ASC-0 IgA ASC). In the Peyer’s patches, a lower number of IgM and IgA ASC were found in the oligo6- supplemented pig in comparison with the control pig. The mRNA expression of cytokines IL-6, TGFb and IL-10 in the spleen and Peyer’s patches was influenced by the fungal glucan. Results suggest a protective effect of both oligosaccharides. The financial support of the Encouragement of Scientific research in Industry and Agriculture, Brussels, Belgium and INVE Technologies is greatly acknowledged.

Raa J., 1996. Reviews in Fischery sciences 4(3):229

The impact of prebiotics during salmonellosis on nutrient retention and Salmonella typhimurium var. Copenhagen excretion in adult pigeons (Columba livia domestica)

G.P.J. Janssens 1 , S. Millet 1 , F. Van Immerseel 2 , M. Hesta 1 , R. Ducatelle 2

1 Laboratory of Animal Nutrition, Ghent Univ., Heidestraat 19, 9820 Merelbeke, Belgium
2 ep.Pathology, Bacteriology and Avian Diseases, Ghent Univ., Salisburylaan 133, 9820 Merelbeke, Belgium

Salmonella is a prominent intestinal pathogen for pigeons. Lactose has been shown the ability to act against Salmonella in chickens (Ziprin et al., 1991). Fructo-oligosaccharides are widely used as prebiotics and these carbohydrates have also been tested with success against Salmonella in chickens (Fukata et al., 1999). Four groups of eight male adult pigeons (Columba livia domestica) were individually oused in metabolism cages and received a drinking water supplement of 2% fructo-oligosaccharides (FOS; Fibrulose® F97, Socodé, B), 2% lactose (LAC) or no supplement (CON and ZERO) for seven weeks. All pigeons were fed an amount of the same commercial feed (Quartes, Belgium) that was below normal intakes, i.e. 20 g/d. At d21 the FOS, LAC and CON pigeons were intubated with 10 9 Salmonella typhimurium var. Copenhagen (STC). Three digestion trials were performed (d8-12; d15-19; d43-47) in which total excreta were collected per pigeon, excreta consistency was scored daily and water and feed intake was measured. All pigeons were weighed at the start of the experiment and at the start and the end of each collection period. Nutrient retention were calculated from proximate analyses of feed and excreta. Two pigeons (FOS, LAC) did not survive the STC challenge. At the end of the trial (d47) all remaining pigeons were killed and dissected for STC counts in crop, spleen, small and large intestine and liver. Caeca were not looked at as they are rudimental in pigeons compared to chickens. Excreta samples from d16, 18, 22, 25, 28, 36 and 43 were analysed for STC. The pigeons lost about 77±27 g over the first week due to restricted feeding. During he first digestion trial (healthy animals), the FOS animals drank more and had less consistent droppings with higher moisture contents. Nutrient retentions did not differ between groups. During salmonellosis, feed intake and excreta consistency dropped whereas water intake increased significantly compared to the first digestion trial and to the ZERO group. In the last digestion trial, all surviving pigeons had recovered and showed normal eating, drinking and excreta consistency, including the FOS pigeons. STC excretion was not significantly different between FOS, LAC and CON, but fibre digestion was higher with FOS and LAC compared to CON, although only significant for LAC. The ZERO group did not show any STC excretion. The effect of LAC and FOS was rather limited, maybe because of a limited adaptation period of the intestinal flora to FOS and LAC.

Ziprin R. et al., 1991. Am J Vet Res 52: 833-837.
Fukata T. et al., 1999. J Food Protection 62: 229-233.

In vitro studies on the effects of short-chain fatty acids on the invasiveness of Salmonella

F.Van Immerseel 1 , J. De Buck 1 , F. Pasmans 1 , P. Velge², E. Bottreau², F. Haesebrouck 1 and R. Ducatelle 1

1 Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
2 Laboratoire de Pathologie Infectieuse et Immunologie, Institut National de la Recherche gronomique, Nouzilly, France.

Increasing the concentration of short-chain fatty acids (SCFA) in the intestinal environment is a well-known nutritional strategy to control pathogenic bacteria in poultry. Addition of prebiotics to the feed, such as fructo-oligosaccharides, can increase butyrate concentration in the caeca. Beads coated or impregnated with formate and propionate are used as feed additives. By doing so, high concentrations of SCFA can be reached in the chicken caecum, which is the predominant site for Salmonella colonization. Therefore a study was carried out to evaluate the effects of SCFA on invasion of Salmonella Enteritidis in intestinal epithelial cells in vitro.

Materials and Methods.
Bacteria were incubated for 4 hours in growth media, upplemented with different concentrations of the individual SCFA formate, acetate, propionate and butyrate and with mixtures of SCFA which mimic the in vivo situation as determined by gas chromatographical analysis of caecal contents of chickens. Thereafter, equal numbers of bacteria were incubated for 1 hour at 37°C with cells of a chicken intestinal epithelial cell line. After rinsing, gentamycin was added for 1 hour to kill extracellular bacteria, whilst letting intracellular bacteria multiply. Then cells were lysed and the number of colony forming units was determined by bacterial titration on brilliant green agar.

Salmonella bacteria grown in propionate and butyrate supplemented medium had a significantly lower invasion of the chicken intestinal epithelial cells, compared with bacteria grown in acetate and formate supplemented medium and controls. Bacteria grown in ‘in-vivo like’ mixtures of SCFA had significantly higher numbers of invaded bacteria compared with butyrate exposed bacteria. Adding 5 times more butyrate to the mixtures did not change the invasion properties of the bacteria as compared to those in the original SCFA mixture.

In vitro data suggest that acetate, present in high concentrations in the chicken caecum, increases invasion of Salmonella spp. in chicken intestinal epithelial cells, compared with propionate and butyrate. As a consequence, systemic spread of the bacteria can be enhanced. Propionate and butyrate have an inhibiting effect on epithelial cell invasion when bacteria are exposed to the individual SCFA. In contrary, increasing the butyrate concentration in in-vivo like caecal mixtures had no effect on epithelial cell invasion compared with SCFA mixtures without additional butyrate supplementation. This indicates that altering the butyrate levels in the caecum of chickens in vivo, as can be done by for example fructo-oligosaccharide addition in the feed, will not decrease invasion of Salmonella in intestinal epithelial cells. The effects on fecal shedding however cannot be evaluated in this model. Moreover, the high concentrations of acetate in the chicken caecum may add to the high susceptibility of newly hatched chicks to Salmonella infection.

Influence of PUFA on immune cell and tissue MAPK in the feline

K.E. Saker 1 , W.R. Huckle 1 , B.E. Cowing 1 , J.H. Herbein 2

1 VA-MD Regional College of Veterinary Medicine and
2 Department of Dairy Science, Virginia Tech, Blacksburg, VA

Epidermal growth factor/mitogen-activated protein kinase (EGFR/MAPK) pathway is a cell-surface associated signal transduction cascade, suggested to be involved in breast cancer cell development. MAPK and its effectors are associated with tumor cell growth that may likely be modulated via the action of cell membrane-incorporated polyunsaturated fatty acids (PUFA) directly or indirectly altering the action of the EGFR/MAPK pathway 1 . The ability to identify alterations in peripheral leukocytes and mammary adipose MAPK based on dietary PUFA concentrations would be beneficial as a cancer prognosticator and anti-tumorogenic agent for the feline cancer patient. We investigated if MAPK could be detected in white blood cell (WBC) populations and mammary adipose, using a feline model, and if its activity was influenced by dietary (n-6):(n-3) PUFA ratio.

Twenty-eight domestic felines were fed one of 4 diets varying in (n-6):(n-3) PUFA ratios for 24 weeks (7cats/diet). The highest (n-6):(n-3) ratio was provided by a commercially available diet. The remaining 3 dietary treatments provided PUFA in successively decreasing (n-6):(n-3) ratios. WBC were isolated and stimulated with 13-phorbol-15-myristateacetate and analyzed for MAPK activity via flow cytometry and immunoblotting, using phospho- and total MAPK monoclonal antibodies. Subcutaneous mammary/inguinal adipose tissue was obtained from all subjects and immediately stored in liquid nitrogen. Tissue was processed and analyzed for n-6 and n-3 PUFA and active MAPK, respectively.

MAPK was detectable in WBC and adipose tissue from all 28 cats. Across all time periods (P=0.02) and within each time period, the percent of immune cells staining positively for activity of MAPK was altered. Increased dietary (n-6):(n-3) PUFA was associated with increased MAPK activity in WBC. Active MAPK in WBC subpopulations appeared to be influenced by cat age and time on diet. Granulocyte populations responded (P=0.0004) to changes in dietary (n-6):(n-3) PUFA by week 12; and the mononuclear cell population responded (P=0.0069) by week 24. Dietary n-6:n-3 PUFA reflected adipose PUFA concentration across all dietary treatments. pMAPK tended to decrease from baseline through week 24 for all (n-6):(n-3) treatment groups, with the lowest (n-6):(n-3) treatment exhibiting the most profound depression (P=0.03) of pMAPK. Subjects with developing tumors exhibited a significant increase in immune cell MAPK over time that mirrored mammary adipose tissue changes.

Our data suggests that dietary PUFA ratio and age of cat influenced MAPK activity in both immune cells and tissues in a similar manner. This implies that immune cell and tissue MAPK can be influenced by dietary PUFA; and that peripheral blood MAPK activity may be a useful indicator of MAPK activity within tumor tissues. This preliminary data suggests a mechanism by which tumor development and growth in a feline cancer model may be modified by dietary PUFA. Further investigation in this area is currently ongoing in our research lab with respect to feline cancer directly and using the feline as a model to evaluate dietary interventions for human breast cancer.

1. Cowing B.C. and K.E. Saker, 2001. J Nutr 131:1125-1128.

Efficacy of a hypoallergenic diet containing soy isolate hydrolysate for the diagnosis and management of food hypersensitivity in dogs: a multicentric field study.

D. Van Pottelberge, V. Biourge, P. Marniquet and R. Sergheraert

Centre de Recherche, Royal Canin, Aimargues, France

Food hypersensitivity is a nonseasonal, pruritic skin disorder of dogs that is associated with the ingestion of a substance found in the dog’s diet. In dogs, food hypersensitivity is the third most common hypersensitivity skin disease after flea bite allergy and atopy. Until recently, the definitive diagnosis of food hypersensitivity can only be made on the basis of elimination diets (i.e. diets made of novel ingredients for the dog). Because they are easily customized and free of food additives homemade diets have often been recommended by veterinary dermatologists for the diagnosis and the management of food hypersensitivity. However, owners are often reluctant to feed homemade diets because they are time consumming and expensive. Moreover, they are difficult to balance. Lately, elimination diets based on protein hydrolysates have become available to veterinarians. Protein hydrolysates have been used with succes to prevent and treat milk allergies in babies. The purpose of this study was therefore to assess the efficacy of a diet containing soy isolate hydrolysate for the diagnosis and the treatment of food hypersensitivity in a multicentric field study.

Materials and methods:
109 dogs from 76 veterinary clinics across Europe and presenting the clinical signs of food hypersensitivity (nonseasonal pruritic skin disease) were included in the study following thorough clinical examination and exclusion of parasitic skin diseases. Based on severity of clinical signs, oral prednisone and/or antibiotherapy were allowed at initiation of the diet for 1 and 2 weeks respectively. Owners of those dogs were then instructed to feed exclusively and for 2 months a diet with soy isolate hydrolysate as the main source of protein (Hypoallergenic Programme, Royal Canin) as only treatment. After 30 and 60 days on the diet, dogs were re-evaluated by the veterinarian. Pruritus was scored (0= absent, 1=mild, 2=moderate, 3=severe) and skin lesions (erythema, excoriation, alopecia, …) recorded at each visit. Owners were also asked questions to assess compliance, palatibility and digestive tolerance to the diet. Dogs were considered as cured if the pruritus score was 0 and complete resolution of the skin lesions was observed.

78/109 (72 %) completed the study. Among the dogs that did not complete the study 50 % (16 dogs) were dropouts and 50 % were excluded because of poor compliance or drug treatment. In the dogs that completed the study, 25 % showed complete recovery (No pruritus and absence of skin lesion) , 41 % showed marked improvement (decrease in pruritus by at least 2 scores, minor skin lesions left) and 34 % little (pruritus improved by 1 score , major skin lesions left) or no improvement. Pruritus scores improved from grade 3-2-1 to 0 in 39 % of the dogs, from grade 3-2 to 1 in 38 % and grade 3 to 2 in 8 %. No improvement or worsening was observed in 15 %. Palatibility and digestive tolerance were considered as very good by owners.

Those results indicate that food hypersensitivity might be more prevalent in the population of dogs presented to European veterinarians than previously reported. A diet based on soy isolate hydrolysate might be beneficial for the diagnosis and treatment of food hypersensitivity in dogs.

Parenteral nutrition with or without early enteral nutrition in young dogs with parvovirosis

Jürgen Zentek 1,2 , Kerstin Will 2 , Ingo Nolte 2

1 Veterinary University of Vienna
2 School of veterinary medicine Hanover

Aim of this study was to investigate the effect of parenteral nutrition and early enteral nutrition in dogs suffering from canine parvovirosis with regards to the clinical outcome, the xylose absorption capacity, haematology and serum biochemistry.

Material and methods:
Dogs ( n = 19, age: 2 – 12 months) with parvovirosis (hemorrhagic gastroenteritis, age < 12 months, leucopenia < 6 x 10 9 /l) were randomised either to receive parenteral nutrition for 4 days (group P, n = 9) or parenteral nutrition and additionally a hydrolysed enteral nutrition (group PEN, n = 10) from the second day from admission to the clinic. The parenteral formula contained amino acids (Aminosteril® KE 10 % without glucose: 49.8 ml/kg BW 0.75 x day), lipids (Lipovenös® 20 %: 12.5 ml/kg BW 0.75 x day), carbohydrates and electrolytes (Glucosteril® 50 %: 35 ml/kg BW 0.75 x day and Jonosteril® D5: 21 ml/kg KM 0.75 x day; Fresenius, Bad Homburg, Germany) and provided 5 g amino acids and 0.5 MJ ME/kg BW 0.75 x day. The total infusion was administered within 10 hours. Group PEN received additionally 74 kJ/kg BW 0.75 enterally from the second day and 148 kJ/kg BW 0.75 for remaining days of the study. The enteral formula was hydrolysed by the addition of pancreatin and was used to hydrolyse t had the following composition; 60 % cottage cheese, 10 % sunflower-oil, 12.3 % glucose, 2.5 % egg yolk, 1.7 % mineral/vitamin supplement, 2.4 % sodium bicarbonate, 1 % pancreatin and 10 % water. Blood was collected to measure haematology and clinical chemistry. Concentrations of glucose, triglycerides, electrolytes and blood gases were measured before starting the infusion and after 6 and 10 hours. Fibrinogen, total protein, albumin, liver enzymes, total bilirubin, cholesterol, urea and creatinin were controlled daily before starting parenteral nutrition and 6 hours later. Plasma concentrations of immunoglobulin A and G were measured on day 1 and 3 of the infusion interval. At day 5 a xylose absorption test was performed in order to measure the intestinal capacity to absorb carbohydrates.

In group PEN all 10 dogs survived, 2 of the 9 dogs of group PN died. The parenteral infusions were tolerated without clinical signs of distress. Early enteral feeding was tolerated by most dogs, but vomiting was observed mainly on the first day of application. Haematology and clinical chemistry showed anaemia, hyperfibrinogenaemia, hypoproteinaemia, hypoalbuminaemia, acidosis, hyperglycaemia and low serum potassium und sodium levels. In few cases bilirubinaemia, elevated concentrations of the alkaline phosphatase and azotaemia appeared. Immunoglobulin A and G plasma concentrations were low in all patients compared to aged matched controls. The absorption of xylose was decreased in both groups compared to healthy controls, when tested on the fifth day of the treatment. There was no obvious influence of early enteral nutrition compared to parenteral nutrition alone.

In conclusion, patients suffering from canine parvovirosis tolerate parenteral nutrition with comparably short infusion intervals of 10 hours. Early enteral nutrition with hydrolysed enteral liquid diet did not show clear advantages compared to parenteral nutrition, but small number of patients requires more extensive clinical work up.

Effects of dietary antioxidant supplementation before and after oral acetaminophen challenge in cats

A. S. Hill 1 , S. L. O’Neill 2 ,M. M.Christopher 2 ,Q. R. Rogers 1

1 Dept. of Molecular Biosci,
2 Dept. of Path., Micro., and Immuol., Univ. Calif., Davis, CA

Since lipoic acid (LA), vitamin E (E), and cysteine (cys) are used to treat or prevent oxidative damage in diabetic polyneuropathy and acute hepatocellular damage in humans, antioxidants could benefit the nutritional management of similar diseases in cats. This study investigates the effects of these antioxidants on markers of oxidant damage and immune activity in cats before and after a challenge with oral acetaminophen (Ac).

Twenty-four intact adult cats were divided into 4 groups (3 male and 3 female per group, 3 of same sex per cage) and housed in a controlled environment. For 25 weeks, group A was fed a basal dry diet and groups B, C, and D received this diet supplemented with, respectively, E (2 g/kg DM) + cys (9 g/kg DM), LA (150 mg/kg DM), or all 3 antioxidants. Cats were fed daily, weighed twice weekly, and had venous blood drawn every 5 weeks. Assays done were: CBC, serum chemistry analysis, lymphocyte blastogenesis, malondialdehyde (MDA), protein carbonyl (PC), 8-OH d-guanosine (8OH-dG), reduced glutathione (GSH), free amino acids, LA and dihydrolipoic acid (DHLA). At 15 weeks, all cats received one 90 mg/kg dose of oral Ac. Clinical effects were observed and methemoglobin (MetHgb) concentrations measured before and after dosing.

Health, weight, CBC and serum chemistry measures remained normal throughout the study. No notable differences arose between groups for any oxidant marker before Ac challenge except that lymphocyte blastogenesis increased significantly at wk 5 for groups C and D. For all groups, MetHgb increased significantly within 4 hours of dosing with Ac: C > D > A and B, and returned to baseline by 24 hours. Clinically, cats showed mild or no facial edema and cyanosis, which both resolved by 24 hours. Day 1 after Ac dosing, group C cats had significantly less GSH and greater 8OH-dG than controls, while group B cats had the lowest increase in PC. These measures reached baseline by the next sampling point. Plasma LA in C and D cats plateaued by wk 10, while DHLA peaked once at wk 10.

LA, E, and cys, fed alone or in combination, produced no consistent changes in markers of oxidant damage or immune activity. After Ac dosing, LA supplementation resulted in the greatest MetHgb increase, while E + cys exerted a protective effect from LA.

LA does not act as an antioxidant in cats at 150 mg/kg DM, but E + cys may provide some beneficial effects.

The effect of trial length on canine fecal microflora response to chicory ingestion

G.L. Czarnecki-Maulden, A.R. Patil

Nestle Purina Product Technology Center, St Joseph, Missouri, USA

Consumption of chicory, a rich source of the soluble fiber inulin, results in increased fecal bifidobacteria in dogs (Czarnecki-Maulden and Russell, 2000). Bifidobacteria are beneficial bacteria that help improve the intestinal environment. The length of time required for dietary changes to cause a change in fecal microflora has not previously been published. Therefore, a study was conducted to determine optimal trial length for dog fecal microflora trials. Eight Beagle dogs (4 males, 4 females) from the Nestle Purina kennel were used in the trial. Dogs ranged in age from 6 to 14 years of age. All dogs were fed a nutritionally complete extruded dry diet that did not contain chicory during the initial 4 weeks of the trial (Phase 1). This phase served as a washout to normalize fecal microflora levels. Fecal quality scoring, digestibility, and fecal microflora analysis were done for baseline comparison. All dogs were then fed the same diet containing 2% chicory for 4 weeks (Phase 2). Fecal scoring and digestibility were done on days 8-13 of each phase. Fecal samples were collected weekly for microflora analysis. Fecal microflora analysis was done by differential plating on selective media. Fecal moisture was significantly higher when the dogs were fed 2% chicory. However, this slight increase in fecal moisture did not result in decreased fecal consistency. Fecal quality was excellent in all dogs. Likewise, fecal quantity and frequency of defecation were not affected by chicory ingestion. Dry matter digestibility was significantly higher when dogs consumed chicory. This was reflected in a slight but non-significant increase in nitrogen digestibility. Fecal bifidobacteria levels were stable throughout the control phase. Fecal bifidobacteria were significantly higher than the control on days 14, 21 and 28 of chicory consumption. The average response to chicory ingestion increased linearly between days 7 and 21 (r 2 = 0.958, y = 0.326 x + 0.105). Thus, while chicory consumption resulted in a significant increase in fecal bifidobacteria by day 14, the average response was greater on day 21. An increase or decrease in a bacterial population of 0.75 log cfu/g feces is typically considered by microbiologists to be physiologically significant. We therefore considered a 0.75 log increase in bifidobacteria (vs control phase) to represent a significant response to chicory ingestion. Based on this criterion, fecal bifidobacteria increased within 7 days of chicory ingestion in some dogs. Other dogs took 21 days to respond. The average response was slightly over 1 log (10 fold). However, bifidobacteria increased as much as 2 logs in some dogs. The variability in response could not be correlated with age or previous dietary history. In conclusion, chicory ingestion resulted in a significant increase in fecal bifidobacteria and digestibility. Soluble fibers such as chicory should be fed to dogs for at least 21 days in order to determine potential effects on fecal microflora.

Czarnecki-Maulden G.L. and T.J. Russell. 2000. FASEB J 14(4):A488.

Influence of organic feeding and housing on “health” parameters in organic pig fattening

S. Millet*, M. Hesta*, E. Cox°, E. Ongenae # , S. De Smet # , G.P.J. Janssens*

*Laboratory of Animal Nutrition, Ghent University, Heidestraat 19, B-9820 Merelbeke; ° Department of Virology, Parasitology and Immunology, Ghent University, Salisburylaan 133, B-9820 Merelbeke # Department of Animal Production, Ghent University, Proefhoevestraat 10, B-9090 Melle

Environment, production of safe feeds and animal welfare are major points of concern in organic production systems. Interest in organic production is growing over the last years. However, organic agriculture makes only a small percentage of agriculture and scientific knowledge on this production form is limited. The influence of housing and feeding type, either an organic or a conventional one, on set of “welfare” parameters was monitored in the present study.

Material and methods
A group of 32 pigs grown in an organic way and housed in an organic stable was compared to a group of 32 conventionally grown pigs that were housed in a conventional stable. In each stable 8 groups of 4 pigs were formed (each time 2 barrows and 2 gilts), equally divided over two diets, either an organic or a conventional one, thus implying 4 replicates per diet and housing combination. The pigs were injected with bovine thyroglobuline at onset and three weeks later to obtain specific immune response. Serum samples were taken at onset, at 3, 6, 9 weeks after onset and in the slaughterhouse. Specific antibodies titers against bovine thyroglobuline were measured in this serum samples. In the slaughterhouse, lactate level was measured on whole blood with a lactate analyzer (accusport; Boeringer Mannheim, Castle Hill, Australia). Cortisol level at slaughter was measured in plasma of blood samples taken in the slaughterhouse.

There was no clear effect of feed on the measured parameters. The organic housed pigs showed a more rapid response on the bovine thyroglobuline injection than the conventional ones. The lactate level of the organic housed pigs mounted to a significantly higher amount in the pigs out of the conventional stable than those grown in the organic stable. The cortisol level at slaughter was not influenced by housing type.

Influences of an organic feed on “health” characteristics could not be concluded out f the findings of the present study. The difference in immune response can be due to the housing type itself but also to the difference in breeding. As housing type did not influence the cortisol level at slaughter, the higher lactate level in the conventional pigs will probably be due to a ’training’ effect rather than to a stress effect. This study was supported by the Belgian Ministry of Small Enterprises and Agriculture.

Effects of lactulose as feed additive on chyme composition and intestinal microflora of weaned piglets

R. Tabeling 1 , O. Stuke 1 , S. Bollmann 2 , G. Amtsberg 2 , J. Kamphues 1

1 Institute of Animal Nutrition, School of Veterinary Medicine Hannover
2 Institute of Microbiology and Infectious Diseases, School of Veterinary Medicine Hannover

Due to its highly fermentable character lactulose is used by intestinal microflora. Effects of microbial lactulose fermentation in the large intestine proved from studies for human therapeutic and preventive use are laxation and reduced ammonia absorption. Also growth and increase of bifidobacteria and lactobacilli, and reduction of clostrides, E. coli and salmonella in intestine are described effects. In this study effects of lactulose in the diet of weaned piglets on their chyme composition and intestinal microflora were investigated.

10 piglets (age 21-28 days, Ø 7.35 kg BW) were offered a nonpelleted starter diet (per kg DM: 15.2 MJ ME, 170 g crude protein, 33 g crude fiber) ad libitum. The experimental diet (lac.) contained 5 % of a lactulose preparation (25.1 g lactulose /kg diet) in exchange for corn starch (con.). Feed intake, dry matter content and pH in faeces were determined daily. 11-15 days post weaning piglets were sacrificed 6 h ppr. (feed removed 2 h before killing). The digestive tract was divided into stomach, small intestine (part 1-3), caecum, colon ascendens and rectum. Analyses made in chyme of different digestive parts were: fresh matter and dry matter content; pH-value; concentration of lactulose, short chain fatty acids, l-lactate, ammonia, and lipopolysaccharides and counts of aerobes and anaerobes, E. coli, enterococci/streptococci, Gram negative anaerobic bacteria, lactobacilli and Clostridium perfringens.

Similar values were observed for feed intake, dry matter content and pH of aeces and intestinal chyme. The lactulose content was higher in ileal chyme compared to stomach. In caecal and colonic chyme lactulose was not detectable (n.d.). Ammonia concentration in the 1 th part of small intestine (mmol/l FM con. 6.15 ± 1.63; lac. 3.37 ± 0.35) and caecum (mmol/l FM con. 13.5 ± 4.54; lac. 5.90 ± 1.66) was markedly reduced when lactulose was added to the diet. The amount and pattern of short chain fatty acids and the l-lactate content was not influenced in intestinal chyme estimated from stomach, 3 rd part of small intestine and colon. The content of lipopolysaccharides showed a distinct increase in the chyme of colon ascendens. Counts of E. coli tended to be lower in small intestine 3 and were markedly reduced in colon ascendens, whereas other counts of bacteria were unaffected. lactulose (g/kg DM) pH-value NH3 (mmol/l FM) LPS (mg/g FM) part of con. lac. con. lac. con. Lac. con. lac. intestine 8 ±s 8 ±s 8 ±s 8 ±s 8 ±s 8 ±s 8 ±s stomach 5.98 5.96 1.67 0.39 1.82 0.47 5.04 1.68 3.48 0.92 1.16 1.17 1.30 1.08 small int. 3 n.d. 25.5 16.8 6.30 0.39 6.66 .39 5.14 2.23 3.58 1.40 7.95 7.14 2.94 1.76 colon asc. n.d. 5.93 0.42 5.78 0.30 18.9 6.69 11.0 5.64 202 a 108 365 b 110

Lactulose was digested almost completely in the small intestinal tract, and did not cause a laxative effect in weaned piglets. Although lactulose in large intestine was not dectectable any more the intestinal microbial ecosystem was influenced in reduction of E. coli counts in colon but lactobacilli and enterococci/streptococci were not favoured markedly. Also the capacity for fixation of ammonia was observed in several parts of intestine when lactulose was added.