Experimental studies on effects of diet on Lawsonia intracellularis infections in fattening boars in a natural infection model

Abstract

BackgroundLawsonia intracellularis is one of the most economically important pathogens in swine production. This study tested the hypothesis that the composition of diets for pigs has an impact on the excretion of L. intracellularis in a natural infection model.ResultsFifty boars (~ 90 kg BW) from a SPF-farm with a strict hygiene and management regime for reducing the spread of an L. intracellularis infection up to the beginning of the final fattening period were transported, regrouped and randomly allotted to groups of five animals each at the research facility. After a 1-week acclimatisation period groups were fed one of five diets 4 weeks before slaughter. These were either a finely ground pelleted diet (FP) or a coarsely ground meal diet (CM), both consisting of wheat (40.0%), barley (39.3%), soybean meal (16.0%), soybean oil (2.0%) and minor components. In the other meal diets parts of wheat, barley and soybean meal were substituted either with 22% cracked corn (CORN), 16.9% dried whey (WHEY) or 30% raw potato starch (RPS). The animals had a comparable serological status in a blocking-ELISA immediately before the start and at the end of the feeding experiment. Values increased significantly during the trial. In all subgroups (FP/CM/CORN/WHEY/RPS), shedding was detected in week 0 (genome equivalents = GE; log10 GE L. intracellularis/g faeces: 2.46 ± 2.64/3.58 ± 2.54/3.43 ± 2.37/2.30 ± 3.16/2.58 ± 2.73). The average number of L. intracellularis microbes in faeces during the trial period did not differ between the groups (log10 GE L. intracellularis/g faeces: 3.40 ± 1.53/3.01 ± 1.41/3.80 ± 1.71/3.98 ± 2.20/4.08 ± 2.13). In animals fed the WHEY-diet, significantly lower counts of L. intracellularis were found in the caecal content. The acetate content in the caecum was negatively correlated with the serological results at the end of the trial (r = − 0.36; P = 0.010). Butyrate concentrations in the caecal content were negatively correlated with the number of L. intracellularis in the caecum (r = − 0.32; P = 0.023).ConclusionTherefore, this study provides preliminary evidence that there might be specific dietary effects on the course of a L. intracellularis infection.

The role of lactose in weanling pig nutrition: a literature and meta-analysis review

“…This indicates that lactose was not digested by the fattening pig, rather it was fermented. Furthermore, the increased lactic acid coincided with a reduction in Lawsonia intracellularis, which is a pathogen that can cause intestinal damage and disease in swine [38]. This study, therefore, further demonstrates the potential prebiotic effect from lactose fermentation.…”

“…The adult pig, on the other hand, has limited lactase activity in the small intestine and, therefore, lactose may be a significant substrate for microbial fermentation in the small and large intestine. Pierce et al [38] reported that butyric acid concentration linearly increased and a ratio of acetic acid to propionic acid linearly decreased in the feces of growing-finishing pigs fed diets containing 0 up to 12% lactose. These results indicate that a certain amount of lactose entered the hindgut and was fermented causing shifts in microbial metabolite production.…”

Performance, Fermentation Characteristics and Composition of the Microbiome in the Digest of Piglets Kept on a Feed With Humic Acid-Rich Peat

“…The concentrations of these acids were about 140–160 mM (29). Significantly higher concentrations of SCFA could also be measured in fattening boars when fed ad libitum (30). At 218.8 mmol/kg cecal content, the sum of acetate, propionate, and butyrate was considerably higher than in the piglets in the present study.…”

Lawsonia intracellularis: Revisiting the Disease Ecology and Control of This Fastidious Pathogen in Pigs

“…The authors of the above study believe that maternal feeding of scFOS may enhance the beneficial microbiota of the sows which are then transmitted to the piglets, where the microbes increase the production of short chain fatty acids in their gut ( 102 ). Another recent study has produced preliminary evidence that feed composition influences L. intracellularis infections in farmed pigs ( 103 ). Though few specific studies have investigated L. intracellularis control by using prebiotics, this approach appears promising and is mediated by the increase in beneficial microbes.…”