Influence of infection with Brachyspira hyodysenteriae on clinical expression, growth performance, and digestibility in growing pigs fed diets varying in type and level of fiber

Abstract

Research on effects of different fiber types and levels on infection with Brachyspira hyodysenteriae on growth performance and nutrients digestibility in pigs is scarce. The objective of the current study was to investigate the effects of infection with B. hyodysenteriae when feeding diets varying in soluble and insoluble dietary fiber (DF) on the expression of swine dysentery, growth performance and digestibility of organic matter (OM) nutrients. A total of 96 growing pigs (26.9 ± 2.5kg) were used for the experiment and divided into 6 blocks. The growing pigs were fed one of four diets for 12 weeks: Low fiber (LF), high fiber (HF), high soluble fiber (HS) and high insoluble fiber (HI). After two weeks, half of the pigs were inoculated with B. hyodysenteriae. Half of the pigs in each group were euthanized at week 6 for measurement of the apparent digestibility at ileum, cecum, colon and total tract. The remaining pigs were maintained to observe and analyze clinical expression of fecal score and excretion of B. hyodysenteriae, growth performance and total tract digestibility up to 12 weeks. In the current study, the experimental diets did not influence the expression of infection in the pigs. The body weight (BW) and average daily gain (ADG) were in line with the results of clinical expression from week 4 to 6. However, the ADG of the infected pigs started to recover from week 6 (P < 0.05), and then recovered from week 8 to 12 (P < 0.05). The infection with B. hyodysenteriae did not impair apparent ileal digestibility (AID; P > 0.05), whereas the apparent digestibility of OM, total non-starch polysaccharide (NSP), non-cellulosic polysaccharide (NCP) and cellulose in the cecum of the infected pigs was higher than non-infected pigs (P < 0.05). The apparent colonic digestibility of ash and nitrogen was higher in non-infected pigs than in infected pigs (P < 0.05). The pigs fed the LF diet had a higher digestibility in all segment of the intestinal tract, whereas the HS diet had the lowest AID but higher or similar to the LF diet in the cecum, colon and the total tract (P < 0.05). The pigs fed the HF and HI diets, with high proportion of insoluble fiber, had a lower digestibility in the hindgut than the other two diets (P < 0.05). In conclusion, the infection with B. hyodysenteriae negatively influenced clinical signs of swine dysentery and growth performance but did not impair AID, and neither soluble or insoluble DF influenced the expression of the infection.

Improving the consistency of experimental swine dysentery inoculation strategies

“…Examples of previous published research help to highlight this point and how challenging Brachyspira inoculation can be. For instance, intragastric inoculation of 40 mL of a strongly hemolytic strain of B. hyodysenteriae (strain B204) broth containing 1 × 10 8 colony forming units (CFU)/mL for 3 days (1.2 × 10 10 CFU total dose) resulted in 55.5% (5/9) SD incidence (Trial 2 of [ 20 ]), whereas intragastric inoculation of 50 mL (1 × 10 9 CFU/mL) of a Danish field isolate of B. hyodysenteriae broth following a similar methodology (1.5 × 10 11 CFU total dose) resulted in only 20.8% (10/48) incidence of SD by another laboratory [ 21 ]. This variability in incidence highlights the need to establish minimum infective doses for the Brachyspira species/strains and experimental conditions specific to each laboratory, and the importance of full disclosing all methodological details in studies to help decipher differences among B. hyodysenteriae strains, environmental factors, and host related factors like genetics and microbiota.…”

“…Recent studies evaluating different levels of soluble or insoluble dietary fiber have also showed variable results. On one hand, fiber concentration (high vs. low) and type (soluble vs. insoluble) did not effect fecal score in a Danish study, however, this result should be taken with caution due to the low incidence of MMHD across all groups [ 21 ]. On the other hand, several USA studies indicate high concentration of insoluble fiber in the diet promotes expression of SD.…”

“…The most common inoculation technique to induce SD through experimental challenge is intragastric inoculation of B. hyodysenteriae propagated in solid or liquid media for one or multiple consecutive days. While there are minor laboratory specific modifications, this technique has shown an incidence of MMHD ranging from 20 to 100% [ 11 , 17 – 21 ]. In our lab, intragastric inoculation is the gold standard technique to induce SD in challenge experiments.…”

The Effect of Reduced Crude Protein on Growth Performance, Nutrient Digestibility, and Meat Quality in Weaning to Finishing Pigs

“…In the growing phase, the ADG was decreased in pigs fed the LP diet based on the protein recommendation of the NRC (2012), except almost complete compensatory growth found in finishing pigs. Several factors, including feed restriction, early age growth retardation, and intestinal diseases, can potentially influence compensatory growth [ 30 , 31 , 32 ]. Rao, et al [ 33 ] reported that lysine-restricted feeding in the early phase of finishing pigs decreases growth performance, but recovery was found, showing the magnitude of compensatory growth in the late phase.…”

Acute infection with Brachyspira hyodysenteriae affects mucin expression, glycosylation, and fecal MUC5AC

“…In general, a higher percentage of fermentable fiber may be beneficial to pigs for those diets that are based on less highly digestible ingredients (barley, triticale) (Hansen et al, 2010;Hansen et al, 2011), and pigs fed a poorly fermentable fiber diet with high insoluble fibers such as the biofuel coproducts like distillers dried grain with soluble (DDGS) present with a quicker onset of SD and higher disease incidence when challenged with strongly b-hemolytic Brachyspira species (Wilberts et al, 2014a). Conversely, a recent study suggested that expression of SD was likely not strongly associated with fiber type (Lee et al, 2022). The discrepancy in findings among these studies is likely due to the differences in experimental designs and the specific source of dietary fiber.…”