Haemorrhagic bowel syndrome (HBS) is globally recognized as a sporadic cause of death in finishing pigs. Mortality rates have occasionally been reported to be as high as 7%. Affected pigs do not normally exhibit any clinical signs before being found dead. The pigs are in good body condition and the abdomen is often distended. The stomach is usually full of feed. The intestines are red and contain blood tinged fluid. Microscopically the affected intestinal tissue seems to be “oozing” blood from the capillaries. These findings are very similar to “twisted gut” but no twist can be detected. The final diagnosis is often made after eliminating all other infectious agents associated with bloody diarrhea. These Swiss researchers wanted to identify predictors or causal components for the appearance of HBS using case farms (mortality rate caused by HBS ≥ 1.5%) in comparison with control farms (mortality rate caused by HBS ≤ 0.25%). They focused on feed ingredients, feed quality and size, and gastrointestinal pathogens.
The researchers found the following:
- The inclusion of sugar beet as a feed component in liquid feeding systems was found to be associated (p = 0.03) with farms identified as HBS cases. (sugar beet is highly fermentable in the intestine). (Possibly similar to what can sometimes be seen with inclusion of DDGs in North American finishing diets)
- In liquid feeding systems a higher percentage of small particles (< 2 mm) in the meal was associated with a higher risk of being an HBS case farm (p = 0.02), while no relevant association was detected for the use of pellets. (Fine grind feed provides greatly increased surface area for digestion and fermentation processes to work on)
- In dry feeding systems the number of total aerobes in dry matter samples collected at the first and last feed outlet tubes, was associated with a higher incidence of HBS (p = 0.03).
- Faecal sample analysis showed a difference (p < 0.05) in the prevalence of Brachyspira pilosicoli in the herd category (case vs. control herd).
Take Home Messages
- A common theory about HBS is that when a sudden increase in digestible / fermentable substrate enters the intestine there is an opportunity for bacteria such as Clostridium perfringens to “bloom” (rapid increase in numbers). This bloom may be associated with production of toxins that affect the intestinal wall. This hypothesis has not been proven scientifically but it seems to make sense when you consider that HBS is often associated with engorgement, fine grind feed, pelleted feed (also fine grind) , whey and other carbohydrate rich feeds.
- It is important to maintain consistency of feed intakes such that overeating does not occur. Overeating or engorgement usually occurs after feed intake is limited by out of feed events, feeder management issues or feed quality issues such as mycotoxins that temporarily suppress appetite. Engorgement will suddenly allow for a lot of substrate available for digestion / fermentation to be available in the lumen of the intestine.
- The researchers commented that Brachyspira pilisicoli detection was associated with HBS in this study but the study was not designed to definitively demonstrate that B. pilisicoli was linked to HBS in individual cases. It may be that the factors associated with increasing HBS were also increasing the prevalence of B. pilisicoli in high HBS herds.
Reference: Fabienne Holenweger , Peter Spring , Negar Khayatzadeh , Andreas Hofer , Gertraud Schüpbach-Regula , Alexander Grahofer Case-control study on associations of hemorrhagic bowel syndrome in swine with feed characteristics and intestinal pathogens Porcine Health Manag . 2024 Oct 19;10(1):43. doi: 10.1186/s40813-024-00397-3.
