Hemorrhagic Bowel Syndrome (HBS) in Dairy Cattle

Posted by Dr. Sara Barber on March 01 2007 00:00

Nutritional Aspects of the Dairy to Monitor when Experiencing HBS

1. Monitor for TMR mixing inconsistencies using the Penn State Particle Separator on total mixed rations and forages. Particle separation measurements should be taken of the forages going into the TMR and then again after the TMR is mixed. Additionally, refusals should be analyzed for course particles to determine if sorting is occurring. If sorting is occurring or course particles are lacking from TMR mixing, then this would contribute to the likelihood of cows to develop HBS.
2. Note any major feeding changes occurred in the past 1-2 years. Energy densities in rations should be compared to determine if they are higher now than in prior years. Observe if non-fiber carbohydrate (NFC) levels are approaching or greater than 40% in the ration. Observe if herds are transitioning from dry hay forages to an ensiled forage system.
3. Monitor for how long the bunk is empty. Is this time consistent from day to day? Are cows fed at the same time everyday? Is feed pushed up so it is always available?
4. Evaluate the consistency of the manure and if there is grain coming through into the manure.
5. Are dry matter intakes higher than in the past? Higher production cows will have higher dry matter intakes, and if rumen problems are an issue, it’s easier for these cows to develop HBS than ones with lower dry matter intake.
6. Examine the TMR for nutrient composition using wet chemistry analysis to assure the ration formulated on the computer is the same as what’s being offered to the cow.
7. Has there been other herd problems such as increased number of sole abscesses? This would suggest that rumen acidosis could be contributing to the HBS.
8. Monitor the herd and individual cow buttefat tests and determine if excessive fat:protein inversions exist. A dairy herd with more than 10% fat:protein inversions may have sub-acute ruminal acidosis which could predispose to HBS.
9. Monitor blood calcium levels at calving. Cows freshening with slightly lower than average calcium can exhibit hypo-motility of the rumen and preclude HBS. In addition, too much potassium in the blood could tie up magnesium resulting is a syndrome similar to not having enough calcium resulting in rumen stasis. Transition cow management should be monitored if low calcium or high potassium blood levels exist.
10. Minimizing the amount of soil coming in with the crop to lessen numbers of pathogenic spores. Avoid over-application of manure and correctly time slurry applications. Follow good harvest management practices and use a research proven forage additive to ensure optimum fermentation of the crop.
11. Analyze ensiled forages for fermentation. Several commercial laboratories now offer fermentation-testing services that can examine silages of pH, silage acid composition, and ammonia nitrogen levels to determine if poor fermentation has predisposed the silage to Clostridial fermentation.