Source: PennState Extension
What is gut health?
Gut health refers to how well nutrients from feed are absorbed and how well pathogens are contained within the digestive tract. Every portion of the digestive tract needs to have a secured barrier to keep microbes inside the tract. A strong barrier can be referred to as good gut health. When the barrier is weak, microbes or pathogens can exit the digestive tract and enter into the body/blood stream, which can cause numerous diseases3.
How is the digestive tract barrier weakened?
Animal stress negatively affects the gut barrier, allowing pathogens to invade. Some periods of stress in cattle’s lives are weaning2, 12, transportation18, feed restriction20, 19, acidosis4, 7, 11, and excess heat1, 15, 16. This period of stress compromises gut health and can result in some other diseases, including laminitis14, 17, liver abscesses17, 13, acute interstitial pneumonia10, and inflammation9 (Figure 1). If your animals have ever experienced these diseases, then your animals may have experienced compromised gut health. Maintaining proper gut health can help prevent these diseases and their resulting economic losses.
Is gut health only related to the rumen?
Many know that maintaining rumen health is a key for production success. The rumen, or the fermentation vat, is used for feed digestion and provides energy to maintain the animal and production. However, there is more to cattle digestive tracts than just the rumen. The entire digestive tract from start to end needs to be in in tip-top shape to prevent pathogens in feed from escaping from the digestive tract. The small and large intestine has drawn the attention of some researchers to further the understanding of how stress affects gut health in these regions of the digestive tract. The intestinal tract has just one cell layer protecting the body from the intestinal contents, compared to the multiple layers of protection in the rumen. Therefore, the intestinal tract relies heavily on the immune system to protect it from invading pathogens, which uses energy that the animal would otherwise use for production and performance.
Digestive tract diseases, which can include, salmonella, cryptosporidium (crypto), and E. coli, can negatively affect the barrier to the digestive tract. Once damage occurs, a pathway for other bacteria, toxins, and pathogens is opened, causing the animal to be susceptible to diseases (Figure 1). For example, an animal that is under a crypto challenge potentially increases the number of pathogens that can pass through the digestive tract barrier6, 8, which opens the door to other diseases that can manifest in other parts of body. Proper prevention of digestive tract diseases, in combination with proper feeding strategies can improve animal health beyond the gut.
How do you prevent the gut barrier from being weakened?
Mitigation strategies include minimizing periods of stress. Ensure that proper handling procedures are used when handling cattle. Beef quality assurance (BQA) goes over methods to properly handle animals to minimize stress. If you have not been BQA certified, contact your local extension office about the next available training. In addition, do not let animals go for extended periods with no feed. A short-term feed restriction can have negative effects on gut health, and thus allow pathogens to escape and cause disease. Acidosis occurs when cattle are fed high-grain or rapidly fermented diets, which cause a pH drop in the digestive tract. The drop in pH can cause the gut barrier to weaken, so proper feed transitioning will help maintain gut health. A good rule of thumb is to keep animals comfortable. Quick changes or extreme heat/cold could alter the gut health status, causing disease and economic losses.
How is gut health related to respiratory disease?
The diseases discussed can be related to the respiratory tract. Researchers have shown that the body communicates through lymphatic tissue. The lymphatic system is part of the immune system, and it helps stop invading pathogens from causing disease. Fluid within the lymphatic system can be used as a pathway for pathogens to move from one location in the body to another. If a pathogen is not stopped in the lymphatic system these pathogens can reside in other locations in the body. More specifically, lymphatic tissue in the gut can communicate to lymphatic tissue in the lungs5 through the lymphatic pathway. Therefore, pathogens from the gut can reach the lungs via the lymphatic system and cause respiratory disease (Figure 1).
Gut health is a key component to a successful operation. Stress can weaken the gut barrier. If pathogens pass through the gut barrier, these pathogens can become opportunistic and cause numerous diseases at the cost of the operation. By maintaining ideal gut health, animals should experience fewer immune challenges, which allows more animals to grow efficiently.
1Baumgard, L. H., and R. P. Rhoads. 2013. Effects of Heat Stress on Postabsorptive Metabolism and Energetics. 1(1):311-337.
2Boudry, G. l., V. Péron, I. Le Huërou-Luron, J. P. Lallès, and B. Sève. 2004. Weaning Induces Both Transient and Long-Lasting Modifications of Absorptive, Secretory, and Barrier Properties of Piglet Intestine. The Journal of Nutrition 134(9):2256-2262. doi: 10.1093/jn/134.9.2256
3Eckel, E. F., and B. N. Ametaj. 2016. Invited review: Role of bacterial endotoxins in the etiopathogenesis of periparturient diseases of transition dairy cows. Journal of dairy science 99(8):5967-5990.
4Emmanuel, D. G. V., K. L. Madsen, T. A. Churchill, S. M. Dunn, and B. N. Ametaj. 2007. Acidosis and Lipopolysaccharide from Escherichia coli B:055 Cause Hyperpermeability of Rumen and Colon Tissues. Journal of Dairy Science 90(12):5552-5557.
5He, Y., Q. Wen, F. Yao, D. Xu, Y. Huang, and J. Wang. 2017. Gut–lung axis: The microbial contributions and clinical implications. Critical Reviews in Microbiology 43(1):81-95. doi: 10.1080/1040841X.2016.1176988
6Hunt, E., Q. Fu, M. U. Armstrong, D. K. Rennix, D. W. Webster, J. A. Galanko, W. Chen, E. M. Weaver, R. A. Argenzio, and J. M. Rhoads. 2002. Oral Bovine Serum Concentrate Improves Cryptosporidial Enteritis in Calves. Pediatric Research 51(3):370-376. doi: 10.1203/00006450-200203000-00017
7Khafipour, E., D. O. Krause, and J. C. Plaizier. 2009. A grain-based subacute ruminal acidosis challenge causes translocation of lipopolysaccharide and triggers inflammation. Journal of Dairy Science 92(3):1060-1070.
8Klein, P., T. Kleinová, Z. Volek, and J. Šimůnek. 2008. Effect of Cryptosporidium parvum infection on the absorptive capacity and paracellular permeability of the small intestine in neonatal calves. Veterinary Parasitology 152(1):53-59.
9Kvidera, S. K., E. A. Horst, M. Abuajamieh, E. J. Mayorga, M. V. S. Fernandez, and L. H. Baumgard. 2017.Glucose requirements of an activated immune system in lactating Holstein cows. Journal of Dairy Science 100(3):2360-2374.
10Loneragan, G. H., D. H. Gould, G. L. Mason, F. B. Garry, G. S. Yost, D. L. Lanza, D. G. Miles, B. W. Hoffman, and L. J. Mills. 2001. Association of 3-methyleneindolenine, a toxic metabolite of 3-methylindole, with acute interstitial pneumonia in feedlot cattle. American journal of veterinary research. 62(10):1525-1530. doi: 10.2460/ajvr.2001.62.1525
11Minuti, A., S. Ahmed, E. Trevisi, F. Piccioli-Cappelli, G. Bertoni, N. Jahan, and P. Bani. 2014. Experimental acute rumen acidosis in sheep: Consequences on clinical, rumen, and gastrointestinal permeability conditions and blood chemistry1. Journal of Animal Science 92(9):3966-3977. doi: 10.2527/jas.2014-7594
12Moeser, A. J., K. A. Ryan, P. K. Nighot, and A. T. Blikslager. 2007. Gastrointestinal dysfunction induced by early weaning is attenuated by delayed weaning and mast cell blockade in pigs. American Journal of Physiology-Gastrointestinal and Liver Physiology 293(2):G413-G421. doi: 10.1152/ajpgi.00304.2006
13Nagaraja, T. G., and M. M. Chengappa. 1998. Liver abscesses in feedlot cattle: a review. Journal of animal science. 76(1):287. doi: 10.2527/1998.761287x
14Nocek, J. E. 1997. Bovine Acidosis: Implications on Laminitis. Journal of Dairy Science 80(5):1005-1028.
15Pearce, S. C., V. Mani, R. L. Boddicker, J. S. Johnson, T. E. Weber, J. W. Ross, R. P. Rhoads, L. H. Baumgard, and N. K. Gabler. 2013a. Heat Stress Reduces Intestinal Barrier Integrity and Favors Intestinal Glucose Transport in Growing Pigs. PLOS ONE 8(8):e70215. doi: 10.1371/journal.pone.0070215
16Pearce, S. C., V. Mani, T. E. Weber, R. P. Rhoads, J. F. Patience, L. H. Baumgard, and N. K. Gabler. 2013b. Heat stress and reduced plane of nutrition decreases intestinal integrity and function in pigs1. Journal of Animal Science 91(11):5183-5193. doi: 10.2527/jas.2013-6759
17Vermunt, J. J. 1992. “Subclinical” laminitis in dairy cattle. New Zealand Veterinary Journal 40(4):133-138. doi: 10.1080/00480169.1992.35718
18Wan, C., P. Yin, X. Xu, M. Liu, S. He, S. Song, F. Liu, and J. Xu. 2014. Effect of simulated transport stress on the rat small intestine: A morphological and gene expression study. Research in Veterinary Science 96(2):355-364.
19Wood, K. M., S. I. Palmer, M. A. Steele, J. A. Metcalf, and G. B. Penner. 2015. The influence of age and weaning on permeability of the gastrointestinal tract in Holstein bull calves. Journal of Dairy Science 98(10):7226-7237.
20Zhang, S., R. I. Albornoz, J. R. Aschenbach, D. R. Barreda, and G. B. Penner. 2013. Short-term feed restriction impairs the absorptive function of the reticulo-rumen and total tract barrier function in beef cattle1. Journal of Animal Science 91(4):1685-1695. doi: 10.2527/jas.2012-5669