Maintaining the health of beef feedlot cattle is essential for optimal growth, feed efficiency, and productivity. While the focus often rests on the rumen, the hindgut plays a critical role in the digestive process and overall health of cattle. The hindgut includes the cecum, colon, and rectum, where fermentation of undigested feed occurs.

Recent evidence suggests that acidosis in beef cattle has an equally strong impact on the hindgut as compared to the rumen^1,2,3. The hindgut is more vulnerable to acidosis of beef cattle for a number of reasons (see Figure 1):

• Structural differences
• Differences in buffering capacity:
  • Lack of saliva and protozoa in the hindgut
  • Presence of mucus layer in the hindgut
• Differences in immune function
  • The immune system of beef cattle is attenuated in the rumen vs. robust in the hindgut

Signs that are typically attributed to rumen acidosis of beef cattle, like for example frothy and loose faeces, are actually symptoms of hindgut acidosis in beef cattle⁴.

Hindgut acidosis of beef cattle occurs when there is rapid fermentation of carbohydrates in the hindgut. This excessive hindgut fermentation results in an accumulating of organic acids which in term reduces de pH within the hindgut (see Figure 2). Hindgut acidosis of beef cattle results in a shift of the microbiota population and causes damage of hindgut lining, resulting in a phenomenon called “leaky gut”^4,5.

The shift in microbiota population can cause dysbiosis. This imbalance in the microbial population can disrupt fermentation processes, leading to reduced nutrient absorption and digestive issues. The hindgut can now even become a breeding ground for pathogens like E. coli and Salmonella, leading to diseases that affect animal health and pose risks to food safety.

“Leaky gut” in beef cattle will result in systemic inflammation. If immune cells are activated, they use glucose, which would normally be used for processes to support growth. Hindgut acidosis therefore results in a reduction of feed efficiency. Avoiding hindgut acidosis in beef cattle is therefore essential for efficient production of meat.

Stressful conditions in feedlots, such as high stocking densities and abrupt dietary changes, can negatively impact hindgut health of feedlot cattle.

Prevention strategies for hindgut acidosis in beef cattle are very similar to those that are employed to prevent sub-acute rumen acidosis (SARA) in beef cattle.

• Balanced diets: feeding balanced diets with appropriate fibre content helps maintain a healthy fermentation process in the hindgut. Including forages and avoiding excessive grains can reduce the risk of hindgut acidosis of beef cattle significantly.

• Gradual dietary changes: introducing new feeds gradually allows the hindgut microbiome of beef cattle to adapt, reducing the risk of dysbiosis and acidosis.

• Feed management: Beef cattle need to be able to eat 12-14 meals per day. This means that feed should be available 24 hours per day, and each animal should have unlimited access to the feeding fence.

• Stress reduction: implementing stress reduction techniques, such as proper handling and providing adequate space, helps maintain overall gut health of beef cattle. Feedlot receiving cattle are particularly vulnerable during the period immediately after arrival in the feedlot. Transport and mixing of receiving beef cattle from different sources causes a lot of stress. On top of this, receiving cattle are facing a dietary change and as they usually come from different farms, they carry different pathogens with them that will start circulating within the newly formed group of animals.

• Hygiene and sanitation: maintaining clean feed and water sources, as well as proper manure management of beef cattle manure minimizes the risk of pathogenic contamination in the hindgut.

Nutritional solutions are particularly well positioned to support gut health of beef cattle, due to the direct contact of dietary supplements with gastrointestinal tissues. In cattle, strategies in this direction have focused on rumen health. However, targeting the hindgut of beef cattle represents an opportunity for further improvement. The use of dietary compounds to improve large intestine health is well established in monogastric species. In cattle, a major limitation is the availability of rumen bypass technologies to specifically reach the hindgut with this type of interventions. There are however a number of dietary compounds that can be utilized to support gut health of beef cattle.

Probiotics for beef cattle are live microorganism that confer a health benefit for the host by positively influencing gastrointestinal ecology (e.g. limiting nutrient availability to pathogens, producing organic acids, etc.). The development of probiotics for ruminants is bound to practical constraints as microorganisms should survive manufacturing and storage. Thus, the utilization if this type of products is limited to rumen applications. An example is the use of live yeasts, which interact with microbial populations, ultimately improving digestibility and rumen function of beef cattle.

Prebiotics for beef cattle are feed ingredients that are non-digestible for the host. In contrast, they are fermented by the microflora, selectively stimulating the growth and function of beneficial bacteria. This group includes components of yeast cells like mannan-oligosaccharides, beta-glucans, fructo-oligosaccharides and inulin, among others. Prebiotics for beef cattle are particularly well suited to target the hindgut, as rumen bypass technologies can be applied to them without affecting their viability⁴. Selko Lactibute contains rumen protected gluconic acid. Delivering gluconic acid to the hindgut results in performance and health improvements of beef cattle^6,7 (see Table 1).

Zinc has shown beneficial effects on intestinal health in multiple species including ruminants. Its mechanism of action is not fully understood but likely includes upregulation of tight junction proteins between intestinal cells, enhancing epithelium repair and immune modulation^8,9,10,11. On the other hand, excessive supplementation of minerals represent an environmental concern due to excretion in manure and can have a negative impact on fibre digestibility. Alternative mineral sources, like Selko IntelliBond trace minerals might represent an opportunity to optimize the beneficial effects of zinc by reducing toxicity and improving availability, without increasing dietary doses¹².

Regular monitoring of beef cattle health and feed quality allows for early detection of hindgut issues. Adjusting management practices based on these observations can mitigate potential problems of receiving beef cattle in feedlots.

The hindgut plays a crucial role in the overall health and productivity of beef feedlot cattle. Addressing the major challenges to hindgut health through balanced diets, gradual feed changes, and appropriate supplements for beef cattle can prevent “leaky gut” as a result of acidosis, dysbiosis, and pathogen proliferation. Implementing effective prevention and mitigation strategies ensures that cattle maintain optimal health, leading to better growth rates, feed efficiency, and overall performance in feedlot settings. By prioritizing hindgut health, beef producers can enhance the welfare of their cattle and achieve higher productivity, ultimately benefiting the entire beef production industry.