Successfully weaning and starting calves on feed can be a rewarding time of year for producers and sets the calf up for future performance. However, the most common time for a calf to contract bovine respiratory disease (BRD) is within the first four weeks postweaning. With BRD costing the beef industry over $1 billion dollars annually, prevention is key in reducing treatment costs and lost performance. The digestive tract contains approximately 70% of the immune system; therefore, maintaining a healthy gut should be at the top of the list when planning nutritional strategies for starting calves on feed and will help reduce economic losses associated with BRD.
When discussing the topic of gut health, we are referring to the animal’s ability to efficiently absorb and utilize nutrients and keep microbes and pathogens contained within the gut. If the lining or barrier of the digestive tract becomes weak, microbes and pathogens can escape and enter the body, causing numerous diseases, including BRD. Cattle stressors such as weaning, transportation, commingling, changes in diet and diet restriction have a negative impact on the gut lining and overall performance.
We know calves enter the post-weaning phase experiencing stress, so reducing the stressors that can be controlled is important for reducing the negative effects on gut health. Two stressors occur simultaneously in the first couple of weeks post-weaning. The first is the change in diet, going from a combination of mother’s milk, forage and/or creep feed to 100% full feed. The second is diet restriction, caused unintentionally by the calves pacing the fenceline looking for their mothers and most being unaccustomed to feedbunks. Providing familiar feed, such as long-stem grass hay, to tcalves for the first couple of days will aid in bunk breaking. Offering clean, fresh water is as important to health and performance as feed and will encourage feed intake. Additionally, offering low-moisture blocks in areas along the fenceline can provide needed vitamins and minerals and will stimulate feed and water intake.
There are many good articles and blogs providing tips for transitioning calves to full feed. The key point to remember is calves should be consuming 2.5% to 3% (100% dry matter basis) of their bodyweight within a couple of weeks. Once calves are on full feed, minimizing changes to the diet will aid in the proper adaptation of rumen microflora and overall gut health. Quickly and safely transitioning calves to full feed will help minimize digestive upsets, such as bloat, and negative effects on the gut.
Providing a vitamin and mineral supplement in the weaning/growing ration is crucial not only for gut health but for overall animal health and performance. Vitamins and minerals are necessary nutrients for microflora within the rumen, in addition to immune function and growth. Providing a source of chelated trace minerals to calves post-weaning can further improve immune function and performance through the growing phase and set the calf up for future production.
Natural feed additives, such as prebiotics and probiotics, are excellent options for including in the diets of newly weaned calves to improve gut health during stressful events. Prebiotics are defined as nondigestible food ingredients that have beneficial effects on an animal by selectively stimulating the growth and/or activity of bacteria within the digestive tract. Prebiotics provide “food” for the microbes that already exist within the digestive system. This helps maintain a healthy gut microbial ecosystem, leading to a healthy gut overall. Prebiotics such as mannan oligosaccharides (MOS) have been shown to reduce the risk of pathogenic bacteria from colonizing the gut and keeping them at manageable levels. Additionally, they prevent toxins from passing through the intestinal walls into the bloodstream. The increase in gut health observed with feeding prebiotics leads to improvements in performance and overall animal health, especially in stressed cattle.
Probiotics are live microorganisms (such as live yeast and bacteria) that have beneficial effects on health. Like prebiotics, probiotics can improve gut health by stimulating the development of a healthy microbial ecosystem, preventing pathogenic bacteria, such as clostridium, from colonizing the intestines, improving overall digestion and improving health. Commonly used species of bacteria to improve gut health and performance in newly weaned calves belong to the genera bacillus, lactobacillus, bifidobacterium and enterococcus. Live yeast cultures, such as Saccharomyces cerevisiae 1026, have also been added to diets to promote digestion and utilization of nutrients.
Prebiotics and probiotics work well when combined. When incorporating them into the diet, choose a product that has been proven to work in cattle and comes from a trusted manufacturer, and feed the product daily.
Getting newly weaned calves off to a good start is important for their future productivity. Including discussions around gut health as part of the nutritional strategies implemented in your feeding program can lead to increased performance, reduced treatment costs and more profitable production.
