CALF_News_April_May_2018

20 CALF News • February | March 2018 • www.calfnews.net Q: What are the negative impacts of extensive stress on cattle? Chris Hagedorn: To best explain this, first think about yourself and how stress impacts your body. Stress can often lead to elevated blood pressure and increased respiratory rate, affecting circulatory and respiratory systems. In addition, high levels of stress hormones can weaken your body’s immune system, making you more susceptible to illness. The same is true for cattle. Animal nutrition studies performed at universities like Iowa State University and Arizona State University, among others, have found that in cattle, stress compromises the gut lining by disrupting the absorption of nutrients and increasing susceptibility to nutritional stressors. For example, any foreign material such as toxins, bacteria, viruses or partially digested material can pass into the blood stream, initiating an immune response. Think about the gut lining like a fence between your neighbor’s herd bulls and your first-calf heifers. If the fence is properly maintained, no problem. If it’s poorly maintained, you may be in for a challenging calving season. For heifers, extensive stress has also been shown to alter reproductive hormone levels, leading to breeding issues like depressed estrous cycles and/or early embryonic death. Q: Do you consider all stress to be bad? Hagedorn: By no means is all stress bad. For example, vac- cinations and exercise are both forms of positive stress. Again, we’ll use the human body as an example. Vaccines introduce foreign material into the body in order to generate an immune response. Side effects of vaccines, like a slight fever, put stress on the body’s immune system, but in doing so, prepare it to fight off future illnesses. Exercise is another great example. Exercising puts stress on our muscles, circulatory and respiratory systems, but in return, helps strengthen the cardiovascular system so that it works more efficiently. For animals, the goal is to identify each of the different stressors and understand both the positive and negative effects. Q: Is it realistic to try to eliminate all sources of stress? Brian Fieser: Absolutely not. Going back to what Chris alluded to earlier, the goal is to understand the impact stress has on an animal. Once we identify if the stress response is positive or negative, we can implement beneficial management strategies. This is where nutrition plays a key role. We have all heard that an ounce of prevention is worth a pound of cure. Nutri- tion is proactive. By providing supplemental nutrients that complement the diet, and enhancing the diet with feed addi- tives such as yeast, botanicals and extracts, we enhance the animal’s comfort level and ability to cope with stress. If the animal is comfortable, performance should move in a favorable direction. Q: Nutritionally, what are most impactful ways to help cattle cope with stress? Dr. Fieser: Nutrition is the first opportunity to help an animal cope with stress. Any time an animal experiences stress, the body spends energy (in combination with other nutrients) to alleviate that negative impact. As nutritional components divert to the immediate need of combating stress, nutrient stores are depleted and potentially inhibit production (i.e. animal growth and/or reproduction). By including supple- ments that complement existing feed resources prior to a stress event, we are able to provide the animal with nutrients that can then be stored in the body. This enables the animal’s physiol- ogy to respond quickly, minimizing any negative consequences of a stress event. ADM customer Bob Fox shares a photo of his herd grazing on pasture during the summer months in Holton, Kan. His cattle were fed RumeNext®-B as a component of their supplementation. A 2013 study conducted by experts at Ohio State University reported that the impact of heat stress on U.S. livestock producers is estimated to exceed $1 billion annually. These losses impact all segments, from seedstock to cow-calf and feedlot.While it’s unrealistic to believe all sources of stress can be eliminated, companies like Archer Daniels Midland Company (ADM) are developing proactive nutri- tional strategies and incorporating bioactive feed components to help cattle cope with symptoms of stress and perform to their full potential. ADMAnimal Nutrition™ experts Brian Fieser, Ph.D., beef nutritionist, and Chris Hagedorn, ruminant product manager, offer insight on the impact of heat stress and strategies for year-round mitigation. Heat Stress ADM Discussion on