Starting calves on feed can be one of the greatest challenges that feeders face. On arrival, calves are coping with multiple sources of stress occurring within a short amount of time, or compounded stress, which can lead to inflammation, depressed immunity, and reduced gut integrity, resulting in reduced feed intake and increased susceptibility to disease.
When trying to better understand the cause of morbidity and mortality in newly received calves, two scenarios can be considered: 1) whether the calf first got sick and then quit eating, or 2) if the calf first quit eating and then got sick. Sounds like the familiar chicken or the egg causality dilemma, right? Truth is, there are many physiological and metabolic processes that could argue either scenario relating to receiving calf feed intake and disease incidence. More importantly, preventative strategies and practices that collectively address health and nutrition, as well as proper management, are key in achieving a successful start.
Maintaining an active client-patient relationship with your veterinarian to develop an effective receiving health protocol is of utmost importance. Recommendations for which vaccines to use and proper procedures for pulls and treats can vary depending on time of year, origin of cattle, cattle type, and prevalence of some diseases in certain regions; thus, the importance to work with your veterinarian and reevaluate health protocols frequently.
When an animal is under stress, there is a change in endocrinal regulation that causes the release of cortisol, a stress hormone, altering the effectiveness of both the inflammatory and immune responses. An inflammatory response requires a variety of proteins and other molecules including antibodies to fight against infection, disease, pathogens, and/or toxins. Therefore, when a newly arriving calf has reduced intake, it is nutrient deficient, in a stressed state and being introduced to different pathogens in a new environment, the chances of sickness and death loss are high.
It’s fairly safe to say, that given the opportunity to implement effective preventative strategies to reduce morbidity is often preferred over dealing with a group of sick animals. Benefits of an adequate acclimation period have been researched, recommended and implemented to allow cattle time to rehydrate, nourish and rest in a holding pen prior to processing, to help newly received calves cope with the effects of compounded stress. More specifically, during transport, cattle are withheld from feed and water and unable to lay down to rest for an extended period of time. Proper receiving facilities and management practices which provide ample access to fresh clean water, long-stemmed good quality grass hay and a dry place to lie down for new arrivals have shown to provide improvements in cattle comfort and reduced morbidity and mortality.
Being prepared and having a plan for each set of cattle will lead to greater success. Be sure to consider incoming cattle weight, breed, sex, origin, risk of death loss or sickness, and time of year. Many producers classify their risk level and apply proper health protocols to ensure appropriate strategies are in place.
Getting the animals on feed is a vital step in ensuring adequate nutrient supply for optimal immune response. Proper function of all physiological processes in the body, including the immune system, are dependent on the supply and availability of macro- and micronutrients.
For instance, many physiological processes in the body are energy and protein intensive to activate and maintain a response. Energy is required to perform most of the metabolic processes in the body, which can negatively affect growth, thermoregulation and immune function when there is insufficient energy in the diet. Similarly, protein is a macronutrient that is also required in most of the physiological processes and considered an essential nutrient especially in tissue accretion, nutrient transfer, immune function and in repairing damaged cells. Furthermore, other macronutrients, vitamins, and minerals are required in adequate concentrations to ensure proper nutrient balance to perform all bodily functions.
The receiving period imposes several environmental and dietary changes that can alter rumen and gastrointestinal function due to feed and water deprivation, which may cause feed intake to remain depressed for days or even weeks once calves regain access to feed and water. During this period, calves need to replenish circulating glucose and nutrient levels and reestablish gut microbiota homeostasis for adequate immune, gastrointestinal and endocrine functions, otherwise gastrointestinal and/or respiratory diseases may occur.
One of the greatest challenges is adapting calves to eating a diet made up of unfamiliar feeds out of an unfamiliar feed bunk in an unfamiliar environment. The importance of diet palatability, availability and formulated to meet or exceed the calf ’s nutritional needs cannot be over emphasized. Starting diets are often formulated to exceed nutrient requirements or have increased nutrient density to compensate for reduced intake and to supply deficient calves with adequate nutrients. However, once calves are on feed, nutrient dense diets can also be counter-productive as they can create rumen stress influencing pH and metabolism, that can lead to feed refusals, inconsistent intakes, digestive upsets and ultimately impaired immune function.
Another important consideration to the diet is the addition of effective feed additives. Ionophores, direct fed microbials, prebiotics, enzymes and phytogenic feed additives are considered useful and effective strategies often used to improve diet acceptance, consistent intakes, support rumen fermentation and overall gut health.
Management procedures are equally as important as the vaccines chosen or how the ration is formulated. For instance, facility design and low-stress handling practices are the first experiences that cattle face when unloading off the truck. Proper evaluation and solutions to challenge areas, such as footing, noise, shadows, etc. that risk cattle health or prevent cattle from flowing through the facility are important area to consider. In addition, low-stress handling practices such as moving cattle slowly and refraining from using hotshots and loud noises to move cattle can reap greater benefits in how the cattle acclimate to their new environment.
One of the most impactful management decisions at the feedyard is determining when the changes in diet occur and the amount of feed fed to a pen of cattle, also known as bunk management. Bunk management is key in optimizing cattle performance and requires consistency in delivering the right diet, the right amount of feed and at the right time. It is important to work with your nutritionist to establish bunk management procedures and a feeding program that will address receiving challenges and encourage optimal feed intake during acclimation and throughout finishing.
Negative effects on health and growth performance in receiving calves are often associated with compounded stress, reduced feed intake and disease challenge that can greatly impact economic performance. However, implementing effective health, nutrition, and management protocols will provide the greatest opportunity for optimal success in receiving throughout finishing.