Complexity means distracted effort. Simplicity means focused effort. I lean on this quote from Edward De Bono when managing teams and thinking about scours prevention.
Scours by definition is complex: a complex clinical symptom associated with multifactorial diseases that prevent the intestine from absorbing fluids and nutrients.
A number of scours pathogens, as well as environmental and nutritional stressors, can ignite this type of health event. In about 75 percent of scours cases, the worst of all pathogens is present: rotavirus.
Calves with rotavirus are twice as likely as those without to break with cryptosporidium, an opportunistic disease, and 17 times more likely to require respiratory treatment at or before movement into the first group pen.
Other scours pathogens also can play a devilish role, such as E. coli, coronavirus and salmonella. But if you are pulling your hair out over scours treatments during that first week of a calf’s life, chances are rotavirus is your primary culprit. Rotavirus symptoms last only five to seven days, but calves shed the pathogen into their environment for 13 days post-infection.
Do you ever throw up your hands and assume there’s only so much you can do? You don’t have to turn to the same old vaccination tactics or pile on unproven methods and rely on a strategy of hope.
Counter the complexity of scours with a focused effort. A focused approach simplifies the challenge before you and creates confidence in your prevention program.
Let’s get mission critical and look at key management practices for materially reducing scours, so that anyone on your operation who works with calves won’t wonder what could or should be done to minimize the influence scours has on your herd’s future.
Provide the right antibodies in the right amounts – quickly
Wherever there are vaccines, there are people hoping to prompt an immune response that will stimulate antibody production in order to prevent scours. However, research shows that a 100 percent vaccine response rate is biologically impossible, and calves are left unprotected. Circumventing vaccines, human health scientists long ago began working on stimulating antibody production outside of the body, in a lab. They were able to mimic naturally occurring antibodies. They learned to control the volume of antibodies produced and optimized them to target specific diseases. Similar technology is doing the same for scours prevention.
Optimized antibodies are crucial to improving upon today’s typical success rate for scours prevention. These are highly protective antibodies targeting a disease of particular concern according to the life-stage of the animal. They bind to their associated pathogen, rendering the pathogen ineffective whether it’s in the animal or the environment. These antibodies are superior to ones we aim for to achieve successful passive transfer.
A scours-prevention medicine composed of optimized antibodies can give calves a guaranteed dose of immediate immunity. In this scenario, calves receive the antibodies directly, bypassing the need for vaccination and antibody stimulation. This is tremendously important in light of the fact that vaccine variability leads to a vaccination success rate of only about 80 percent.
In addition to the type of antibodies calves receive, the volume, or level, of antibodies is just as important. That’s because the ratio of pathogen load to the level of protective antibody predicts the severity of scours outbreaks. To understand this, simply visualize a double-pan balance scale, which functions like a see-saw.
Weighted to Favor Antibodies
- If the protective antibody side of the scale is heavier than the pathogen side, infection is avoided.
Equally Weighted Scale
- If the two sides are balanced, you are getting by but living a bit on the edge. Outbreaks are more likely to be triggered by minor stressors, such as temperature fluctuation or feeding inconsistencies.
Weighted to Favor Pathogens
- If the pathogen side of the scale is heavier than the antibody side, pathogens will attach to the intestinal wall and rapidly reproduce — the calf becomes infected. During infection, intestinal tissue can be permanently damaged restricting nutrient absorption and slowing rate of gain.
Imagine a calf born with a perfect blueprint for success, but with the scale tipped in scours’ favor. The calf’s genetic potential is officially missed, and you lose an opportunity to further develop her or him into a robust, top contributor. Scours will have smudged the ink on the paperwork and ripped a few holes in it, but that’s nothing compared with what could follow.
As the prized calf quickly sheds and amplifies pathogen load in the environment, exposed herd mates will further pull down the pathogen side of the scale, damaging the entire calf crop. This is the s#!t show you want to avoid.
Follow more than one path to prevention
To quickly reset your operation with more weight on the protective antibody side of your scale, and to bring focus to your calf-care efforts, incorporate additional management techniques and avoid others.
It’s the most important issue mentioned at every calf and immunology conference. But colostrum, like scours, can seem complicated at times. Here are my high points:
- Feed 4 liters within 1 hour of birth, aiming for a total of 50g/L or 200g/feeding of IgG (general mass of antibody to achieve successful passive transfer). Verify 50g/L of IgG by:
- Refractometer reading of 22% minimum
- Hydrometer reading in green segment, tested at room temperature (70°F/21°C)
- You cannot see IgG; thickness of colostrum or color has nothing to do with antibody levels
- Bacteria doubles every 20 minutes when colostrum is not refrigerated. Clean collection and quick refrigeration can mean the difference between nature’s perfect super food or bacteria soup.
- Feeding temperature should be the target body temperature for the calf (~104°F/40°C)
Nonverified antibodies – those that have not passed a USDA testing and verification process for scours prevention – represent, perhaps, the greatest indicator of uncertainty around scours-prevention methods. Results are anecdotal. Including them in a focused effort to prevent scours will only cloud your understanding of what is and isn’t working.
Fresh, frozen colostrum or transition milk, for example, can provide nonspecific antibodies. But their results are unclear due to their nonspecific nature.
Whole egg or egg powder is a source of IgY (egg yolk antibodies), not a source of IgG. These types of antibodies are cheap and easy to produce. But a calf is not a chicken, so their value is biologically limited, while the quantity of specific antibody is also highly variable and unregulated.
Weigh the value of using (and relying on) nonverified antibodies against the uncertainty of their results.
Remove visible organic matter on hutches and equipment. Plus, break down the invisible biofilm layer on surfaces and feeding equipment (especially hoses) with a sodium hypochlorite or chlorine dioxide disinfectant. Sanitizers need 10 to 15 minutes to work.
The sun can be a powerful disinfectant. Leave one row of hutches sit empty for about 2 weeks with hutches tipped on end, and old bedding removed, so the sun’s rays can reach the ground or slab. Moving new calves into hutches nearly the same day you move a weaned group out means that a newborn, who spent the last nine months in an aseptically clean hot tub, is under full attack from the ground-level pathogen mound the prior calf took 56 days to accumulate.
Strive for a calf kitchen that’s as “dry as possible,” an often-repeated mantra that conjures another favorite quote: In wine there is wisdom, in beer there is freedom, and in water there is bacteria. Minimize moisture in and around the hutch area. Dump wastewater and milk down a drain or away from the hutch lane. Be cautious when filling buckets to avoid overspray.
Rotavirus, like many other scours pathogens, is a fecal oral disease, meaning it is transferred through the consumption of manure particles.
- Any calf born in a drylot or free stall is a high-risk calf. Avoid calving in these areas.
- Remove calves from the maternity pen quickly, before they can do a wobbly nose-dive into a pile of manure.
- Treaters and feeders should wear gloves, plus treaters should disinfect boots when moving from pen to pen.
- Finally, logistics are important. A newborn should never cross the path of older animals. Scours pathogens are active within older animals even though these animals have aged to the point where they’re no longer susceptible to these pathogens. The older animal serves as the host, shedding high levels of pathogen. Using the same trailer to move newborns, weaned calves, or cull cows is a solid no-no.
You can do this
You work in an inherently dirty environment. Pathogen load ebbs and flows, meaning the amount of protective antibody needed on your double-pan scale to assure zero scours is nearly impossible to pinpoint. And yet, minimizing the severity and frequency of scours outbreaks is well within your reach.
Shine a spotlight on your calf program and highlight what’s mission critical for you and your calf-care crew. Break down scours complexities into simpler, achievable goals.
You do not have to settle for the status quo.