Ron Torell with his wife, Jackie.
Cow Camp Chatter
Nutritional loose stools (a.k.a. milk scours)
Spring 2010 in northeastern Nevada was nontypical. Grass was late due to the extended cold and damp weather, resulting in cows and calves held in confinement on feed grounds later than normal. When the grass did come, it appeared fast and strong, resulting in heavy lactation of cows. These conditions contributed to overeating among calves. As they were drug to the branding fire, a higher-than-normal percentage of 20- to 50-day-old calves were exhibiting what many of the old-timers called milk scours. A portion of these calves progressed into infectious scours with dehydration and/or death. Confusing milk scours with infectious scours often occurs in cow country.
The professional community refers to milk scours as nutritional loose stools. Nutritional scours are usually caused by overconsumption of milk in conjunction with stress to the calf due to a breakdown in management routines or environmental factors including sudden changes in the weather or cold, damp, stormy conditions.
A technical description and understanding of how milk is digested in the gut of a calf is required to make a clear distinction between nutritional and infectious scours. The initial digestion of milk occurs in the abomasum (fourth stomach) and progresses further through the intestines. One of the first effects of stress in calves is a reduction of acid secretion into the abomasum. This reduces both the ability of the clot to form and the digestion of milk proteins.
Nutritional scours are the end result of an oversupply of lactose in the intestines caused by milk moving too rapidly out of the abomasum so that it cannot be broken down quickly enough.
Learn how to identify early signs of dehydration in a calf and don't be afraid of using a thermometer, Thain recommends. "Dehydration and fever outside of normal is a strong indicator of infectious scours." Nutritional scours may progress to infectious scours, which are caused by a high population of pathogens. Pathogens use excess lactose as a nutrient source to increase in numbers. The rate of lactose digestion is then further reduced as a result of damage to the intestinal walls by these pathogens. This damage also causes body fluids to leak into the gut, thereby increasing the rate at which the calf dehydrates.
John Mass, University of California Extension veterinarian, explains: "A case for nutritional scours has never been made in the scientific literature. If a calf has diarrhea, is dehydrated and depressed (anorexic), the cause is infectious. The culprit has always been a bug or two plus or minus low colostral antibodies. In reality, we should not refer to nutritional loose stools as milk scours. Some of these calves that are overconsuming on milk become constipated, which is actually a more common condition than loose stools. You may have a hard time believing constipation in these calves, but drink a half gallon of milk or eat a block of cheese sometime and observe the outcome. The calves that are dehydrated, depressed and are running a fever have a bug or two. The loose-stool calves that are otherwise healthy in all likelihood are exhibiting nutritional loose stools, a.k.a. milk scours."
According to David Thain, University of Nevada Cooperative Extension veterinarian, "Being able to recognize early signs or indicators [that] distinguish nutritional from infectious scours and applying early treatment [are] paramount to success and saving calves. For example, if the stool has a terrible smell, it is possibly infectious, such as cryptosporidium. Signs that may indicate an infectious pathogen are blood in the stool, extremely watery stools, discoloration of the stool and a distended belly."
Learn how to identify early signs of dehydration in a calf and don't be afraid of using a thermometer, Thain recommends. "Dehydration and fever outside of normal is a strong indicator of infectious scours. A healthy, vibrant calf with very loose stools showing no signs of dehydration, no fever or appetite suppression is probably experiencing nutritional loose stools. This is the calf to watch closely to make sure this condition does not progress into infectious scours."
Eureka, Nev., Veterinarian J.J. Goicoechea asserts that management is key.
“We need to raise the resistance and lower the challenge through 12-month management of the cow and calf,” he says. “This involves body condition preservation of the cow with a well-thought-out and executed vaccination program and maintaining a sound year-round mineral program. It is critical that a proper mineral program be in place in order for your vaccination program to work properly. Generally the results are a thriftier fetus at birth with a sound immune system in place. The newborn is then able to receive adequate quality and quantity of colostrum in a timely manner, all raising the resistance. Lowering the challenge would include factors such as proper sanitation measures at calving, reducing concentration of cows with baby calves on calving and feed grounds, providing windbreaks and dry, clean loafing areas.”
Goicoechea says, “Calving in the brush during the warmer months of May or June will do more for reducing the incidence of scouring calves, nutritional or infectious, than any other management practice we can apply. Brush calving in synchrony with Mother Nature reduces the challenge tremendously.”
Adhering to sound management practices year-round and remaining observant of milk-scouring calves to ensure the condition does not progress into infectious scours is the take-home message from these professionals. Any parent who has changed their share of diapers can attest to the fact that fecal consistency can change drastically from day to day, or even within a day, and often serves as a signal of either a dietary change or the presence of an infectious agent. The same principal applies to these young calves. Be observant!
That's enough for this month. As always, if you would like to discuss this article or simply want to talk cows, do not hesitate to contact me at 775-385-7665 or e-mail me.
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