Over my 25-plus years of working with dairy and beef animals, I’ve been privileged to walk a lot of pens and look at a lot of manure. One thing I have learned is: While we don’t know exactly what is going in the cow’s mouth, we can have a very good idea of what she’s doing with that feed and what’s coming out. This article will focus on what manure can tell us about the cow’s nutrition level and her health.
A mature dairy cow with a bodyweight of around 1,400 pounds will produce around 100 pounds of feces per day depending on dry matter and water intake. It will also depend on the digestibility of the diet and subsequent retention of nutrients within the body and utilization for milk production. With this level of daily feces production, this provides a lot of material for observation. Observation of manure should be a regular event on the dairy.
In walking pens and observing manure, there are three “C’s” that should be given attention:
1. Consistency – General appearance largely depends on water content, feed moisture content and feed retention in the animal.
- Normal fecal material has a breakfast oatmeal-like consistency and forms a dome-shaped patty about 1 to 2 inches high with an indention (divot) in the center.
- Looser feces also may result from intake of high levels of rumen-degradable protein or excessive protein intake in general. This feces appearance may be a result of increased water consumption and turnover as the body attempts to excrete excess nitrogen along with that in urine.
- Decreased water, protein intake or excessive fiber intake often results in firmer feces, which will pile up higher even to the point of appearing as firm balls.
- Conversely, diarrhea or very loose manure may be the result of infection, parasites or as a result from extensive hindgut fermentation of carbohydrates (starch) and increased acid production. This may be an indicator of ruminal acidosis or subacute ruminal acidosis. Manure may also be loose during periods of heat stress when fiber intake may be reduced.
- There may also be issues when there are a wide range of manure appearances as one observes the overall pen surface. Widely varying manure consistencies may indicate an improperly balanced or mixed diet. Either result in variation in the diet a group of cows are consuming. Ideally, the manure in each pen or pasture will be as consistent, across the pen, as possible.
2. Content – This refers to the physical as well as chemical content. In a perfect world, fecal samples should indicate uniform digestion of most feeds and forages offered to the animal.
- If you observe significant amounts of undigested grain or long forage particles (greater than half an inch), this may be indicative of poor ration formulation, low forage quality, insufficiently chopped forages, poor rumen fermentation or possibly extensive hindgut fermentation.
- As mentioned, the presence of large forage particles or undigested grains may indicate cows are not ruminating properly or that rumen passage rate is too fast. It may be due to inadequate effective fiber necessary for stimulating rumination or maintaining normal rumen pH.
- Substantial amounts of undigested grain particles may indicate grain overfeeding, improper grain processing on-farm or during corn silage chopping/processing. Nutrients from these large particles are not highly available to the rumen microbes or the animal itself.
- Look closely to determine if the finely ground grain particles (not easily seen) may be present.
- A whitish color or film on the surface of dried manure indicates undigested starch is present.
- The presence of large amounts of mucus may indicate chronic gut inflammation or injury. In some cases, actual mucin (intestinal lining) tissue may be observed, which indicates damage to the large intestine, once again, possibly caused by extensive hindgut fermentation and low pH.
- Manure that appears foamy may suggest acidosis or high levels of hindgut fermentation resulting in gas production.
3. Color – Fecal color is influenced by feed type, bile concentration and the passage rate of forages, feeds and digesta.
- Typically, manure is dark green when cattle are grazing fresh forages. It darkens to more of a brownish color as hay intake increases.
- When cows consume a ration (TMR or partial TMR) containing large amounts of grain, feces are usually more of a yellow-green color. This color results from the combination of grain and forage and will vary as related to the amount of grain and processing.
- If an animal experiences very loose stools or diarrhea, feces may change to more of a gray color.
- Fecal color may also be different in cows being treated with drugs or antibiotics.
- Dark brown/black or bloody manure may indicate hemorrhaging in the GI tract from watery dysentery (coronavirus infection), mycotoxins or coccidiosis.
- Light green or yellowish, watery diarrhea can result from bacterial infections such as salmonella.
Manure observation is an extremely valuable tool on the farm. As mentioned, it gives us a very complete picture of what is going on in the cow as a result of her diet and health and should be used regularly.
Dr. Steve Blezinger is a management and nutritional consultant with an office in Sulphur Springs, Texas. He can be reached at Steve Blezinger or at (903) 352-3475.
Some nutritionists use a manure scoring system that can be of value. Manure is scored on a 1 to 5 basis, with a score of 1 being very liquid to 5 being extremely dry and segmented.
A manure score of 1 is of cream soup consistency. It can indicate a sick animal or a highly digestible ration that contains excess protein, carbohydrates or minerals and low fiber, as discussed above. The addition of hay will slow down the rate of passage and thicken the manure.
Manure that scores a 2 doesn’t stack; the pat is usually less than 1 inch thick and lacks consistent form. This manure has the consistency of cake batter. Excess protein, carbohydrates and low fiber characterize the diets that produce this manure. Rate of passage is very high, and adding hay to this diet will slow it down to allow for more absorption in the intestinal tract.
Manure score 3 is close to ideal and will typically start to take on a normal pat form. The consistency will be like thick pancake batter or breakfast oatmeal. It will exhibit a slight divot in the middle. The pat will be deeper than a score 2 pat but will not stack much.
A score 4 manure is thicker, becoming deeper and beginning to stack. The consistency of the manure will be equivalent to thick peanut butter. This manure indicates a lack of degradable rumen protein, excessive low-quality fiber or inadequate carbohydrates in the diet. Supplementation of additional rumen-degradable protein can increase total diet digestibility.
The highest and least desirable score is 5. This manure is firm and stacks well over 2 inches in height. It will also have clearly defined segments and is very dry. This manure indicates the cow is eating a poor-quality forage in the diet that is inadequate for protein and carbohydrates and high in low-quality fiber. Rate of passage has slowed down to the point that excess water has been reabsorbed in the intestines.
A final comment is: Cattle should be in good health for manure scoring to be accurate. Cattle that are sick or receiving a poorly formulated or mixed ration or other conflicts may exhibit varying manure appearance from that shown. Manure scoring is a valuable tool to determine the quality of nutrition the cow has recently consumed and can be used effectively to adjust supplementation to prevent loss of body condition.