This document discusses evaluating dairy cow manure as a way to understand rumen function and digestion. Manure evaluation can indicate whether changes need to be made to the cow's diet formulation. Fermentation in the rumen and hindgut produces organic acids, microbial protein, and gases. Insufficient fiber intake can lead to acidosis and poor digestion seen in manure. Proper particle size and effective fiber are important for rumination, buffering, and manure characteristics. Certain feed ingredients or moldy feeds may cause diarrhea visible in manure.

1. Manure Evaluation: Key To Nutrition
And Herd Health
Prepared by:
Dr Abdollah (khosrow) Samiei
Dairy Cow Nutritionist (PhD)
Reviewed by:
Professor Mike Hutjens
University of illinois

2. Dairy Farm
Manager
veterinarian
Technicians
Comfort
Nutritionist
To improve the performance of Dairy Cows

3. Dairy Cows Don’t Lie To You
 Evaluation of manure will give a good idea of rumen
function and feed digestion.
 After interpreting the signs in the manure, you can
decide whether it is necessary to change the formulation
of the diet for the optimal performance of the animal
(production and health) or not?

4. Feed fermentation products at the end of the
digestive tract (cecum and large intestine)
 Organic acids (acetate, propionate, butyrate, etc.)
 Microbial protein
 Gases
 These products are similar to rumen fermentation
products.

5. Rumen (Fermentation)
Cecum & Large Intestine
Where Does Feed Digest?
Crude Protein
Carbohydrates
(NDF & NFC) Small Intestine (Enzymic)
True Protein
Starch
Lipids
Crude Protein
Carbohydrates
(NDF & NFC)
Mary Beth Hall
Wisconsin University

6.  In the rumen, the produced organic acids are absorbed, if
the environment is buffered by saliva or effective fiber is
consumed in the appropriate amount, there will be no
problem, but otherwise, rumen acidosis will be observed
in the herd.
 Due to the absence of a buffer system at the end of the
digestive tract, organic acids produced in that
environment will cause to a decrease in pH.
 Microbial protein produced at the end of the digestive
tract is not available for cows.

7. Gas
Microbial
protein
Organic acids
Fates of Fermentation Products
Rumen Hindgut
Feces
Recycled
Absorbed
Absorbed Absorbed
Belch/Bloat Feces
Fermentation Products
Mary Beth Hall
Wisconsin University

8. NFC Digestion Characteristics
Organic acids
Sugars
Starches
Fructans
Pectic
Substances
Glucans
Potentially
ferment to
Lactic acid
Decreased
fermentation
at low pH
Digested by
Mammalian
Enzymes
Support
microbial
Growth
Mary Beth Hall
Wisconsin University

9. NFC Types and Sources
Organic Acids:
Silages
Whey
Steep liquor
Sugars:
Molasses
Bakery waste
Fresh forages/ hays
Beet & citrus pulps
Almond hulls
Starch:
Grain silages
Corn, sorghum
Small grains
Bakery waste
Wheat midds
Soluble fiber:
Legume forages
Beet & citrus pulp
Soybean meal
Mary Beth Hall
Wisconsin University

10. Gas Pocket
S.I.
Esophagus
Liver
Rumen
.
Fluid Fraction
Fiber Mat

11. S.I.
Esophagus
.
Rumen
Fiber Mat
concentrate
Forage

12. Which Fiber mat is acceptable?

13. Penn State Particle Separator

14. Penn State Particle Separator (PSPS)
Screen Particle Size Corn silage
%
Haylage
%
TMR
%
Upper
Sieve
19 mm 3 - 8 10 - 20 2 - 8
Middle
Sieve
19 – 8 mm 45 - 65 45 - 75 30 - 50
Lower
Sieve
8 – 4 mm 20 - 30 30 - 40 10 - 20
Bottom
Pan
< 4 mm < 10 < 10 30 - 40

15. Upper Sieve
 The 0.75-inch (19-mm) sieve was designed to
capture forage or feed particles that would be
buoyant in the rumen (form the forage mat)
and provide material that would require
substantial additional cud chewing by the
cow. In theory this would supply additional
buffering to the rumen and help modify rumen
pH.
 Rations with too much coarse material,
especially if it exceeds 10% on the top sieve,
can extend eating time beyond the natural
three to five hours per day.

16. Middle Sieve
 The 8-mm sieve collects primarily forage particles
that will be part of the forage mat in the rumen,
but will be broken down faster with less cud
chewing and will hydrate in the rumen faster to
allow more rapid rumen microbial breakdown.
Both the amount of cud chewing required and the
hydration rate will depend on the digestibility of
the forage contained in this fraction.
 The balance between the long particles retained
on the top sieve and the particles on the second
sieve will affect the balance between eating time
and resting and rumination time for the cow.

17. Lower Sieve
 Feed particles found on this sieve will
primarily be small forage pieces that are
often, but not necessarily, high fiber in
nature. Initially these particles will likely be
trapped in the forage mat of the rumen, but
they can be broken down easily with minimal
rumination or by rapid microbial action.
Typically they will hydrate quite rapidly and
will not remain trapped in the fiber mat for a
long period of time. In either event these feed
particles will have a small, yet significant,
impact on buffering the rumen.

18. peNDF
(physical effective NDF)
 The concept of physically effective NDF (peNDF) has been
proposed to estimate the NDF portion of the diet that
stimulates chewing activity, salivary buffer production and
possibly the formation of the rumen mat.
 Mertens (1997) proposed that to ensure a ruminal pH of
6.0, dietary peNDF should be maintained at or above 21%.

19. calculating peNDF
 Adding the fraction of particles together from
the top three sieves of the Penn State Particle
Separator gives us the pef (physical
effectiveness factor) for the forage or TMR.
 peNDF = pef x %NDF
 For example, if 5% of a TMR is retained on the
top sieve, 55% on the 8 mm sieve, and 15% on
the 4 mm sieve, then the pef to use in
calculating peNDF would be 0.75 (0.05 + 0.55
+ 0.15). So, for a ration containing 30% NDF,
the peNDF would be 22.5%.

20. When fed the right amount of dietary
fiber of adequate particle size…
 When fed the right amount of dietary fiber of
adequate particle size, the lactating cow
produces approximately 25 to 50 gallons of
saliva per day (98 to 190 L/d). The primary
buffering compounds in saliva are carbonate
(HCO3-) and phosphate (HPO4-2) ions, and
these compounds are very strong buffers at
high pH. Knowing the percentage or amount
of the diet that will encourage cud chewing is
therefore important in the overall goal of
maintaining proper rumen pH in dairy cows.

21. Diarrhea caused by diet is not a
disease, but the result:
 Imbalance of effective fiber in the diet
or increase of starch in the consumed
diet.
 Moldy feed and silage also lead to
diarrhea.

22. The gases produced at the end of the digestive tract will not
be expelled through belching.
Therefore, the feces will be thin and contain very small or
very large bubbles.

23. If the cow has bloat, because there is a lot of gas in the rumen,
you’ve seen the foamy manure.

24. Foamy manure

25. If the effective fiber of the diet is not enough, the
fiber mat is thin or the pH of the rumen is low
(acidosis), the feed materials will not be digested
well and will pass through the rumen quickly.

26. If the effective fiber of the ration is high, rumination will be
prolonged and the consumed feed will remain in the
rumen to a greater extent, so the particles inside the
manure will be smaller.

27. High-yielding cows consume a lot of feed, so
feed materials are not digested and pass
through the digestive tract quickly, and large
and long sizes of feed materials are seen in the
manure.
Coarsely ground grain in manure

28. Due to the insufficient physical effective NDF, feed
materials such as cotton seeds, citrus pulp such as
oranges, and green grass pass through the rumen and
digestive tracts completely.
Fiber > 1cm
Whole cotton seed

29. In order to make the starch and protein available in the corn
grain, it should be made into meal. Finely ground grains are
higher in digestibility because there is more surface area
for the rumen bacteria to attach.

30. Bubbles and corn in manure usually signal that excess
corn is fermenting in the gut. This can lead to many health
problems, with hemorrhagic bowel syndrome.
Cracked corn

31. When corn is not finely ground enough, it is much more likely to
come through in the lower gut. It needs to be ground more finely,
but then you really have to make sure you have enough effective
fiber so that the cows aren’t tipped over into ruminal acidosis from
supplying more digestible starch.

32. cows fed the cracked corn had higher milk urea nitrogen levels
which indicates that protein was less efficiently fermented in the
rumen (ammonia is captured as microbial protein).

33. A large amount of bakery waste or contamination
with fungus lead to diarrhea in dairy cows.

34. Moldy, spoiled feeds in the ration, like this clump of
bad silage that wasn’t cleaned off of the silo can also
cause diarrhea to appear sporadically across the herd.

36.  Increasing protein in the diet with soybean meal
resulted in feces with a lower score and dry matter
than using corn gluten meal.
 Soybean meal is more degradable and would result
in more rumen ammonia than corn gluten meal. As a
result water might be needed to excrete excess
nitrogen via the urine.

37. Diarrhea

38. Adapted from Hoof Care for Dairy Cattle, 1992. J.E. Nocek
LAMENESS
Environment/Management
• Stress
• Trauma
• Exercise
• Trimming
Weakened Claws (Hooves)
• Breakdown in Supportive Connective Tissue
• Poor Quality Horn Formation
Metabolic Disorders
• Milk Fever
• Ketosis
Genetics Vaso-Constriction/Dilation
Nutrition
• Excessive Grain
• Finely Chopped Forage
• Improper Feeding Management
• Incorrect Ratio of Concentrate to Forage
Increased Lactic Acid Production
Lowered pH
Infectious Diseases
• Metritis
• Mastitis
• Retained Placenta
Death of Gram Negative Bacteria
Molds/Mycotoxins Endotoxin Release
Histamine
LAMENESS:
CAUSES AND SEQUENCE OF EVENTS

39. Sometimes, a large amount of sand/soil may be
found in manure. When cows consume a great deal
of soil, it may be a non-specific indication of
digestive upset or ruminal acidosis.

40. When you wash the manure with clean water, you
can see the mucin. Mucin can be seen in pieces or in
long strands. Its color is brown or gray or darker.

41. Mucin casts
3.5 inches (9 cm)
Mucins are glycoproteins with many oligosaccharide chains
which interact with each other and create a gel.

42. The mucus lies as a membrane on the apical side of the intestinal
cells and protects the epithelium from being damaged by
endogenous secretions and microorganisms.

43. Damaging the lining of the large intestine creates mucin casts.
This can happen due to too much hindgut fermentation (Low pH).
mucin or fibrin that the cow produces covers the damaged area.

44. If you feed a group of dairy cows the same diet, about
5% of them will have different manure than the rest of
the herd.
If there is a big difference between the manure of the
cows, it means that the cows have been fed differently,
and this is due to the selection of feed materials by the
cow or separate feeding of concentrate and forage to
dairy cows.

45. Sometimes, you get clay-like balls of manure (not real
normal), that plug things. These are associated with
the gut not working well.

46. If you find small clay-like balls of manure,
then this is a sign of poor rumen function.

47. when you are walking a herd, keep your eyes open to evaluate:
Rumination
Body condition score
Rumen Scoring
Locomotion Scoring
Manure scoring
Materials in manure
Particle size in TMR

48. Adult cows eat between 7 and 12 meals a day.
Each meal lasts 45 minutes.
Lactating dairy cows spend about 4.5 h/d eating (range:
2.4–8.5 h/d) and 7 h/d ruminating (range: 2.5–10.5 h/d),
with a maximum total chewing time of 16 h/d.
Rumination starts 45 minutes after eating.
2 hours after feeding, at least 60% of resting cows
should be ruminating, and if this number reaches 80%,
there will be no problem of acidosis.

49. Feeding Behavior
(Dado and Allen—Michigan State University)
1st lactation Older
Meal size (kg) 1.8 2.5
Meal bouts (#) 11.3 10.8
Eating time (min) 284 314
Rumination (min) 453 460
Milk yield (kg) 28.7 37.5
Dry matter intake (kg) 20.0 24.5

50. Sampling of Manure

51.  All samples should be weighed individually
before they are washed through in a manure
sieve.
 Completely transfer each sample into a manure
sieve, gently wash through the manure until the
water coming out of the bottom of the sieve
runs clear.

53. Rinse the sample until the water runs clear.

55. Nasco Digestion
Analyzer

56. Manure Screen
Nasco Digestion Analyzer
Goal Range% Optimum Range%
Top 0 - 20 10 - 20
Middle 25 - 35 25 - 35
Bottom More than 50 50 - 55

57. Use the scoop or a comparable-sized container and grab
a sample in the 500- to 600-gram range from 10 to 12
representative cows.
It is best when benchmarking the herd to not take samples
on the extremes of the manure consistency spectrum.
An important tip is to wring out excess water from the
sample residue on each screen, then weigh the amounts.
Note the totals and calculate each screen as a percent of
the total weight.

58. Top screen interpretation
 Mature forages with low-quality fiber that contain high
undigestible fiber fractions or a lack of sufficient rumen
ammonia to feed fiber-digesting bacteria might be
probable causes.
 Top screen percentages between 25% to 40% are typical
of herds struggling to generate milk volume.
 In situations with mycotoxins, endotoxins, poor rumen
function or acidosis, we can see mucin casts in the top
screen.
 Another common finding in the top screen is gelatinized
starch, which is often a sign of hindgut fermentation. This
is due to a lack of fiber and starch being digested in the
hindgut and is the result of fiber and starch fraction not
being fully fermented in the rumen.

59. Screen two interpretations
 Based on experience in using the manure separator, the
percentage in the second manure screen has a positive
correlation to both milk production and milk components,
similar to the Penn State shaker box. Percentages lower than
20% are indicative of fast fermentable diets with higher levels
of digestible fiber and non-fibrous carbohydrates.
 Second screen percentages higher than 35% are usually
indicative of poor fiber fermentation, whereby rumen pH
dropped too fast to stimulate proper rumen conditions for the
growth of specific fiber-fermenting bacteria.

60. Bottom screen interpretation
 The bottom manure screen percentage and
the bottom pan of the Penn State shaker are
highly correlated. Diets heavy in the bottom
pan of the shaker box that contain fast
fermentable forage fiber, readily degradable
starches and non-fibrous carbohydrates are
usually higher in percentage in the manure
screen.

61. Walking the pens
 Get an idea of the variation
 In groups
 Between groups
 Between rations
 Sample 4-6 pies/group for
particle size

62. Good
Bad
When the rumen is working
well, fecal particle size is
very fine.
When rumen function is not
normal, you can get very
coarse fiber coming through.

63. You do not want to see much coarse
material 1 cm or longer in the manure.

64. We had to add more corn meal to the herd’s ration to
make up for the corn from the silage that wasn’t
available to them.

65. This undigested feed represents feed that never
had a chance to be converted to milk.

66. Differences in the amount of solids in a set
volume reflect differences in the amount of gas
or liquid in the manure.
Dry cows will tend to have a greater proportion of solids
in their manure than lactating cows – this is normal.

67. Team 21
April 12, 2003
We shouldn’t help cows in their
search to find ways to sort.

68. TMR Sorting Happens !
Cows sort by pushing with their nose (14cm). Particles half this length (<7cm) are not as
easily sorted.

69. If the size of the forage is long, the
dairy cows will choose concentrate.

70. TMR Particle Size
(Penn State Shaker Box)

71. If corn forage is not chopped well,
it will remain in the feed bunk.

72. The best way is to prepare total mixed rations. When
preparing total mixed rations, try to pay attention to the
effective fiber of the ration.

73. The saliva of cattle is rich in
bicarbonate and serves as an
important buffer to modulate
rumen function and acid
production. If particle size is
too small, chewing and thus
saliva production will be
reduced, putting the cow at
risk of developing acidosis
and overall poor rumen
health.

74. What are cud balls and how to detect them?
Cows with Sara will often
drop their cud; cud balls are
small balls of feed which the
cow has spat out. Cud balls
are often found at the front
of cubicles where the cow
spits it out while lying down.

75. Cud balls as a sign of SARA (Sub Acute Ruminal
Acidosis), usually an individual cow lose their cud, not
many cows if it was SARA more cows would exhibit this.

76. Heat Stress causes ruminal acidosis.

77.  Panting
 Decreased rumination
 Drooling
 Slug feeding
 Sorting

78. Heat Stress
Decrease in blood CO2
due to increase in
breathing rate
The kidney maintains this
ratio by exuding HCO3
The amount of
HCO3 in the rumen
decreases
Increased
Panting
A large amount of
saliva coming out
of the mouth
Reduced
DMI
Decreased
rumination
Decreased
saliva secretion
Decreased rumen pH followed by acidosis

79. 5
5.2
5.4
5.6
5.8
6
6.2
6.4
6.6
Cool Hot HR HG C-HR H-HR C-HG H-HG
Rumen
pH
Ruminal Response to Heat Stress
Mishra, et al. 1970
J. Anim. Sci. 30:1023
Cool = 18.3C (65F), Hot = 29.4C (85F)
HR = high roughage, HG = high grain

80. Water pH
 Recommendations - pH 6.5 to 8.5
 Water consumption in dairy cow:
132 – 170 liters per day.
 If the pH is highly acidic (less
than 5.5), acidosis and reduced
feed intake may occur.
 Highly alkaline water (over 9) may
cause digestive upsets and
diarrhea, lower feed conversion
efficiency and reduce intake of
water and feed.

82. Score 1
 The manure is thin and feed particles can be
seen in it.
 Too much protein or starch in the diet, too
many minerals or too little effective fiber in
the diet leads to dilution of manure.
 A lot of urea in the digestive tract also creates
an osmotic gradient and leads to watery
manure.
 This manure score is seen in sick cows (for
example salmonella or winter dysentery) ,
cows that have off feed and cows that feed on
pasture.

84. Manure come out of the cow in an arc.

85. Salmonella
Salmonellosis is an infection of the digestive tract caused by the
bacterium, Salmonella enterica.

86. winter dysentery
Winter dysentery is an acute, highly contagious GI disorder that
affects housed adult dairy cattle, primarily during winter.

87. Score 2
 The manure is thin.
 The manure is spread on the ground and its
height is less than 2.5 cm.
 Lack of effective fiber in the diet leads to
dilution of manure.
 It is seen in cows that feed on the pasture or
in fresh cows.

89. Score 3
 It is a favorable score for manure.
 The height of the manure is 3.75 to 5 cm.
 It consists of 2 to 5 concentric rings with a
small hole in the middle.
 When the manure drops making a slow hand
clap sound.

90. dimples
Stacks up 2.54 to 3.81 cm
2 to 4 concentric rings

91. Boot test: when the boot is lifted there is no footprint left in the
pile, and the manure doesn’t stick when lifting the boot.

92. Score 4
 Dry cows and heifers often pass this type of
manure.
 It is observed in diets based on dry cereal
straw.
 It may be due to not feeding sufficient protein
or rumen degradable protein.
 For dry cows and heifers this manure is
acceptable, but always check the composition
of the ration anyway.

93. Stacks up 5 to 7.6 cm.

94. Boot test: when the boot is lifted
the manure sticks to the sole
and a footprint is left behind.

95. Score 5
 Stiff balls of manure (similar to horse manure).
 Dry cows and heifers often pass this type of
manure.
 It is observed in diets based on dry cereal straw.
 Cows that have blockage problems in their
digestive tracts will have such manure.

96. Diets based on dry cereal straw

97.  The cattle are likely protein deficient, and the source of
forage is of poor-quality (or needs to be ground to a
shorter length). This can also be an indication of salt
deficiency and/or dehydration, or both. Increasing the
amount of degradable, soluble, or total protein,
decreasing the amount or physical form of the fiber,
increasing starch level, decreasing grain particle size
(such as fine grinding or steam flaking), and providing
more minerals (especially potassium and sodium) can
cause manure scores to decline (for example from 5 to 4).
An important point for nutritionist:

98. Stacks up over 7.6 cm

99. Boot test: an impression of the sole
is left on the top of the manure.

100. In milking cows, check that the ration is
balanced and adjust accordingly. Check
individual cows for disease (ketosis).

101. Cow Manure Scoring
Dry Cow (far-off) 3.5
Close-up 3
Fresh 2.5
High Production 3
Late Lactation 3.5

102. The color of manure
 The color of manure is affected by the amount
of feed consumed, the amount of bile and the
amount of feed passing through the digestive
tract.

103. The manure of cows that feed on fresh
forage or pastures are dark green in color.

104. If the ration is based on hay, its
color will be brown.

105. If the ration is based on cereal grains in
abundance, the manure color will be gray.

106. Bleeding in the small intestine
causes black manure.

107. Bleeding in the rectum results in
brown manure with red streaks.

108. Bloody diarrhea is associated
with coccidiosis.

109. Oil in manure suggests there is
too much fat in the cows diet.

110. Manure from cows fed corn silage based diets was
lighter in color than manure from cows fed
alfalfa/corn silage mixtures.
corn silage
alfalfa/corn silage mixtures

111. Thank You Very Much For Your Attention

112. In preparing this presentation, I have used
the articles of professor Mike Hutjens and
professor Mary Beth Hall, so I appreciate
and thanks these dear experts.
Dr Khosrow Samiei
Dairy Cow Nutritionist (PhD)