Seven experiments evaluated the effect of basal diet and dietary cation-anion difference (DCAD) on urinary and fecal pH, and DMI. Dry-matter intake(DMI) was reduced by DCAD level in dry-rolled corn basal diets but not in diets that included 20% wet distillers grains (WDGS). Urinary pH decreased with DCAD level in all experiments. Fecal pH was not influenced by either DCAD level or basal diet. Altering DCAD in concentrate diets with or without WDGS does impacturinary pH

Erickson, Galen E.

Klopfenstein, Terry J.

Luebbe, Matt K.

Meyer, Nathan

English

UNL | Libraries

University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Nebraska Beef Cattle Reports Animal Science Department 
2009 
Effect of Dietary Cation-Anion Difference on Intake and Urinary pH 
in High Concentrate Diets 
Matt K. Luebbe 
University of Nebraska - Lincoln, mluebbe2@unl.edu 
Galen E. Erickson 
University of Nebraska-Lincoln, gerickson4@unl.edu 
Terry J. Klopfenstein 
University of Nebraska-Lincoln, tklopfenstein1@unl.edu 
Nathan Meyer 
University of Nebraska-Lincoln, nmeyer2@unl.edu 
Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr 
 Part of the Animal Sciences Commons 
Luebbe, Matt K.; Erickson, Galen E.; Klopfenstein, Terry J.; and Meyer, Nathan, "Effect of Dietary Cation-
Anion Difference on Intake and Urinary pH in High Concentrate Diets" (2009). Nebraska Beef Cattle 
Reports. 526. 
https://digitalcommons.unl.edu/animalscinbcr/526 
This Article is brought to you for free and open access by the Animal Science Department at 
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Nebraska Beef Cattle 
Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 
Page 94 — 2009 Nebraska Beef Report  © The Board of Regents of the University of Nebraska.  All rights reserved.
Effect of Dietary Cation-Anion Difference on Intake 
and Urinary pH in High Concentrate Diets
Matthew K. Luebbe
Galen E. Erickson
Terry J. Klopfenstein
Nathan F. Meyer1
Summary
Seven experiments evaluated the 
effect of basal diet and dietary cation-
anion difference (DCAD) on urinary 
and fecal pH, and DMI. Dry-matter 
intake (DMI) was reduced by DCAD 
level in dry-rolled corn basal diets but 
not in diets that included 20% wet 
distillers grains (WDGS). Urinary 
pH decreased with DCAD level in all 
experiments . Fecal pH was not influ-
enced by either DCAD level or basal 
diet. Altering DCAD in concentrate 
diets with or without WDGS does 
impact urinary pH.
Introduction
Nitrogen loss may be reduced by 
shifting the equilibrium from NH
3
 to 
NH
4
 by acidification of cattle waste. 
The majority (60-80%) of N excreted 
by feedlot cattle is in the urine. Low-
ering urinary pH may reduce the 
amount of ammonia volatilized by 
shifting a greater proportion of N 
into the ammonium form. One way 
to reduce urinary pH is by lowering 
the dietary cation-anion difference 
(DCAD). Dietary cation-anion dif-
ferences can be changed to induce 
metabolic acidosis, which aids in 
calcium homeostasis at the onset of 
lactation (Goff et al., 2004, Journal of 
Dairy Science). Lowering DCAD has 
an impact on animal performance, 
blood pH, and urine pH. If urine and 
pen surface pH can be lowered by 
altering DCAD in concentrate diets, 
N losses may be reduced. The objec-
tive of these experiments was to deter-
mine the influence of basal diet and 
DCAD level on urinary and fecal pH 
and DMI.
Procedure
Lambs
Fifteen wether lambs (75 ± 7 lb) 
were used in five consecutive 3 x 3 
Latin squares. Basal diets consisted 
of 82.5% dry-rolled corn (DRC), 
7.5% alfalfa hay, 5% molasses and 5% 
supplement (DM). Dietary cation-
anion difference was calculated as 
milliequivalents (mEq) of [(Na + 
K) – (Cl + S)] per 100 g of feed DM. 
Ammonium chloride, ammonium 
sulfate and calcium chloride were 
used to lower DCAD to 0, -8, -16, -24 
and -45 mEq, replacing urea, fine 
ground corn and limestone. Sodium 
bicarbonate and potassium carbonate 
were used to increase DCAD to +16, 
+24, +32 and +40 mEq, replacing fine 
ground corn. Periods were 14 days 
in length with an 11-day adaptation 
to the diet, and 3-day urine collec-
tion period. Urine pH was measured 
immediately after collection at 0700, 
1300 and 1900 hours in all experi-
ments. Lambs were fed once daily at 
0700 for ad libitum intake. Lamb data 
were analyzed as separate 3 x 3 Latin 
squares with model effects for period, 
treatment, time and the treatment x 
time interaction as fixed effects and 
lamb as a random effect . Orthogonal 
contrasts were used to test signifi-
cance for the highest order polyno-
mial.
Steers
Eight steers (688 + 53) were used 
in two consecutive 4 x 4 Latin squares 
with basal diets consisting of either 
dry-rolled corn (DRC) or wet distill-
ers grains (WDGS), replacing DRC 
at 20% of diet DM, 7.5% alfalfa hay, 
5% molasses and 5% supplement 
(DM). Basal diets were 8 mEq for the 
DRC diet and -2 mEq for the WDGS 
diet. Calcium chloride was used to 
lower DCAD to -2, -12 and -22 mEq 
in the DRC square and -12, -22 and 
-32 mEq in the WDGS square. Period 
length, DM offered, and urine collec-
tion procedures were the same as for 
the lamb experiments. In addition to 
urine collection, feces were collected 
at 0700, 1300 and 1900 hours and 
composited within day for pH mea-
surement. Manure pH was analyzed 
using a 1:1 ratio of distilled water and 
as-is sample. 
Urinary pH for steers was ana-
lyzed as separate 4 x 4 Latin squares 
with period, treatment, time and the 
treatment x time interaction as fixed 
effects and steer as a random effect. 
Fecal pH for steers was analyzed in a 
similar manner without time and the 
treatment x time interaction in the 
model. Orthogonal contrasts were 
used to test significance for the high-
est order polynomial. 
Results
Lambs
Dry matter intake was not different 
(P > 0.05) among DCAD level in all 
experiments. In experiment 1, DMI 
was similar (P = 0.81) among treat-
ments. Dry-matter intake decreased 
linearly (P = 0.02) with DCAD level 
in experiment 2. Numerically, DMI 
was lower for the negative DCAD 
treatments compared with the control 
(+8) or positive DCAD treatments in 
experiments 3, 4 and 5.
The treatment x time interaction  
for urinary pH was not significant  
(P > 0.70) in all experiments. Urinary 
pH decreased linearly (P < 0.01) in 
all experiments. The differences in 
urinary pH from the highest to lowest 
DCAD level in experiments 1 through 
5 were 1.65, 2.31, 2.01, 2.65 and 2.70, 
respectively. From the lamb experi-
ments it appears DCAD does not have 
a consistent influence on DMI but is 
effective in manipulating urinary pH 
at different levels of DCAD.
© The Board of Regents of the University of Nebraska.  All rights reserved. 2009 Nebraska Beef Report  — Page 95 
Steers
Dry-matter intake for steers in 
the DRC experiment was greatest 
(P = 0.05) for animals consuming 
DCAD level +8, lowest for -32, and 
intermediate for -2 and -12 (Table 1). 
In the WDGS experiment, DMI was 
not influenced (P = 0.52) by DCAD 
level (Table 2). The treatment x time 
interaction for urinary pH was not 
significant in either experiment  
(P > 0.60). Urinary pH for steers 
in the DRC experiment decreased 
quadratically (P < 0.01) with DCAD 
level from 7.70 to 5.82. In the WDGS 
experiment urinary pH was greater 
(P < 0.01) for -2 compared with -12, 
-22 and -32 (7.70, 6.40, 5.90 and 
5.82, respectively ). Fecal pH was not 
different among DCAD levels in 
either the DRC or WDGS experiment  
(P = 0.63 and P = 0.35, respectively). 
There also was no relationship  
(r = 0.02, P = 0.94) of fecal pH to 
urine pH. Results from the steer 
experiments are similar to those of 
the lamb experiments, with an incon-
sistent influence of DCAD level on 
DMI. Urinary pH can be manipulated 
with DCAD level in either DRC or 
WDGS basal diets while fecal pH is 
not influenced.
The relative proportions of NH
3
 
compared to NH
4
 are 0.1%, 1%, 10% 
and 50% at pH of 6, 7, 8 and 9 (Court 
et al., 1964 Journal of Soil Science). 
When evaluating all DCAD levels 
from both the lamb and steer experi-
ments, there appears to be a consistent 
trend in lowering urinary pH (Figure 
1). Lowering DCAD in high concen-
trate diets with or without WDGS 
decreases urinary pH and may reduce 
ammonia losses from steers or lambs 
fed negative DCAD diets.
1Matthew K. Luebbe, research technician; 
Galen E. Erickson, associate professor; Terry 
J. Klopfenstein, professor; Nathan E. Meyer, 
research technician, Animal Science, Lincoln, 
Neb.
Table 1. Effect of DCAD level on DMI and urinary pH for lambs.
Experiment DCAD1 DMI, lb/d Urine pH DMI2 pH3,4
1 0 2.93 6.67a
 8 2.88 7.09b 0.81 < 0.01
 16 3.05 8.32c
2 -8 3.20 6.10a
 8 3.13 8.21b 0.09 < 0.01
 24 2.97 8.41b
3 -16 2.82 6.37a
 8 3.48 8.22b 0.49 < 0.01
 32 3.12 8.38b
4 -24 2.31 5.84a
 8 3.24 8.00b 0.07 < 0.01
 40 3.79 8.49c
5 -45 2.15 5.88a
 8 3.13 7.98b 0.13 < 0.01
 40 3.13 8.58c
1Dietary cation-anion difference, mEq of [(Na + K) – (Cl – S)].
2F-test statistic for the effect of DCAD level on DMI.
3F-test statistic for the effect of DCAD level on urinary pH.
4 Linear and quadratic (P < 0.05) effect of DCAD level on urinary pH in all experiments.
a,b,cWithin a column, means without a common superscript letter differ (P < 0.05) within each experi-
ment.
Table 2. Effect of dietary cation-anion difference and basal diet on DMI, urinary pH and fecal pH of 
steers.
   DCAD1
Item 8 -2 -12 -22 -32 SEM2 P-value3 Linear4 Quadratic5
DRC6
DMI, lb/d 20.1a 17.2ab 18.0ab 14.4c  1.6 0.05 0.02 0.76
Urinary pH 7.70a 6.40b 5.90c 5.82c  0.13 < 0.01 < 0.01 < 0.01
Fecal pH 5.92 5.74 5.74 5.83  0.16 0.63 0.28 0.64
WDGS7
DMI, lb/d  19.1 21.7 19.6 19.7 1.7 0.52 0.96 0.40
Urinary pH  6.14a 5.88b 5.71b 5.90b 0.10 < 0.01 < 0.01 < 0.01
Fecal pH  5.86 5.45 5.80 5.61 0.23 0.35 0.16 0.43
1Dietary cation-anion difference, mEq of [(Na + K) - (Cl + S)].
2Standard error of the mean.
3F-test statistic for the effect of DCAD level.
4Contrast for the linear effect of DCAD level within experiment.
5Contrast for the quadratic effect of DCAD level within experiment.
6Dry-rolled corn basal diet.
7Wet distillers grains basal diet.
a,b,c Within a row, means without a common superscript letter differ (P < 0.05).
Figure 1. Effect of DCAD level on urinary pH.
9.5
8.5
7.5
6.5
5.5
U
ri
n
e 
pH
LAMBS 11 treatments, 15 means
STEERS 4 treatments, DRC
STEERS 4 treatments, WDGS
-45 -24 -16 -8 0 9 16 24 32 40
DCAD


Effect of Dietary Cation-Anion Difference on Intake and Urinary pH in High Concentrate Diets

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Nebraska Beef Cattle Reports Animal Science Department 2009 Effect of Dietary Cation-Anion Difference on Intake and Urinary pH in High Concentrate Diets Matt K. Luebbe University of Nebraska - Lincoln, mluebbe2@unl.edu Galen E. Erickson University of Nebraska-Lincoln, gerickson4@unl.edu Terry J. Klopfenstein University of Nebraska-Lincoln, tklopfenstein1@unl.edu Nathan Meyer University of Nebraska-Lincoln, nmeyer2@unl.edu Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr  Part of the Animal Sciences Commons Luebbe, Matt K.; Erickson, Galen E.; Klopfenstein, Terry J.; and Meyer, Nathan, "Effect of Dietary Cation-Anion Difference on Intake and Urinary pH in High Concentrate Diets" (2009). Nebraska Beef Cattle Reports. 526. https://digitalcommons.unl.edu/animalscinbcr/526 This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Nebraska Beef Cattle Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Page 94 — 2009 Nebraska Beef Report  © The Board of Regents of the University of Nebraska.  All rights reserved.Effect of Dietary Cation-Anion Difference on Intake and Urinary pH in High Concentrate DietsMatthew K. LuebbeGalen E. EricksonTerry J. KlopfensteinNathan F. Meyer1SummarySeven experiments evaluated the effect of basal diet and dietary cation-anion difference (DCAD) on urinary and fecal pH, and DMI. Dry-matter intake (DMI) was reduced by DCAD level in dry-rolled corn basal diets but not in diets that included 20% wet distillers grains (WDGS). Urinary pH decreased with DCAD level in all experiments . Fecal pH was not influ-enced by either DCAD level or basal diet. Altering DCAD in concentrate diets with or without WDGS does impact urinary pH.IntroductionNitrogen loss may be reduced by shifting the equilibrium from NH3 to NH4 by acidification of cattle waste. The majority (60-80%) of N excreted by feedlot cattle is in the urine. Low-ering urinary pH may reduce the amount of ammonia volatilized by shifting a greater proportion of N into the ammonium form. One way to reduce urinary pH is by lowering the dietary cation-anion difference (DCAD). Dietary cation-anion dif-ferences can be changed to induce metabolic acidosis, which aids in calcium homeostasis at the onset of lactation (Goff et al., 2004, Journal of Dairy Science). Lowering DCAD has an impact on animal performance, blood pH, and urine pH. If urine and pen surface pH can be lowered by altering DCAD in concentrate diets, N losses may be reduced. The objec-tive of these experiments was to deter-mine the influence of basal diet and DCAD level on urinary and fecal pH and DMI.ProcedureLambsFifteen wether lambs (75 ± 7 lb) were used in five consecutive 3 x 3 Latin squares. Basal diets consisted of 82.5% dry-rolled corn (DRC), 7.5% alfalfa hay, 5% molasses and 5% supplement (DM). Dietary cation-anion difference was calculated as milliequivalents (mEq) of [(Na + K) – (Cl + S)] per 100 g of feed DM. Ammonium chloride, ammonium sulfate and calcium chloride were used to lower DCAD to 0, -8, -16, -24 and -45 mEq, replacing urea, fine ground corn and limestone. Sodium bicarbonate and potassium carbonate were used to increase DCAD to +16, +24, +32 and +40 mEq, replacing fine ground corn. Periods were 14 days in length with an 11-day adaptation to the diet, and 3-day urine collec-tion period. Urine pH was measured immediately after collection at 0700, 1300 and 1900 hours in all experi-ments. Lambs were fed once daily at 0700 for ad libitum intake. Lamb data were analyzed as separate 3 x 3 Latin squares with model effects for period, treatment, time and the treatment x time interaction as fixed effects and lamb as a random effect . Orthogonal contrasts were used to test signifi-cance for the highest order polyno-mial.SteersEight steers (688 + 53) were used in two consecutive 4 x 4 Latin squares with basal diets consisting of either dry-rolled corn (DRC) or wet distill-ers grains (WDGS), replacing DRC at 20% of diet DM, 7.5% alfalfa hay, 5% molasses and 5% supplement (DM). Basal diets were 8 mEq for the DRC diet and -2 mEq for the WDGS diet. Calcium chloride was used to lower DCAD to -2, -12 and -22 mEq in the DRC square and -12, -22 and -32 mEq in the WDGS square. Period length, DM offered, and urine collec-tion procedures were the same as for the lamb experiments. In addition to urine collection, feces were collected at 0700, 1300 and 1900 hours and composited within day for pH mea-surement. Manure pH was analyzed using a 1:1 ratio of distilled water and as-is sample. Urinary pH for steers was ana-lyzed as separate 4 x 4 Latin squares with period, treatment, time and the treatment x time interaction as fixed effects and steer as a random effect. Fecal pH for steers was analyzed in a similar manner without time and the treatment x time interaction in the model. Orthogonal contrasts were used to test significance for the high-est order polynomial. ResultsLambsDry matter intake was not different (P > 0.05) among DCAD level in all experiments. In experiment 1, DMI was similar (P = 0.81) among treat-ments. Dry-matter intake decreased linearly (P = 0.02) with DCAD level in experiment 2. Numerically, DMI was lower for the negative DCAD treatments compared with the control (+8) or positive DCAD treatments in experiments 3, 4 and 5.The treatment x time interaction  for urinary pH was not significant  (P > 0.70) in all experiments. Urinary pH decreased linearly (P < 0.01) in all experiments. The differences in urinary pH from the highest to lowest DCAD level in experiments 1 through 5 were 1.65, 2.31, 2.01, 2.65 and 2.70, respectively. From the lamb experi-ments it appears DCAD does not have a consistent influence on DMI but is effective in manipulating urinary pH at different levels of DCAD.© The Board of Regents of the University of Nebraska.  All rights reserved. 2009 Nebraska Beef Report  — Page 95 SteersDry-matter intake for steers in the DRC experiment was greatest (P = 0.05) for animals consuming DCAD level +8, lowest for -32, and intermediate for -2 and -12 (Table 1). In the WDGS experiment, DMI was not influenced (P = 0.52) by DCAD level (Table 2). The treatment x time interaction for urinary pH was not significant in either experiment  (P > 0.60). Urinary pH for steers in the DRC experiment decreased quadratically (P < 0.01) with DCAD level from 7.70 to 5.82. In the WDGS experiment urinary pH was greater (P < 0.01) for -2 compared with -12, -22 and -32 (7.70, 6.40, 5.90 and 5.82, respectively ). Fecal pH was not different among DCAD levels in either the DRC or WDGS experiment  (P = 0.63 and P = 0.35, respectively). There also was no relationship  (r = 0.02, P = 0.94) of fecal pH to urine pH. Results from the steer experiments are similar to those of the lamb experiments, with an incon-sistent influence of DCAD level on DMI. Urinary pH can be manipulated with DCAD level in either DRC or WDGS basal diets while fecal pH is not influenced.The relative proportions of NH3 compared to NH4 are 0.1%, 1%, 10% and 50% at pH of 6, 7, 8 and 9 (Court et al., 1964 Journal of Soil Science). When evaluating all DCAD levels from both the lamb and steer experi-ments, there appears to be a consistent trend in lowering urinary pH (Figure 1). Lowering DCAD in high concen-trate diets with or without WDGS decreases urinary pH and may reduce ammonia losses from steers or lambs fed negative DCAD diets.1Matthew K. Luebbe, research technician; Galen E. Erickson, associate professor; Terry J. Klopfenstein, professor; Nathan E. Meyer, research technician, Animal Science, Lincoln, Neb.Table 1. Effect of DCAD level on DMI and urinary pH for lambs.Experiment DCAD1 DMI, lb/d Urine pH DMI2 pH3,41 0 2.93 6.67a 8 2.88 7.09b 0.81 < 0.01 16 3.05 8.32c2 -8 3.20 6.10a 8 3.13 8.21b 0.09 < 0.01 24 2.97 8.41b3 -16 2.82 6.37a 8 3.48 8.22b 0.49 < 0.01 32 3.12 8.38b4 -24 2.31 5.84a 8 3.24 8.00b 0.07 < 0.01 40 3.79 8.49c5 -45 2.15 5.88a 8 3.13 7.98b 0.13 < 0.01 40 3.13 8.58c1Dietary cation-anion difference, mEq of [(Na + K) – (Cl – S)].2F-test statistic for the effect of DCAD level on DMI.3F-test statistic for the effect of DCAD level on urinary pH.4 Linear and quadratic (P < 0.05) effect of DCAD level on urinary pH in all experiments.a,b,cWithin a column, means without a common superscript letter differ (P < 0.05) within each experi-ment.Table 2. Effect of dietary cation-anion difference and basal diet on DMI, urinary pH and fecal pH of steers.   DCAD1Item 8 -2 -12 -22 -32 SEM2 P-value3 Linear4 Quadratic5DRC6DMI, lb/d 20.1a 17.2ab 18.0ab 14.4c  1.6 0.05 0.02 0.76Urinary pH 7.70a 6.40b 5.90c 5.82c  0.13 < 0.01 < 0.01 < 0.01Fecal pH 5.92 5.74 5.74 5.83  0.16 0.63 0.28 0.64WDGS7DMI, lb/d  19.1 21.7 19.6 19.7 1.7 0.52 0.96 0.40Urinary pH  6.14a 5.88b 5.71b 5.90b 0.10 < 0.01 < 0.01 < 0.01Fecal pH  5.86 5.45 5.80 5.61 0.23 0.35 0.16 0.431Dietary cation-anion difference, mEq of [(Na + K) - (Cl + S)].2Standard error of the mean.3F-test statistic for the effect of DCAD level.4Contrast for the linear effect of DCAD level within experiment.5Contrast for the quadratic effect of DCAD level within experiment.6Dry-rolled corn basal diet.7Wet distillers grains basal diet.a,b,c Within a row, means without a common superscript letter differ (P < 0.05).Figure 1. Effect of DCAD level on urinary pH.9.58.57.56.55.5Urine pHLAMBS 11 treatments, 15 meansSTEERS 4 treatments, DRCSTEERS 4 treatments, WDGS-45 -24 -16 -8 0 9 16 24 32 40DCAD

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1518&amp;context=animalscinbcr

Effect of Dietary Cation-Anion Difference on Intake and Urinary pH in High Concentrate Diets

Abstract

Similar works

Full text

Available Versions

UNL | Libraries

DigitalCommons@University of Nebraska