Eighteen spring-calving heifers were paired by expected calving date and assigned to treatment. Treatments were a high undegradable intake protein supplement (CON) or one based on dry corn gluten feed (TRT). Heifers were fed to consume low-quality hay ad libitum. Supplement type did not affect body condition, milk production, or calf ADG. TRT heifers lost less weight than CON heifers. There was no effect of supplement on forage intake. Intake changed cubically with respect to calving; decreasing 17% during the three weeks prior to calving, and increasing 18% the week after calving

Adams, Don C.

Applegarth, Andrew F.

Klopfenstein, Terry J.

Loy, Tim W.

Musgrave, Jacqueline A.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Nebraska Beef Cattle Reports Animal Science Department 1-1-2004 Effect of Gestation and Supplementation on Intake of Low-Quality Forage Tim W. Loy University of Nebraska-Lincoln Don C. Adams University of Nebraska-Lincoln, dadams1@unl.edu Terry J. Klopfenstein University of Nebraska-Lincoln, tklopfenstein1@unl.edu Jacqueline A. Musgrave University of Nebraska-Lincoln, jmusgrave1@unl.edu Andrew F. Applegarth University of Nebraska-Lincoln, andy.applegarth@unl.edu Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr  Part of the Animal Sciences Commons Loy, Tim W.; Adams, Don C.; Klopfenstein, Terry J.; Musgrave, Jacqueline A.; and Applegarth, Andrew F., "Effect of Gestation and Supplementation on Intake of Low-Quality Forage" (2004). Nebraska Beef Cattle Reports. 199. https://digitalcommons.unl.edu/animalscinbcr/199 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. 2004 Nebraska Beef Report — Page 10Effect of Gestation and Supplementation onIntake of Low-Quality ForageTim W. LoyDon C. AdamsTerry J. KlopfensteinJacki A. MusgraveAndy Applegarth1SummaryEighteen spring-calving heiferswere paired by expected calving dateand assigned to treatment. Treatmentswere a high undegradable intake pro-tein supplement (CON) or one basedon dry corn gluten feed (TRT). Heiferswere fed to consume low-quality hayad libitum. Supplement type did notaffect body condition, milk production,or calf ADG. TRT heifers lost lessweight than CON heifers. There wasno effect of supplement on forageintake. Intake changed cubically withrespect to calving; decreasing 17%during the three weeks prior to calv-ing, and increasing 18% the week aftercalving.IntroductionPre-partum nutrition has provento be an important determinant ofsubsequent reproductive perfor-mance, calf health and performanceand overall ranch profitability.Many spring-calving herds relyheavily on low-quality forages tomeet the nutritional needs of cowsand heifers. However, often theseforages are of low enough qualitythat passage rate is slowed, result-ing in reduced intake. Someresearch has indicated that advanc-ing gestation may inhibit intakeimmediately prior to calving, asfetal development exerts a physicallimitation. In addition to reducedcapacity to accommodate largevolumes of forage, changes in hor-monal profile occurring beforeparturition may inhibit intake aswell. The net result is low intake ofa low-quality feed at a time whennutrient requirements are increas-ing.Gestating heifers are particularlyat risk due to their reduced capacityto consume bulky feeds and theirhigher nutrient requirements rela-tive to mature cows. Gestatingheifers grazing native range in theNebraska Sandhills consumed only1.3% of BW (2001 Nebraska BeefReport, pp. 19-22), which translatesinto a negative energy balance dur-ing late gestation. Providing a non-bulky, energy-dense supplementlate in gestation may improvefemale performance by correctingenergy deficiencies that occur as aresult of intake depression.The objective of this trial was toexamine the effect of gestation onintake of low-quality forage and tocompare the effect of two supple-ments on intake, BCS, weightchange, and milk production.ProcedureThe study was conducted at theGudmundsen Sandhills Laboratorynear Whitman, NE. Eighteenspring-calving heifers (894.8 + 71.0)were paired by expected calvingdates and assigned to one of twotreatments. Treatments (Table 1)included an undegradable intakeprotein (UIP) supplement (CON;n = 4), and a dry corn gluten feed-based supplement (TRT; n = 5).Grass hay was fed for ad libitumconsumption. Refusals wereweighed weekly, with hay and ortsamples collected at that time forDM analysis. Upland (3.8% CP,48% TDN) and meadow (9.1% CP,58% TDN) hays were ground witha bale processor and combinedsuch that the quality of forageoffered was similar to what wouldcommonly be available throughstanding winter range (1997Nebraska Beef Report, pp. 3-6). Bothsupplements were formulated tomeet metabolizable protein (MP)and energy requirements (2000Nebraska Beef Report, pp. 7-10).The supplements used and thefeeding schedule of each werebased on a previous study (2003Nebraska Beef Report, pp. 5-8) inwhich the CON supplement wasused to meet metabolizable proteinrequirements, while the TRTsupplement was designed to meetenergy demands as well as proteinrequirements. In general, theamount of each increased as gesta-tion advanced, however the TRTsupplement was increased to alarger extent (Table 1).The trial began December 18 andconcluded May 7, with weights andbody condition scores (BCS)recorded on two consecutive daysat those times. Heifers wereweighed and assigned BCS every28 days throughout the study, withdata taken in the morning beforePage 11 — 2004 Nebraska Beef Reportalthough studies showing thiseffect have not been conducted withheifers in late gestation. A substitu-tion effect was not observed in thisstudy, even with TRT supplementfed as high as 6.8 lb per day. Ifheifers in late gestation are eating tomeet the high energy demandsassociated with rapid fetal develop-ment but are limited by physical fill,it appears supplements can be fedat a high level without reducingforage intake.Forage intake changed cubically(P < 0.03) during a seven-weekperiod around calving (Figure 1).Maximum DM intake for the entiretrial (26.3 lb) occurred three weeksprior to calving, and was 17%lower (21.9 lb) at calving. By theweek after calving, intake hadreturned to 25.7 lb, an 18% increase.Total DM intake differed(P < 0.01) by treatment before calv-ing (Figure 2). Relative to CON, TRTheifers averaged 17% higher DM in-takes during the five-week periodprior to calving. This is attributableto the fact that TRT heifers received5.2 lb more supplement than CONheifers, without a concomitantreduction in forage intake. Few dataare available that report intakesduring this stage of production.Forage and heifer descriptors wereused in the NRC (1996) NutrientRequirements of Beef Cattle modelto compare predicted vs observedintakes. The model under-predictedtotal DM intake for all heifers, withpredicted total intake similar to ob-served forage intake. Total intakefor CON heifers was 4 to 5% higherthan predicted. Because TRT heiferswere fed higher levels of supple-ment, there was a larger under-pre-diction (25%) of total DM intake.Average calving date was March19. Heifers calved within six daysof their pen mates with one excep-tion, in which the pair calved 14days apart. The average number ofdays between heifers within a penwas 2.1 days. The pen with the two-week lag between heifers showed anearly level intake pattern through-(Continued on next page)Table 1. Composition and feeding schedule of treatment supplements.TreatmentItem CON TRTIngredient, % DMDry gluten feed — 72.00Feather meal 40.00 —Sunflower meal 30.00 22.40Wheat middlings 26.25 —Molasses 2.50 2.50Bentonite — 2.50Salt 1.00 —Starch — 0.25Fat — 0.25Vitamin premix 0.26 0.05Trace mineral premix — 0.05Feeding schedule, lb/dayJanuary 1.0 3.6February 1 to 14 1.1 5.1February 15 to calving 1.6 6.8Figure 1. Change in voluntary forage intake three weeks before and after calving.Week 0 represents the week both heifers in the pen calved. Intakechanged cubically (P = 0.03) over time.302520151050Forage intake, lb DM-3 -2 -1 0 1 2 3Time relative to calving, weeksy = 0.0833x3 + 1.2738x2 - 5.5929x + 30.743R2 = 0.5908feeding. Milk production wasmeasured in May using a 12-hourweigh-suckle-weigh. Briefly, calveswere sorted for approximately eighthours, commingled and allowed tonurse, then re-sorted for approxi-mately 12 hours. Calves were thenweighed, allowed to nurse, andre-weighed. The difference in thetwo weights was assumed to befrom milk intake. Calf birth weightsand ADG from birth to the conclu-sion of the trial were recorded.In the intake analysis, time zerorepresents the last intake measuredbefore the second heifer in each penhad calved. Times (1, 2, etc.) repre-sent weeks relative to calving, withnegative numbers representingweeks prior to calving and positivenumbers after calving. A penremained on the treatment supple-ment and experimental hay mixtureuntil both heifers had calved, atwhich time all heifers were fed acommon supplement and ad libi-tum meadow hay.ResultsVoluntary forage intake was notaffected by treatment, and no timeby treatment interaction wasdetected. Previous data have shownthat supplementing at high levelscan reduce voluntary forage intake,2004 Nebraska Beef Report — Page 12out, likely due to the increasedintake during lactation of oneheifer, masking the decreasedintake during late gestation of theother.Heifers weighed 895 lb in Janu-ary and did not differ by treatment.By May, CON heifers had lost 54 lb,compared to three lb for TRT(P = 0.02). The lack of differences inforage intake suggests that weightdifferences were not due to treat-ment effects on rumen fill. AverageBCS was 5.2 in January and 5.0 inMay and was not affected by treat-ment. Weight and BCS data appearto disagree, although more animalsmay be necessary to detect treat-ment effects on body condition.While no difference was observedin condition, the difference inweight change may suggest thatsupplementing a high-energy feedin a non-bulky form allowed TRTheifers to maintain energy balance.With a loss of over 50 lb, heifers inthe CON group appear to have beenin a negative energy balance enter-ing the breeding season. A largernumber of animals is necessary tomeasure differences in reproductiveperformance that could result fromtreatments applied during gesta-tion.Some producers express concernthat feeding higher levels of energyin late gestation may lead to heavierbirth weights and an increased in-cidence of dystocia. Average birthweight in this trial was 78.7 lb, andwas not affected by treatment. Twoheifers from each treatment wereassisted at calving. Average milkintake by calves nursing CONheifers was 14.0 lb, and 10.8 lb forTRT (P = 0.12). Calf weight in May(167.7 lb) and calf ADG from birthto May (1.79 lb/day) were notaffected by treatment.In conclusion, voluntary forageintake by bred heifers changedcubically with respect to calving.Intake declined prior to calving andincreased rapidly after calving.Feeding a high level of a supple-ment high in digestible fiber did notreduce forage intake, did not affectbirth weights or calf performanceand decreased cow weight loss.1Tim Loy, research technician; DonAdams, professor Animal Science, NorthPlatte; Terry Klopfenstein, professorAnimal Science, Lincoln; Jacki Musgrave,research technician; Andy Applegarth,manager, Gudmundsen SandhillsLaboratory.○○○○○○○○○○○○○○○○○Figure 2. Effect of supplement on total dry matter intake over time. ‘CON’ = undegradable intake proteinsupplement; ‘TRT’ = dry corn gluten feed-based supplement. Values within a week differed(P < 0.05) between treatments from -8 to 0 weeks.36322824201612840Total DM intake, lb/dCONTRT-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6Time Relative to Calving, weeks

Effect of Gestation and Supplementation on Intake of Low-Quality Forage

UNL | Libraries

University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Nebraska Beef Cattle Reports Animal Science Department 
1-1-2004 
Effect of Gestation and Supplementation on Intake of Low-Quality 
Forage 
Tim W. Loy 
University of Nebraska-Lincoln 
Don C. Adams 
University of Nebraska-Lincoln, dadams1@unl.edu 
Terry J. Klopfenstein 
University of Nebraska-Lincoln, tklopfenstein1@unl.edu 
Jacqueline A. Musgrave 
University of Nebraska-Lincoln, jmusgrave1@unl.edu 
Andrew F. Applegarth 
University of Nebraska-Lincoln, andy.applegarth@unl.edu 
Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr 
 Part of the Animal Sciences Commons 
Loy, Tim W.; Adams, Don C.; Klopfenstein, Terry J.; Musgrave, Jacqueline A.; and Applegarth, Andrew F., 
"Effect of Gestation and Supplementation on Intake of Low-Quality Forage" (2004). Nebraska Beef Cattle 
Reports. 199. 
https://digitalcommons.unl.edu/animalscinbcr/199 
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. 
2004 Nebraska Beef Report — Page 10
Effect of Gestation and Supplementation on
Intake of Low-Quality Forage
Tim W. Loy
Don C. Adams
Terry J. Klopfenstein
Jacki A. Musgrave
Andy Applegarth1
Summary
Eighteen spring-calving heifers
were paired by expected calving date
and assigned to treatment. Treatments
were a high undegradable intake pro-
tein supplement (CON) or one based
on dry corn gluten feed (TRT). Heifers
were fed to consume low-quality hay
ad libitum. Supplement type did not
affect body condition, milk production,
or calf ADG. TRT heifers lost less
weight than CON heifers. There was
no effect of supplement on forage
intake. Intake changed cubically with
respect to calving; decreasing 17%
during the three weeks prior to calv-
ing, and increasing 18% the week after
calving.
Introduction
Pre-partum nutrition has proven
to be an important determinant of
subsequent reproductive perfor-
mance, calf health and performance
and overall ranch profitability.
Many spring-calving herds rely
heavily on low-quality forages to
meet the nutritional needs of cows
and heifers. However, often these
forages are of low enough quality
that passage rate is slowed, result-
ing in reduced intake. Some
research has indicated that advanc-
ing gestation may inhibit intake
immediately prior to calving, as
fetal development exerts a physical
limitation. In addition to reduced
capacity to accommodate large
volumes of forage, changes in hor-
monal profile occurring before
parturition may inhibit intake as
well. The net result is low intake of
a low-quality feed at a time when
nutrient requirements are increas-
ing.
Gestating heifers are particularly
at risk due to their reduced capacity
to consume bulky feeds and their
higher nutrient requirements rela-
tive to mature cows. Gestating
heifers grazing native range in the
Nebraska Sandhills consumed only
1.3% of BW (2001 Nebraska Beef
Report, pp. 19-22), which translates
into a negative energy balance dur-
ing late gestation. Providing a non-
bulky, energy-dense supplement
late in gestation may improve
female performance by correcting
energy deficiencies that occur as a
result of intake depression.
The objective of this trial was to
examine the effect of gestation on
intake of low-quality forage and to
compare the effect of two supple-
ments on intake, BCS, weight
change, and milk production.
Procedure
The study was conducted at the
Gudmundsen Sandhills Laboratory
near Whitman, NE. Eighteen
spring-calving heifers (894.8 + 71.0)
were paired by expected calving
dates and assigned to one of two
treatments. Treatments (Table 1)
included an undegradable intake
protein (UIP) supplement (CON;
n = 4), and a dry corn gluten feed-
based supplement (TRT; n = 5).
Grass hay was fed for ad libitum
consumption. Refusals were
weighed weekly, with hay and ort
samples collected at that time for
DM analysis. Upland (3.8% CP,
48% TDN) and meadow (9.1% CP,
58% TDN) hays were ground with
a bale processor and combined
such that the quality of forage
offered was similar to what would
commonly be available through
standing winter range (1997
Nebraska Beef Report, pp. 3-6). Both
supplements were formulated to
meet metabolizable protein (MP)
and energy requirements (2000
Nebraska Beef Report, pp. 7-10).
The supplements used and the
feeding schedule of each were
based on a previous study (2003
Nebraska Beef Report, pp. 5-8) in
which the CON supplement was
used to meet metabolizable protein
requirements, while the TRT
supplement was designed to meet
energy demands as well as protein
requirements. In general, the
amount of each increased as gesta-
tion advanced, however the TRT
supplement was increased to a
larger extent (Table 1).
The trial began December 18 and
concluded May 7, with weights and
body condition scores (BCS)
recorded on two consecutive days
at those times. Heifers were
weighed and assigned BCS every
28 days throughout the study, with
data taken in the morning before
Page 11 — 2004 Nebraska Beef Report
although studies showing this
effect have not been conducted with
heifers in late gestation. A substitu-
tion effect was not observed in this
study, even with TRT supplement
fed as high as 6.8 lb per day. If
heifers in late gestation are eating to
meet the high energy demands
associated with rapid fetal develop-
ment but are limited by physical fill,
it appears supplements can be fed
at a high level without reducing
forage intake.
Forage intake changed cubically
(P < 0.03) during a seven-week
period around calving (Figure 1).
Maximum DM intake for the entire
trial (26.3 lb) occurred three weeks
prior to calving, and was 17%
lower (21.9 lb) at calving. By the
week after calving, intake had
returned to 25.7 lb, an 18% increase.
Total DM intake differed
(P < 0.01) by treatment before calv-
ing (Figure 2). Relative to CON, TRT
heifers averaged 17% higher DM in-
takes during the five-week period
prior to calving. This is attributable
to the fact that TRT heifers received
5.2 lb more supplement than CON
heifers, without a concomitant
reduction in forage intake. Few data
are available that report intakes
during this stage of production.
Forage and heifer descriptors were
used in the NRC (1996) Nutrient
Requirements of Beef Cattle model
to compare predicted vs observed
intakes. The model under-predicted
total DM intake for all heifers, with
predicted total intake similar to ob-
served forage intake. Total intake
for CON heifers was 4 to 5% higher
than predicted. Because TRT heifers
were fed higher levels of supple-
ment, there was a larger under-pre-
diction (25%) of total DM intake.
Average calving date was March
19. Heifers calved within six days
of their pen mates with one excep-
tion, in which the pair calved 14
days apart. The average number of
days between heifers within a pen
was 2.1 days. The pen with the two-
week lag between heifers showed a
nearly level intake pattern through-
(Continued on next page)
Table 1. Composition and feeding schedule of treatment supplements.
Treatment
Item CON TRT
Ingredient, % DM
Dry gluten feed — 72.00
Feather meal 40.00 —
Sunflower meal 30.00 22.40
Wheat middlings 26.25 —
Molasses 2.50 2.50
Bentonite — 2.50
Salt 1.00 —
Starch — 0.25
Fat — 0.25
Vitamin premix 0.26 0.05
Trace mineral premix — 0.05
Feeding schedule, lb/day
January 1.0 3.6
February 1 to 14 1.1 5.1
February 15 to calving 1.6 6.8
Figure 1. Change in voluntary forage intake three weeks before and after calving.
Week 0 represents the week both heifers in the pen calved. Intake
changed cubically (P = 0.03) over time.
30
25
20
15
10
5
0
Fo
ra
ge
 i
nt
ak
e,
 l
b 
D
M
-3 -2 -1 0 1 2 3
Time relative to calving, weeks
y = 0.0833x3 + 1.2738x2 - 5.5929x + 30.743
R2 = 0.5908
feeding. Milk production was
measured in May using a 12-hour
weigh-suckle-weigh. Briefly, calves
were sorted for approximately eight
hours, commingled and allowed to
nurse, then re-sorted for approxi-
mately 12 hours. Calves were then
weighed, allowed to nurse, and
re-weighed. The difference in the
two weights was assumed to be
from milk intake. Calf birth weights
and ADG from birth to the conclu-
sion of the trial were recorded.
In the intake analysis, time zero
represents the last intake measured
before the second heifer in each pen
had calved. Times (1, 2, etc.) repre-
sent weeks relative to calving, with
negative numbers representing
weeks prior to calving and positive
numbers after calving. A pen
remained on the treatment supple-
ment and experimental hay mixture
until both heifers had calved, at
which time all heifers were fed a
common supplement and ad libi-
tum meadow hay.
Results
Voluntary forage intake was not
affected by treatment, and no time
by treatment interaction was
detected. Previous data have shown
that supplementing at high levels
can reduce voluntary forage intake,
2004 Nebraska Beef Report — Page 12
out, likely due to the increased
intake during lactation of one
heifer, masking the decreased
intake during late gestation of the
other.
Heifers weighed 895 lb in Janu-
ary and did not differ by treatment.
By May, CON heifers had lost 54 lb,
compared to three lb for TRT
(P = 0.02). The lack of differences in
forage intake suggests that weight
differences were not due to treat-
ment effects on rumen fill. Average
BCS was 5.2 in January and 5.0 in
May and was not affected by treat-
ment. Weight and BCS data appear
to disagree, although more animals
may be necessary to detect treat-
ment effects on body condition.
While no difference was observed
in condition, the difference in
weight change may suggest that
supplementing a high-energy feed
in a non-bulky form allowed TRT
heifers to maintain energy balance.
With a loss of over 50 lb, heifers in
the CON group appear to have been
in a negative energy balance enter-
ing the breeding season. A larger
number of animals is necessary to
measure differences in reproductive
performance that could result from
treatments applied during gesta-
tion.
Some producers express concern
that feeding higher levels of energy
in late gestation may lead to heavier
birth weights and an increased in-
cidence of dystocia. Average birth
weight in this trial was 78.7 lb, and
was not affected by treatment. Two
heifers from each treatment were
assisted at calving. Average milk
intake by calves nursing CON
heifers was 14.0 lb, and 10.8 lb for
TRT (P = 0.12). Calf weight in May
(167.7 lb) and calf ADG from birth
to May (1.79 lb/day) were not
affected by treatment.
In conclusion, voluntary forage
intake by bred heifers changed
cubically with respect to calving.
Intake declined prior to calving and
increased rapidly after calving.
Feeding a high level of a supple-
ment high in digestible fiber did not
reduce forage intake, did not affect
birth weights or calf performance
and decreased cow weight loss.
1Tim Loy, research technician; Don
Adams, professor Animal Science, North
Platte; Terry Klopfenstein, professor
Animal Science, Lincoln; Jacki Musgrave,
research technician; Andy Applegarth,
manager, Gudmundsen Sandhills
Laboratory.
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
Figure 2. Effect of supplement on total dry matter intake over time. ‘CON’ = undegradable intake protein
supplement; ‘TRT’ = dry corn gluten feed-based supplement. Values within a week differed
(P < 0.05) between treatments from -8 to 0 weeks.
36
32
28
24
20
16
12
8
4
0
T
ot
al
 D
M
 i
nt
ak
e,
 l
b/
d
CON
TRT
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
Time Relative to Calving, weeks


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Effect of Gestation and Supplementation on Intake of Low-Quality Forage

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