Department of Animal Science Florida Agricultural
Mimeograph Series No. 63-13 Experiment Station
COMPAATIVE FEEDING VALUE OF DRIED CITRUS PULP
AND GROUND SNAPFED CORN FOR FATTENING IAMBS/
C. B. Ammerman, P. E. Loggins and L. R. Arrington2/
The comparative feeding value of dried citrus pulp and ground
snapped corn and the effect of shearing upon summer gains of fattening
lambs in dry lot was studied.
Dried citrus pulp is an important by-product feedstuff particu-
larly in the southeastern United States. It has been used mainly in
the feeding of dairy cattle (Arnold et al., 1941; Becker and Arnold,
1951; and Keener et al,, 1957) but has also found wide acceptance as a
source of nutrients for beef cattle (Kirk and Davis, 1954; and Peacock
and Kirk, 1959). Since -dred citrus pulp has not been extensively
used in practical feeding of lambs and has not been evaluated for this
species in controlled experiments, it seemed desirable to evaluate
this feedstuff as a source of nutrients for fattening' lambs.
Two group-feeding experiments, bothapproxi tely 9 days in
length, were conducted. Experiment 1 vIa sc onucted fro J-3.y 25 to
October 20, 1960 and experiment 2 was cohndcted from Ju.e15 to
September 5, 1961. The rations fed in the t:io pexper nts are shown
in table 1. Either dried citrus pulp or ground-snapped corn consti-
tuted 66% of the total ration. Cottonseed meal,'oermudagrass hay and
salt were added in similar amounts and defluorinated phosphate and
calcium carbonate or ground limestone were added to make the calcium
and phosphorus levels more nearly equal in the two rations. As indi-
cated in table 6 the ground snapped corn rations contained 14.18 and
15.690 protein and the dried citrus pulp rations contained 12.98 and
14.61% protein for the two experiments.
/ This study was supported in part by funds from the Citrus Processors
Association, Winter Haven, Florida and the defluorins.ted phosphate
was supplied by Smith-Douglass Company, Norfolk, Virginia.
Simmerman, Assistant Animal Nutritionist; Loggins, Assistant Animal
Husbandman; Arrington, Associate Animal Nutritionist. The assist-
ance of 14. C. Jayaswal, J. L. Morgan, J. U. Stokes and J. E. Wing
is gratefully acknowledged.
Table 1. Composition of rations
Dried citrus pulp
Snapped corn, ground
Cottonseed meal (412 protein)
Salt (trace mineralized)2/
Vitamins A & D6i
66.0 66.0 -
22.0 22.0 22.0 22.0
9.5 9.5 9.5 9.5
0.7 0.7 1.0 1.0
0.5 0.5 0.5 0.5
1.3 1.0 -
1- -- + +
1 100.0 00.0 100.0 100.0
Ground through one-half inch mesh screen in hammer mill.
2/ The Carey Salt Company, Hutchinson, Kan., listed minimum
analysis in percent; Fe, 0.27; Mn, 0.25; Cu, 0.033; Co,
0.01; Zn, 0.005; I, 0.007; and NaCl, 95.9.
SSmith-Douglass Company, Norfolk, Va.
/ The Dicalite Company, National Bank of Commerce Bldg., New
Orleans 12, La.
SFine-Cal, Calcium Products Division, Georgia Marble Co.,
6/ 2000 I.U. Vitamin A palmitate and 200 I.U. Vitamin D2 added
per pound of ration.
Sixty-eight Florida native or Native-Rambouillet crossbred wean-
ling lambs were fed in two experiments. The lambs were randomly
allotted to treatment according to breed and sex. In experiment 1,
two lots of 6 ewe lambs and 2 wether lambs each were fed either the
dried citrus pulp ration or ground snapped corn ration. In experiment
2, nine ewe lambs were randomly assigned to each lot and two lots were
assigned to each of the dietary treatments. To study the effect of
shearing on lamb performance, 3 ewe lambs and 1 wether lamb were
sheared in each lot in experiment 1 and in the second experiment, 5 of
the 9 ewe lambs in each lot were sheared. The lambs were group fed in
pens which provided access to adequate shelter. The rations were hand
fed twice daily according to appetite and refused feed was weighed back
every few days as required. The lambs were individually weighed at
weekly intervals and live slaughter grades were obtained at the end of
experiment 1 and at the beginning and end of experiment 2 by the same
- 3 -
Climatological data were obtained during the experimental periods
so that effects of shearing could be related to certain environmental
Proximate analyses of feed samples were made according to the
methods of A.O.A.C. (1960) and gross energy was measured with an adia-
batic oxygen bomb calorimeter. The data were analyzed statistically by
analyses of variance as described by Snedecor (1956).
Results and Discussion
Climatological data Climatological data obtained during the two
feeding trials are shown in table 2. The average daily high temperature
during experiment 1 was 88.80 F. and during experiment 2, it was 91.0
F. There was more variation, however, in the average high temperature
for experiment 2 and actually 9 out of 13 weeks had an average tempera-
ture of 900 F. or above. In comparison with this, only 3 weeks during
experiment 1 had average temperatures above 900 F. Nineteen and one-
half inches of rainfall occurred during the first experiment and 26.2
inches during the second experiment.
Table 2. Climatological data obtained
during the two experiments/
Experiment 1 Experiment 2
Av. high temperature, F. 88.8 91.0
Av. low temperature, F. 69.8 70.2
Av. daily total solar
radiation, LangleysL 4T77 597
Total rainfall, in. 19.5 26.2
l/ Temperature and rainfall data obtained from U. S. Weather
Bureau Monthly Publication "Florida Climatological Data"
and solar radiation data obtained from U. S. Weather
Bureau Monthly Publication "Climatological Data National
Summary." The assistance of K. D. Butson, Agronomy
Department, Fla. Agr. Exp. Sta. in securing these data is
2/ One Langley unit is equal to 1 gram calorie per square
centimeter of area.
Effect of ration Lamb gains, feed conversion and live slaughter
grades for the two experiments are shown in table 3. In experiment 1
the average initial weights were similar and the average daily gains of
0.27 lb. for the lambs fed citrus pulp and 0.25 lb. for the lambs fed
ground snapped corn were not significantly different. In general, gains
of this magnitude would not be considered good gains for fattening lambs;
however, the experiments were summer trials and the gains were comparable
to those obtained previously at the Fl.orida station under similar condi-
tions (Loggins et al., 1959). Slightly more feed was required per pound
of gain by those lambs receiving the ground snapped corn ration and the
lambs fed citrus pulp graded slightly higher having an average live
slaughter grade of approximately middle choice.
Table 3. Effect of ration on
lamb gains, feed conversion and grade
Experiment 1 Experiment 2
Citrus Corn Citrus Corn
No. lambs 16 16 18 .8
Initial vt., bo. 62.8 61.6 61.2 60.7
Average daily gain, lb. 0.270 0.254 0.287 0.325*
Feed per pound gain, lb. 8.56 9.80 9.10 8.55
Initial gradeL/ 8.8 8.6
Final grade 10.8 10.3 12.0 12.2
Improvement in grade 3.2 3.6
: Live slaughter grades scored as follows: 7 = low good;
8 = good; 9 = high good; 10 = low choice; 11 = choice;
and 12 = high choice.
Difference significant at 5% level.
At the end of the feeding period, the two wether lambs in each lot
were slaughtered and the rumens were examined. The ruminal epithelium
of the lambs fed ground snapped corn was considered to be a normal
flesh color while that of the lambs fed dried citrus pulp was brown to
dark brown in color. Except for the discoloration, no other differences
were observed which could be attributed to citrus pulp.
The initial weights of the lambs in experiment 2 were similar to
those in experiment 1 and even though there were higher environmental
temperatures 'during the second trial (table 2) the lambs gained faster
and graded higher than in the first experiment. The lambs fed the
ground snapped corn ration gained significantly faster (0.33 compared
with 0.29 lb. per day) and required slightly less feed per pound of
gain than did the lambs fed the dried citrus pulp ration. Final live
slaughter grades of about top choice and average improvement in grade
were comparable for both treatments.
The results obtained in this experiment are similar to those re-
ported with fattening cattle. Kirk et el. (1953) and Chapman et .l.
(1953) compared dried citrus pulp with ground snapped corn for' fattening
steers. The first study involved 3 years of dry lot feeding of yearling
and two.year-old steers while in the second study either dried citrus
pulp or ground snapped corn was fed at the rate of about 5 lbs. per head
daily to steers on pasture. In both studies average daily gains were
slightly greater when ground snapped corn was fed but less feed was
required per pound of gain by the cattle fed citrus pulp. In later
research, Peacock and Kirk (1959) reported no significant differences in
daily gain, improvement in slaughter grade, or dressing percent between
steers in dry lot when fed a concentrate containing 70% dried citrus
pulp or ground snapped corn adequately supplemented with protein and
other essential nutrients.
Effect of shearing The effect of shearing on summer gains and
live slaughter grade is summarized in table 4. Shorn lambs gained
slightly more but not significantly more, and final grades were compara-
ble in experiment 1. In experiment 2, the shorn lambs gained signifi-
cantly more (0.32 compared with 0.28 Ib. per day). Final grades were
comparable but the shorn lambs had a significantly greater improvement
in slaughter grade (P-<.05). Thus, in the experiment which yielded
higher average daily gains and was conducted under a higher average
environmental temperature with greater solar radiation, a significant
effect of shearing was evident. There was no suggestion of an inter-
action between shearing and ration as measured by body weight gain.
Menzies and Erhart (1959) reported equal gains for shorn and unshorn
lambs when fed on fall wheat pasture in Kansas while Warren and Carmon
(1957) in Georgia obtained average daily gains of 0.33 lb. for wooled
lambs and 0.30 lb. for shorn lambs (P<0.05) when fed during the winter.
Table 4. Effect of shearing on lamb gains and grades
Average daily gain, Ib. 0.279 0.248
Final grades_ 10.4 10.7
Average daily gain, lb. 0.324 0.284*
Initial grade 8.3 9.1
Final grade 12.1 12.0
Improvement in grade 3.8 2.9*
/ Live slaughter grades scored as follows: 7 = low good;
8 = good; 9 = high good; 10 = low choice; 11 = choice;
and 12 = high choice.
Difference significant at the 5% level.
Feed consumption Average daily feed consumed and feed refused
are shown in table 5. The lambs had received a ground snapped corn
ration prior to the time the experiments were initiated and this may have
accounted for the lambs receiving this feed eating sooner and consuming
more total feed earlier in the trial than did the lambs receiving the
dried citrus pulp ration. During the first week of both trials, the
lambs receiving the ground snapped corn ration consumed 0.25 Ib. more
feed daily than those receiving the citrus pulp ration. For the entire
feeding period, the lambs fed the ground snapped corn ration consumed an
average of 0.12 Ib. more daily for trial 1 and 0.15 lb. more daily for
trial 2. Bulkiness of the feed also may have been a factor in affecting
feed consumption since the citrus pulp ration weighed 180 less per unit
of volume than the corn ration. The citrus pulp ration had a density of
20.5 Ibs. per cubic foot and the ground snapped corn ration 24.9 lbs.
Table 5. Average feed consumed
and refused per head daily
Feed Consumed Refused feed
Experiment 1 Ib. Lb. of total fed
Citrus 2.40 0.078 3.15
Corn 2.52 0.091 3.49
Citrus 2.71 0.48 15.05
Corn 2.86 0.32 10.06
: All values expressed on a 900 dry matter basis.
More of each ration was consumed and more refused during the
second experiment (table 5). This may have been due in part to more
liberal feeding in the latter trial. In experiment 1, 3.15% of the
total citrus pulp ration was refused compared with 3.49% of the
ground snapped corn ration refused. In experiment 2, 15.05C of the
total citrus pulp ration fed was refused which was 1 1/2 times the
amount of the ground snapped corn ration refused.
The nutrient composition of the rations fed and of the refused
feed is shown in table 6. The refused feed from the corn ration was
rather similar in composition to the ration fed. There was, however,
slightly more protein and fiber in the refused feed causing a corre-
sponding decrease in nitrogen-free extract. For both experiments,
the citrus pulp rations contained an average of 13.8% protein while
the refused feed from this ration contained an average of 26.50 pro-
tein. The refusal of the citrus pulp ration was greater in experi-
ment 2 and while the ration as fed in this trial contained 14.61S
protein, the feed actually consumed contained only 12.620 protein.
Thus while 12.62% protein may have been adequate for fattening lambs
under the conditions of this experiment, serious problems could have
been encountered had the complete ration been borderline in protein.
The nature of the feed refused suggested a dislike for the finer parti-
cles of the ration perhaps the finer particles of the citrus pulp
itself and with the inability to separate these from the cottonseed
meal this could account for the higher level of protein. The increased
ash content also suggested that citrus fines were being refused since
this material has been shown to be high in minerals (Ammerman et al.,
Table 6. Nutrient composition of rations and refused feed/
Ether Crude free
Protein Ash Extract Fiber Extract Therms/lb.
Ground Snapped Corn
Ration 14.18 4.87 1.25 14.56 55.14 1.74
Refused feed 14.98 4.64 0.83 20.12 49.43 1.75
Dried Citrus Pulp
Ration 12.98 6.61 1.61 16.50 52.30 1.69
Refused feed 27.26 9.50 0.86 15.16 37.22 1.68
Grcuund Snapped Corn
Ration 15.69 4.54 1.76 13.65 54.36 1.75
Refused feed 17.46 5.53 1.10 15.68 50.23 1.71
Dried Citrus Pulp
Ration 14.61 6.26 1.76 14.15 53.22 1.70
Refused feed 25.79 10.00 1.22 14.31 38.68 1.72
1 All values expressed on a 90% dry matter basis.
Two 90-day summer feeding trials involving 68 lambs were conducted
to compare rations containing either 66% dried citrus pulp or ground
snapped corn as feeds for lambs in dry lot and to determine the effect
of shearing upon summer weight gains under Florida conditions. The
results of these feeding trials may be summarized as follows. (1) Both
dried citrus pulp and ground snapped corn can be used in lamb feeding
programs. Lambs fed citrus pulp gained slightly more the first year
while in the second year the lambs fed ground snapped corn gained signifi-
cantly more. (2) Shearing significantly improved average daily gains and
live slaughter grades in the experiment conducted under higher environ-
mental temperatures and in which heavier lamb gains were obtained.
(3) Lambs began eating the ground snapped corn ration more readily and
had a higher average daily consumption of the corn ration for both trials.
(4) These trials suggest that where considerable sorting and selection of
feed occurs the nutrient composition of the feed consumed iay be consider-
ably different from that of the feed fed.
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