Progress Report Series No. 56 
June 1955
AGRICULTURAL EXPERIMENT STATION
of The Alabama Polytechnic Institute, Auburn, Ala.
* * * * E. V. SMITH, Director 
. . . ?
CALEY PEA SILAGE and JOHNSONGRASS HAY
in the RATION of DAIRY COWS NOV 14
W. B. Kelley, L. A. Smith, and George E. Hawkins, JrI
Good quality roughage is of primary importance to the success of dairy farm-
ing. Dairy cows should be provided a liberal allowance of good quality roughage
at all times. When pastures are short or cannot be grazed because of weather
conditions, it is essential that cows be fed harvested roughage in the form of
hay, silage, or a combination of both. Therefore, where economically possible,
all surplus forage should be harvested and stored.
Caley peas (Lathvrus hirsutus), a common crop in the Black Belt Area, make
surplus growth in the spring. Research results at experiment stations 
in other
states indicate that surplus spring growth of forage 
may be preserved satisfac-
torily as silage. Conversely, hay-making conditions are generally poor during
the spring. It would appear, therefore, that the surplus growth of 
Caley peas
should be preserved as silage.
Since there was a lack of information concerning the nutritive 
quality of
Caley pea silage, an experiment was conducted during the winter 
of 1954-55 to
compare Caley pea silage with Johnsongrass hay in the ration 
of lactating dairy
cows. Johnsongrass hay was used as the comparative 
forage because it is the
most common hay crop in the Black Belt Area.
Procedure
The Caley pea silage fed in this study was 
harvested with a field forage
harvester and stored in an upright silo during the spring of 1954. Sodium meta-
bisulfite, at the rate of 8 pounds per ton, was added to the Caley pea forage 
as
a preservative. This silage, which was green in color and had a 
pleasant aroma,
contained 74 per cent moisture when fed. The Johnsongrass hay fed 
during the
experiment was harvested in the summer 
of 1954 and was of good quality. This
hay was field-cred and made with a hay conditioner, 
which cracks the stems to
hasten curing.
2
i_/ Superintendent, Black Belt Substation; 
Assistant Superintendent, Black
Belt Substation; and Associate Dairy Husbandman, Agricultural 
Experiment Station
of the Alabama Polytechnic Institute.
.2/ Mimeographed report, "Report of 
Results from Testing Hay Crushing
Machines." J. L. Butt, 'W. B. Kelley, 
C. M. Martin, and L. A. Smith. Issued
May 1953.
I)
The apparent digestible dry matter contents of the Caley pea silage and the
Johnsongrass hay were determined by. feeding these roughages to yearling steers
that weighed approximately 500 pounds. The average apparent digestibility of
dry matter in Caley pea silage was 55.0 per cent, and that of Johnsongrass hay
was 59.4 per cent. The digestible protein contents on dry matter basis were:
Caley pea silage,. 6.99 per cent; Johnsongrass hay, 3.24 per cent.
The experimental animals were Jersey cows from the Black Belt Substation
herd. During the 2 weeks preceding the experimental period, the cows were fed
Caley pea silage and .JohnsongraSs hay free choice. Immediately preceding 
the
experiment, they were assigned., according to level of milk production, to three
groups of eight cows: each. The average daily levels of milk production of cows
in the three groups were 30.7, 30.7, and 30.8 pounds. During the 6-week experi-
mental period, one group was fed .Caley pea silage, a second group was fed Caley
pea silage plus.Johnsongrass hay, and the .third group was fed Johnsongrass hay.
Concentrate feeding was equalized among the three groups of 
cows; therefore,
any differences between groups with respect to milk production may be attributed
to the roughage. The concentrate was fed twice daily while the cows were in the
stanchions at milking time, and the amounts fed were adjusted at 2-week intervals.
The concentrate mixture consisted of 100 parts ground oats, 20 parts cottonseed
meal (41 per cent protein), and 1,2 parts salt. This mixture was calculated 
to
contain approximately 17 per cent crude protein.
Silage and hay were fed free choice to the cows in individual stalls. Hay
and silage were weighed out twiice daily in ordet to keep fresh 
roughage before
the cows at all times. The refused roughage was weighed back once daily.
Twice daily.the cows were turh d out of the stalls for water, exercise, and
milking. The amount of milk produced at each.milking was weighed and recorded,
Butterfat content of the milk was determined bi-weekly from daily composite
samples, and. the milk was corrected to 4 per cent butterfat for comparison.
In determining the economic aspects of feeding the forages, prices charged
for silage and hay were actual costs of producing, harvesting, storing, and feed-
ing the forages. 'These costs were determined in a previous study at the Black
Belt Substation../ Since two of the ingredients in the concentrate mixture were
purchased and production costs were not available on the oats, the third ingredi-
ent, the concentrate was charged at the prevailing retail price.
Result, and Discussion
The average daily intakes of Caley pea silage and Johnsongrass hay per cow,
by weekly periods, are given in Table I. Changes in the average consumption of
forages throughout the experimental period are shown in Figure 1 The cows fed
Johnsongrass hay alone and those, fed a combination of hay and silage consumed
approximately the same amount of dry matter. Cows fed Caley pea silage as the
only roughage consued les.s forage dry matter than cows in the other groups.
_/ Mimeographed report, "The Cost of Producing, Harvesting, Storing, and
Feeding Caley Pea Silage, 1954." W. B. Kelley and L. A. Smith. Issued April
1955.
Table 1. Average Daily Consumption of Caley Pea 
Silage an4. of Johnsongrass Hay,
by Weekly Periods, Black Belt Sustation, 1954-55
Consumption per cow per 
day
Period
Silage group* Silage-plus-hay group Hay group*
Pounds PoundsoundsPounds
(Silage) (ay)
1st week 36.7 14.3 12. 16.9
2nd week 4703 19.0 13.4 20.1
3rd week 46.6 19.5 13.0 
19.7
4th week 49.7 17.8 12.9 18,3
5th week 4809 15.7 12.9 19.4
6th week 47.0 1Q.0 1392 19.3
AVERAGE 46.0 17.2 13.0 19.0
* Silage averaged 26 per cent dry matter.
* Hay averaged 92,7 per cent dry matter.
Lb. dry matter per
100 lb. body weigh
2.4
2.2
t
o---- 4
2.0
1.8
1.6
1.4
1.2
Legend:
0 ?Caley pea silage
and
Johnsongrass hay
bt~/ .R
V& (:
:igure 1. Average intake by weeks of dry forage per 100 pounds of body weight!
-3-
- ---
e
d, o o
IF-I~i-
,,Y"9
17085,7
The maximum daily level of intake of Caley pea silage by cows in this study
was 49.7 pounds, which is similar to the 53.3 pounds of Johnsongrass silage con-
sumed by cows in a previous study_/f Nevertheless, the 
maximum consumption of
Caley pea silage dry matter was approximately 25 per cent less than the maximum
consumption of Johnsongrass silage. These results suggest that dows weighing
approximately 800 pounds may be expected to consume between 45 and 55 pounds of
fresh silage daily and that the nutrient intake from siage will vary with mois-
ture content and digestibility of the silage.
The quality of the Johnsongrass hay fed 
during this study appeared to be
similar -to that of Johnsongrass hay fed during the winter of 1953-54 in another
study.. The average daily consumption of hay was 19.0 pounds per cow for the
present study, however, as compared with 14.1 pounds per cow during the 1953-54
study. Therefore, it is evident that difference in quality between forages may
not be apparent to the feeder.
The relationship between the type of roughage fed to the cows and the aver-
age daily production of milk is shown in- Table 2, The average daily milk produc-
tion for the entire experiment was slightly greater for cows in the Johnsongrass
hay group than fo'r cowS in the other roughage groups. Statistically, 
however,
the differences in milk production between roughage groups wee not significant.
The variation within groups 
was relatively large.
Analysis of the milk production by weeks reveals significant 
differences
between roughage groups. In every week except the second, the cows on Johnson-
grass hay produced more milk than did' the cows on Caley pea silage or those on
a combination of Caley pea silage and Johnsongrass hay. The levels of production
of the cows fed Caley pea silage as the only roughage and those fed Johnsongrass
hay as the only roiigh age dropped rapidly during the first 2 or 3 weeks. There-
after, changes in production by cowS in these groups were small. The level of
production of cows fed the silage and hay, combination decreased at a rapid rate
during every week except the second; this rate of decline was significantly
greater than that of c6ws fed Johisongrass hay only.
Intake of digestible protein by cows on Johnsongrass hay only was 
very low
and probably accounts for the rapid decline in milk production by cows fed this
roughage. On the other hand, the rapid decline in milk production by cows fed
Caley pea silage only probably was the result of inadequate intake of digestible
nutrients. The rapid decline in milk production by cows fed a combination of
Johnsongrass hay and Caley pea silage does not appear to be related to dietary
inadequacy of either protein or energy.
The cows in all roughage groups lost body weight during the 6-week experi-
mental period. Average losses in weight per cow for all groups were: Caley pea
silage, 60 pounds; Johnsongrass hay and Caley pea silage, 
50 pounds; and Johnson-
grass hay, 59 pounds. Although the cows fed Caley pea silage 
consumed less dry
matter than cows in the other groups, losses in body weight 
by cows in all groups
were similar. This indicates that nutrients supplied 
by Caley pea silage were
efficiently assi..il ted.
4/ Mimeographed report, "Johnsongrass Silage and Johnsongrass 
Hay Feeding
Experiment with Dairy Cows, Black Belt Substation." W. B. 
Kelley, L. A. Smith,
and George E. Hawkins, Jr. Issued February 1955.
B,/J. L. Butt et al., OD. *it.
-4-
Table 2. Average Daily Production of 4 Per Cent 
Fat Corrected Milk by Cows Fed
Caley Pea Silage, Johnsongrass Hay, or the Two Forages Combined,
by Weekly Periods, Black Belt Substation, 1954-55
Period Forage groups
Period , .
Silage Silage-plus-hay Hay
Pound s PoundsPounds
Pre-experimental 30.7 
30.7 30.8
Ist'week 29.3 29.5 29.7
2nd week 27.8 29.1 28.2
3rd week 26.4 27.4 28.0
4th week 26.0 26.3 27.5
5th week 25.7 25.4 27.5
6th week 25.7 24,5 27.6
AVERAGE .26.8 27.0 2 .1
Pounds, milk
Legend:
31 X Caley pea .silage
O ---- Johnsongrass hay
30 & Caley pea silage
and
2)Johnsongrass hay
28 0
o- -,.0- --
27
26
Figure 2. Relationship between forage fed 
and average daily production of milk
corrected to 4 per cent butterfat, by weeks.
-5..
Table 3. Costs and Returns for Milk Produced
Johnsongrass Hay, or the Two Forages 
Combined,
by Cows Fed Caley Pea Silage,
Black Belt Substation, 1954-55
.. . . . , ,, .
- u
..
Roughage groups
Sil age Silage-plus-hay Hay
4% FCM per cow, pounds 1,126 1,134 1,180
Value of milk per cow* $64.18 $64.64 $67.26
Feed costs per cow:**
Caley pea silage $ 5.46 $ 2.04
Johnsongrass hay ---- 3.99 $ 5.88
Concentrates 10.83 10.83 10.83
Total $16.29 $16.86 $16.71
Feed cost per 100 pounds of milk $1.45 $1.49 $1.42
Value of milk per cow above feed
cost $47.89 $47.78 $50.55
* Milk was evaluated at $5.70 per
** Costs were 
figured on 
basis of
ton, and concentra'tes at $60 per ton.
ance for wastage.
100 pounds.
silage at $5.64 per ton, hay at $13.05 per
The hay cost includes 12.5 per cent allow-
A summary of the results of the feeding trial is presented in Table 3. The
Johnsongrass hay group returned $2.66 more per cow above feed cost than the Caley
pea silage group, and $2.77 more per cow than the Caley pea silage--Johnsongrass
hay group. Costs of making silage and hay will vary from farm to farm. There-
fore, the small variations in returns between groups are not considered significant.
Summary
Results of this experiment and the results of a previous study involving
the harvesting of Caley peas as silage show that this crop can be made into good
quality silage..' A dairyman may expect satisfactory results from feeding Caley
pea silage to dairy cattle provided the dry matter intake by cows is sufficient
to meet their energy requirements. In this investigation, the dry matter intake
of Caley pea silage was low, resulting in slightly lower total milk production
than that from feeding Johnsongrass hay.
There was no advantage in milk production from feeding a combination of
Johnsongrass hay and Caley pea silage over feeding either the hay or the silage
alone. This result was due to some peculiarity of Caley pea silage and Johnson-
grass hay fed in combination and might not be expected when other silages and
hays are fed in combination.
6/ Progress Report Series No. 55. "Summary of a One-Year Test on Cost of
Producing, Harvesting, Storing, and Feeding Caley Pea Silage, Black Belt Substa-
tion, 1954." W. B. Kelley and L. A. Smith. Issued April 1955.
-6-