/ 70 -
LIMITED VS FULL FEED OF COOCE,'TRATES FOR FATTeNING
STEERS ON ST. AUGUSTINE PAI-,TUih A1iD SILAGL
D. 17. Beardsley 1/
This report presents the results of the first
in a series of steer feeding trials comparing
the value of various levels of concentrates fed
to steers being fattened on pasture and on grass
silage in the dry lot.
EVERGLADES STATION iMi LO REPORT 5$-7
Belle Glade, Florida
January 10, 1955
FEB 3 1955
-ILJ U-,--<^' M'v u'tJ'^ L'^ t^( IU, ''_ U,'I-''L' _"- U-'t^ 1 '^C_'t.'' N
LIMITED VS FULL FEED OF CONCENTRATES FOR FATTENING
STEERS ON ST. AUGJC TINE PASTORh AND SILAGE
D. W. Beardsley 1/
The practice of feeding supplementary concentrates to steers on pasture
has increased considerably in this area in the last few years. Studies begun at
the Everglades Station in the thirties have shown this to be an economical method
of producing steers of acceptable finish for slaughter.
Because of the fluctuation in feed and cattle prices, the program for
fattening steers on grass cannot re:iain fixed from year to year if the maximum
return is to be obtained for the investment in cattle and feed. Under present
conditions it is highly desirable to make maximum use of roughage consistent with
the production of quality beef.
In an attempt to obtain some of the answers to questions arising from
the use of pastures and silages for the major portion of a fattening ration, a
series of feeding trials was begun comparing limited with full feed of concen-
trates to steers on pasture, and limited concentrates with grass silage in the
dry lot. The first trial was conducted during the spring of 1954. Another trial
is now in progress.
Method of Procedure
Sixty steers, mostly two-year olds, of grade Angus, Hereford, Brahman
and Devon breeding, were divided into uniform lots of ten steers each. Five lots
received their respective supplements while grazing on Roselawn St. Augustine
pasture. The sixth lot was fed St. Augustine grass silage in the drylot. Each
lot on pasture had access to 4 acres of Roselawn St. Augustine grass.
The steers on pasture were fed equal parts of ground snapped corn, dried
citrus pulp, and straight mill-run blackstrap-l or urea-fortified (4% urea)./ black-
strap molasses. The steers on silage were fed similarly except that cottonseed meal
and urea replaced part of the corn and pulp. The steers on pasture receiving 6
pounds of total concentrates daily per steer were given straight mill-run black-
strap. Tlhen on full feed, the urea fortified molasses was given to supply the extra
crude protein needed. A complete mineral mixture was riven free-choice to all lots.
At bi-weekly intervals throughout the feeding period, samples of the
growing tips and leaves of the grass in the pastures were taken and analyzed for
crude protein. These analyses ranged from 15 to 18 percent crude protein on a dry
The St. Augustine grass silage was made from rather mature grass and had
considerable dead leaves and stems in it. It was ensiled in an upright concrete
silo with a small amount of blackstrap molasses added to some layers. When fed out,
the silage had a very rancid, butyric acid odor, but consumption did not seem to be
affected appreciably. Chemical analysis of the material as fed showed 6 to 8 per-
cent crude protein on a dry-matter basis.
I/ Assistant Animal Husbandman, Everglades Experiment Station, Belle Glade, Florida
/ ill-run heavy blackstrap molasses, 8h.5 degrees brix, was furnished by United
States Sugar Corporation, Clewiston, Florida. The urea-fortified molasses was
also mixed by U.S.S.C.
/ Urea (Two-Sixty-Two) was furnished by E. I. duPont de Nemours & Company
All steers were given their concentrate supplement once a day, in the
morning. The drylot fed steers received silage in the morning with the concen-
trates and as much more silage in the evening as would be cleaned up by the next
morning. The full-fed steers on pasture were given as much of the concentrate
mixture as they would clean up before the next feeding.
The various treatments were as follows:
Lot I Pasture only.
Lot II Pasture plus 6 lbs. of concentrates per steer
for 120 day-.
Lot III Pasture plus 6 lbs. of concentrates per steer
for 60 days; full feed for 60 days.
Lot IV Pasture alone for 60 days; full feed for 60
Lot V Pasture plus full feed of concentrates for 120
Lot VI Silage plus 6 lbs. of concentrates for 60 days;
9 lbs. for 60 days, fed in drylot.
Results and Discussion
The steers were slaughtered at Ocala and paid for on the basis of
carcass grade-out. Individual slaughter data was obtained on all steers. The
results of the trial are shown in Tables 1 and 2.
Good gains were made by all five lots of steers on pasture. As would
be expected, the steers which received the most concentrates made the highest
gains, those on grass alone, the lowest gains, and the ones on limited concentrates
were intermediate. The steers in Lot V on full feed attained a maximum consump-
tion of 19.5 pounds of total concentrates after about 4i weeks on test. They main-
tained'this rate of consumption for about 6 veeks and then began to refuse a little
feed regularly. The amount of the ration was reduced to 16.5 pounds per steer, then
gradually brought back to 18 pounds and continued at this level for the rest of the
trial. Lots III and IV, full-fed for a shorter period, attained this maximum con-
sumption level of 19.5 pounds per steer in 3 to 4 weeks and maintained this level
for the remainder of the feeding period.
The steers fed the St. Augustine silage plus limited concentrates in
drylot, made no better gains than the ones on grass alone. The consumption of
silage was about what was expected. Since the steers getting 6 pounds of concen-
trates daily per head in Lot II made considerably better gains than the silage-fed
group, the silage was obviously inferior to the fresh grass. Again, this might be
anticipated because the grass was at its best during the spring and the silage was
only fair quality.
Although the steers on grass alone made good gains, they did not carry
much finish and consequently made little iaproveaent in grade. The full-fed
steers carried the most finish and attained the highest average grade. One steer
in this lot, graded as a common feeder at the beginning of the test, still graded
only a utility slaughter steer after 120 days on feed. Throughout the feeding
period it was observed that the higher grading steers at the beginning of the test
were thriftier, made better gains, and scored higher at slaughter than the steers
given the lower feeder grades.
Table 1. Gains and Rations of Steers Fattened on Pasture and Silage.
Lot Number I II III IV V VI
Number of steers 10 10 10 10 10 10
Av. initial wt. Ibs. 733 723 734 731 728 670
Av. final wt. Ibs. 908 941 966 953 981 845
Total gain/steer, lbs. 175 218 232 222 253 175
Av. daily gain, lbs. 1.45 1.81 1.94 1.85 2.11 1.45
Av. daily ration, lbs.
Ground snapped corn 2.0 4.0 6.22/ 5.8 1.9
Dried citrus pulp 2.0 4.0 6.21/ 5.8 1.9
Blackstrap lholasses 2.0 4.0 6.21/ 5.8 2.5
Urea (262 % C.P.) -- ( .24) (.25)2/ (.23)2/ .22
Cottonseed meal (41% C.P.) -- 1.4
i4ineral mixture 0.03 0.01 0.03 0.02 0.03 0.09
St. Augustine silage -- -- 42.1
St. Augustine pasture/ 101 78 49 61 23 -
Av. lbs. feed per cwt. gain
Ground snapped corn -- 110 206 167 277 130
Dried citrus pulp 110 206 167 277 130
Blackstrap molasses 110 206 167 277 ,171
Urea (262% C.P.) (6.2)1/ (6.7)2/ (11.08)2/ 1
Cottonseed meal (41% C.P.) -- --. 95
Mineral mixture 2.12 0.74 1.42 1.26 1.46 5.83
St. Augustine silage -- 2890
St. Augustine pastureW 6938 4292 2516 3320 1078
I/ Fed last 60 days only.
Fed as urea-fortified (4% urea) molasses last 60 days only.
Fed as urea-fortified (14 urea) molasses.
SCalculated on basis of TDN estimated in supplement and grass, and amount of
TDN estimated necessary for maintenance and gains.
Table 2. Ration Costs and Marketing Data on Steers Fattened on Pasture and Silage.
I II III IV V VI
Av. Killing t., Ibs.i/ 841 887 903 881 912 772
Av. Shrink, We/ 7.3 5.7 6.6 7.6 7.0 8.5
Av, Dressing percentage3/ 57.2 60.1 61.1 60.7 62.2 56,1
Feeder grades: common 2 2 2 2 2 2
medium 7 8 8 7 7 8
good 1 0 0 1 1 0
Carcass grades: utility 7 1 2 1 1 6
commercial 2 8 6 8 6 4
good 1 1 2 1 3 0
Feed cost per cwt. gain 4/ $ 2.0 $ 8.10 $13.50 $13.10 $18.60 $20.30
Total feed cost per steer 4.20 17.77 31.51 26.97 47.19 35.61
Av. cost per steer
into feed lot 297.97 95.67 96.98 97.77 97.64 88.64
Av. selling price
per cwa. 6 13.90 16.05 16.24 15.89 17.32 13.12
Gross return per steer 126.28 151.09 156.92 151.46 169.94 110.88
Net return per steer 1/ 24.11 37.65 28.43 26.72 25.11 -13.37
Eight on arrival at slaughter house, Ocala.
Based on final test weight at Belle Glade and killing
Based on killing weight and warm carcass weight.
Calculations based on the following feed prices:
Ground snapped corn ........................
Citrus pulp ................... .
Straight mill-run blackstrap molasses .......
Urea-fortified (4% urea) .......
Cottonseed meal .........................
Urea (262 % C.P.) .........................
Mineral mixture .................. ......
Y/ Feeder steer prices used:
weight at Ocala.
6/ Calculated from final test eight at Belle Glade and the following dressed
carcass prices received per cwt.:
over 400 lbs,
under 400 lbs.
7/ No special charge is made for labor.
The gross return per steer was greater for the 'ull-fed lot, but the
increased feed cost reduced the net return to just slightly more than the lot on
grass alone. The steers which received 6 pounds of concentrates daily throughout
the test gave the greatest net return, more than 50 percent greater than either
Lot I or Lot V. The net loss on the silage-fed steers would indicate that it does
not pay to try to fatten steers on low quality silage with a limited amount of
Although the averages do not show it, individual steer records indicate
that the three steers in Lot V which attained the ,ood slaughter grade averaged
-6h400 per steer net return, or about two and a half times that of the lot as a
From the relatively good gains and the thriftiness of the steers during
this feeding study, it would appear that the grass supplied adequate protein to
balance at least 6 pounds of a mixture of ground snapped corn, citrus pulp and
blackstrap molasses. 1*hen full feed of concentrates was given, the urea in the
fortified molasses supplied enough more crude protein to balance this ration. It
should be emphasized that this trial was held during the spring and early summer
when the grass is usually at its best. Under other conditions where the supply of
the grass is limited and the quality is poor, the amount of crude protein supplied
in this manner would probably be inadequate. At no time during this study did there
appear to be any shortage of grass for any of the lots.
In a 120-day feeding trial held in the spring, comparing limited and full
feed of concentrates for fattening steers on pasture and silage, average daily gains
ranged from 1.45 pounds for steers on grass alone, to 2.11 pounds for steers on full
feed. The rate of gain was correlated with the amount of concentrate fed. Steers
fed fair quality grass silage plus limited concentrates in the drylot made no better
gains than steers on grass alone.
As would be expected, the lot which received full feed the entire test
attained the highest average carcass grade and the lot on grass alone the lowest.
Calculations based on feeder steer and feed prices in effect during the
test indicated a greater margin of profit was obtained from the lot fed 6 pounds of
concentrates per steer-daily throughout the feeding period. The steers fed silage
in the drylot showed a net loss.
It is suggested that higher quality steers capable of attaining the good
slaughter grade on full feed might be potentially more profitable than lower quality
steers on limited feed or no concentrates.
Steers fed concentrates while on good grass may be expected to obtain
adequate protein from the grass to balance 6 pounds of a mixture of ground snapped
corn, citrus pulp and blackstrap molasses. Crude protein to supplement a full feed
of this mixture to steers on good grass may be satisfactorily supplied by urea.