Animal Husbandry and Nutrition Florida Agricultural
Mimeograph Series No. 59-3 Experiment Station
PASTURE VS. CONCRETE FOR GROWING-FINISHING SWINE
H. D. Wallace end G. E. Combs
Not many years ago good pasture was considered an essential nutri-
tional and economic factor in the fattening of market swine. Many early
experiments demonstrated that pasture saved 10-15 percent in concentrates
and up to 50 percent In protein supplement.' However, as stated in Carroll
and Kriders' textbook on swine production, the experiments reporting such
savings were, in reality, Illustrating the advantage of adequate rations
(on pasture) over inadequate rations (on concrete), rather than the super-
iority of feeding on pasture over feeding on concrete.
With present day rations, properly fortified with protein, minerals
and vitamins, the special nutritional value of green forage has lost much
of Its importance for growing-finishing swine. This fact, along with the
increased costs of growing pasture, has necessitated a re-evaluation of
pasture in the feeding program.
This study was designed to compare the rate of gain, efficiency of
gain, and production costs for pigs full fed on excellent legume forage,
pigs limited fed on excellent legume forage, and pigs full fed in concrete
Fifty-one crossbred pigs (Duroc x Spotted Poland China and Hampshire
x Lendrace) were divided into three similar groups and fed according to
the following plan.
Wallace and Combs, Associate and Assistant Animal Husbandman, res-
pectively, Florida Agricultural Experiment Station. The assistance
of W. E. Collins and L. S. Taylor, Swine Herdsmen, Is gratefully
Lot I Full-fed In concrete confinement
Lot 2 Full-fed on excellent legume pasture
Lot 3 Fed 75-80 percent of a full ration on
excel lent legume forage. Pigs In Lot 2
served as the reference lot for regulation
of feed Intake.
Composition of Concentrate Mixture Fed to All Lots.
Weaning to 125 lbs. 125 lbs. to 210 Ibs
Ground yellow corn 77.0 84.3
Soybean oilmeal (44% solvent) 20.3 13.0
Ground limestone 1.0 1.0
Steamed bonemeal 1.0 1.0
Iodized salt 0.5 0.5
Trace mineral mix .:0.1 0.1
Fortafeed 2-49C (American Cyanamid) 0.1 0.1
Aurofac 10-A (American Cyanamid) ** 0.1 0.1
Contains 2,000.mg riboflavin, 4,000 mg pantothenic acid, 9,000 mg niacin
and 10,000 mg of choline chloride per Ib.
** Contains 10 gm. chlortetracycline per lb.
Pigs in Lots I and 2 were self-fed. Pigs in Lot 3 were hand-fed
twice per day. Lots 2 and 3 were placed in one acre plots of pasture. The
planting consisted of a mixture of Hairy Peruvian Alfalfa 25 pounds, Ken-
lard red clover 18 pounds, and Crimson clover 12 pounds. This mixture
was seeded at the rate of 20 pounds per acre and fertilized with 500 lbs.
of 0-12-12 fertilizer at the time of seeding. Forage was available to the
pig! throughout the experiment. However, near the end of the experiment it
wes necessary to shift pigs in Lot 3 to a new pasture area(because pasture D
became sparse in their original plot.
The pigs were weighed off experiment by lot as the lots reached an
average final weight of approximately 210 pounds. The experiment was
started on April 4, 1958 and was terminated on August 2, 1958.
Results and Discussion
A summary of the results of the experiment is presented in Table I.
Pigs full-fed on pasture (Lot 2) gained 1.75 pounds per day and re-
quired 3.45 pounds of feed per pound of gain. Pigs fed on concrete (Lot I)
gained 1.68 pounds per day and required 3.56 pounds of feed per pound of
gain. The difference in gains was not statistically significant and the
feed saved by the pasture amounted to only 18.1 pounds per pig. The
limited-fed pigs -(Lot 3) gained considerably slower as might be expected.
They gained 1.39 pounds per day and required 3.38 pounds of concentrates
per pound of gain. This amounted to a feed saving by the pasture of only
29.7 pounds per pig.
It was estimated that the full-fed pigs (Lot 2) required .75 acre
of pasture while the restricted pigs (Lot 3) required 1.50 acres. Using
the cost data as footnoted in Table I, it was determined that the cost
of 'forage production was $27.90 per acre.
Since the experimental forage plots had been utilized by sows prior
to the start of this experiment only $17.90 per acre was charged to this
study. On this basis total feed costs per .100 pounds of pork produced
were $12.46, $12.58, and $12.79 for the concrete pigs, full-fed on pasture,
and limited-fed on pasture, respectively. Thus the net value of the pasture
per acre was $5.23 for the full-fed pigs and $6.12 for the limited-fed
pigs. it Is interesting to note that the full-fed pigs actually utilized
the forage to better advantage than did the limited-fed pigs.
Summary and Conclusions
An experiment involving 51 weanling pigs has been conducted to
compare the performance and feed costs of finishing pigs in concrete
confinement vs. on excellent legume.forage.
Gains were approximately the same on pasture and concrete.
When pigs were given a full concentrate ration the forage reduced
feed requirement only about 3 percent. On a ration restricted to 80 percent
of a full Intake the saving was 5 percent. These savings were very small
and fell far short of paying for the expense involved in growing the forage.
It should be emphasized, however, that this study was concerned with
qrowing-finishing swine. Good pastures are still an important part of a
sound program for the sow herd during gestation and lactation.
Table I. FERFCOMANCE OF PIGS FED ON PASTURE VS. CONCRETE
Restricted to 80% of
Treatment Concrete Full-Fed on Pasture Full Ration on Pasture
Lot Number I 2 3
Number of pigs 17 16 17
Days on feed 98 94 119
Av. initial wt., lbs. 44.6 45.9 45.5
Av. final wt., Ibs. 209.0 2t0.3 210.7
Av. daily gain, Ibs. 1.68 1.75 1.39**
Daily feed consumed per pig, Ibs. 5.97 6.04 4.70
Feed required per Ibs. gain, ibs. 3.56 3.45 3.38
Feed saved per pig by pasture, Ibs. -18.1 29.7
Acres pasture required per lot .75 1.5
Feed replaced per acre of pasture, lbs. --. 362.0 336.6
Value of feed replaced per acre of pasture ---- $12.67 $11.79
Cost of pasture per acrel/ --- $17.90 $17.90
Net value of pasture per acre --- $-5.23 $-6.12
Total feed costs per 100 Ibs. pork $12.46 $12.58 $12.79
Mixed feed costs per 100 Ibs. pork $12.46 $12.07 $11.83
Pasture costs per 100 lbs. pork ----- $ 0.51 $ 0.96
Sale price of pigs per cwt. $23.50 $23.50 $23.50
Original cost of pigs per head $12.00 $12.00 $12.00
Gross returns per head over feed and cost of pig $16.03 $16.74 $16.38
Gross returns per j00 lbs.pork sold $ 7.96 $ 7.96 $ 7.77
Av. on foot grade2' Choice No. I Choice No. I Choice No. I
** Gained significantly slower than either of other two lots. (P .01)
I/ Seed $8.40; Fertilizer $7.50; Land preparation and seeding $12.00. Total $27.90
per acre (pasture utilized before start of experiment) $17.90 per acre chargeable.
per acre, loss $10.00
2/ Although all lots averaged choice No. I, it should be pointed out that the pigs in Lot 3 were definitely on the
oaner side and probably hung carcassc3 carrying a higher percentage of lean cuts. No carcass data were obtained
n this experiment.