Everglades Station Mimeo Report EES66-6 November, 1965
S GRAZING TRIAL 'RESULTS (1964-1965)
SC. E. Haines and.R. .J Allen, Jr.
SNumerous systems have been proposed and tried in an effort to correctly
evaluate pasture forages throughout the world., Although most 6f the schemes
h'abe merit, each one has certain shortcomings which are difficult to complete-
ly eliminate. The total productivity of a pasture forage is dependent upi'on
the length of grazing period, the number of animals involved, the nutritional
quality and the amount of the material consumed. The evaluation' of a forage
with grazing animals may lead to a biased conclusion if all four of these fac-
tors .are not considered .
Grazing cattle have been used at the Everglades Experiment" Station for'
several years to compare the productivity of various species of pasture .grasses.
-In recent ;years, the most.prominent pasture,.grasses on the organic soils of
south Florida have been Roselawn St. Augustinegrass, Argentine Bahiagrass,
paragrass, and Pensacola Bahiagrass. .Yearling steers have been used'to con-
'' tiruously graze these grasses and a comparison of their productivity in each
of two recent:years.has been reported by Haines and Alien (1, 2), The infor-
mation presented in this report is a continuation.of these studies. '
Sixteen pasture blocks,- each 'two acres: in size, were used in the-present
Study. Four blocks were establishedd to ~e-ach of 'the four -varieties. of grass
listed above and the lots were randomized within a 'forty-acre field. Year-
ling steers, termed "testers", continuously grazed the grass blacks. :.'During
seasons of abundant forage growth, additional steers ("grazers") were placed
in the blocks to consume the excess forage. The "grazers" were kept in a
"pool group" when not in the test blocks and the same individuals were used
as "grazers" for specific blocks throughout the course of the trial.
The steers were both purebreds and various crosses of these breeds and
allotment to the blocks was made on the basis of their breeding and'weight.
Each block contained a mineral box and water cup. The trial was conducted
for 36 weeks. It began on October 22, 1964, and was terminated on July 1,
1965, to allow for the initiation of the next cycle of this-project. All
animals were individually weighed every two weeks.
During a winter period.of 16 weeks, one half of the steers on each of the
grasses were supplemented with either cottonseed meal or corn meal. These two
pasture supplements were fed at the rate of 1.5 pounds per head daily. The
yearlings in the other half of the test blocks received no supplemental feed-
stuffs during the trial.
1/ Assistant Animal Husbandman and Assistant Agronomist, respectively,
Everglades Experiment Station, Belle Glade, Florida.
Animal gains during the 16-week pasture supplementation period indicated
that both corn meal and cottonseed meal generally improved the gains of steers
on the test blocks. The lowest response from the supplements was by the
steers on Pensacola Bahiagrass and the highest by the steers on paragrass.
Comparing the two supplements, it appears that cottonseed meal was superior
to corn meal for steers on paragrass, Argentine Bahiagrass and Pensacola Bahia-
grass but not for steers on St. Augustinegrass pasture. Responses to similar
treatments used in a previous trial were also variable. The average weight
changes during the period of supplementation are shown in Table 1.
Gains of the "tester" steers for the entire test period (252 days), as
shown in Table 1,-indicate that the benefits from the pasture supplements
were maintained only by the steers on St. Augustinegrass, The beneficial
respohses.to the winter supplements by steers on the other three grasses were
minimized in the subsequent spring and summer grazing seasons, This suggests
that most of the non-supplemented steers "caught up" to the winter-supplement-
ed steers in the periods bf letter pasture growth. A similar trend was evident
in the previous study which included the same treatments. Thus, it appears
that the use of either 1.5 pounds of cottonseed meal or corn meal per head daily
as winter supplements for steers on pasture is of doubtful value.
Table 1. Average Pounds Gained by "Tester" Steers for the Supplementation
Period and the Total Test Period. 1/
CSM Cornmeal None None
Supplement Period 86 114 79 44
Total Test Period 273 255 233 230
'Supplement Period 38 19 11 -14
Total Test Period 198 235 183: 215
Supplement Period- 113 98 88 90
Total Test Period 211 196 210 225
Supplement Period 96 58 83 90
Total Test Period 208 178 195 211
1/ Supplement Period, Dec. 17 April 8; Total Period, Oct. 22 July 1.
:Table 2 shows the total.weight gained and number-of grazing' days for
"tester" and grazerr" steers combined. Argentine Bahiagrass produced:the
most pounds of beef per acre and also supported the greatest number of steers
While paragrass:was the lowest:in these production factors. Since the test
- period was ,252 days both of the' bahiagrasses- and St.,.Augustinegrass carried
San average of more than.two steers per acre in,the trial. .Actuallyithe Ar-
gentine Bahiagrass had an average stocking rate'.of slightly more ..than. 2i.6.
.steers per acre; ;During May, .the siocking rate" for both Argentine and Pensa-
cola Bahiagrass climbed to five steers per.acre while St. Augustinegrass' was
'supporting four.'steers per acre.,,-,; .:.
Individual gains were the highest in April and May and the lowest in
December, January and February. This seasonal trend also has been evident
in previous years. Steers on paragrass posted the largest weight losses
(winter season) and also recorded the highest individual gains (May 6-20)
of any of the groups. In order to compare the average gains from grasses
for the entire 252 day period, only the data from the "tester" steers was
used because they were on the pastures for the entire time. The inclusion
of data from the grazedt" steers would tend t6-bias this information since
they were in the blocks only during theperiods of abundant forage growth.
and when gains were the most rapid. The overall average daily gain for
"tester" steers on Roselawn St. Augustinegrasswas 0.95:pounds. This was
greater than the 0.82, 0.84 and 0.78 pounds of:daily gain for steers on
paragrass,-Argentine Bahiagrass and Pensacola Bahiagrass, respectively.
Thus, the individual gains made by steers on paragrass compared favorably
with those on the bahiagrasses even though total productivity was poorer
for paragrass. Differences in stocking rates accounted for this variation.
In all of the recent years of this trial, the bahiagrasses have been stock-
ed at higher rates than the other grasses and yet individual daily gains
have usually been the lowest.
Table 2. Total Weight Gains (lbs) and Grazing Days Per Acre.
Kind of Grass Total Gains Grazing Days
St. Augustine 534 536
Para 328 469
Argentine Bahia 671 679
Pensacola Bahia 600 637
Yearling steers were used to compare the productivity of four pasture
grasses during a 252 day period. "Tester" steers remained on the pastures
continuously while grazerr" steers were added or removed to compensate for
seasonal fluctuation in forage growth. One-half of the "tester" steers re-
ceived a pasture supplement for 16 weeks of the winter season.
A daily intake of 1.5 pounds of cottonseed meal or corn meal in the win-
ter stimulated gains to a slight extent in steers on all four grasses during
the supplementation period. However, this advantage diminished in the subse-
quent spring and summer grazing.periods. For the entire trial, Argentine Bahia-
grass produced the most pounds of gain per acre (671 lbs.) and also showed the
highest stocking rate (679 grazing days). Other grasses in descending order of
total productivity were Pensacola Bahiagrass, Roselawn St. Augustinegrass and
paragrass. The average daily gains of "tester" steers was 0,84, 0.78, 0.95,
and 0.82 pounds for Argentine Bahiagrass, Pensacola Bahiagrass, Roselawn St.
Augustinegrass. and paragrass, respectively. Periods of high productivity for
all grasses occurred in April and May while December, January and February
proved to be poor months for production.
1. Haines, C. E. and R. J. Allen, Jr.. 1963. Grazing trial results for one
year (1961-1962). EES Mimeo6 pt. 64-7.
2. Haines Ci E. and R. J, Allen, Jr.. 1905i Grazing trial results for one
year (1963-1964). EES Mimdo Rpt,. 866- i-