S-^J ; Everglades Station Mimeo Report EES65-7 jI;
Nutritional Adequacy of Permanent Grass Pastur,"
of Florida for Beef Cows
Herbert L. Chapman, Jr. O 1 1964
At the present only an estimated 10 percent of tN proved pa s
in Florida are grass-legume mixtures, leaving approxima ed
of the improved pastures comprised of permanent grasses. Ff.re-
search reports (1, 3, 4, 5, 6, 7, 8) have evaluated the more widely
used. permanent pasture grasses under various conditions. These reports
have shown that the quality of the grasses is affected by a number of
factors, including soil type, forage variety, fertilization program,
amount of grazing, season of the year, forage maturity and climatic
conditions, such as rainfall and temperature. Proper evaluation of
the nutritional value of pasture grasses is important but is also some-
times difficult. The quality of the improved grasses used in south
and central Florida are not all the same and it is not possible to
evaluate them ad such. However, the above mentioned reports indicate
a general trend in permanent grass pastures that apparently exists on
both mineral (sand) and organic (muck) soils.
Generally, permanent grass pastures in south and central Florida,
that have no legumes mixed in, if, properly managed, will provide an ex-
cess of feed from April through August and a deficiency during November
through February. Pasture quality will vary in March and September,
primarily due to climatic variables. The general relationship.of the
nutritional adequacy of these grasses to the nutritional requirements
of beef cows is schematically presented in figure 1.
M J J A S .N D -J F M XM J' J.- A.T S O: NW D
(Months of year).
Figure 1. General relationship between nutritional adequacy of perma-
nent grasses in Florida and nutritional needs of beef cows.
The most important time, nutritionally speaking, in a cow's life
is two months before and three to four months after calving, during
which time her daily requirements for total digestible nutrients and
I/ Animal Nutritionist, Everglades Experiment Station, Belle Glade,
digestible protein may increase 50", over the maintenance amount required
the rest of the year (9). The cows must be able to give birth to a strong,
healthy calf, provide milk for the calf, and be in good enough physical
condition to breed back while still nursing the calf during this period,
of extra nutritional requirement. In the majority of south and central
Florida this period of the cow's life cycle occurs when the quality and
quantity of permanent pasture grasses are at their lowest value nutri-
tionally. Currently used pasture grasses generally will not furnish the
nutrients that are necessary for a good. beef cow to produce to her inherent
ability 12 months of the year. Each cattleman should determine if it
is possible for him to economically provide the necessary nutrients for
his cows during the winter months. This may be done in various ways.
Where possible, grass-legume mixtures are excellent (7). Also, cattle-
men are fortunate in Florida to have access to excellent energy-type
supplemental feeds, such as citrus pulp, blackstiap molasses; When a
protein supplement is required, a mixed supplement may be more desirable
than a single feed. Some ranchers find it more convenient tO use hay,
silage, temporary pasture, or possibly a combination of several supple-
ments. A more detailed, discussion of supplemental feeding of beef cattle
on pasture is available (2).
1. Blaser, R. E., R. S. Glasscock, G. B. Killinger and W. E. Stokes.
Carpet grass and legume pastures in Florida. Fla. Agr. Expt. Sta.
Bull. 453. 1952.
2. Chapman, H. L., Jr., F. M. Peacock, W. G. Kirk, R. L. Shirley and
T. J. Cunha. Supplemental feeding of beef cattle on pasture in
south Florida. Fla. Agr. Expt. Sta. Bull. 665. 1964.
3. Haines, C. E., and R. J. Allen, Jr. Grazing trial results for one
year (1959-1960). E.E.S. Mimeo Report 61-110. 1961.
4. _V__ __ E.E.S. Mimeo Report 62-26. 1962.
5. E.E.S. Mimeo Report 64-7. 1963.
6. Hodges, E. M., D. W. Jones and W. G. Kirk. Grass pastures in central
Florida. Fla. Agr. Expt. Sta. Bull. 484A. 1958.
7. Koger, M., W. G. Blue, G. B. Killinger, R. E. L. Greene, H. C. Harris,
J. M. Myers, A. C. Warnick and N. 'Ganmon, Jr. Beef production, soil,
and. forage analysis, and economic return from eight pasture programs
in north-central Florida. Fla. Agr. Expt. Sta. Bull. 631. 1961.
8. Kretschmer, A. E., Jr. and N. C. Hayslip. Evaluation of several
pasture grasses on Immokalee fine sand. in south Florida. Fla. Agr.
Expt. Sta. Bull. 658. 1963.
9. National Academy of Sciences. Nutrient requirements of domestic
animals, Number 4. Nutrient requirements of beef cattle. 1958.