• TABLE OF CONTENTS
HIDE
 Front Cover
 Table of Contents
 Introduction
 Review of literature
 Oat pasture for lactating cows
 Oat pasture for dairy heifers
 Discussion of results
 Summary and conclusions
 Acknowledgement
 Literature cited














Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 584
Title: Value of oat pasture for dairy cattle
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 Material Information
Title: Value of oat pasture for dairy cattle
Series Title: Bulletin - University of Florida Agricultural Experiment Station ; 584
Physical Description: Book
Language: English
Creator: Marshall, Sidney P.
Publisher: University of Florida Agricultural Experiment Station
Publication Date: 1957
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Table of Contents
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Introduction
        Page 3
    Review of literature
        Page 4
    Oat pasture for lactating cows
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
    Oat pasture for dairy heifers
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
    Discussion of results
        Page 16
    Summary and conclusions
        Page 17
        Page 18
    Acknowledgement
        Page 19
    Literature cited
        Page 19
        Page 20
Full Text


Bulletin 584


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
J. R. BECKENBACH, Director
GAINESVILLE, FLORIDA








Value of Oat Pasture for Dairy Cattle


SIDNEY P. MARSHALL


Fig. 1.-Oat pasture at the Dairy Research Unit, grazed in strips as
shown here, provided winter nutrients for dairy cows.


April 1957


















CONTENTS


REVIEW OF LITERATURE .. .

OAT PASTURE FOR LACTATING COWS
Method of Procedure
Experimental Results
Distribution of Feed Supply
Composition of Oat Forage .......
Milk Production and Body Weight ( h.i. -
Total Digestible Nutrients Obtained from Pasture
Alfalfa Hay Equivalent Obtained from Pasture
Feed Replacement Value, Calculated Production Cost, Net Re-
turns, and Cost of Total Digestible Nutrients from Pasture

OAT PASTURE FOR DAIRY HEIFER .
Method of Procedure
Experimental Results.
Body Weight Gains and Supplemental Concentrate Feeding
Total Digestible Nutrients and Return Per Acre from Pasture
Supplemental Feeding of Hay on Pasture

DISCUSSION or RESULTS

SUMMARY AND CONCLUSIONS


LITERATURE CITED








Value of Oat Pasture for Dairy Cattle

SIDNEY P. MARSHALL

The largest expense item in the production of milk and in
raising dairy herd replacements is feed. A survey of milk pro-
duction costs in six Florida areas (13)1 revealed that feed pur-
chases comprised 52.8 percent of the total. Since this cost factor
is large, the possibilities of effecting economies in the feed sup-
ply would seem to offer an opportunity to improve the efficiency
of dairy production.
Pastures generally are the cheapest source of feed and dairy
cattle can use large proportions of quality forage in supplying
their nutritive requirements. As the percentage of feed ob-
tained from pasture increased, production costs decreased for
the Florida herds enrolled in the 1953 Dairy Herd Improvement
Association program (12). These records indicated that the
proportion of feed obtained from pasture profitably could be
increased to 35 or 50 percent without causing a decline in pro-
duction. According to records obtained from 19 Florida dairy
farms, the cost of total digestible nutrients obtained principally
from permanent type pastures was only 1.47 cents per pound.
The amount of feed obtained from pasture by Florida dairy
cattle is relatively small, particularly during fall and winter
months. A survey (15) for a five-year period (1950-55) shows
that the percentage of total feed obtained from pasture during
the months of November, December, January, February, and
March was 13.1, 11.4, 10.7, 17.5, and 26.0, respectively. Daily
consumption of hay and other roughages per cow during this
period averaged 4.7, 6.0, 4.6. 4.6, and 2.5 pounds for the respec-
tive months. This information reveals that concentrates were
the principal sources of feed and indicates a need for additional
pasture or other roughage during this period.
Oats are reported to be the best temporary winter pasture
for Florida (9) and to produce forage during much of the period
when permanent pastures are dormant or low in productivity.
Soil and climatic conditions are most favorable for their growth
in the north-central, northern, and western parts of the state.
However, they are grown for pasture also in southern Florida.
This study of the feeding value, yield of total digestible nutrients
per acre, and returns that may be anticipated from oat pasture


'Italic figures in parentheses refer to Literature Cited.






Florida Agricultural Experiment Stations


was undertaken to aid dairymen in determining its usefulness
in their feeding programs.

REVIEW OF LITERATURE
Milk-stimulating qualities of green oat forage, 6 to 12 inches
high, were compared with those of alfalfa hay in trials at the
Alabama station (5). When digestible dry matter from imma-
ture oat forage was substituted at 0, 50, and 100 percent levels
for digestible dry matter allowances provided by alfalfa hay, the
persistency index of milk flow was 88, 99, and 99 percent for the
respective levels. Digestibility of the oat forage dry matter
averaged 79.4 percent, as compared with 58.8 percent for that
of the alfalfa hay.
At the Texas station (3), grazing oat pasture is reported to
have increased milk production an average of 4.0 to 5.5 pounds
daily as compared to periods when such pasture was not avail-
able.
Work in South Africa (16) indicated that high milk produc-
tion could be maintained without supplementary concentrate
feeding if oat pasture was utilized effectively. Cows fed 23
pounds of alfalfa hay and grazed four hours per day on oat
pasture produced an average of 28.0 pounds of milk, as com-
pared with an average of 24.3 pounds per day for a control group
receiving the same amount of hay plus an average daily allow-
ance of 4.73 pounds of concentrate.
When oat pasture 6 to 12 inches tall was the principal rough-
age consumed, six Ayrshire cows decreased in butterfat test
from an average of approximately 4.3 percent to 2.6 percent
within a week (7). The milk of some cows tested as low as
0.9 percent. However, milk production rose slightly, and health
of the cows was not affected. When the animals were changed
to another type of roughage, the butterfat test quickly returned
to normal.
In an 18-week trial, heifers grazing Arlington oats made
average daily gains of 1.91 pounds, as compared with 1.64 on
rye and 1.63 on rescue grass (8).
Oats provided pasture from January 27 to May 2 in 10 years
of tests at Tifton, Georgia (4). Beef cattle made average annual
gains of 95.5 pounds per acre of pasture grazed and the carrying
capacity was about one animal per acre.
The acreage of oats planted in Florida was 123,000 in 1950
and had increased to 188,000 in 1955 (14). Most of the acre-






Value of Oat Pasture tor Dairy Cattle


ages presumably have been used for pasture, since only 20,000
to 40,000 acres were harvested annually during that period.
Although the quality of immature oat forage has been re-
ported to be excellent, information is needed on the amount of
feed nutrients this pasture will provide and the role it may play
in the feeding program of the dairy herd. Therefore, in addi-
tion to studying the feeding value of oat pasture for lactating
cows and dairy heifers, this experiment was planned to deter-
mine the amount of total digestible nutrients obtained per acre,
seasonal distribution of the feed supplied, and the net returns
realized per acre.

OAT PASTURE FOR LACTATING COWS
METHOD OF PROCEDURE
Southland oats were planted on three two-acre fields of Or-
lando fine sand in 1951 and 1952. Floriland oats, released in
1953, were used that year, since it appeared that they might be
more disease resistant than Southland. The procedure employed
for the production of oats was essentially that recommended by
Henderson (6). Planting dates, seeding rates, and fertilization
practices for each year are shown in Table 1.

TABLE 1.-PLANTING DATES, SEEDING RATES AND FERTILIZATION PRACTICES
BY YEARS FOR OATS GRAZED BY LACTATING COWS.

Year
1951-52 1952-53 1953-54
Planting date .--........ October 16 I October 14 iSeptember 25
Seeding rate
per acre, bu................. 2 3 3
Mixed fertilizer **
applied per acre, lbs. 500 500 500
Nitrogen applied as top-
dressing, per acre, lbs. 64 66 89.3
Number of nitrogen
top-dressings, av. ...... 4 2 2.7

Southland oats grazed in 1951-52 and 1952-53. Floriland oats grazed in 1953-54.
** 4-7-5 fertilizer used in 1951 and 1952. 8-8-8 used in 1953.

The oats were grazed when the forage was six to eight inches
tall in 1951-52 and 8 to 10 inches tall the latter two seasons.
The fields were grazed rotationally and the cows kept on the







Florida Agricult ral Experiment Stations


pastures continuously, except when removed for milking. The
number of cows grazing the pasture was adjusted according to
the available supply and anticipated growth of forage. Shade,
water, salt, steamed bonemeal, and an iron-copper-cobalt mineral
mixture were provided in each pasture.
The cows were milked twice daily. Butterfat tests were made
on an aliquot of one day's production of each animal at the be-
ginning and at bi-weekly intervals during the experiment. The
animals were weighed following the morning milking on three
consecutive days at the beginning and end and at 28-day inter-
vals during the experiment.
A concentrate mixture was offered each cow at the rate of
1 pound per 3.5 pounds of 4 percent fat-corrected milk produced.
Adjustment of the allowance of each animal was made at bi-
weekly intervals. The concentrate mixture, containing 16 per-
cent of crude protein, was composed of the following ingredients:
hominy feed, 400 pounds; ground oats, 200 pounds; wheat bran,
200 pounds; peanut meal, 45 percent crude protein, 106 pounds;
salt, 9 pounds; and steamed bonemeal, 9 pounds.
Samples of oat forage representing the plant portions con-
sumed by the cows were taken during each of the four rotations
of 1951-52. These samples were analyzed for moisture and crude
protein (N x 6.25) by methods described by the Association of
Official Agricultural Chemists (2).

EXPERIMENTAL RESULTS
Grazing was begun on December 15, December 9, and No-
vember 21 during the successive years. The interval between
planting and initiation of grazing ranged from 56 to 60 days and
the seeding date appeared to be the principal factor affecting the
time the oats were ready to graze. The length of grazing sea-
sons ranged from 118 to 139 days and each of the three plots
was grazed four rotations per season.
Distribution of the Feed Supply.-The average carrying ca-
pacity of the pasture was 0.8 cow per acre in 1951-52 and 1.2
cows per acre during each of the following grazing seasons.
Less feed usually was obtained from oat pasture during January
and early February than in earlier or later periods. In order
to have a larger amount of feed available for the cattle in Jan-
uary and February, an accumulation of forage, consistent with
retention of high quality, was made in late fall for use during






Value of Oat Pasture for Dairy Cattle


the colder period. The seasonal distribution of total digestible
nutrients obtained from oat pasture is shown by years in Fig. 2.
Earlier grazing and a larger amount of feed were obtained
from the pasture in the fall of 1952 than other years. Early
planting, application of more nitrogen in the fall, and heavier
precipitation (a total of 14 inches for October, November, and
December) were factors contributing to these conditions.
Composition of Oat Forage.-Portions of the oat plant com-
parable to that eaten by the cows were taken for analysis during
each of the four rotations in 1951-52. These forage samples
taken during the successive rotations contained 14.9, 16.4, 14.6,
and 16.4 percent of dry matter; and 3.07, 4.30, 3.83, and 4.05
percent of crude protein on the fresh weight basis. The date
and rotation number when oat samples were collected and their
dry matter and crude protein content are shown in Table 2.

TABLE 2.-COMPosITION OF SOUTHLAND OAT FORAGE SAMPLES, 1951-52.

Pasture Dry Crude Protein
Date Rotation Matter, Fresh Dry Matter
Collected Number Percent Forage, Basis,
Percent Percent
12/24/51 1 14.9 3.07 20.67
1/14/52 2 16.4 4.30 26.14
2/19/52 3 14.6 3.83 26.27
3/25/52 4 16.4 4.05 24.70



Good quality was maintained in the forage during each rota-
tion, as indicated by its relatively high crude protein and low
dry matter content. The crude protein content values are sim-
ilar to the analyses of 14.0 percent dry matter and 22.8 percent
crude protein on the dry matter basis reported for oat pasture
by Morrison (10).
Milk Production and Body Weight Changes.-Daily milk pro-
duction of the Jersey and Guernsey cows averaged 23.9, 28.2,
and 27.7 pounds during the respective grazing seasons, with a
three-year average of 26.6 pounds of milk containing 5.4 percent
butterfat. Expressed as 4 percent fat-corrected milk, the aver-
age daily production was 28.9, 35.1, and 32.9 for the successive
seasons.













Percent of
Total Yield


12
11
10
9


7
6



3
2
1


November December January february

MONTHS


o 1951-52
A 1952-53

0 1953-5h


March A-------il
March April


Fig. 2.-Percentage of the yield of total digestible nutrients grazed each week from oat pasture by lactating cows.







Value of Oat Pasture for Dairy Cattle


TABLE 3.-VALUE OF OAT PASTURE:: GRAZED BY LACTATING Cows, BY YEARS
AND THE AVERAGE FOR THREE YEARS.


Grazing period ......

Length of grazing
period, days .... ....
Number of pasture
rotations ..............


Av. initial weight
of cows, lbs. .......
Av. change in body
weight per cow,
lb s ........ ....... ......


Av. daily milk pro-
duction per cow,
lb s. ......... ....
Av. daily production
4 percent fat-cor-
rected milk, per
cow, lbs ......


T.D.N. obtained
from pasture,
per acre, lbs ....
Alfalfa hay equiva-
lent obtained from
pasture, per acre,
tons ..... ........ .. -
Percent of T.D.N.
obtained from
pasture ........... .
Av. daily concen-
trate consumption
per cow, lbs. .......


Calculated feed re-
placement value
obtained from
pasture, per acre..
Calculated cost of
pasture produc-
tion, per acre ....
Calculated net re-
turns from pas-
ture, per acre ....
Cost of total digest-
ible nutrients,
per pound ....


1951-52

12,15/51-
5/ 2/52

139

4



819


+33.3


1,237.9



1.23


63.2


Year
1952-53

12 9 52-
4/6/53

118

4



882


Three-
Year
1953-54 Average


11/21/53-
3.23/54

122

4



840


-2.1 +5.1


1,478.0



1.47


57.5


8.4 10.2


$ (68.88


1,684.3



1.68


62.8


8.8


126.3

4



847


+12.1


1,466.7


1.46


61.2


9.1


S 82.32 $ 94.08 $ 81.76


$ 41.60 $ 37.93 $ 44.69 $ 41.41


$ 27.28 $ 44.39 $ 49.39 1$ 40.35


$ 0.0336 $ 0.0257 $ 0.0265 $ 0.0282


* Southland oats were ueld in 1951-2 and 1952-53, and Floriland in 1953-54.






Florida Agricultural Experiment Stations


Average initial body weights of the cows used during the
successive trials were 819, 822, and 840 pounds. Gains per
animal averaged 33.3 pounds during the first season, but changes
in body weight were relatively small during the latter two
(-2.1 pounds in 1952-53 and +5.1 pounds in 1953-54). Results
of the experiment are summarized in Table 3.
Total Digestible Nutrients Obtained from Pasture.-Total
digestible nutrients grazed per acre from oat pasture by the
cows were calculated (1) to be 1,237.9, 1,478.0, and 1,684.3 pounds
for the respective seasons, with a three-year average of 1,466.7
pounds. The animals obtained from the pasture an average of
10.9 pounds of total digestible nutrients daily, which was ade-
quate to support body maintenance and the production of 12.4
pounds of 4 percent fat-corrected milk. Pasture supplied 61.2
percent of the cows' total digestible nutrient intake. The re-
maining portion was furnished by a concentrate allowance aver-
aging 9.1 pounds daily per animal.
Alfalfa Hay Equivalent Obtained from Pasture.-A method
usually employed to describe the nutritive benefits obtained from
a pasture is the amount of a well-known roughage that would
be required to replace it. Alfalfa hay has been used most com-
monly as the reference roughage in expressing the feed replace-
ment value of quality pasture forage high in crude protein con-
tent. Using 50.3 percent as the total digestible nutrient con-
tent of alfalfa hay (10), the alfalfa hay equivalent value of oat
pasture averaged 1.23, 1.47, and 1.68 tons per acre during the
successive grazing seasons.
Feed Replacement Value, Calculated Production Cost, Net
Returns, and Cost of Total Digestible Nutrients from Pasture.-
The financial benefits that may be derived from the utilization
of a pasture by dairy cattle is an important factor in determining
the desirability of adopting it in a feeding program. In arriving
at the net returns realized from oat pasture, its value was cal-
culated by multiplying the alfalfa hay equivalent produced per
acre by a market value of $56.00 per ton for alfalfa hay. Pro-
duction costs were determined by using prevailing market prices
for seed, fertilizer, and land rent; and by making assessments
for cultural practices based on local charges f(r custom work
where pastures were 10 acres or larger.
Seed costs averaged $2.37 per bushel and fertilizer prices per
ton were: 4-7-5 fertilizer, $41.00; 8-8-8 fertilizer, $52.25; and
ammonium nitrate, $95.00. Assessments per acre for cultural






Vabte o, (Jar kaosruiwi ,or Daiary Cattle


practices were as follows: breaking land, $2.33; disking, $1.17;
drilling seed and fertilizer, $3.00; and applying nitrogen top-
dressings, $1.17. Land rental charge was based on $4.00 per
acre, with $2.00 per acre debited for oat production and the
remainder charged against temporary pastures grown on the
area during the summer.
The production cost per acre of oat pasture averaged $41.41,
with annual variations ranging from $37.93 to $44.69 per acre.
Feed replacement value of the pastures for the successive years
were $68.88, $82.32, and $94.08 per acre.
Annual production costs of total digestible nutrients obtained
from pasture ranged from 3.36 to 2.57 cents per pound, with a
three-year average of 2.82 cents. Total digestible nutrients
would have cost 5.57 cents per pound from alfalfa hay at $56.00
per ton, or from a concentrate mixture at $83.60 per ton.

OAT PASTURE FOR DAIRY HEIFERS
METHOD OF PROCEDURE
Three fields of Scranton loamy fine sand averaging 2.3 acres
each were seeded to Southland oats in 1950, 1951, and 1952.
Three comparable areas were seeded to Camellia oats in 1951
and 1952. The fields planted to Southland oats in 1951 were
seeded to Camellia in 1952, and vice versa. The procedure em-
ployed for oat production was that recommended by Henderson
(6). Planting dates, seeding rates, and fertilization practices
are shown in Table 4.
Grazing was started when the oats were about six to eight
inches tall the first two years and 8 to 10 inches tall in 1952.
The Southland and Camellia oats were grazed rotationally, using
different groups of heifers. The animals were maintained on
the pastures continually except when removed for weighing.
Body weights were taken on three consecutive days at the be-
ginning and end and at 28-day intervals during the experiment.
The number of animals grazing each variety of oat pasture was
adjusted according to the available supply and anticipated
growth of forage.
Salt, steamed bone meal, and an anemia-preventive mineral
mixture were offered free choice. Two pounds of a 16 percent
crude protein concentrate mixture per animal were offered daily
to those grazing Southland oats in 1950-51, but none was fed
during the subsequent two grazing seasons. Shade and fresh
water were available in each pasture.






Florida Agricultural Experiment Stations


TABLE 4.-PLANTING DATES, SEEDING RATES AND FERTILIZATION
PRACTICES BY YEARS FOR OATS GRAZED BY HEIFERS.

_Year
1950-51 1951-52 1952-53
Southland Oats

Planting date ....-----------------.... November 6 October 20 October 15
Seeding rate per acre, bu. ...... i 2.6 2.0 3.0
4-7-5 fertilizer applied per
acre, lbs. ........................... ... 447 476 506
Nitrogen applied as top-
dressing, per acre, lbs. .......... 66.1 65.8 66.7
Number of nitrogen
top-dressings, av ............... 3.3 4 2

Camellia Oats

Planting date .........---- ....... .......... ... October 22 October 16
Seeding rate per acre, bu ........................ 2.5 3.0
4-7-5 fertilizer applied per acre, lbs.... ... 492 512
Nitrogen applied as top-dressing,
per acre, lbs. ...................... ............ .. 65.9 66.7
Number of nitrogen top-dressings, av. ...4 2


EXPERIMENTAL RESULTS
The grazing-management method and production procedure
for Southland and Camellia oats were comparable in 1952-53.
These practices were not comparable to those of previous ex-
periments because the oats were grazed at a taller height and
a little more fertilizer and seed were used than in earlier years.
Likewise, slightly more fertilizer and seed were used in 1951-52
for Camellia oats than for Southland. However, differences in
results obtained between varieties for the same years were less
than those between years for the same variety (Table 5).
Grazing was started 44 to 60 days after planting, with shorter
intervals accompanying the October plantings. The length of
grazing season ranged from 135 to 154 days, and the number of
pasture rotations from 4.0 to 5.7 per season.
Body Weight Gains and Supplemental Concentrate Feeding.-
Heifers grazing Southland oats were offered two pounds of con-




TABLE 5.-VALUE OF OAT PASTURES FOR DAIRY HEIFERS, BY YEARS AND THE AVERAGES FOR TWO YEARS.

Southland Oat Pasture Camellia Oat Pasture
H Two-
Two- Two- Year
Year Year Year Yeai Year Average,
I Average Average Both
19)50-51 11951-52 1952-53 1951-5 1951-52 1952-53 1951-53 Varieties
Grazing period 5/51- 12/5/51- 12/ 3/52- 12/5/51- 12/ 3/52-
/21'51 5/7/52 4/17/53 5/7/52 4/19/53
Length of grazi)n period, days. 139 154 1:5 144.5 154 137 145.5 145.0
Number of pasture rotations... 5.7 5.0 4.0 4.5 5.0 4.0 4.5 4.5

Av. initial weight, lbs. ......... 518.3; 527.1 57:.2 550.2 523.9 (;02.3 563.1 556.7
Av. daily gain per animal, lbs... 1.24 1.10 1.I 7 1.14 1.12 1.1: 1.13 1.14
Gains expressed as percentage of
normal growth rate ........... 17.1 145.2 159.: 152.3 142.: 149. 145.8 149.1
Av. gain per acre, lbs..... .... ... 2.5.1 198.2 27(.4 237.3 214.8 252.(i 233.7 235.5

T.D.N. obtained from pasture,
per acre, lbs .. ................. 1,722. 1,567.3 2,152.4 1,85 .8 1 83.5 2,0 187 .2 1,8(;8.0
Alfalfa hay equivalent obtained
from pasture, per acre, tons. 1.71 1.56 2.14 1.85 1.67 2.(1; 1.87 1.8(

Percent of required T.D.N. I
obtained from pasture .... ... 84.; 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Av. daily concentrate consump-
tion per animal, Ibs................ 2.0 0.0 0.0 0.0 0.0 0.0 0.0 I 0.0

Calculated feed replacement
value of grazing, per acre ..... 5.71; $ 87.36 $ 119.84 $ 103.(i0 $ 93.52 $ 115.3(; $ 104.44 $ 104.02
Calculated cost of pasture pro- 9
duction, per acre ...... $ 42.1(; $ 41.47 ,$ 37.)93 $ 3).70 $ 43.03 I $ 38.05 $ 40.54 $ 40.12
Net returns from pasture,
per acre ..... ..... .. ............ $ 53.(10 $ 45.89 $ 81.91 $ (3.90 $ 50.49 $ 77.31 $ (3.90 $ 63.90
Cost of total digestible nutrients,
per pound .. ................ $...... i $ 0.0245 $ 0.02(i5 $ 0.017( $ 0.0213 $ 0.025(i $ 0.0184 $ 0.0216 I $ 0.0215
The stanilirld growth curve of Jersey f~Iemali. reported by Ragsdale (Mo. Agr. Exp. Sta. Hll. 336:i. 19:I1) was used for the rompairiion.






Florida Agricultural Experiment Stations


centrate daily in 1950-51. Although this 'allowance was con-
sumed, the animals did not eat hungrily and frequently the man-
ger was not cleaned until several hours after feeding. There-
fore, no supplemental concentrate was offered during subsequent
years.
Average body weight gains each year of heifers grazing oat
pastures were above normal for animals of their breeds and ages
(11). In 1950-51, when the heifers consumed an average of two
pounds of concentrate daily per animal, their average initial
weight was 548.3 pounds and they gained an average of 1.23
pounds daily, which was 176.1 percent of the normal growth rate.
During the following two years average growth rate was ap-
proximately the same for the heifers grazing each variety of
oats without supplemental feed. Those on Southland oats made
a two-year average gain of 1.14 pounds daily, as compared with
1.13 pounds daily for those on Camellia oats. These gains aver-
aged 149.1 percent of the normal growth rate.
Average gains in body weight per acre of oats grazed were
higher in 1952-53 than for the previous season. However, the
difference in gains between the two varieties was relatively small
each year. Average gain in weight for the two seasons was 237.3
pounds on Southland and 233.7 on Camellia oats. A portion of

Fig. 3.-Dairy heifers made satisfactory growth on oat pasture alone.






Value of Oat Pasture for Dairy Cattle


the 285.1 pounds of gain per acre of oats grazed in 1950-51 was
supported by the concentrate allowance of two pounds daily per
animal.
Total Digestible Nutrients and Returns per Acre from Pas-
ture.-The average of 2,110.6 pounds of total digestible nutrients
per acre obtained from the pastures in 1952-53 was considerably
larger than the average of 1,625.4 in 1951-52. Increasing height
of forage to about 8 to 10 inches before grazing as compared to
six to eight inches during previous years is thought to be the
important factor in the higher yield of total digestible nutrients
obtained the latter season. Rainfall did not favor the higher
yields in 1952-53, since precipitation was lower and distribution
poorer during that growing season than for the comparable
period of 1951-52. Increasing the seeding rate from two to three
bushels per acre in 1952-53 presumably did not influence the re-
sults, since Morey and co-workers (9) observed that raising the
seeding rate from two to as high as six bushels per acre did
not increase forage yields.
The calculated production cost of oat pasture was relatively
uniform, ranging from $37.93 to : 4:;.,:' per acre. Feed replace-
ment value of the pastures ranged from $87.36 to $119.84 per
acre and varied according to the amount of total digestible nu-
trients obtained. Since the production costs of pasture were
relatively constant, the net returns per acre paralleled rather
closely the feed replacement values. These net returns ranged
from $45.89 to $81.91, with a two-year average of $63.90 for
each variety.
Production cost of total digestible nutrients ranged from
2.65 to 1.76 cents per pound. Since production costs of pasture
were relatively constant, the total digestible nutrients obtained
from it were least expensive during the year that yields were
higher.
Supplemental Feeding of Hay on Pasture.-The effect of feed-
ing hay to heifers grazing oat pasture was studied in a 101-day
trial from December 3, 1952, through March 13, 1953. Four
heifers grazing three Southland oat pastures rotationally were
fed Western prairie hay, No. 1, free choice, and four similar
heifers were grazed on three comparable pastures without re-
ceiving supplemental hay. Salt, steamed bonemeal, an anemia-
preventive mineral mixture, and water were available in each
i)asture.






Florida Agricultural Experiment Stations


The heifers offered prairie hay each consumed an average
of 1.9 pounds daily. Initial body weights of these animals aver-
aged 493 pounds and they made average daily gains of 1.62
pounds, which was 195 percent of the normal growth rate.
Initial weights of the heifers grazing oat pasture without hay
averaged 483 pounds. They gained an average of 1.23 pounds
daily, which was 162 percent of the normal growth rate. The
heifers fed hay gained an average of 0.39 pounds more per day
than did the controls.

DISCUSSION OF RESULTS
In 1951-52 and in 1952-53 the planting dates, seeding rates,
and fertilizer applications for Southland oats grown on Scranton
loamy fine sand (grazed by heifers) and on Orlando fine sand
(grazed by cows) were approximately the same. During these
two seasons, oats grown on Scranton loamy fine sand produced
an average of 501.8 pounds more of total digestible nutrients
per acre, the grazing season was 16 days longer, and the interval
between seeding and initiation of grazing was 10 days shorter.
Differences between Camellia and Southland varieties grown on
Scranton loamy fine sand were quite small.
The height at which oats were grazed is thought to be an
important factor affecting the amount of feed obtained from this
pasture. Beginning in 1952-53 oats were grazed at a height of
approximately 8 to 10 inches, as compared with six to eight
inches during the preceding season. Even though rainfall was
less during the 1952-53 growing season than for that of the
previous year, heifers obtained an average of 485.2 pounds and
cows an average of 240.1 pounds more total digestible nutrients
per acre than during the preceding season. Although the cows
derived 446.4 pounds more total digestible nutrients per acre
from pasture in 1953-54, when precipitation about equaled that
of 1951-52, a portion of this increase is attributed to the applica-
tion of 25.3 pound more nitrogen per acre. The differences in
seeding rates apparently were unimportant, since Morey and
co-workers (9) reported no increase in forage yields when the
rate was raised from two to as high as six bushels per acre.
In Australia (7) milk from six Ayrshire cows averaging
almost three gallons per day declined in fat from 4.3 to 2.6 per-
cent within a week after grazing was begun on oat pasture
6 to 12 inches tall. These animals consumed 1 pound of concen-
trate per 4.3 to 5.7 pounds of milk produced. During the three






Value of Oat Pasture for Dairy Cattle


grazing seasons reported herein, the butterfat content of milk
produced by the Jersey and Guernsey cows averaged 5.4 percent,
and all records appeared to be within the normal range. How-
ever, the ratio of 1 pound of concentrate consumed per 3.5
pounds of 4 percent fat-corrected milk produced was narrower
than that in the Australian trial.
The two pounds of concentrate per animal offered daily to
the heifers in 1950-51 were consumed with indifference, and the
average daily gain of these animals was only 0.09 pounds more
than the average of those on pasture without supplemental feed
during the following two years. Therefore, this supplemental
concentrate did not appear to be needed by the animals.
When four heifers grazing Southland oats were offered West-
ern prairie hay, they consumed an average of 1.9 pounds daily
and gained a daily average of 1.62 pounds, which was 0.39 pounds
more than the control animals gained. Feeding this hay did not
seem to have any effect on the loose fecal consistency observed
in animals grazing immature oats. Although a small number of
animal comparisons are represented by these data, it appears that
hay may be used advantageously to supplement oat pasture.
Net returns were higher and production cost per pound of
total digestible nutrients lower for oat pastures producing largest
yields of feed. Since production costs of pastures were relatively
constant, their profitableness increases with rises in feed replace-
ment value. Therefore, the two-year net return for oats grown
on Scranton loamy fine sand was $63.90 as compared with a three-
year average of $40.25 for those on Orlando fine sand.
Production cost per pound of total digestible nutrients aver-
aged 2.82 cents from oats grown on Orlando fine sand. The two-
year average was 2.15 cents from those on Scranton fine sand
and was only 1.80 cents per pound for 1952-53. The latter figure
compares favorably with the value of 1.47 cents per pound re-
ported for total digestible nutrients obtained almost entirely
from Florida permanent pasture (12), and is cheaper than can
be obtained from purchased concentrate or hay.

SUMMARY AND CONCLUSIONS
Immature oat pasture provided excellent quality forage
for dairy cattle during the latter part of fall, winter, and early
spring. Oats grazed by lactating cows had an average carrying
capacity of 1.1 cows per acre. However, the pasture furnished
less feed from early January through mid-February than during






Florida Agricultural Experiment Stations


preceding and succeeding periods. Thus, an accumulation of
forage, consistent with retention of good quality, should be made
in late fall for use during this colder period.
The three-year average daily production of cows grazing oat
pasture was 26.6 pounds of milk containing 5.4 percent butterfat.
This production was equivalent to 32.3 pounds of 4 percent fat-
corrected milk. The animals obtained a daily average of 10.9
pounds of total digestible nutrients from pasture, which was
sufficient for body maintenance and the production of 12.4 pounds
of 4 percent fat-corrected milk. The remaining portion of their
total digestible nutrient intake was supplied by an average daily
allowance of 9.1 pounds of concentrate per animal.
During two years, heifers grazing oats without supplemental
feed gained an average of 235.5 pounds per acre of pasture.
Their average daily gain of 1.14 pounds was 149.1 percent of
the normal growth rate. When two pounds of concentrate mix-
ture were fed to heifers on oat pasture in 1950-51, their average
daily gain was 1.23 pounds, or 0.09 pounds above the two-year
average of those receiving no supplemental feed. This observa-
tion indicates that feeding two pounds, or less, of concentrate
daily to heifers grazing high-quality oat pasture will have little
or no effect on rate of gain.
Heifers offered Western prairie hay free choice while grazing
oat pasture consumed an average of 1.9 pounds and gained an
average of 1.49 pounds daily. Although feeding hay did not
appear to have any effect on the loose fecal consistency of animals
grazing immature oats, their daily gain was 0.39 pounds more
than that of control animals receiving only pasture.
More feed was obtained from oats when grazed at a height of
about 8 to 10 inches in 1952-53 than at six to eight inches in
1951-52. Although rainfall was less and its distribution poorer
in 1'.V-5:;, heifers obtained an average of 485.2 pounds and cows
240.1 pounds more total digestible nutrients per acre than during
the previous season.
Oat pasture was an economical source of feed. High net re-
turns and low production cost per pound of total digestible nutri-
ents were dependent primarily upon large yields of total digest-
ible nutrients per acre. Oat pasture (on Orlando fine sand)
grazed by lactating cows produced an average of 1,466.7 pounds
of total digestible nutrients per acre. Net returns averaged
S40.35 per acre, and production cost of total digestible nutrients
was 2.82 cents per pound. Heifers grazing oats on Scranton







Value o: Oat a.sti.re for[ Dair0, Cattle


loamy fine sand obtained at two-year average of 1,868.0 pounds
of total digestible nutrients per acre. The return per acre of
$63.90 was higher and production cost of 2.15 cents per pound
of total digestible nutrients lower than that of the pasture on
Orlando fine sand.


ACKNOWLEDGMENTS

Appreciation is expressed to H. L. Somers and A. B. Sanchez for assist-
ance in supervising the management of cattle and pastures during the ex-
periments.

LITERATURE CITED
1. Amer. Soc. Agron., Amer. Dairy Sci. Assoc., Amer. Soc. Anim. Prod..
and Amer. Soc. Range Ilgmt. Joint Committee. Pasture and
range research techniques. Agron. Jour. 1: 39-50. 1952.
2. Association of Official Agricultural Chemists. Official and tentative
methods of analysis. 7th ed. 1950.
3. COPELAND, O. C. Calcium supplement and oat grazing beneficial to
production, health and vigor in milk cows. Tex. Agr. Exp. Sta.
55th and 56th Ann. Repts.: 11. 1942-43.
4. Georgia Coastal Plain Experiment Station 25th Annual Report. Bul.
42: 76. 1945.
5. HAWKINS, G. E., JR., and K. M. AUTREY. Performance of dairy cows
on immature oat forage. Jour. Dairy Sci. 38: 613. 1955.
6. HENDERSON, J. R. Recommended practices for the production of field
crops and pastures for the calendar year 1950. (Mimeographed.)
Florida Agricultural Extension Service. 1950.
7. MCCLYMONT, G. L., and R. Paxton. The effect of grazing oats on but-
ter-fat content of milk. The Agr. Gaz. 58: 551-53. 1947.
8. McCULLOUGH, M. E. The utilization of winter pasture by growing
dairy heifers. Proc. Assoc. Sou. Agr. Workers 52nd Ann. Con-
vention: 83-84. 1955.
9. MOREY, D. D., W. H. CHAPMAN and R. W. EARHART. Growing oats in
Florida. Fla. Agr. Exp. Sta. Bul. 523. 1953.
10. MORRIsoN, F. B. Feeds and Feeding. 21st ed. The Morrison Publish-
ing Co. 1948.
11. RAGSDALE, A. C. Growth standards for dairy cattle. Mo. Agr. Exp.
Sta. Bul. 336. 1934.
12. REAVES, C. W. Contributions of Florida farms to the feed supplies of
some selected milking herds. M. S. Thesis. Library, University
of Florida. 1956.
13. SPURLOCK, A. H., D. L. BROOKE, and R. E. L. GREENE. Cost of producing
milk in selected areas of Florida. Agr. Econ. Ser. 51-4. Univer-
sity of Florida Agricultural Experiment Stations. 1951.







Value o: Oat a.sti.re for[ Dair0, Cattle


loamy fine sand obtained at two-year average of 1,868.0 pounds
of total digestible nutrients per acre. The return per acre of
$63.90 was higher and production cost of 2.15 cents per pound
of total digestible nutrients lower than that of the pasture on
Orlando fine sand.


ACKNOWLEDGMENTS

Appreciation is expressed to H. L. Somers and A. B. Sanchez for assist-
ance in supervising the management of cattle and pastures during the ex-
periments.

LITERATURE CITED
1. Amer. Soc. Agron., Amer. Dairy Sci. Assoc., Amer. Soc. Anim. Prod..
and Amer. Soc. Range Ilgmt. Joint Committee. Pasture and
range research techniques. Agron. Jour. 1: 39-50. 1952.
2. Association of Official Agricultural Chemists. Official and tentative
methods of analysis. 7th ed. 1950.
3. COPELAND, O. C. Calcium supplement and oat grazing beneficial to
production, health and vigor in milk cows. Tex. Agr. Exp. Sta.
55th and 56th Ann. Repts.: 11. 1942-43.
4. Georgia Coastal Plain Experiment Station 25th Annual Report. Bul.
42: 76. 1945.
5. HAWKINS, G. E., JR., and K. M. AUTREY. Performance of dairy cows
on immature oat forage. Jour. Dairy Sci. 38: 613. 1955.
6. HENDERSON, J. R. Recommended practices for the production of field
crops and pastures for the calendar year 1950. (Mimeographed.)
Florida Agricultural Extension Service. 1950.
7. MCCLYMONT, G. L., and R. Paxton. The effect of grazing oats on but-
ter-fat content of milk. The Agr. Gaz. 58: 551-53. 1947.
8. McCULLOUGH, M. E. The utilization of winter pasture by growing
dairy heifers. Proc. Assoc. Sou. Agr. Workers 52nd Ann. Con-
vention: 83-84. 1955.
9. MOREY, D. D., W. H. CHAPMAN and R. W. EARHART. Growing oats in
Florida. Fla. Agr. Exp. Sta. Bul. 523. 1953.
10. MORRIsoN, F. B. Feeds and Feeding. 21st ed. The Morrison Publish-
ing Co. 1948.
11. RAGSDALE, A. C. Growth standards for dairy cattle. Mo. Agr. Exp.
Sta. Bul. 336. 1934.
12. REAVES, C. W. Contributions of Florida farms to the feed supplies of
some selected milking herds. M. S. Thesis. Library, University
of Florida. 1956.
13. SPURLOCK, A. H., D. L. BROOKE, and R. E. L. GREENE. Cost of producing
milk in selected areas of Florida. Agr. Econ. Ser. 51-4. Univer-
sity of Florida Agricultural Experiment Stations. 1951.







20 Florida Agricultural Experiment Stations

14. USDA Bur. Agr. Econ., Orlando, Fla. Florida annual crop summaries.
1950-1955.
15. USDA Bur. Agr. Econ., Orlando, Fla. Cooperating with Fla. Dept. of
Agr., Dairy Div., Milk production and feed reports. 1950-55.
16. VERBEER, W. A. Oats and wheat as grazing for high producing cows.
Farming in So. Africa. 21: 545-47, 552. 1946.




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