• TABLE OF CONTENTS
HIDE
 Front Cover
 Abstract
 Table of Contents
 Introduction
 Animal nutrient requirements
 Least-cost rations
 Summary
 List of cited references
 Appendix














Title: Methodology for determining nutrient requirements and least-cost supplements for Florida beef cow herds
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 Material Information
Title: Methodology for determining nutrient requirements and least-cost supplements for Florida beef cow herds
Physical Description: Book
Language: English
Creator: Melton, Bryan E.
Publisher: Food and Resource Economics Dept., Agricultural Experiment Stations, Institute of Food and Agricultural Services, University of Florida
Publication Date: 1979
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Spatial Coverage: North America -- United States -- Florida
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Table of Contents
    Front Cover
        Front Cover
    Abstract
        Page i
    Table of Contents
        Page ii
        Page iii
    Introduction
        Page 1
    Animal nutrient requirements
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    Least-cost rations
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
    Summary
        Page 23
        Page 24
        Page 25
        Page 26
    List of cited references
        Page 27
        Page 28
    Appendix
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
Full Text
-- nq


Economic


A Methodology for Determining

SNutrient Requirements



Least-Cost Supplements:

.for Florida Beef Cow iHerds-


III ~LPe~, ,III


Source Economics Department
- Experiment Stations
Food and Agricultural Sciences
f Florida, Gainesville 32611


.. -- Bryan E..- Mel
-. .. '. .- -. V .
*.. .- -.. .


" '* .-


-: I


.....~i.........


.. ..... ... ~
~- -~-----








ABSTRACT


Published estimates of dry matter (DM), metabolizable energy (ME)
and digestible protein (DP) relationships for beef cows are combined with
average growth curves of two breeds in two Florida locations to estimate
specific breed by location nutrient recommendations. These recommendations
are tabulated by age of cow on a monthly basis to correspond to commercial
conditions involving ration decisions over intervals greater than one day.
Adjustments in nutrient recommendations due to lactation and pregnancy are
also reflected in the analysis and in the resulting tables of nutrient
recommendations'(Appendix Tables 1-40).
The methodology, as well as the economic importance of nutrient
recommendations and supplemental feeding, are illustrated through a linear
programming determination of least-cost supplemental rations for four
hypothetical Florida cow herds. Assuming constant non-feed variable costs
per cow of $80.27 for all four herds, supplemental feed represents from
44% to 51% of per cow variable costs. Per animal supplement costs, and
thus per animal variable costs, are lower for British-cross cows in each
location. Due to production differences, however, in South Florida Brahman-
cross cows have lower variable costs per kg of calf weaned than British-
cross cows; in North Florida, the opposite is the case. There is, there-
fore, strong evidence of an economically significant breed type of location
interactions in ration requirements and production.

Key Words: Nutrient Requirements, Economic Rations, Beef Cow Herds.







TABLE OF CONTENTS

Page

ABSTRACT . . . . . . i
INTRODUCTION. . . . . . . 1
ANIMAL NUTRIENT REQUIREMENTS. . . . . 2
Methodology . . . . . . 3
Dry Matter . . . .. . ... 3
Energy . . . . . . 5
Lactation Adjustments . . . . 7
Pregnancy Adjustments . . . . 8
Protein. . . . .... ... 9
Lactation Adjustments. .. . . . ... 10
Application to Florida . . . . ... 10
LEAST-COST RATIONS. . . . ... . 12
Examples. . . . . . . 13
Herd Nutrient Requirements . . . .. 13
Supplemental Nutrient Requirements . . . 15
Linear Programming Model . . . . .. 16
Linear Programming Solutions .. . . . 20
SUMMARY . . . . . . . 23
LIST OF CITED .REFERENCES . . . . .. 27
'PPEIIDIX ... .. . . . . . . 29


LIST OF TABLES

Table Page

1 Nutrient requirements for each of the assumed 900-cow
Florida herds. . . . . . .. 14
2 Hypothesized forage nutrient production by period of the
year. . . . .. ... . 15
3 Supplemental nutrient requirements for each of the assumed
900 cow-cow Florida herds. .. . . .17
4 Nutrient concentrations of feeds available for the
formulation of supplemental rations . . ... 18
5 Average prices by period of the year for supplement feeds
in 1976 . . . ... . . 19






LIST OF TABLES (Continued)

Table Page

6 Least-cost supplemental rations for each of the assumed
900-cow Florida herds . . . ... . 21
7 Per animal production for each of the assumed 900-cow
Florida herds. ................ . 22
8 Summary of variable costs per animal and per weight of
weaned calf for each of the assumed 900-cow Florida
herds. . . ...... . . .. 24








A METHODOLOGY FOR DETERMINING
NUTRIENT REQUIREMENTS AND LEAST-COST SUPPLEMENTS
FOR FLORIDA BEEF COW HERDS


Bryan E. Melton


INTRODUCTION

Fulfilling animal nutrient requirements is a major economic considera-
tion in .any modern livestock enterprise. For example, approximately 80%
of the variable costs of feedlot beef gain are due to feed costs [9]. In
swine finishing operations typical of the Corn Belt, feed costs are esti-
mated to represent 55% to 60% of post-weaning costs [6], while in dairy
and poultry operations feed costs account for approximately 50% to 60%, or
more, of"the variable costs of production [1].
Because the beef cow.herd typically obtains the majority of its nutri-
ent-needs by grazing forages, determining least-cost rations has received
less attention in commercial cow-calf operations than in any other type of
livestock enterprise. There are, however, certain aspects of the cow-calf
production system, and certain periods of time, that warrant more detailed
consideration of least-cost rations. For instance, the cow herd must typi-
cally be maintained as a unit throughout the year. The manager cannot
afford to sell the entire herd when grazing is exhausted and later buy a
2
new herd when sufficient forages are again available. Thus, during winter
months and droughts, when forage production is sharply curtailed, the
manager must often provide supplemental feeds to maintain the herd. Further-
more, certain forage varieties exhibit relatively low concentrations of one
or more of'the nutrients required by the beef cow through part or all of
the year. Thus, in many cases, almost continuous supplemental feeding is


AssistanL Professor of Food and Resource Economics and Adjunct Assistant
Professor in Animal Science. University of Florida, Gainesville.

INumbers in brackets ([]) refer to references.

Typically, major culling of the herd would result in losses of cumu-
lative genetic progress as the herd is again expanded. In such cases,
selling the herd would have a prohibitively high opportunity cost.








required to fulfill the animal's nutrient requirement. If the manager fails
to adequately fulfill these requirements, the production of the herd can
suffer, not only in the current year, but often in future years as well [8].
Such conditions, coupled with relatively low profit margins and recent
drastic feed and livestock price variability, have accentuated the need for
accurate least-cost rations in cow-calf management decisions.
Specifying animal nutrient requirements is a major problem in deter-
mining least-cost rations for the Florida cow herds. Recommendations of
the National Research Council (NRC) [19] form the most widely used refer-
ence for the specification of animal nutrient requirements, but because
these recommendations are general in nature, they may be inappropriate for
herd and management conditions specific to Florida. For instance, NRC
recommendations are in the form of daily requirements per animal. As a
producer attempts to evaluate the nutrient requirements of his specific
herd over longer time intervals such as the winter months, he must aggre-
gate the NRC recommendations over both time and animals. These recommend-
ations, however, fail to reflect any differences in nutrient requirements
due to breed of cow or environment, or even to fully describe the range of
physiological conditions potentially exhibited by a breeding animal in the
course of a year. Thus serious errors could occur in aggregating NRC
recommendations to determine the nutrient requirements for a specific
Florida cow herd.
In this paper an alternative method of determining the nutrient re-
quirements of the cow herd is utilized to adjust NRC recommendations for
Florida conditions. Because this method draws heavily from the NRC re-
commendations, it is intended to modify and supplement these recommenda-
tions, not to replace them as general nutrient requirement guidelines.
The use of this method is then illustrated through emperical examples and
the linear programming solution of least-cost ration problems for various
hypothetical Florida cow herd situations. As such, these examples are
intended only to illustrate the application of.the methodology--not to
provide specific cow herd analyses.

ANIMAL NUTRIENT REQUIREMENTS

In least-cost rations for the cow herd, dry matter, energy and pro-
tein are of primary importance. The required amounts of each of these










nutrients is affected by numerous variables including the weight of the
animal, its stage of life or age, its breeding or genetic potential, its
physiological condition such as pregnancy or lactation status and its
environment. A methodology for determining the nutrient requirements of
a Florida cow herd should, therefore, reflect the interrelationships be-
tween these variables and each nutrient considered.

Methodology

For each of the primary nutrients considered, various estimates have
been made of the relationship between animal-weight and the required level
of the nutrient. Additional estimates, although more limited, have also
been made of the added.nutrient requirements caused by lactation or preg-
nancy. These estimates underlie the NRC recommendations, and form an
,adequate starting point from which to develop more detailed nutrient re-
quirement recommendations for Florida cow herds.

Dry Matter

In:general, dry matter recommendations are.:an estimate of-the expected
daily dry weight of a particular ration type consumed by an animal under
ad-libitum feeding conditions [19]. While the observed daily dry matter
consumption is affected by the animal's body size, age and condition, as
well as ration type and environment, it is generally in the range of 1.5%
to 3% of-body weight [19]. For beef cows, that predominantly utilize
roughage, the upper limit of daily dry matter consumption is reduced to
approximately 2.5% of body weight [8]. Using 2% of body weight as an
average, daily dry matter recommendations for an animal in the cow herd
can be expressed as
DMt = .02 (1)

where:

DMt = the weight of dry matter consumption, in kilograms (kg), by a
cow on day t; and
Wt = the cow's body weight, in kilograms, on day t.

The maximum dry matter consumption, as determined by stomach capacity, is
assumed to be a 2.5% of body weight, or 125% of the average consumption.
The animal's age, condition and breed or genetic potential, as well as








the production environment, must then be considered in modifying this recom-
mendation for a specific cow herd. Animal growth curves developed by
animal breeders can be used to modify these recommendations.
The growth curve of an animal describes the animal's weight at a
given age, or point in time. In the form proposed by Brody [7], a growth
curve may be expressed mathematically as

Wt = A Bekt (2)

where:
A = the asymptotic maximum weight;
B = the integration constant;
k = the rate of maturity;
t = days of age, and
e = the base of the natural logarithm functions.
When the parameters A, B and k are estimated, either for an animal or for
a herd as the average of the animals in the herd, equation (2) will reflect
not only the effects of age, but also the effects of condition, genetic
ability and the production environment on animal body weight [7].
If a growth curve of the form specified by Brody [7] were substituted
into equation (1), the daily dry matter consumption of an animal could
be rewritten as
DMt = .02(A Be-kt) (3)

To determine the expected dry matter consumption of an animal over periods
of time greater than one day, requires integrating the function over the
appropriate time interval of the animal's life. For instance, the recom-
mended dry matter for an animal of age t0 to complete the following
(t t0) days, such as over the winter, would be obtained as

t

DM = DMtdt (4)


t
fkt 1'
=.02 (A Be-)dt

to

= .02[(t t0)A + B k(e-kt1 e-kt




-5




where:
DM. = the dry matter required over the specified time interval for an
1 animal in the ith group, and
all other variables are as previously defined.
Finally, by performing the same integration for each age group, or class,
represented in the herd, the modified dry matter requirement of the-herd
may be obtained as
n
DM = a.DMi (5)
i=l1
where:
DM = the dry matter requirements of the herd over the specified time
interval;
a. = the-number of animals in the ith .age group; and

n =:the number of age groups represented in the herd.

'Energy

Whereas dry matter recommendations.are commonly expressed in units of
-dry feed weight, the energy requirements for the cow.herd may be stated
in megacalories (MCal) of metabolizable energy (ME). As the name implies,
NE is the portion of energy intake that can be metabolized by the animal.
Thus, ME requirements, are influenced by type of ration. For the Florida
cow herd, primarily grazing forages., the ration affect is minimal. Beyond
ration t.,pe, ME requirements are.also influenced by the same variables as
dry matter consumption, and the production stage or phsyiological condition
of the animal. For instance, a growing animal requires more energy than
the same animal just maintaining weight. Pregnancy and lactation similarly
increase an animal's energy requirement [17 and 19].
Considering the simplest case first, Neville and McCullough have
estimated the daily ME requirement of a non-lactating, non-pregnant cow
to be [21]

ME = .1374Wt75 + 6.3Gt (6)

where:

MEt = the ME required by an animal-on day t; and

Gt = the weight gain, in kilograms, of the animal on day t.

By recognizing that daily gain (Gt) can be expressed as the change in








weight with respect to time, or

Gt = t (7)
dt
It is possible to modify this relationship in the same manner as the dry
matter recommendations by using a Brody-type growth curve like equation
(2). The modified daily ME requirementmay then be expressed as

MEt = .1374(A -Be-kt).75 + 6.3(kBekt) (8)


As with the dry
animal of age t0 to
by integration as


matter requirement, the energy requirement for an
complete a specific time period (t1 t0) is obtained


t1
HME = MEtdt

t-


t

= .1374 (A

to


= 4( 1374


t
- Be-kt).75dt + 6.3 kBe-ktdt

tO


Y + a4 tanh-
3 2a


YL) tan-l(YtL]


( k t I
-6.3(Be -kt) + C t
I0


where:
ME. = the ME required by the ith age of animal (to) over the specified
time interval;
Yt = (A Be-kt) 25
a = A"25
tanh- = the hyperbolic arctangent function;
tan- = the trigometric arctangent function; and
all other variables as previously defined.
If animals are neither lactating nor pregnant, the herd ME requirement is


--------I-n-.-;c~,,- ~i~.~. -.-..,


--- ---- ; -.-~., 1 -;-.,









then simply the sum of ME. values over the n age'groups, when each is
weighted by the number of animals in the group (-ai), or
n
ME = a iMEi (10)
i=l1
Lactation adiustnents. If animals in the herd are lactating, the MiE
requirements specified must be adjusted to reflect the higher energy
-requirements.of lactation. For lactating cows, Neville and McCullough have
estimated the daily ME requirements to be [21]
LMEt, = .1784W75 + .7443M + 8.2G (11)
t* + .7443Mt*+ 8.2Gt*

where:
LMEt-= the daily ME requirement of a lactating non-pregnant cow on
the t* day of lactation;
Mr, = the daily milk production in kilograms; and

all other variables .are .as previously defined.
From data presented by Neidhardt, et al [20] the lactation cycle for
Brahman cows in the tropics is estimated to be

Mt = 6.86606 +..02242t* .000355 t*2 + .00000095t*3 (12)

with R = .99 and all estimated regression coefficients significant at .001
level or better. Reynolds, et al [221 have shown that Brahman-cows exceed
cows of predominenantly British breeding by approximately 1.2 kg per day, a
figure generally in agreement with results found by Hentges and Howes [14].
Thus, in general, the lactation cycle may be expressed as

Mt* = b + .02242t* .000355t*2 + .00000095t*3 (13)

where b varies by breed.


For a cow in the ith age group the ME required for a specified lactation
time interval (t* t*0) is obtained.as

t*
1

MEi LMEtdt* (14)
t* 0
0










LMEi = 4(.1784
k


-
3


+.7443 (bt* + .Ol011t*2


+ a tanh Y tan1 Y 8.2(Bekt*
K 8.2(Be-

- .0001183t*3 + 0000002375t*4 + t


The per animal lactation adjustment for the ith group in the lactation
interval (t*1 t*0) is simply the difference between (12) and (9), or


LA. = LME. MEi
1 1 1


(15)


Pregnancy adjustments. Adjusting the ME requirement for pregnancy
requires considering the energy required by the fetus for normal pre-natal
growth. Moe and Tyrell [18] estimated that for a given, non-lactating
cow the added daily requirement of ME for the maintenance of normal preg-
nancy could be expressed as


PMEt, = .000567 e 0174t' .75
tj


(16)


where:
PMEt, = the daily ME requirement for pregnancy on day t' of gestation;
and
W. = the weight of the ith cow group in kilograms on the date of
conception (t' = 0)
Over the gestation cycle interval, the ME requirement for pregnancy
of the ith age group of cows is obtained as


t'
PA. =


PMEt,dt'


(17)


t 10 t'l
= .75f

t0
0


.000567 e 0174tdt'


=.000567Wi [e0174t1 -e.0174t6
.0174
The total energy requirement of the herd may then be obtained by
appropriately summing the adjustments and base requirements weighted by










animal numbers. Mathematically, this may be expressed as
n
ME =E (aME + iLAi + YiPA.) (18)

where:
ME = the ME requirement of the herd over the specified time interval;
; = the number of animals in the ith age group that are lactating;
i = the number of animals in the ith age group that are pregnant; and
all other variables are as previously defined.
The resulting ME value will thus be adjusted for the major factors affect-
ing animal energy requirements in a specific Florida herd.

Protein
While protein is potentially as important to the beef cow as energy,
fewer estimates of its requirement are available--possible because ruminants
have the ability to synthesize much of their own protein requirement from
energy and a source of nitrogin in the ration. The NRC recommendations for
digestible protein reflect constant daily protein amounts equal to 2.8% of
dry matter consumption for non-lactating cows [19]. Furthermore, this value
is invariant with respect to stage of gestation.
Assuming the figure of 2.8% is correct for digestible protein, and an
average dry matter intake of 2% of body weight, the daily digestible pro-
tein requirement may be expressed as
DPt = (.02)(.028)Wt (19)

= .00056Wt

where DPt = the daily digestible protein requirement in kilograms. The
requirement of an animal of age t0 over the interval (t1 tO) is then
t

DP. = DPtdt (20)

to t0

= .00056f (A Be-kt)dt

to

= .00056 [(t t0)A + B/k(e-ktl ekt0)]








where DP. = digestible protein requirement in kilograms of an animal in
the ith age group over the specified time interval.
Lactation adjustments. To adjust this recommendation for lactation
ability, a quadratic equation is hypothesized to describe NRC recommenda-
tions as

MAt, = (.0068Mt, .00032M2 ) (.02Wt,) (21)

where MAt* = the daily digestible protein adjustment for lactation. Over
an interval of the lactation cycle (t*1 = t* ), and for an average milk
production (M0 = b)3, this produces the adjustment (MA.)
t*

MA. = MAtdt*

t*0 t*

= (.0068Mo .00032M ) .02 Wt*dt

t*
0
As with dry matter and energy, the digestible protein requirement of the
herd is then obtained as the weighted sum,
n
DP =E (a DP. + B.MA.)
i= 1 1 1 1

Application to Florida
To illustrate the application of this methodology under Florida con-
ditions, four alternative herd and location situations are considered.
These herds may be broadly categorized as located in either North or South
Florida and either primarily British and British-cross cattle (such as
Hereford and Angus) or Brahman x British crosses containing from 1/4 to
5/8 Brahman breeding (2 locations x 2 breed groups).
The growth curves necessary to describe these four alternative sit-
uations were estimated using data from University of Florida experimental
herds located at the Belle Glade Agricultural Research and Education
Center (AREC) [16] and at the Gainesville Beef Research Unit (BRU) [15].


3The function described by (13) could have been substituted for Mt*
in (21) but the resulting 9th degree polynomial becomes mathematically
cumbersome for relatively small changes in MiAt, over the lactation cycle.









As such, the AREC herd is assumed to represent herds under top-management
in South Florida, while the BRU herd represents top management herds in
North Florida. The resulting growth curves, estimated by techniques of
non linear regression [4, 12], are as follows:
Herd I. Brahman-cross cows in South Florida
-.0019t
W = 485.20 457.04 e -01 (22)
Herd II. British-cross cows in South Florida
-.0017t
Wt = 470.98 449.97 e '01 (23)
Herd III. Brahman-cross cows in North Florida
Wt = 518.06 500.26 e .0022 (24)
Herd IV. British-cross cows in North Florida
W = 511.39 450.26 e-'02 (25)

In each case, all estimated regression coefficients (A, B and K defined
in equation (2), p. 4-5), evaluated using their asymptotic standard errors,
are significantly different from zero at the 10% level.
In general, these growth curves indicate that a larger mature size
and faster absolute growth rate can be expected with cattle in M!orth Florida
than in South Florida. In addition, the British-cross cattle also exhibit
increases relative to Brahman-cross cattle under North Florida conditions.
Whether these increases are genetic, conditional or environmental in
nature, the result is an increase in the animals' nutrient requirements.
These estimated growth curves allow monthly nutrient recommendations
to be calculated for animals of various ages in each of the four herd
situations considered. By assuming that milk production is a constant 1.2
kg per day more for Brahman-cross cows than for British-cross cows, the
animal nutrient requirements are computed as shown in Appendix Tables 1
through 40.
The selection of monthly time intervals in these recommendations
reduces the aggregation problems associated with daily recommendations,
such as NRC, but still allows for changes in physiological condition that
would not be possible with annual recommendations. Animal nutrient re-
quirements can be estimated over intervals longer than one month by simply
summing the appropriate monthly recommendations from these tables. For
instance, the energy requirement of a 5-year old Brahman-cross cow in
South Florida during the 3-month period immediately following the calving







season would be 1287.68 MCal (428.99 + 429.23 + 429.46) if she were not
lactating, and 2154.35 MCal (1287.68 + 289.31 + 292.05 + 285.31) if she
were lactating. By performing the same operations for each age group
represented in the herd, and weighting the result by animal numbers, the
nutrient requirements may be estimated for any specific herd, over any
given time interval. For instance, if 75% of the 5-year old Brahman-cross
cows are lactating then their average ME requirement is 1937.68 MCal (.25 x
1287.68 + .75 x 2154.35). This value, times the number of 5-year old cows,
is the total ME requirement for this age group.
Obviously, though the math is relatively simple, it can become tedious
to calculate herd nutrient requirements from these tables for a diverse
herd. An alternative approach is to utilize high-speed computers, or
even modern programable calculators, to directly calculate nutrient require-
ments from the derived nutrient functions (equations 4,9,14,17,20 and 22),
the estimated growth curves and a specific herd structure (age distribution
and calving rate). In this manner the herd's nutrient requirements over any
time interval are actually easier to calculate by this revised methodology
than by using the simpler, and potentially less accurate, NRC [19] values
directly.

LEAST-COST RATIONS
Once the nutrient requirements of a specific cow herd have been ob-
tained, either by the appropriate summings of the values from Appendix Tables
1 through 40 or by direct computation, it is possible to proceed with the
determination of least-cost rations for the herd. Because in the short-
run commercial cow-calf producers in Florida typically face a relatively
fixed herd, grazing a relatively fixed amount of pasture forage, the least-
cost ration problem may be expressed as a problem of determining the least-
cost supplemental ration. In other words, the pasture forage already exists.
If it is not grazed by the herd it has few, if any, alternative uses.4
Under these conditions, producers should attempt to utilize the pasture for-
age resource to its maximum. In the nutrients required by the herd exceed
this maximum, producers should then attempt to minimize the cost of the
supplemental feeds necessary to correct the herd nutrient deficiencies.


In the case where pasture forage has no alternative use its oppor-
tunity cost is zero, implying that it is a free resource to the producer.









Examples
To illustrate the determination of least-cost supplement rations for
Florida cow herds, .a herd of -900 cows is hr',ai:hesized for each of the four
alternative situations (breed and locations) previously described. The
900 cows, ranging from.2 to 18 years of age at calving time, are assumed
to be equally distributed across nine age groups (2, 3, 4, 5, 6, 7, 8-10,
11-18). For simplicity, it is further assumed that calving occurs in
February, at a constant 75% calving rate for all age groups and no .death
losses are considered in these examples.

Herd Nutrient Requirements
The nutrient requirements of each of these hypothetical herds are cal-
culated by the ,previously described methodol c(,'.: and the recommendations
represeriteJ!- by Appendix Tables 1 through 40. I-n -computing the herd nutrient
requirements the year is broken into four periods approximately correspond-
ing-to the-physiol.ogi.cal stages of an:-animal's year as follows:

December-February (DJF): the last 1/3 of gestation:
March-Hay (MAM): the first 3 months post-
partum = from calving to
breeding;
June-September (JJAS): the lactation period from
breeding season through
weaningof the calf; and
October-November (ON): the two months from weaning
through the second 1/3 of
gestati on.
For comparison, the resulting herd nutrient reccr.redations are summarized
in Table 1 along with estimates derived fror. NR1C recommendations [19].
For these hypothetical herds the recommended nutrient levels obtained
by the modified procedure are clearly similar to those .obtained using ;RC
recommendations. In general, the modified recommendations indicate slightly
higher levels of DM and ME, but lower levels of DP, than NRC recommendations.
For different herd structures, such as a relatively young herd, these differ-
ences could be larger due to the failure of NRC recommendations to recognize
continued growth among young cows and high .DP recommendations made by NRC
for replacement heifers [19]. Differences between the modified and the NRC
recommendations are also less for the British-cross herds than for the
Brahman-cross. Because NRC recommendations were derived primarily from













Table 1.


Nutrient requirements for each of the assumed 900-cow Florida herds


Modified Recolmiendations


Period


Nutrient


Herd II


Herd III


i!RC Reconinenda t lons
Ilerd 11 lerd 1Ill


Herd IV


DJF



MAM



JJAS



ON


Overall


DM (103 ko)
HE 103 MCal)
DP (103 kg)

DM (103 kq)
ME (103 MCal)
DP (103 kg)

DM (103 kg)
ME (103 MCal)
DP (103 kg)


DM (103 kg)
ME (103 MCal)
DP (103 kg)

DM 103 kq)
MIE 103 ICa l)
DP 103 kg)


753.79
1355.30
21.11

761.12
1760.16
39.11

1024.09
2272.99
52.81

497.84
797.08
13.94

3036.84
6185.53
126.97


720.51
1317.15
20.17

728.69
1663.61
34.85

981.95
2145.65
49.58

475.28
771.70
13.31

2906.43
5898.11
117.91


816.53
1441.10
22.86

823.24
1848.51
43.13

1105.98
2384.58
58.03

539.91
845.14
15.12

3285.66
6519.33
139.14


801.95
1422.41
22.46

808.75
1771.47
40.65

1086.88
2285.14
54.79

530.23
833.88
14.85

3227.81
6312.90
132.75


685.23
1318.59
20.84

786.24
1523.34
42.18

1048.32
2031.12
56.24

372.60
749.40
11.46

2892.39
5622.45
130.72


677.95
1304.03
20.84

778.05
14.98.77
41.77

1037.40
1998.36
.55.69

367.80
739.80
11.22

2861.12
5540.96
129.52


714.35
1354.99
21.57

819.00
15!t.086
44.23

1092.00
2118.48
58.97

391.80
792.60
11.94

3017.15
5854.93
136.71


lHerd IV

714.35
1354.99
21.57

810.81
1580.67
43.82

1081.08
2107.56
58.43

391.80
783.00
11.70

2998.04
5826.22
135.52


a I


I in l mpmilila *__
__~~~~ ~ ~ ~~~~~~~ iJ___ _~ _____~_~ ~__~__1_ _


__~~ ~ m Irel__ ~-I-








.observations on Dritish-type cattle, this is to be expected [19].

Supplemental Nutrient Pequirements
To determine the nutrient amount that must be provided by supplemental
rations (using the modified nutrient recommendations shown in Table. ) it
is necessary to reduce.the nutrient needs of each herd by the amount of
the nutrients.supplied by grazed pasture forage. In this paper it is
assumed each herd grazes primarily improved grass pastures. The assumed
nutrient production of these pastures in each of the four periods of the
year is summarized in Table 2.

Table 2. Hypothesized forage nutrient production by period of the year

December March- June- October-
February May September November
(DJF) (r Iv ) (JJAS) (ON)

Dry Matter (103 kg) 44.25 783.08 2578.71 44.25

Metabolizable
energy (103 MCal) 72.00 1415.62 4428.58 76.00

Digestible ,
protein (10G'kg) 2.50 48.55 153.11 2.63

To estimate the supplemental amount needed of each nutrient, it is
assumed that when the forage available exceeds the minimum requirement,
animals wiTllconsume until either the excess is exhausted or the upper
limit of their dry matter consumption is reached. For instance, the
pasture's "dry matter production during the JJAS periods is 2578.71 thousand
kg. Table I indicates that Herd I (Brahman-cross cows in .south Florida)
would be expected to consume 1024.09 thousand kg of DM'. Thus, forage
production e;-ceeds the expected consumption by 1554.62 thousand kg. The
maximum consumption, estimated as 125% of r'ecoiimended, also fails to
utilize all of-.the forage produced by 1298.60 thousand kg. In such cases,
it is assumed that the surplus forage can be carried forward to the fol-
lowing period of.30% of its initial value. Thus the 1298.60 thousand kg
of excess DM in the JASO period would yield 389.,58 thousand kg to be
added to the 44.25 thousand kg produced in the following period (ON).5


While DM is not actually reduced, the reduction may reflect a reduced
acceptability or palatability of more mature forage.







Following this method, the amount of nutrients to be supplied by
supplemental feeds are computed using the modified herd nutrient recom-
mendations shown in Table 3. The producer then attempts to satisfy these
nutrient requirements at the least-cost using an appropriate combination
of the available feeds shown in Table 4.
From Table 3 it is clear that supplemental feeding is unnecessary
only in the third period of the year. In the remaining periods when supple-
mental feeding is required the average prices of the feeds available for
supplemental rations, calculated from Feedstuffs [10] for 1976 are summa-
rized in Table 5.

Linear Programming Model
All the proceeding information can be analyzed with a mathematically
programming procedure known as linear programming. This method allows
for the optimization (maximization or minimization) of a linear objective
function subject to a set of linear constraints [5, 11, 13].
In determination of the least-cost supplement for each of the
hypothetical Florida cow herds the problem may be represented in the
standard algebra of linear programming as follows [13]:
14 3
Min Z = E CXjk (26)
j=1 k=l
14 3
b >ZZ al jkXk > b1 (27)

14 3

S a2jk jk b2 (28)
j=1 k=1
14 3
a 3jjk b3 (29)
j=l k=l
All X.k > 0 (30)
where:
Z = the annual supplemental feed costs to be minimized for each herd;
Xk = the quantity of the jth feed in the kth period;

Cjk = the cost per unit of the jth feed in the kth period;
JK









Table 3. Supplemental nutrient requirements for
900-cow Florida herds.


each of the assumed


Period Nutrient Herd I Herd II Herd III Herd IV

DJF DM (103 kg) 709.54 676.26 772.28 757.70
Max 886.93 845.33 976.41 958.19
ME (103 MCal) 1283.30 1245.51 1369.10 1350.41
DP (103 kg) 18.61 17.67 20.36 19.96

MAM DM (103 kg) 0 0 40.16 25.67
Max 168.32 127.78 245.97 227.86
ME (103 MCal) 344.54 247.99 432.89 355.85
DP (103 kg) 0 0 0 0

JJAS D:1 (103 kg) 0 0 0 0
Max 0 0 0 0
ME (103 kg) 0 0 0 0
OP (103 kg) 0 0 0 0

ON DM (103 kg) 64.01 25.65 136.79 119.95
Max 188.47 144.43 271.77 252.20
ME (103 MCal) 52.02 0 152.82 129.25
DP (103 kg) 0 0 0 0










Table 4. Nutrient concentrations of feeds available for the formulation
of supplemental rations

Nutrient concentration per kg of feed
Feedstuff Name DM ME DP
(kg) (MCal) (kg)

Cottonseed hulls .903 1.48 .002

Coastal Bermuda hay .915 1.77 .051

Corn grain .890 3.29 .100

Sorghum grain .890 3.00 .071

Wheat grain .890 3.00 .071

Barley grain .890 3.00 .130

Citrus pulp .900 2.78 .073

Cane molasses .750 2.75 .024

Citrus molasses .650 2.78 .109

Soybean meal .890 2.93 .438

Cottonseed meal .915 2.71 .363

Alfalfa pellets (17%) .927 2.24 .150

Fish meal .920 2.68 .576

Urea (NPN) .990 0.00 2.464


4,1,










Table 5. Average prices by period of the year for supplement feeds in
1976

Price per thousand kg (as fed) in dollars
JFM AMJ ND

Cottonseed hulls 70.93 82.60 78.92

Coastal Bermuda hay 70.00 70.00 70.00

Corn grain 124.44 131.97 116.73

Sorghum grain 121.66 123.80 111.09

Wheat grain 164.58 165.04 122.06

Barley grain 175.17 185.85 175.03

Citrus pulp 87.73 87.53 112.00

Cane molasses 87.08 82.95 88.66

Citrus molasses 54.76 54.28 56.15

Soybean meal 150.32 176.72 206.99

Cottonseed meal 150.87 173.04 197.62

Alfalfa pellets (17%) 149.70 143.03 160.46

Fish meal 303.41 339.24 428.50

Urea (NPN) 181.16 178.62 186.35









b' and bI = maximum and minimum DM requirements, respectively;

b2 and b3 = the minimum ME and DP requirements, respectively; and

aj a2 = the DM, ME and DP concentrations of the jth feed
jk jk in the kth period, respectively.

Linear Programming Solutions
With the feed costs and nutrient concentrations specified in Tables
5 and 4, respectively, and the herd nutrient requirements as set forth
in Table 3, the linear programming model is used to obtain least-cost
rations for each of the four hypothetical Florida cow herds. The optimal
supplemental rations thus obtained are summarized in Table 6. From these
results it should be obvious that the critical aspect of least-cost supple-
ment rations is not the selection of an appropriate feed mixture but
rather the determination of an optimal feed quantity. This can be accom-
plished with reasonable accuracy without the aid of computerized models
such as described in this paper. For example, in all periods requiring
supplemental feed the primary deficit nutrient is ME. In DJF and ON an
amount of DM is also required. Simple observation of the nutrient con-
centrations and prices of the feeds and common sense would lead to the
feeding of hay in these periods. Similarly, in MAM when little or no DM
is required and it is only necessary to supplement the energy production
of new forage growth the obvious choice is molasses. In each case, the
optimal quantity is simply the minimum amount of the feed required to meet
minimal animal requirements. While it must be emphasized that these re-
sults are intended primarily as examples, similar results may be obtained
for most Florida cow herd situations.
It is obvious from Table 6 that the cost of supplemental feed can
be a major factor in cow herd management. This point may be further illus-
trated by an analysis of per animal costs and production. Assuming steer
weights to be 8% greater than heifer weights, [3, 23], the weight of
weaned calves may be calculated from the previously described growth
curves. With the assumed 75% calf crop, production per cow in terms of
weight of calf weaned can then be estimated by assuming a cow has an equal
probability of producing either a steer or a heifer calf. Calf production
by each of the hypothetical herds is thus summarized in Table 7.
With an assumed non-feed variable cost of $80.27 per cow [2], costs











Table 6. Least-cost supplemental rations for each of
cow Florida herds


the assumed 900-


As Fed Quantity (10" kg) Cost ($)
Coastal Citrus
Bermuda hay Molasses


54,281.50
6,726.92
4,897.20
65,905.62


51,735.60
4,842.32
1,962.10
58,540.02


59,081.40
8,452.48
10,465.00
77,998.88


57,966.30
6,947.84
9,176.30
74,090.44


Herd I
DJF
MAM
ON
Total

Herd II
DJF
MAN
ON
Total

Herd I!I
DJF


775.45


'69.96
845.41


739.08


28.03
767.11


844.02


149.50
993.52


828.09


131.09
959.18


123.93


123.93


89.21


89.21


155.72


155.72


128.00


128.00


ON
Total


Herd IV
DJF
MAM
ON
Total


--






Table 7. Per animal production for each of the assumed 900-cow Florida herds

Herd I Herd II Herd III Herd IV


Average weaning weight of heifer
calves (kg) 178.53 156.10 202.89 215.55

Average weaning weight of the
steer calves (kg) 192.81 168.59 219.12 232.79

Average weaning weight of all
calves (kg) 185.67 162.32 211.00 224.18

Calves produced per cow .75 .75 .75 .75

Average weight of calf weaned
per cow (kg) 139.25 121.74 158.25 168.14










per cow and per weaned calf can be derived using the least-cost supple-
ment rations shown in Table 6. These costs are summarized in Table 8.
For the four hypothetical herds, supplemental feed costs range from 44%
of total variable costs for Herd II to 51% for Herd III. Again, these
results are intended as illustrative. Thus, although these results in-
dicate a comparative advantage to be gained with British-cross type
cattle in North Florida (Herd IV), such comparisons may not be valid.
Variations in the forage growing season, reproductive rate or non-feed
variable costs between North and South Florida that are not considered
in these examples could easily alter regional advantages in cost. Sim-
ilarly, cost per cow can be misleading due to production differences,
as evidenced by a comparison of Herds I and II. On a per cow basis,
Herd II appears superior for South Florida, but on the basis of weaned
calf weight Herd I has a lower cost. Thus comparisons of-the results in
Table 8 must be made with care. Even so, with relatively low profit mar-
gins, and prices for weaned calves only slightly greater.than variable
.costs per kg of weaned calf, accurate least-cost supplement rations are
especially important.
With supplemental feed costs representing from 40% to 50% of the
variable costs per kg of calf weaned and low calf prices, purchasing and
feeding more than:the required amount of feed can obviously be economical-
ly disastrous. The failure to adequately meet herd nutrient requirements,
however, can substantially reduce production and create equally disastrous
results. On this basis, it is obvious that the accurate appraisal of
animal nutrient requirements can be of critical economic importance in
modern beef herd management in Florida.

SUMMARY

In this study published estimates Of dry matter (DM), metabolizable
energy (ME) and digestible protein (DP) relationships for beef cows were
combined with average growth curves of two alternative breed types in two
alternative Florida locations to estimate specific breed by location


In reality, non-feed variable costs may vary greatly by regions
due to modified production and environmental conditions. Similarly, fixed
costs may also vary due to such components as land charge, taxes, etc.
that are regional in nature.









Table 8. Summary of variable costs per animal and per weight of weaned calf for each of
900-cow Florida herds


the assumed


Herd I Herd II Herd III Herd IV
per cow per kg per cow per kg per cow per kg per cow per kg
calf calf calf calf

Non-feed variables costs 80.27 .576 80.27 .659 80.27 .507 80.27 .477

Supplemental feed cost:

DJF 60.31 .433 57.48 .535 65.65 .415 64.41 .383

MAM 7.47 .054 5.38 .044 9.39 .059 7.72 .046

ON 5.44 .040 2.13 ,018 11.63 .073 10.20 .061

Total variable cost 153.49 1.102 145.31 1.194 166.94 1.054 162.60 .967









nutrient recommendations. These recommendations were tabulated on a
monthly basis, by age of cow, to correspond to.commercial conditions in-
volving ration decisions over intervals greater than one day. Potential
adjustments in nutrient recommendations due to lactation status.and preg-
nancy were also-reflected in the analysis and in the resulting tables of
nutrient recommendations (Appendix Tables 1-40).
In general the nutrient recommendations are quite similar to those
that would be obtained from NRC [19]. Recommendations for the Brahman-
cross typecattle, however, typically deviated more from NRC values than
did the British-cross type cattle. Within breed types, the greatest devi-
ation from NRC values was with respect to younger cows. This can be
largely attributed to the failure of NRC recommendations to reflect con-
tinued growth of less than mature animals (i.e., 2, 3, or 4 year old cows).
In addition, the modified recommendations presented in this paper describe
the full range of physiological conditions exhibited by the breeding cow;
NRC values .do not. Thus, on the average, the modified recommendations
may be preferable to NRC recommendations for.analysis .of Florida's partic-
ular.production conditions and beef cow herds.
The methodology, as well as the.economic importance of nutrient
recommendations and supplemental feeding, was then illustrated through
the determination of least-cost supplemental rations for four hypothetical
Florida cow herds. Each herd differed by breed (2) and location (2) but
was.assumed to be identical with respect to size, age of cows and calving
rate. Additionally, each herd was assumed to have an identical amount
of forage nutrients available from grazing.
Supplemental feeding was found to be required in three of the four
periods of the year examined. Only over the'summer months (June-September),
were excesses.of all nutrients considered produced by the assumed available
forage. 'ME was the i ost frequently deficit nutrient, with the winter
months (Dcember-February) exhibiting the greatest deficiency for all four
herds. Variation in the forage production calendar due to location or
forage variety could obviously alter this finding.
A linear programming model was used to solve for least-cost supple-
mental rations in each of the three nutrient deficit periods of the year
for each of the four herds considered. Fourteen common supplemental feeds
were included in this analysis at their 1976 price levels. The primary








supplemental feed used in the optimal rations was Costal Bermuda hay,
although during the spring months (March-May) it was optimal to provide
a high energy supplement (Citrus molasses) instead. Similar results could,
however, have been obtained with the aid of computerized models. The
selection of the appropriate supplemental feed is rather obvious for cow
herds. Thus, only simple math is required to estimate the optimal quantity
of supplemental feed with reasonable accuracy.
Assuming non-feed variable costs per cow to be $80.27 for all four
herds, the importance of least-cost supplemental rations was further
examined in a "pseudo-budgeting" type of approach. In this analysis it
was found that supplemental feed amounted to between 44% and 51% of per
cow variable costs. For the four herds considered it was found that per
animal variable costs, and thus per animal supplement costs, were lower
for British-cross type cows in a given location.
When the same analysis was conducted on the basis of per kg of calf
weaned, however, different results were obtained. Due to production
(weaning weight) differences, Brahman-cross cows had a lower variable
cost per kg of all calf weaned in South Florida than did British-cross
cows. In the North Florida situation the opposite was the case. There
was, therefore, evidence of breed type by location interactions of
economic significance due to ration requirements and production.
Variable costs per kg of calf weaned were found to be quite high
relative to the average market prices received for weaned calves; thus
creating an economically precarious position for many cow-calf producers.
Of these costs, supplemental feed costs were still found to represent
between 40% and 50% of the variable costs per kg of calf weight weaned.
On this basis, the accurate appraisal of animal nutrient requirements,
and the subsequent determination of economically optimal (least-cost)
rations, is of obvious importance in modern beef herd management in
Florida.









LIST OF CITED REFERENCES

1. Acker, Duane. 1963. Animal Science and Industry. Prentice-Hall,
Inc., N.J.

2. Anderson, C.L. and T.S. Hipp. 1974. Requirements and returns for
for 1000-cow beef herds on flatwood soils in Florida. Fla. Agr.
Ext. Circular 385.

3. Anderson, J.H. and R.L. Willham. 1978. Weaning weight correction
factors from Angus Field data. J. Animal Science. 47:124.

4. Bard, Yonathan. 1974. Nonlinear Parameter Estimation. Academic
Press, N.Y.

5. Beneke, Raymond R. and Ronald Winterboer. 1973. Linear Programming
Applications to Agriculture. Iowa State University Press.

6. Burns, Randy. 1975. Estimated returns from finishing feeder pigs in
Iowa. Iowa Coop. Ext. Service. Publ. M-1159.

7. Brody, S. 1945. Bioenergetics and Growth. Reinhold Publ. Corp.,
N.Y.

8. Church, D.C. 1972. Digestive Physiology and Nutrition of Ruminants,
.Vol. 3, Practical Nutrition. Author, Corvallis, OR.

9. Dyer, I.A. and C.C. O'Mary. 1977. The Feedlot. 2nd ed., Lea and
Febiger, Philadelphia.

10. Feedstuffs: The Agribusiness Weekly. 1976 (selected issues). Miller
Publ. Co., Minneapolis, MN.

11. Gale, David. 1960. The Theory of Linear Economic Models. McGraw-
Hill Book Co., N.Y.

12. Hartley, H.O. 1961. The modified Gauss-Newton method for the fit-
nting of nonlinear regression functions by least squares. Techno-
metrics. 3:369.

13. Heady, Earl 0. and Wilfred Candler. 1958. Linear Programming Methods.
Iowa State University Press.

14. Hentges, J.F.:and J.R. Howes. 1963. Milk production. In T. Cunha,
m. Koger and:A.C. Warnick (ed.) Crossbreeding Beef Cattle. University
of Florida Press, Gainesville. p.p. 93-97.

15. Koger, Marvin (ed.). 1977. Pasture programs and beef cattle breed-
ing systems for beef production in north central Florida. "Fla. Agr.
Exp. Sta. Tech. Bulletin 789.

16. Mbah, A.D. 1975. Growth patterns and efficiency of rotational cross
breeding systems. Unpublished M.S. thesis, University of Florida.







17. Moe, P.W., W.P. Flatt and H.F. Tyrrell. 1972. Net energy value of
feeds for lactation. J. Dairy Science. 55:945.

18. Moe, P.W. and H.F. Tyrrell. 1971. Metabolizable energy requirements
of pregnant dairy cows. J. Dairy Science. 55:480.

19. National Research Council (NRC). 1976. Nutrient Requirements of
Beef Cattle. 5th ed. National Academy of Science, Washington, D.C.

20. Neidhardt, R., D. Plasse, J.H. Weniger, 0. Verde, J. Beltran and A.
Benavides. 1979. Milk yield of Brahman cows in a tropical production
system. Animal Science. 48:1.

21. Neville, W.E. Jr. and M.E. McCullough. 1968. Calculated energy re-
quirements of lactating and non-lactating Hereford cows. J. Animal
Science. 29:823.

22. Reynolds, W.L., T.M. DeRouen and D.C. Meyerhoeffer. 1967. Milk pro-
duction in Angus, Brahman and Zebu-cross cows. J. Animal Science.
26:206 (abstr.).

23. Sellers, H.I., R.L. Willham and R. deBaca. 1970. Effect of certain
factors on weaning weights of beef calves. J. Animal Science. 31:5.





























APPENDIX











APPENDIX: TABLES OF AVERAGE MONTHLY NUTRIENT REQUIREMENTS

For each table of nutrient requirements, the following definitions
hold:

1) Age refers to the age, in years, of an animal as of calving
season.
2) Month after calving is the month after calving season, re-
gardless of whether or not the individual animal had a calf.
3) DM = kilograms of dry matter
ME = megacalories of metabolizable energy
DP = kilograms of digestible protein










Appendix Table 1. Monthly average nutrient requirements for Brahman-Cross


cows in South Florida:


Age = 1


Month Requirements Adjustments for:
after Open, Dry cow Lactation 'Pregnanc
calving DM ME DP ME DP IME

I 160.98 3 4. ;1 4.50 0.0! 0.00 0.00

2 l6n.1I 3J.0.C4 4;71 0.00 3) ).0)

3 175.40 364.7P 4.01 0.00 0.00 0.00

4 182.19 36".I1 5.10 0.00 0.00 .62

5 IPP."60 373.2E 5.28 0.0) 0.00 2.75

6 104. 4 377.03 5.45 0.0" 0.00 4.67

7 200'.25 3O0.5~ 'C.61 0.00 0.03 7. ;4

P 205.73 391.P? 5.76 0.00 0.00 13.51

9 2100 .1 36. 87 5. 90 0.00 0.00 22.96

10 215.61 39.7 6.04 0.00 0.00 3.04C

11 220. 13 2.32.37 6.16 0.00 0.00 56.37

12 224.40 3c4.85 6.28 0.00 0.00 112.83







Appendix Table 2. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 2

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


228.30

232. 1 I

235 71

23 10

242. 30

245.32

248. 18

250. 87

253.41

255.O80

25P. 06

260.20


107,00

3c9Q.27

401.30

403.21

404.qq9

406.67

408.24

40 71

411.09

412.39

413.61

414.775


.39
-6.50

6.60

6.60

6. 78

6.87



7.02

7.10

7.16

7.23

7.20


279.c0

293.22

277.01

264 .04

2 50.70

237 ; Q

230.39

O.CO

0.00

0.00

0.00

0.00


6. A9

7.10

7.30

7,4c

'.6A

7. 81

7.17

0. 00

0.00

0.00

0.00

0.00
0 0


0.00

0 .00

0.00

2.00

3.40

5.78



16.70

2?.40

4q.2P

n2.o 0

130 54










Table 3. Monthly average Nutrient Requirements
cows in South Florida: Age = 3


for Brahman-Cross


Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 262.15 415.7-; 7.34 2q!.42 7.ar 0.00

2 264. 05 416.P1 7.39 2nn,_3 7,070 0.00

3 26 5o.85 417.76 7.44 2n1 .r 4. ,'). 00
4 26.9' 5 11. rr. 7.41 2rr' .5 ". ? ,10.

5 20. 15 41Q.C 7.54 2,4. 9' .25 .1.71

6 270.66 420.?' 7.5A 2141 n 0.12 '..1

7 272. C8 421.04 7.62 234 .1 0..30 1 0.72

8 273.43 421.74 7.66 0.0) ). 10.22

9 27a. 70 422.40 7. 6; 0.O00 3.00 30.;9

10 27,5.' 423.02 7.72 0.0.) C.00 5-?.F

11 277.02 423.61 7.76 0.00 3.00 56

12 278.0 424.16 7 79 0.00 .00 152.26






Appendix Table 4. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 4

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


270.07

280 02
280.02

2RO. 02

28 1 76

2P 2 5

283. 22

284.03

284.70


2R5294
285.24


286f. O

28' *03


24. r66

425.15

425.62

425.05

4 6.46

426. e5

427.21

427.56

427.e9

42 .18

428.47

42g.74


7. 81

7.84


7.87


7.91

7.93

7.95

7.97

'7.99

8.01

P.02

R. 04


2R. 03

200.85

28.4.1

271 ,68

257 .03

243. 1

235.9n

0.00

0.00

0.00

0.00

0.000
20.00


P.3,

. 40




n.54

.58

q. 62

0.00

0.00

0.00

0.00

0.00


0.00

3. 0C

0.00

2.27

3.86

6.56

11.16

1 997

32.20

54.83

33.2"?

159a*48


Appendix












Appendix Table 5. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 5
M-. h--------- ----------


Requirements
Open, Dry cow
DM ME DP


287. r2

28PO.00

288.45

2;PP. R7

289.27

280.e65

290.00

290.34

290 66

290.96

291.24


428. 9 ;

429.23

429.46

429. 7

42 9 q8

430. C7

430.2

430.42

410.5F

430.73

430.87


P. 05

9.06

8.08

8. 0

. 10

P. 11

".12

8.13

9. 1 4

8.15

e.15


Adjustments
Lactation
ME DP


2"9.31

292.09

2e5 .31

272.97 T

25 .0<-

24A .3,*

236. 9

0.00

0.00

0 .00

0.00


P.62






9.71

. 73

0.00

C. 90

0.00

0.00


for:
Pregnancy
ME


- L- ___ CII--_-MEC


00.00

0. CO

0 .00

2.31

31. Q4



11. 27

19.34

32. 88

5'590

95.03


12 291 .50 431.01 8.16


0,00 3.00 16r1.56


Appendix Table 6. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 6


Requirements
Open, Dry cow
DM ME DP


291 75

291 r


42



292.P1

292. 99

293. 16

293. 32

293.46

293 .61

203.74


431.13

47 1.25

4.31.36

431 .47

431.57

431.67

431.76

431.R4

431.02

432.00

432.97

432.14


q. 17

8. I18



8. 19

P. 19

q.20

8.20

8.21

8.21

P.22

8.22

n.22


Adjustments
Lactation
IE DP


2P9. 94

292 .6

2P5.e87

273 .2?



245.3'3

237.33

0.00

0 .0)

0.00


0.00
0.000


9.72

R.73

. 74

S.75

9.76

9.77

A .78


0.00

0000

0.00

0.00


for:
Pregnancy
ME


0f.00

0.00

0.00

2*.34

3.97

6. 75

1 1 .49

1 0.52

33.19

59..43

91. 03

f161 .09


II.IILII
after
calving


Month
after
calving_


F




34





Appendix Table 7. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 7
Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 ,'Q3. 4 12.20 q.23 290.2'1 n.Cn 0.00

293,J .P 422.26 0.23 202. P.7'1 0.00
3 -' 34. 09 432.32 P.23 2qr. 1 .- 0.00
4 7'?4. 20 422.:27 0.24 2 .-1. 5* i'. 0O 2.35

5 294.30 t432.4? 9.24 29*.7O 1.q0 3.99

6 204.39 432.47 R.24 24r." .5 q 5 .70

7 294 .a '432.5? ;.2~ 237.f r". .91 11.54

S 294. 6 432.5 8.25 0.00 0.00 10.61

a 294. C4 432.6oC 0.25 0.00 0.00 33.34

10 294.72 n^2.64 A.25 0.0) 3. 0 956.a

11 294.79 432.68 25 0.00 0.00 O5.38

12 294.86 432.71 .26 O.CO 0.00 13.e6






SAppendix Table 8. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age 8 10

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 295.23 4 32.92 8.27 2c0.47 8q.2 0.00

2 295.27 432.94 .8.27 293.15 8. 92 0.00
3 205.21 432.96 .?77 2P6.34 9.92 0.00
4 205.35 432.00 *.27 273.".? 0.A2 2.235

5 205.3n 433.01 q.27 2 C.l O q.o? 4.00
f. 295.42 433.03 P.27 245.73 8. 3 ^.1
7 295.45 433.05 8.27 237.71 .q93 11.57

a 20o*.49 433.07 8.27 0.00 0..)0 10.67

9 295.50 433.00 8.27 0.0' 3.00 33.45

10 295.E3 433.1C .F.27 0.00 0.00 5,6*86

11 295.56 433.12 P.28 0.0) 30.0 95.67

12 295.58 433.14 8.2P 0.00 0.00 164.35











Appendix Table 9. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 11-12
Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


1 295.84 433.24 8,.28 200.63 0.83 0.00

2 295.85 433.24 8.28 293.31 8.33 0.00

3 295.85 433.24 8.28 286.50 8.83 0.00
4 295.86 433.24 8.28 27J.3 :8.84 2.36

5 295.87 433.24 8.28 259.12 8.84 4.01

6 295.87 433.24 8.28 245.90 8.84 6.02

7 295.88 433.24 8.28 237.87 8.84 11.59

8 295.88 433.24 8.28 0.00 0.00 19.70

9 295.89 433.24 8.28 0.00 0.00 33.49

10 295.89 433.24 0.28 0.00 0.OO0 56.94

11 295.90 433.24 8.29 0.00 0.00 96.80

12 295.90 433.24 8.29 0.00 0.00 164.57






Appendix Table 10. Monthly average nutrient requirements for Brahman-Cross
cows in South Florida: Age = 13-18
Month Requirements -Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DIM ME DP ME DP ME


295.96

'295 496

295.96


295.96
295, 6

295.96

295 .96

295.97

295. 97

295.97

295. 97

295.97


433.24

433.24

433.24

433.24

433.24

433.24

433.24

433.24

433.24

433.24

433.24

433.24


8.29

8.,29

8.29

0.29



8.29

8.29

0* 29

8.29

8.29


8.29
8.29


291 .70

294 44

287. 70

2 75.-1 5

260..4 7

247,.3?

239.30

0 .00

0.00
0.00

0 00
0.00

0.00


3.84

8.84

'8 .84


8.84
8.04

8084

8.84

0.00



0.00

0.00

0.00


0.00

0.00

0.00

2.36

4.01

6.82

11.59

19.70

33.50

56. 95

96 .3

164.62










Appendix Table 11. Monthly average nutrient requirements
cows in South Florida: Age = 1


for British-Cross


Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 143.48 328.71 4.02 0.00 0.00 0.00

2 150.74 334.32 4.22 0.00 0.00 0.00

3 157.64 339.54 4.41 0.00 0.00 0.00

4 164,19 344.41 4.60 0.00 0.00 1.49

5 170.42 348.95 4.77 0.00 0.00 2.54

6 176.32 353.20 4.94 0.00 0.00 4.32

7 181.93 357.18 5.09 0.00 0.00 7.34

8 187*25 360.91 5.24 0.00 0.00 12.48

9 192.31 364.40 5.38 0.00 0.00 21.22

10 197.11 367.68 5.52 0.00 0.00 36.07

11 201.66 370.76 5.65 0.00 0.00 61.33

12 205.99 373.66 5.77 0.00 0.00 104.26







Appendix Table 12. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 2
Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


209. 97

213.88

217.59

221. 11

224.45

227.63

230.64

233.51

236.22

238.80

241.25

243. 58


376.30

378.87

301.29

383.58S

385.73

387.76

389.67

391.48

393.18

394.79

396.32

397.76


5.88

5.99

6.09

6.19

6.28

6.37

6.46

6.54

6.61

6.69

6.76

6.82


246.46

249.90

243. 0

231.85

217.72

205.08

197.62

0.00

0.00

0.00

0 .00

0.00


5.99

6.20

6.40

6.59

6.76

6.91

7.06

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

1 .88

3.20

5.45

9.26

15.74

26.76

45. 50

77.35

131.50











Appendix Table 13. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 3

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


245. 72

247.82

249 62

251. 71

253.51

255.21

256.84

258.38

259.84

261. 22

262 .54

263. 79


399.07

400.36

401.58

402.73

403.82

404.86

405.83

406.76

407.64

408.47

409.25

410.00


6.88

6.94

6.99

7. 05

7.10

7.15

7. 19

7 23

7.28

7.31

7.35

7.39


253.20

256.25

249.80

237.51

223.07

210.14

202.40

0.00

0.00

0.00

0.00

0.00


6.97

7. 09

7.20

7.29

7. 39

7.47

7; 55

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.08

3.54

6.02

10.24

17.40

29.59

50.30

85.51

145.38


Appendix Table 14. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 4

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP. ME DP ME


264.94

-266. 07

267.14

268. 16

269. 13

270.05

270.92

271 .75

272.53

273.28

273.99

274 66


410.68

411.35

411.98

412.58

413.15

413.69

414.21

414.69

415.15

415.59

416.00

416.40


7.42

7.45

7. 48

7.51

7.54

7.56

7.59

7.61

7.63

7.65

7.67

7.69


256.63

259.50

252.87

240 .43

225.83

212 .75

204.87

0.00

0.00

0.00

0.00

0.00


7.50

7.56

7.62

7.67

7.72

7. 77

7.81

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0,00

2.19

3.72

6. 32

10.75

18.27

31.07

52.82

89. 80

152.66




38





Appendix Table 15. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 5

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 275.28 416.76 7.71 258.42 7.79 0.00

2 275.89 417.11 7.72 261.20 7.82 0.00

3 276.46 417.45 7.74 254.49 7.85 0.00

4 277.01 417.76 7.76 241.96 7.88 2.24

5 277.53 418.07 7.77 227.28 7.91 3.81

6 278.02 418.35 7.78 214.13 7.93 6.48

7 278.49 418.62 7.80 206.18 7.95 11.02

8 278.S4 418.88 7.81 0.00 0.00 18.74

9 279.36 419.13 7.82 0.00 0.00 31.85

10 279.76 419.36 7.83 0.00 0.00 54.16

11 280. 14 419.58 7.84 0.00 0.00 92.07

12 280.50 419.79 7.85 0.00 0.00 156.53







Appendix Table 16. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 6

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


280.83

281.16

281.47

281. 77

282. 05

282.31

282 56

282.80

283 03

283.24

283.45

283.64


419.98

420.17

420.35

420.52

420.68

420.8.3

420.98

421.12

421.25

421.37

421.49

421.60


7.86

7.87

7.88

7.89

7.90

7.90

7.91

7.92

7.92

7.93

7.94

7.94


259.37

262.10

255.34

242.77

228.05

214.86

206.87

0.00

0.00

0.00

0.00

0 .00


7.94

7.96

7.97

7.99

8.00

E. 02

8.03

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.27

3.86

6.57

I. 1117

18.98

32. 27

54 .87

93.29

158.60










Appendix Table 17. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 7

Month .Requirements Adj ustments for:
after Open,_ Dry corj Lactation Preganacy
calving DM ME DP ME DP ME

1 283.82 421.71 7.95 259.88 8.02 0.00

2 284.00 421.81 7.95 262.59 8.03 :0.00

3 284.17 421.90 7.96 255.80 8.04 0.00

4 284.32 421.99 7.96 243.21 8.05 2.29

5 284.47 422.00 7.97 228.47 0.06 "3.89

6 204.62 422.16 7.97 215.25 8.06 6.61

7 284 75 422.24 7.97 20..25 8.0'7 11.24

8 284.88 422.32 7.98 0.00 0.00 19.12

9 285.00 422.39 7.98 0.00 0.00 32.50

10 285.12 422.46 7.98 0.00 0.00 55.25

11 285.23 422.52 7.99 0.00 0.00 93.94

12 285.33 422.58 7.99 0.00 0.00 159.70






Appendix Table 18. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 8-10

Month 'Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


285.93

286.00

286.07

286. 13

286. 19

286.25

286. 30

286.35

286.40

286.44

286.49


422. 94

422.98

423.02

423.05

423 .09

-423. 12

,423.16

423.19

423.22

423.25

423.27


8. 01

8.01
8. 0 1

8.01

8.01

8. 01

8.02

8.02

8.02

8.02

8.02


260.25

262.93

2 56.. 13

243.52

228.76

2 15-54

207 .52

0,00

0.00

0 .00

0.00


8. 08
8..08

8.09

8. 09

8.09

8. 10

8.10

0.00

0.00
0.00

0.00


0.00

0.00

0 00

2.30

3.91

6.65

11.30

19.21

32.66

55.52

94.40


12 286.53 423.30 8.02


0.00 0.00 160.49




40





Appendix Table 19. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 11-12


Month
after
calving DM


287.01

287.02

287.04

287 05

287.06

287.OT7

287. 08

287.10

287.11

287.12

287.12

287.13


Requirements
Open, Dry cow


Adjustments
Lactation


ME


423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68


8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04


260.47

263-14

256.34

243. 72

228.96

215 *73

207.70

0.00

0.00

0.00

0.00

0,00


8.11

8.11
8. 11

8.11

8.11





0.00

0.00

0.00

0.00

0.00


for:
Pregnancy
ME


0.00

0.00

0.00

2.30

3.92

6.66

11.33

19.26

32.74

55.66

94.63

160.88


Appendix Table 20. Monthly average nutrient requirements for British-Cross
cows in South Florida: Age = 13-18

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


287.27

287.27

287.27

287.27

287.27

287.28

287.28

287.28

287.28

287.28

287.28

287.28


423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68

423.68


8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04

8.04


260.95

263.65

256.86

244.27

229.53

216.33

208.33

0.00

0.00

0.00

0.00

0.00


8.12

8.12

8.12

8.12

8.12

8.12

8. 12

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.31

3.92

6.67

11.33

19.27

32.76

55.69

94.69

160.98


calving DM,











Table 21. Monthly average nutrient requirements
cows in North Florida Age = 1


for Brahman-Cross


Month Requirements -Adjustments for:
after Open, Dry cow Lactation Prenan
calvinL DM ME DP ME DP ME


192.3*

200.40

2:07.90

214.92

221.413

227.02

233.35
2 3 8 72
238. 72

243.,74

24 43

252. 81


34. 69

399.30

403.50

407. 14

4 1 0 .t 6

414.08O

417.05

419? .7 8

422.2 )

424.61

426. 75

428.73


5.15



5.61

5.02

6.02

6.20

6. S7



6.02



6.96

7.08


0.00

0.00

0.000

0.00

0,00

0.00

0.00

0.00

0 .00

0. 00

0 00

0.00


0..00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00
0 00


0.00

0.00

0.00

1.79

3.04

5.16

H. 78

1 4.92

2 5 36

43. 12

73.31

124.64


Appendix Table 22. Monthly average nutrient requirements for Brahman-Cross
cows.in North Florida: Age = 2


Month
after
calving EM


256. 7'

260.03

264.22

2'r, 7.5 !
2 O ,57
270 73

273e w (5

276.41

278.98

281.39

283.64

285.74

287.70(


Requirements
Open, Dry cow


430.51

4.32.21

4 33 .7 9

435.25

436.60

4 37 7.86

43 9.03

440.1 1

441 .12

4 42.06

442. 94

4 43.75


Adjustments
Lactation
IE DP


'7.19

7.30

7.40

7.49

7.58

7.66

7.74

7.81

7.88

7.94

0.00

8.06


2 89. "8

293.05

286. 70

274.50

260. 13

247.27

23-9.5

0.00

0000

0..00

0.00)

0.00


'7.773

7.95

U.1 5

U. 33

tl. 4< )

8064

8.77

0.00

0.00

0.00

0.00

0.00


for:
Pregnancy
ME


0.00

0.00

0.00

2. 1I

3.70

6.29

10.70

18 .19

30.92

52.56

89.36

15 1.93


SAppend i::


--------~-~I I- -











Appendix Table 23. Monthly average nutrient requirements for Brahman-Cross
cows in North Florida: Age = 3

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 289. 4 444.48 8.11 23.97 0.67 0.00

? 291.20 445.19 8.15 296.85 8.77 0.00

3 ?92? .01 445. 84 8.20 290.24 8 B6 0.00

4 r)p4.32 446.46 8.24 2 7.7') 80.94 2.34

5 295. 73 447.03 A .Lo0 263. 1( 9.01 3.99

6 297.04 44 7.5( 9 12 250. 11 ).08 6. 78

7 298.28 4 448.06 8.35 242.23 9.14 11.52

0 299.43 448.52 8.38 0.00 0.00 19.59

9 300.50 448.95 8.41 0.00 0.00 33.30

10 301.51 449.36 8.44 0.00 0.00 56.61

11 302.45 449.73 8.47 0.00 0.00 96.24

12 303.33 450.08 8.49 0.00 0.00 163.62






Appendix Table 24. Monthly average nutrient requirements for Brahman-Cross
cows in North Florida: Age = 4

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DMI ME DP ME DP ME


J04 1.3

304.00

305.6?

306.30

306* 93

307.52

308.07

308.50

309.07

309.52

309.94


450.40

450.71

450.99

451 .26

451.51

451.74

451.96

452.16

452.35

452.53

452.69


8.52

8.54

S8.56

8.58

8.59

8.61

8.63
8064

8.65

8.67

8.68


295.71

298.47

29 1. 74

279.20

264.50

2b 1. 34

243.37

0.00

0.00

0.00

0.00


9. 09

9.14

9.101

9.21

9.25

9.28

9.30

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.42

4.11

6.99

11 88

20.20

34.35

58.39

99.27


12 310.33 452.85 8.69


0,00 0.00 160.77











Appendix


Table 25. Monthly average nutrient.requirements for Brahman-Cross
cows in North Florida: -Age = 5


Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME.

S ,,310. 69 452.99 8.70 29.6.47 9.2n 0.00

2 311.04 453. 12 1.71 299.1n 9.930 0.00

3 311.36 453.25 8.72 292.40 9.32 0.00

4 311.66 453.36 8.73 279.81 9.34 2.45

5 J11.'94 453.47 (8.73 265.08 9.35 4.17

6 112.21 4531.50 8,74 2') 1.0 7 9. i< 7.0t

7 312.46 453.67 8.75 243.87 9.380 12.04

8 312.69 453.76 0.76 0.00 0.00 20.48

312.00 453.85 ,8.76 0.00 0.00 34.81

10 313.11 4535.92 8.77 0.00 0.00 59.18

11 31.3.29 454.00 8.77 0.00 0.00 100.62

12 313.47 454.07 8.78 0.00 0.00 .171.06






Appendix Table 26. Month average nutrient requirements for Brahman-Cross
cows in North Florida: Age = 6

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


313 6 3

.- I1. 79

I13, 9 1

11 4 0 7
314.07

314.'1 9

31 4 31

314.42

314.52

314.62

314.71

114. P0O

314. *88


4,54-, 1 3
454.19

454 2 4



454.34


14 54 .3
454 .43
454 ,4

4 :/4 5 0

454.54

454.5 7

454.60


8.78

. o 79

B 79

S.7 9



8 .80

'8 80

8.01

8. 81

8.81


3 .8q2


.'9t6. 80

299..-49

22 .-;69

;.IO. 0.1





'2 4A ;;O 9




0. 00




0.00


'). 3 o
9 9.3 U


Q.40

0 4 0
9.41



0.00

0.00


0.00

0.00


0.00

0.00

0.00

2.47

4. I 9

7.13

12.12

20.60

35.02

59.54

101.22

172.09




44






Appendix Table 27. Monthly average nutrient requirements for Brahman-Cross
cows in North Florida: Age = 7

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM HE DP ME DP ME


114. 5;

115.02

315.0'2
3 15a 019

315.14

I 5 *. 2! )

315.25

315.30

315.35

.315.39

315.43

315.47


454. 6 3

454.65

4514.6 7

454 70

454.7?

454.73

54 .75

454.77

454.78

454,79

4 54.81


FI* 82

8.02
13.82

8.82

S.82



~3 83







8.83
8.83
F3 8.33


206.90

29'). 6 .

292.8;'?

260. 20

265.44

252.21

244. 19



0.00

0. 00

0.00


09 41

0.41

) 4 1
9.41

0o. 42

9.42

9 *42'
,1 4 2

9.42

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.47

4020

7.15

12.15

20.65

35.11

59.69

101.49


12 315.51 454.8. 8.83


0.0.) 0.00 172.54


Appendix Table 28. Monthly average nutrient requirements for Brahman-Cross
cows in North Florida: Age = 8 10

Month Requirements Adjustments for
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


315.70

315.72

315.74

315.76

315.77

315.79

315,80

315.82

315.83

315.84

315.85

315.86


454..86

454.036

454.87

454.07

454.87
454.87
454.87

454.86



454.05
454.86

454.86

454.85

454.859

454.84


8.84

8.84

8.84

S.04





8.84



8.84

8.84

A 84
8.84
,9o,64


297.01

299.69

292.88

2100.25

265.49)

252.25

244.22

0. 00

0.00

0.00

0.00

0000


9.43

9.43

9.43

9. 43

S9.43



9.43

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.48

4.21

7.16

12.17

20.68

35.17

59.79

101.64

172.80













Appendix Table 29. Monthly .average nutrient. -requirements for Brahman-Cross
cows in North Florida: Age = 11-12

Month Requirements Adjiistm..rnts for:
after Open, Dry cow .Lactation Pregn-ncv
calving DM ME DP ME DP : HE

1 315*97 455.06 8.85 296.90 9.44 0.00

2 315.98 .455.06 8.85 299.56 9.44 0.00

3 315.98 455,06 8..85 292 *74 9.4-4 .0,00

4 315.98 455.06 8.85 280.10 9.44 2..48

5 315.98 455.06 8.85 265.32 9,44 4.21

6 315.99 455.06 8.85 252.07 9.44 7. 16

7 315.99 .455.06 8.85 244.02 9.44 12.17

8 315 i99 -455.06 8.85 0.00 0.00 20.70

9 315.99 455,06 8.85 0.00 0.00 35.18

10 315.99 4595,06 8.85 0.00 0.00 59.82

11 315.99 455.06 3.85 0.00 0.00 t101.70

12 316.00 455.06 8.85 0.0:00 0.00 172.90






Appendix .Table' 30. Monthly average nutrient requirements for Brahman-Cross
cows in .North Florida: Age = 13-18

Month Requirements Adjustments for:
.after -Open, Dry coj .Lactation Prenancy
calving Dil T 1 D[ "ME 'DP _ME


316.01L

316 .01

316.'01

216.01

316.01

316.01

316.02

316.02

316.'02

31.6.02

316.02

316.02


455,06


455.06

455.06
'455.06
455.06

455.06

455.06



-'4)55,.06
455.06
4 55, 0 6


455.06

-4,55.06
455 *06


8. na"




8,.85
8.e85







8.85
8.85



8.85

0-85


"293.175

296.. 20

289 15

276.27

261 .23

247 *71

239 :37

'0,00

0-o00

0.00

0.00

0.00


9.44



9 .4 4

9.44

9. 44
9.44

9. 44

0.00

0.00


0.00
0.00

0.00


Q.00

0. 00

0.00

2.48

4.21

7.16

12.17

20.70

35.19

59.82

101.71

172.91












Appendix Table 31. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 1

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


183 .57 4

191. 14

198. *

;05. 02

'211i. 14

217.30

222.* 90

228. 17

233 .13

237.79

242.1 1

246.3 1


31- .65

3 fl 9 2 1

392.42

396.31

39').91

403 .25P

40C6.34

400.21



411.37

416.68

4 1 81. 4


5.14

5.35

5.55

5.74

5.92

6.00

6.24

6.39

6.53

6.66

6.78

6.90


0.00

0.00

0.00

0.00

0. 00

0.000

0.00

0. 00
0.00


0.00
0. *00

0.00
0.00


0.00

0.00

0.00

0 .00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00


0.00

0.00

0. 00

1.77

1.01

5. 11

8.69

14.70

25. 13

4?,. 72

72.63

123.48


Appendix Table 32. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 2

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


250.07

253.73

257. 1 1

260. 42

263.47

266.34

269.03

271. 57

273.96

276.21

278. 13


420.78.)

422 .666

424.41

426.05

427.50

429.01

430.35

,431.60

432. 78

433.87

434.90


7.00

7.10

7.20

7.29

7.38

7.46

7.53

7.60

7.67

7 .73

7.79


259. 73

262.9 q

256.166

244.52

2J 30.20

217.3'

209. 75

0.00

0.00

0.00

0.00


7.12

7.32

7.50

7.67

7.82

7.96

8. 08

0.00

0.00

0.00

0.00


0.00

0. 00

0.00

2.1J

3. 6 1

6.16

10.48

17.82

30.29

'5. 50

87.56


12 280.12 435.86 7.8 5


0.00 0.00 140.07












Appendix Table 33. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 3

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME "DP _NME_

1 22. 1 4-16. 74 7.00 264.43 1. 00 0.00

2 28.3 3.3r 43 7 .53 7.95 267. 3 j 0.) 0.00

3 95.55 431.39 3I.00 260.77 8.18 0.00

4 "28. 11 3 1.3 38.04 240.3 H8. 6 2..10

0 9.5 32n5 4).2 1.3 00? 2,3. 9. 3. a 3.'11

6 89.0 7 440.'.8 f.12 P20.o 7 8. 40 6. 65

7 .,91.27 441.10 3.16 212.91 1.46 11.31

S 292.4-1 441.67 8.19 0.00 O.UO 19.22

S 2"73.64 ^442.22 *.22 0.00 0.00 32. 6

10 294.7 442.72 8.25 0.00 0.00 55.56

11 295.74 443.20 8.28 0.00 0.00 04.46

12 296.70 443.65 R.31 0.00 0.00 160O. 9







Appendix Table 34. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 4

Month Reiquirements Adjustments for:
.after Open, Dry cow Lactation Pregnancy
calvinp: DM ME DP ME DP :ME


297.58

290.43

299 3

;' 'it. C)0 )

300 .,6

301. 15

301.98

302. 3 7

303.1

303. 6

304 14


444.06
-444;46

4 /4 ..* 83

.4 4! I Q



4445,12



/046. 3,9
446.516
446. 11

44,. 11

4 4 6.4



4 47 1 1


8033

0.36

n.1.3

n.40

0.42

S,:44

8.46

0.47

8 .49

8.50

0.52


266.5,







735. 48

222.33

21 4 399

0.00

0.00

'0.00

0. 00
O, O0


n.42

8 .4 7









8 .64

0.00

0.00
0 .00
0.00

0.00


0.00

0.00

0 00



4 O

4. 88

11.70

1<9.89

33. 01

57.48

97.72


304.60 447.32 8.53


0.00 0.00 166.14





48






Appendix Table 35. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 5

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME

1 305.02 447.51 0.54 267.60 8.6; 0.00

2 305.41 447.70 8.55 270. 3 9.65 0.00

3 305.82 447.80 8.56 263.57 8.67 0.00

4 106.1 '448.05 9.57 250.9' 8.609 .42

5 1306T,. 44H.21 4.50 2 1.2 7 10.70 4.11

6 306. 84 44'3.36 8.59 223.0 11.7? ,6.99

7 307.15 440,50 8.60 215.0'0 8.73 11.88

8 307. 3 4480.63 8.61 0.00 0.00 20.20

9 307.70 44]. 75 8.62 0.00 0.00 74.35

10 307.95 448.87 8.62 0.00 0.00 50.40

11 308.10 448.98 r 3.63 0.00 0.00 C9.28

12 308.41 449.08 8.64 0.00 0.00 168.79







Appendix Table 36. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 6

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


-10-.6 1

308.01

100. 99

309. 1 7

309.33

309.49

309.63

109. 77

309.90

310. 02.

310.13

310.24


449.1

449.27

449.36

449.44

449.52

449.59

449.66

449.72

449.79

449o84

449.90

449 .95


8.64

0.65

.0 .65

8.66

8 .66

8.67

0.67

8.67

8.68

8.68

8.68

8 .69


268 .0)

270. 79

264.00

251.40

236.66

223.44

215.4.3

0.00

0.00

0.00

0.00

0.00


8.72

8.73

8.74

H. 75

8.76

8.77

8.77

0.00

0.00

0,00

0.00

0.00


0.00

0. 00

0.00

2.44

4.14

7.04

1 1.97

20.36

34.61

58.84

100.03

170.06












Appendix Table 37. Monthly average nutrient requirements for .British-Cross
cows in North Florida: Age = 7


Month
af ter
calving

!


Requirements
Open, Dry cow
SME

450 0 0



4~0. 1

450.1 4

4 0. 1 1

4 0. 22

450.26

450.3 0

45 O.3.3



450.43
afO,/ o


Adjustments
Lactation
ME DP


26, 33

27 1 .0.

264.22

251.60

236.85

223.63

215.61

0. 00
0 6* 0)

0 .00

0.00

0.00


8.77







8.78

0.7')

tl 80

0.00



0.00

0.00

0.00


for:
Pregnancy
ME

0.00

0.*00

0 .00

2'.45

4. 1 (,

7.07

12.02

20.43

34. 7-1

59*05

100.39

170.67


Appendix Table 38.


Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 8-10


Month Requirements


after
calving


DM

111.41
311.4
J I 1 e 4 4


311. 5 7





111 .50
3 I 1 5 3




311 60
311 60

311*64

.111 .66

311.67


Open, Dry cow
SME

450.64

450.67

450. 69

4 0.72

450.75



4 5 0 7'
450).7)

450.81

4t50.84




450.93

450 7
450 '3


Adjustments for:
Lactation Pregnancy
DP ME DP ME


F.72

R. 72

n .72

8 72

8.72

4 .72

S* 72
A.72

H.73

8.73

8.73

F1.73


26f. 52

271 .20

264.39

25 1 701

237.02

223. 79

215.77



0.00
0.00

0. 00
0. 00

0. 00


8 80

8.80







. fl 1

0 00

0.00

0.00

0.00

. *00


0. 00

0 00

0.00

2.45

4.17

7. 08

12. 04

20.47

34.81
too. r1s
5911,l

100.61

171.05


DP

.* 69

8 ;69

R.69

F .70

8.70

8.70

8.70


A. 71


8.71


8.71


.)DM

110. 14



3110. 2



. 10. 2
' 10 .61

3.10. 60

3110. 76

310. 83

310.90

3 1 0 6



3111.02

311.L -











Appendix Table 39. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 11-12

Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


311. t6

311. 87


311.88

3 11 88



311.89

311 *89




311.90


311.90


451.OS
451.05

451.05

451.05

451.05

451.05

451.05

451 .05

451.05

451 .05

451.05

451.05


8.73

8.73

, 7.3

8.733
8.73

8.73

8. 73
8.73

8.73
3 .73

A.73

8.73


268.992

271.62

264.83

252.24

237.50

724.30

216. 30

0.000

0.00

0.00

0.00

0. 00


8.81




8.81


0.81



0,00

0.00

0.00

0.00

0.00
O.00O


0.00

0.00

0.00

2.45

4. I 7

7.09

12.05

20.49

34.84

59.23

100.71

171.21


Appendix Table 40. Monthly average nutrient requirements for British-Cross
cows in North Florida: Age = 13-18
Month Requirements Adjustments for:
after Open, Dry cow Lactation Pregnancy
calving DM ME DP ME DP ME


311.94

311.94

311.94

311.94

311 .94

311.94

311.94

311.94

3 11 .94

311.94

311.94

3 11 .94


451.059


451.05
451 05

451.05

451 .05

451.05

451.05

451.05

451.05

451.05

451.05

451.05


,.73

8.73


8.73

8.73

8.73

0.73


0.73

8.73

8.73

8.73

8.73


274.98

278.08

271.72

259. 5C)

245. 3

232.67

225.24

0.00

0, 00

0.00

0.00

0.00


8.81

8.81










0.00
8.81



O .00

0.00

0.00

0.00

0.00


0.00

0.00

0.00

2.45

4.17

7.09

12.06

20.50

34.85

59.24

100.72

171.24




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