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Title: Dairy ration evaluation
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Permanent Link: http://ufdc.ufl.edu/UF00084562/00001
 Material Information
Title: Dairy ration evaluation
Physical Description: Book
Creator: Harris, Barney.
Publisher: Florida Agricultural Extension Service, University of Florida,
Copyright Date: 1965
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Bibliographic ID: UF00084562
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    Table of Contents
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    Back Cover
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Full Text

CIRCULAR 278
APRIL, 1965


TON- PROFIT DAIRY
POTENTIAL DI

RATION

EVALUATION

BARNEY HARRIS JR.
C. W. REAVES


UNIVERSITY OF FLORIDA
AGRICULTURAL EXTENSION SERVICE
GAINESVILLE, FLORIDA
OES YOUR
',G PROGRAM
.SURE UP?














CONTENTS


3 Introduction
3 Revised Feeding Standards
7 Building the 'Dairy Ration
9 Building the Concentrate Ration
9 Building the "Roughage Mix"
10 Determining the Value of a Feed
12 Pre- and Post-partum Feeding (Challenge Feeding)
13 Avoid Fat-Depressing Rations
14 Urea in Ruminant Rations
15 Vitamin A and Carotene in Dairy Cattle Rations
16 Effects of Nitrate and/or Nitrite on Carotine
and Vitamin A Nutrition
16 Getting the Most from Feeds
17 Importance of Farm Workers
18 Ten Steps in Feeding for Maximum Production and Profit












Building the Dairy Ration
(Revised Feeding Guide and Requirements)
by Barney Harris, Jr. and C. W. Reaves

Introduction
The dairyman's objective should be to improve production,
in terms of milk, fat, protein and solids-not-fat and other traits
of economic importance. As a goal the herd's future average
should reach or exceed what the top 20 to 25 percent of the cows
are now producing.
During the past few years several Florida dairymen have
shown this goal can be a reality. Frequently, however, dairymen
feed for average production which may result in underfeeding
high producing cows and greatly overfeeding low producers. In
order to feed cows adequately and economically, you need to
know the requirements of animals for high production, and to
understand what feeds can be used or substituted to best meet
those requirements at a reasonable cost.

Revised Feeding Standards
Although researchers and progressive dairymen have real-
ized for several years they needed to revise feeding standards
for high producing cows, they have only recently made an effort
in that direction. Several universities now have data available
to substantiate the earlier theory that more energy is required
per pound of milk as the level of production increases.
Even though this is true, dairy records fully demonstrate
that most economical production results from high-producing
cows since requirements for body maintenance are rather
constant for cattle of similar size and weight, regardless of
production. This means a cow producing 40 pounds of milk as
compared to one producing 20 pounds would require-above
basic maintenance-more feed per pound of milk, but would not
require as much total feed as two cows producing 20 pounds
each.
Table I shows the daily maintenance requirements of dairy
animals. You will note a large fraction of the cow's ration is re-










quired for maintenance before she starts being profitable to the
dairyman.
Dairymen with high producing cows have an advantage since
maintenance is distributed over a greater number of production
units. This lowers production cost per unit of salable product.

Table I. Daily Requirements for Maintenance

Cow D.P. TDN' ENE2 Ca. Phos. Carotene
(lbs.) (lbs.) (lbs.) (therms) (Ibs.) (Ibs.) (mg.)
800 .50 6.5 5.8 .035 .017 48
900 .58 7.2 6.4 .040 .020 54
1000 .65 7.9 6.9 .044 .022 60
1100 .70 8.6 7.4 .049 .024 66
1200 .75 9.3 7.9 .053 .026 72
1300 .80 10.0 8.4 .058 .029 78
1400 .85 10.6 8.9 .062 .031 84
1500 .90 11.3 9.3 .066 .033 90
1600 .94 11.9 9.8 .070 .035 96
1700 .97 12.6 10.3 .075 .037 102
1800 1.00 13.2 10.7 .079 .039 108
1 Highest standards as reported in Feeds and Feeding. 22nd Edition.
2 Computed according to body weight. (70 Wkg.) %

Table II contains the current requirements for milk produc-
tion at various levels and percent butterfat. These data show the
total digestible nutrients (TDN) per pound of milk increasing as
the level of production increases. This is due to the increased
feed consumption necessary to maintain high producing cows.
As the cow consumes more feed, digestibility is slightly reduced
since the bacteria and protozoa are subjected to a greater quan-
tity of feed to break down or digest.

Table II. Revised ENE and TDN Recommendations for Milk Production

Pounds of TDN Per Lb. of Milk1
Pounds ENE-
Milk per day 3% Milk Fat 4% Milk Fat 5% Milk Fat 4% Milk Fat
10 .26 .31 .36 .32
20 .27 .32 .37 .33
30 .28 .33 .38 .34
40 .29 .34 .39 .36
50 .30 .35 .40 .37
60 .31 .36 .41 .38
70 .32 .37 .42 .39
80 .33 .38 .43 .39
90 .35 .40 .45 .40
100 .37 .42 .47 .41
1 A Revised Grain Feeding Guide for Lactating Dairy Cows. Memo from Cornell University,
Ithaca, New York.
2 Estimated Net Energy. Developed by Dairy Records Central Processing, Iowa State Uni-
versity, Ames, Iowa.










Other nutrients required (above maintenance) include:
1. 0.05 pound digestible protein (D.P.) per pound of milk.
2. 0.70 gm or .00154 pound of phosphorus (P) per pound of
milk.
3. 1.50 gm or .0033 pound of calcium (Ca) per pound of milk.
4. 125 mg of carotene or 50,000 I.U. of Vitamin A per day for
maintenance, reproduction and lactation appears to be quite
adequate for high producing cows.

Table III includes the requirements for maintenance and milk
production. The two have been added together for the con-
venience of the agent or dairyman.


Table III. Combined requirements for maintenance and milk production
at various levels for cows of three different sizes.

Wt. of
4% FCM Produced/day Animal TDN ENE D.P. Ca. P.
(lbs.) (lbs.) (lbs.) (therms) (lbs.) (lbs.) (lbs.)


800 11.1
1000 12.5
1400 15.2
800 12.9
1000 14.3
1400 17.0
800 16.4
1000 17.8
1400 20.5
800 20.1
1000 21.5
1400 24.2
800 24.0
1000 25.4
1400 28.1
800 28.1
1000 29.5
1400 32.2
800 32.4
1000 33.8
1400 36.5
800 36.9
1000 38.3
1400 41.0
800 42.5
1000 43.9
1400 46.6


10.6 1.25 .051 .035
11.7 1.40 .070 .040
13.7 1.60 .098 .048
12.4 1.50 .101 .048
13.5 1.65 .110 .053
15.5 1.85 .128 .062
16.0 2.00 .134 .063
17.1 2.15 .143 .068
19.1 2.35 .161 .077
20.2 2.50 .167 .079
21.3 2.65 .176 .084
23.3 2.85 .194 .093
24.3 3.00 .200 .094
25.4 3.15 .209 .099
27.4 3.35 .227 .108
28.6 3.50 .233 .109
29.7 3.65 .242 .114
31.7 3.85 .260 .123
33.1 4.00 .266 .125
34.2 4.15 .275 .130
36.2 4.35 .293 .139
37.0 4.50 .299 .140
38.1 4.65 .308 .145
40.1 4.85 .326 .154
41.8 5.00 .332 .156
42.9 5.15 .341 .160
44.9 5.35 .359 .169










Table IV. Composition of Various Feeds


Concentrates
Cereal Grains


Barley, crimped
Corn, No. 2
Corn, snapped
Corn & Cob Meal
Hominy Feed
Milo, ground
Wheat Bran
Oats, crimped
Rice Bran
Dry Roughages
for Roughage Mix
Citrus pulp, dried
Beet pulp, dried
Cottonseed hulls
Peanut hulls
Snapped Corn
Soybean mill feed
Soybran flakes 2
Miscellaneous
Brewers grain, wet
Molasses, citrus
Molasses, cane
Molasses, cane
(on muck)
Urea
Protein
Supplements
Cottonseed meal
Soybean meal
Peanut meal
Corn gluten feed
Corn distillers
dried grains
Brewers grain, dried
Hay
Alfalfa
Bermuda
Pangola
Bahia
Clover
Clover-grass
Pasture
Clover, alsike
Clover, white
Clover, grass
Pangola
Bermuda
Millet, pearl
Oat
1 Estimated Net Energy p
SDigestable protein and t


Crude Dig.
Protein Protein TDN Energy Ca.
(%) (%) (%) (Therms)' (%)

11.8 9.0 76.0 80.0 .06
8.7 6.7 80.0 80.0 .02
7.8 4.8 69.0 66.0 .02
7.4 5.4 73.0 70.0 .04
10.5 7.5 84.0 84.0 .05
10.9 8.5 79.4 78.0 .03
16.4 13.3 67.0 67.0 .13
11.6 9.0 68.0 80.0 -
12.4 8.4 67.4 64.0 .08


6.2 2.7 72.0 70.0
8.8 4.1 68.0 76.0
3.9 43.0 29.0
6.7 1.6 18.8 3.8
7.8 4.8 69.0 66.0
12.0 7.9 37.0 20.0
10.6 8.0 71.7 72.0

5.7 4.2 16.0 16.0
4.1 53.0 45.0
3.0 53.0 45.0

9.0 4.7 60.4 71.3
262.0 (protein equivalent)


41.0 32.5 63.0 63.0
44.0 37.0 78.0 79.0
42.7 38.0 66.0 66.0
24.8 21.3 74.0 71.0

26.6 19.4 82.0 84.0
27.5 22.0 67.0 67.0

15.3 10.9 50.0 40.0
7.1 3.6 44.0 32.0
6.0 2.5 40.0 30.0
5.0 2.0 40.0 28.0
14.0 10.5 60.0 40.0
9.6 5.5 51.0 45.0


Phos.
(%)

.4
.27
.20
.20
.55
.28
1.29

1.36


2.0 .15
.70 .08
.13 .06
.25 .06
.02 .20


4.1 3.2 15.7 14.0 .32 .06
5.1 4.1 12.9 11.2 .25 .09
4.5 3.4 13.9 12.0 .23 .07
2.7 1.8 14.0 12.0 .14 .05
2.8 2.0 15.0 12.6 .14 .05
2.1 1.3 12.8 11.0 -
3.2 2.4 9.2 8.0 .06 .09
er 100 lbs.
herms are estimated.









Crude Dig. Therms
Crop Protein Protein TDN (ENE)
Good Average Poor
Silage' Average Quality Quality Quality Quality
(%) (/) (%) (%) (%) (%)
Corn 2.0 1.2 18 18 14 10
Grain Sorghum 2.4 1.2 16 16 12 9
Oats 2.5 1.3 12 15 10 7
Clover-grass 3.2 2.0 12 13 10 8
Millet 2.0 1.2 9 9 7 6
Pangola 2.1 1.3 10 12 9 7
1 The figures above are average figures taken from data obtained in southern states.


Table V. Percentage of Calcium and Phosphorus in Commonly Used
Mineral Supplements
Calcium Phosphorus
Supplement (R / ) ( %)
Defluorinated phosphate 31-34 13-19
Dicalcium phosphate 20-28 18-21
Steamed bonemeal 24-29 12-14


Trace mineralized salt is an important new feed commodity
to appear on the market. This product is common salt to which
small quantities of other trace minerals have been added. The
mixture most generally sold contains potassium iodide, com-
pounds of cobalt, manganese, iron, zinc and copper. If trace
mineralized salt is used in place of common salt, add at least 20
(preferably 25) pounds per ton of feed. Since trace mineralized
salt does not contain calcium and phosphorus, these two mineral
elements must be supplied in one of the calcium and phosphorus
supplements given in Table V-a ratio of 20 pounds per ton of
feed. The calcium-phosphorus ratio in the ration should range
between 2:1 and 3:1, respectively.
If trace mineralized salt is not included in the feed, the trace
minerals may be added to the dairy ration or supplied in mineral
boxes. Also, a complete mineral mix may be used to supply all
minerals.


Building the Dairy Ration
The first important factor to consider in building a herd's
dairy ration is the amount and kind of roughage required for
the average cow's daily diet. Since there may be marked dif-









ferences from one type of forage to another, the dairyman must
be careful in evaluating the quantity and quality of roughage.
It is also possible to overestimate the quantity and quality of
pasture consumed due to variation in both moisture and stage
of maturity of the forage. A cow will consume less forage if pro-
vided ample amounts of a good concentrate.
Although a cow may consume more than 100 pounds of lush
pasture daily, the average is probably 50 pounds for small
breeds, and 60 pounds for larger breeds. Silage and other stored
forms of roughage can be estimated more accurately since
samples can be collected periodically for approximate analysis.
Also, the dairyman can approximate the weight being fed each
day.
Consider the example of a herd receiving corn silage as the
only roughage. First the digestible protein (D.P.) and total di-
gestible nutrients (TDN) of the roughage is determined and
subtracted from the requirements. The remainder will need to
be supplied by the concentrate.
As an example in building a dairy ration let us consider a
group of 1000-pound cows producing 40 pounds of 4 percent milk
daily.


D.P TDN
(lbs.) (Ibs.)
1. Requirements
(see Table III) 2.65 21.50
2. Roughage supplied:
40-pound corn silage per cow .48 7.20
3. Nutrients needed from
concentrates 2.17 14.30


Calculation of amount grain needed to supply 14.30 pounds TDN
To estimate the pounds of grain needed to obtain the amount
of TDN required from the above grain mixture, use the following
procedure: Assume the dairy concentrate to contain 70 percent
TDN (since most mixtures composed of grain will contain ap-
proximately this amount). Divide the pounds of TDN (14.30)
needed to be supplied with concentrate by 0.7.
Example: The previous problem showed that concentrates
need to supply 14.30 pounds of TDN. The 14.30 0.7 = 20.4
pounds of grain required to supply the needed TDN.








Calculation of percent of protein needed in the grain mixture
To calculate the protein percentage that the concentrate
mixture should have, divide the amount of protein required
(2.17) by the number of pounds of concentrate (20.4) required
and multiply the result by 100.
Example: The previous problem showed that concentrates
need to supply 2.17 pounds of protein. Therefore, 2.17 20.4 x
100 = 10.7 percent digestible protein needed in the grain mix-
ture. This would be equivalent to a 13.5 percent crude protein.
(These figures may now be filled in to complete the foregoing
daily ration per cow.)
If more than one kind of roughage is fed such as pasture
and hay subtract from requirements and continue as in above
example.


Building the Concentrate Ration
In determining what ingredients to include in the concentrate
mix, the dairyman must first consider the base feeds available
and their nutritional value and cost. Cereal grains are base feeds,
with corn and its by-products at the top of the list. Table IV
shows a list of the cereal grains commonly used.
Note that ground corn and hominy feed are high energy
feeds and contain 80 or more Therms of estimated net energy
(ENE) per 100 pounds. Citrus pulp and good quality snapped
corn contain approximately 70 Therms of ENE per 100 pounds
of feed.
After deciding what base feed or feeds to include in the
ration, select the most economical protein supplement. Once a
protein supplement is selected the dairyman must decide if an
extra feed is needed to obtain the necessary bulk, and he should
consider including some molasses or urea. Molasses continues
to be the feed supplying the most economical source of TDN, and
therefore should receive careful consideration.


Building the "Roughage Mix"
The name "roughage mix" has been adopted by Florida
dairymen to mean a fibrous mix fed in addition to the concen-
trate. Generally, the roughage mix will contain from 45 to 60
percent TDN and 6 to 10 percent crude protein as compared to a
concentrate containing 70 percent TDN and 18 percent crude pro-








tein. A roughage mix may contain any number of ingredients
but more often will contain two or more of the following: snap-
ped corn, citrus pulp, cottonseed hulls, cob and shucks, ground
hay and cottonseed meal. The roughage mix is usually too bulky
to feed in the milking parlor and therefore must be fed in the
stanchion barn or outside in a trough.
The greatest advantage in feeding a roughage mix would be
for dairymen having a limited forage (pasture, hay or silage)
program. Also, dairymen having milking parlors find that by
feeding a roughage mix on the outside the remaining nutrient
requirements can be consumed by the cow while in the parlor.
Generally, dairymen having a stanchion milking barn and a
average forage program will feed only one mix. This mix is
called a "single mix". A typical single mix contains about 65
percent TDN and 12 to 14 percent crude protein.
Many dairymen have successful operations with and with-
out a roughage mix. The decision as to which program should
be followed will depend upon the dairyman's operation. The
most important factor is to supply the cows with a balanced
total feeding program at an economical cost.


Determining the Value of a Feed
Basic guides are available to the dairyman for purchasing
feeds on a nutritive value basis. When purchasing feeds it is
a sound practice to select those that will furnish the most TDN
at the least cost and at the same time supply sufficient digesti-
ble protein.
Many feed combinations may be used to form a well-balanced,
efficient and palatable ration. A particular feed may be a bar-
gain one year whereas the next it may be the most expensive.
Market prices of feeds generally fluctuate constantly, but a
small change in the local price will not usually warrant a change
in the ration. Seasonal changes that result in sharp changes in
feed prices, however, demand gradual changes in ration com-
position.
Protein feeds should be purchased on the basis of protein
obtained per 100 pounds of feed. Likewise, the dairyman should
determine the cost of TDN in various feeds before making a
purchase.









For example, to calculate the cost of 100 pounds of TDN:

$2.70 cost of corn per cwt x 100 = $3.37 per 100 pounds TDN in
80.1 TDN in 100 pounds corn corn
$2.60 cost of citrus pulp per cwt x 100 = $3.61 per 100 pounds TDN in
72 TDN in 100 pounds citrus pulp citrus pulp

The best way to determine the cost of feeds is to consider
both the cost per unit of net energy and digestible protein at
the same time, using a "constant for corn" and a "constant for
soybean oil meal" (which are reported for each feed by Morri-
son's Feeds and Feeding in Appendix Table II). The calculation
is based upon No. 2 corn as the base energy feed and soybean
oil meal as the base protein-rich feed.
By knowing the price of these feeds we can calculate the
relative value of all other feeds on an actual price basis.
For example, compare the value of wheat bran as a source
of net energy and digestible protein with No. 2 corn at $3.00
per cwt and soybean oil meal at $4.00 per cwt.
According to Morrison's Appendix Table II, wheat bran has
a "constant for corn" of 0.619 and a "constant for soybean
meal" of 0.218. Multiply the price of corn-$3.00 x 0.619 =


Constants for Some Common Feeds and their Comparative Values
(Based on No. 2 corn @ $60.00 and soybean oil meal
@ $80.00 per ton, respectively)

"Constant "Constant Value
Feed for corn" for SOM" Per Ton
Corn Meal 1.00 0.00 $60.00
Hominy Feed 1.043 0.012 63.54
Rice Bran 0.715 0.086 49.78
Oats (not over 25%) 0.924 0.076 61.52
Wheat Bran 0.619 0.218 54.60
Snapped Corn 0.853 -0.031 48.70
Citrus Pulp 1.037 -0.101 54.14
Beet Pulp 1.014 -0.064 55.72
Molasses, Cane (not over 10%) 1.058 -0.169 49.96
Brewers' grains, wet 0.121 0.081 13.74
Cottonseed Hulls 0.435 -0.069 20.58
Corn Cobs 0.595 -0.095 28.10
Soybean Meal 0.000 1.000 80.00
Cottonseed Meal (Solvent, 41%) 0.025 0.770 63.10
Cottonseed Meal (41% Protein Gr.) 0.128 0.773 69.52
Peanut Meal (Solvent, 41%1) 0.195 0.636 62.58
Peanut Meal (Solvent, 50%) -0.169 1.160 82.66
Brewers' grain, dried 0.374 0.464 59.56
Corn Distillers' Dried Grains 0.709 0.342 69.90
Corn Gluten Feed 0.424 0.440 60.64








$1.86; and the price of soybean meal $4.00 x 0.218 = $0.87.
Add the products $1.86 + $0.87 = $2.73 per cwt.
Thus, $2.73 is the value of wheat bran in comparison with
corn and soybean meal at the above prices. When you can buy
wheat bran for less than $2.73 per cwt, it would pay to feed more
wheat bran in the ration. At any price above that, it would be
less economical than corn. (A minus sign before the constant
indicates the product is to be subtracted, instead of added.)
Purchase feeds wisely, always being careful to read the
analysis on the feed tag of a commercial feed. The chemical
analysis lists the crude protein which is about 70 to 80 percent
digestible in most concentrates. When buying a commercial
mix to supplement other grains, be sure to consider the cost
per pound of digestible protein.
The percent fiber is also very important. Feeds high in crude
fiber are usually low in digestibility. A good quality dairy mix
will contain 10 percent or less crude fiber (preferably less).
So-called "bargain" feeds may contain 12 to 16 percent fiber.
Don't buy roughage in a bag at the price of a good concentrate.
Where silage, green chop, and/or pasture are grown on the
farm, only high analysis feeds need be purchased.
As a guide to buying commercial feeds, remember that total
digestible nutrients will decline about 112 percent, for each
percent increase in crude fiber, and cash value will decline about
21/ percent.

Pre- and Post-partum Feeding
(Challenge Feeding)
High-producing cows tend to lose body weight during the
first two to three months of lactation. How much weight
a cow loses will depend upon her condition at the time of fresh-
ening and the method of feeding during the early weeks follow-
ing calving.
A few years ago most dairymen were not too concerned
about feeding the cow during the first few days after calving.
Now, however, this image is changing and dairymen are grad-
ually increasing the grain feeding two to three weeks pre-
partum to accustom the cow to heavy feeding required following
freshening.
Liberal feeding immediately after calving stimulates the
cow to reach a high peak of lactation 30 to 45 days after









parturition. Using this scheme, the dairyman allows the cow
to respond rapidly, approaching her genetic potential for pro-
ducing milk.
Dairymen have noted that once a cow has reached her
peak of production whether it be 40 pounds or 90 pounds -
an 8 to 10 percent gradual monthly decline results. This gradual
decline continues regardless of the feeding regimen that follows.
Alfalfa hay or young pasture will give a boost in production,
but after three to four days the gradual decline continues.
The best scheme, therefore, is to feed liberal amounts of
good quality roughage in addition to grain feeding during this
early lactation period in order to stay ahead of production and
cause the cow to peak within 30 to 45 days. After the peak is
reached, grain feeding should be adjusted according to pro-
duction level.


Avoid Fat-Depressing Rations
Generally, Florida dairymen feed less silage and hay than
dairymen in other sections of the country. This means the larger
part of feed requirements must come from the concentrate por-
tion of the ration. In addition to the concentrate, some dairy-
men feed a "roughage mix" that may contain some cottonseed
hulls, ground hay or cob and shucks as a source of fiber and
bulk.
Low fat milk generally is caused by a lack of roughage in
the ration. Fat content may be depressed by:
Feeding small quantities of roughage and large quantities
of concentrates.
Feeding extremely succulent roughages and large quantities
of concentrates.
Feeding limited quantities of roughage in combination with
a dairy mix that contains a high percentage of heated or
pelleted concentrates.
Feeding all roughage in a finely ground form.
To return butterfat to normal, add roughage to the ration
in the form of silage, hay or other high fibrous feeds, or add
1.0 to 3.0 percent sodium or potassium bicarbonate to the grain
mixture. Remember, bicarbonates have no nutritive value when
added to a dairy ration, but simply aid in creating conditions
within the rumen similar to those when normal amounts of








roughage are fed. Apparently the sodium or potassium bicar-
bonate help control rumen acidity resulting from the reduced
saliva output caused by low roughage rations.
Since bicarbonates tend to be unpalatable to some cows,
the dairyman must gradually add the bicarbonate to the ration.
Molasses helps to overcome the unpalatability caused by bi-
carbonates.
As a practical working guide, somewhere between 0.50 and
1.0 pounds of long hay or equivalent per cwt. of live animal a day
appears to be the minimum level to maintain good rumen con-
ditions for a normal milk fat test.


Urea in Ruminant Rations
The gradual increase in urea feeding during the last 10 years
has caused dairymen to raise many questions regarding its
proper use.
Urea, as a feed ingredient, is a synthetic crystalline material
produced by combining carbon dioxide and ammonia under high
pressure. It is a simple nonprotein organic compound which
contains as a commercial preparation 42% nitrogen and is po-
tentially equivalent to a 262% protein feed. Urea, as such,
contains no food value but when added to a ration adequate in
energy, supplements the natural proteins in feeds.
How much urea can be added to the ration? The dairyman
should first determine the level of protein desired in the ration.
Most concentrates (dairy mix) are 20 percent protein. Gen-
erally, it requires approximately 14 pounds of urea and 86
pounds of ground corn to replace 100 pounds of soybean meal.
Urea is an excellent source of crude protein when fed at the
proper level; but, when fed at excessive levels it is toxic. For
maximum performance the intake of urea for dairy cattle should
not exceed more than 3 percent of the dairy mix or 1 percent
of the total mix on a dry matter weight basis.
Most dairymen prefer to feed 40 pounds of urea per ton of
the dairy mix (2 percent). If a single mix is used (combination
of dairy mix and feeds such as ground hay, cottonseed hulls,
etc.) add only 20 pounds urea per ton (1 percent). Rations
containing low levels of protein and high levels of readily-
available carbohydrates (cereal grains and 7 to 10 percent
molasses) promote urea utilization.








Does Urea affect Palatability? It has been quite well establish-
ed by researchers that urea-containing feeds are slightly less
palatable than feeds containing natural proteins. However,
usually this is not a real problem with most herds when urea
is added at the recommended level. Generally, this problem
appears when cattle are first changed to feeds containing urea
but it will clear up in a short time. The palatability problem
is seldom noticed when cattle receive rations containing 6 to 9
per cent molasses.
The rumen contains many kinds of bacteria and protozoa.
Some of these microorganisms utilize roughages while others
utilize concentrates. Also, only certain kinds of bacteria can
utilize urea, along with energy feeds, to build protein. For this
reason, urea-containing rations should be gradually introduced
to the cow so that the microorganisms that utilize urea will
have ample time to multiply and increase in numbers.


Vitamin A and Carotene in
Dairy Cattle Rations

Carotene provitaminn A or a precursor of Vitamin A) is de-
stroyed when roughage is dried and bleached; hence a deficiency
may result under drought conditions. Grains (including yellow
corn) and cereal by-products contain little Vitamin A and will
not supply the cow's requirements. Carotene is abundant, how-
ever, in growing pasture, silage and well-cured hay.
Generally, the first symptoms that appear in Vitamin A
deficient animals are excessive lacrimation (tears or watery
eyes), thin or water diarrhea, nasal discharge, coughing, and pul-
monary involvement. Night blindness may result in the early
stages of a deficiency.
A deficiency of Vitamin A may be corrected by (1) including
in the ration those feeds that are excellent sources of Vitamin A
such as good legume hay and pasture; (2) by adding 4 to 5
million International Units of a stabilized source of Vitamin A
per ton of feed; or (3) injecting Vitamin A.
A high-producing cow requires about 50,000 International
Units of Vitamin A or 125 mg. of carotene per day. The pounds
of various feeds that meet these requirements are shown in
Table VI.








Table VI. The Carotene Level in Various Feedstuffs
Feed
Ingredient Carotene Required
Mg./lb. (Lbs.)
1. Fresh green legumes and grasses, immature 15 to 40 5
2. Legume hays-high quality ..---------.- -35 to 40 4
3. Non-legume hay of average quality -
pangola and bermuda 4 to 8 20
4. Non-legume hay-high quality -- 9 to 14 12
5. Corn and sorghum silages 2 to 10 25
6. Grass silage good quality ---- 15 to 20 8
7. Grains except yellow corn .01 to.02 -
8. Yellow corn and by-products --- 0.5 to 2.0 75
9. Citrus pulp ..... .. ------- 0.1 1250
10. Beet pulp --.- ---...- 0.1 1250


Effects of Nitrate and/or Nitrite on

Carotene and Vitamin A Nutrition

Since the results from most research indicate dietary nitrate
and/or nitrite accelerates Vitamin A depletion from body
stores and increases destruction of carotene, most commercial
mixes now contain approximately 2000 I.U. per pound of feed.
The uptake and transport of nitrate in plants varies, de-
pending to a large degree on the rate of nitrogen fertilization,
and the limited moisture supply. Grasses appear to be more
susceptable to nitrate accumulation than legumes. The greatest
accumulation of nitrate occurs in the stems and lowest in seeds
with the leaves somewhere in between.
In order to safeguard against a possible Vitamin A de-
ficiency when cattle are grazing on highly fertilized pastures,
dairymen should add approximately 2000 I.U. of Vitamin A
to each pound of the dairy mix or 4 million I.U. of Vitamin A
per ton.

Getting The Most from Feeds
Milk production of dairy herds is often limited more by the
feed and care they receive than by the inherited ability of the
cows to produce. Challenge feeding is recommended to de-
termine each cow's potential. It is not just heavy grain feeding.
Any man or boy can dole out feed to a cow or fill a manger,
but it takes an alert dairyman with knowledge of feeds and
cows to feed for high production with efficient use of feed.









Efficient Milk Production Requires Feeding:
The right feeds
In the right amounts
To the right cows
At the right time
After determining those feeds that furnish the necessary
nutrients at lowest cost, the dairyman must know how much
feed is needed to meet the requirements of each cow. Individual
care can be given to cows in a large herd if the dairyman follows
a few basic requisites:
1. Identify each cow (identification must be easily visible
by feeder and milker)
2. Make a record of each cow's production
3. Make a list showing cow's feed requirements
4. Develop a workable plan for carrying out the feeding
program for each cow or for cows grouped according to
production. Dividing the herd into three production
groups is a practical feeding plan.

The dairyman should develop the practice of quickly noting
the following conditions in the herd:
1. A lame cow
2. Foot-rot starting
3. Cow in heat-and make sure which one it is in heat
4. Cow off to herself, doesn't move out freely (sign of
illness)
5. Lack of appetite-doesn't eat feed in barn or no real
interest in it
6. Feces loose and foul smelling (as when not digesting
feed, overfed, or sick)
7. Feces too firm
8. Eyes dull and listless
9. Muzzle dry and not cleaned off (as possible indication
of fever).









Importance of Farm Workers


Some men do not see, others see but do not have the energy
or initiative to do something. Men generally fall into three
classes:
1. Those who do not see what is happening around cows
and barns
2. Those who see what happens, but do nothing about it
3. Those who see and do something about it.
Some men seem to see what is going to happen and do some-
thing about it before great harm is done to a cow or her pro-
duction. The keen eye of the herdsman can tell much about the
well-being of his cows. A good herdsman is not only a lover of
good cattle, he has the know-how, the ability and the willing-
ness to get the job done.


Ten Steps in Feeding for Maximum
Production and Profit
1. Accustom dry cows to milking herd ration, the last two
weeks, feeding 1 to 11/2 percent of body weight daily.
2. Feed at this level until fourth day after calving, if her
appetite will take it. Heavy feeding at freshening reduces
danger of ketosis.
3. Lead milk yield up to peak. After fourth day, increase
grain 1 pound daily as long as cow eats the feed readily
to determine her "cow power" to produce. (Watch the
cow carefully. If digestive upsets occur or appetite fails,
reduce the feed, until the cow is ready for more).
4. Follow milk yield down. After the cow has peaked
(30 to 45 days), adjust grain feeding after weighing
milk each month. (May feed by production groups.)
5. Watch cows for condition. There is an art as well as
science in feeding.

Feed young cows extra for growth:
2-year olds --- ----- .- .......... .3 to 4 lbs. daily
3-year olds -- -------- -- --- .1 to 2 lbs. daily








6. Feed high-producing cows several times a day. Cows
should receive good quality feeds 5 to 6 times a day.
(Feeds may be in the form of concentrates, silage, hay,
green chop or pasture.)
7. Change feeds gradually to allow for buildup of rumen
organisms to handle different feeds.
8. Feed amounts of forages that will result in most profitable
production. Large amounts of good quality forage aid
production, while large amounts of low quality roughage
reduce the cow's capacity for milk production.
9. Adjust concentrate mixture to quality and quantity of
roughage and pasture.
10. Buy feed as economically as possible considering ingre-
dients, seasonal purchase and volume discounts.




















































































COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)

Agricultural Extension Service, University of Florida.
Florida State University and United States Department of Agriculture, Cooperating
M. O. Watkins, Director




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