USING DHI RECORDS FOR FEEDING DAIRY CATTLE
DAIRY HERD IMPROVEMENT
1985
HUTJENS, M.F., & BATH, D.L.
VOLUME: NCDHIP HANDBOOK
Feed costs represent from 30 to 60 percent of the total cost of
producing milk. This is one area that dairy managers can control
through skillful purchasing of feeds and production of top quality,
homegrown feeds. Optimal milk yield per cow is dependent on
providing the correct nutrients to cows at various phases of the
lactation curve. By using your Dairy Herd Improvement (DHI)
records, you can accurately feed your cows, maintain peak milk and
milk persistency, reduce feed costs and maintain an inventory of
feed needs. Review your DHI records because different dairy record
processing centers (DRPC's) provide various features and
guidelines. Sample 1 gives an example of a stage of lactation herd
profile offered by a DRPC. Keep in mind that the DHI recommended
levels of grain and nutrients will be only as good as the values
that are reported.
Discovering Weak Links In Feeding Programs
Carefully evaluate peak milk yield. For each additional pound of
milk at peak milk yield, an additional 200 to 225 pounds of milk
will be produced normally during the entire lactation. Low dry
matter intake, protein and energy shortages or off-feed problems
will lower peak milk yield as well as persistency of milk
production throughout the lactation. Table 1 lists values for
Holstein cows for diagnostic purposes.
Young cows drop 8 percent per month compared to 10 percent declines
per month for older cows after peak milk. Metabolic disorders such
as milk fever, fatty liver, displaced abomasum and ketosis which
are related to feeding will affect peak milk and persistency.
Several DRPC's calculate monthly persistency values (Sample 2;small version,
large version) to determine if milk production of individual cows is
dropping too fast. Check with your DRPC since some states compare milk
changes to the previous month while others will compare milk drops to a
standard milk projection curve. Another item to watch is changes in
projected 305-day lactation yields. If these levels increase during the
lactation, persistency is desirable, but peak milk may have been too low.
Declines in projected totals may indicate a problem resulting from
insufficient feeds, unbalanced rations or other feed-related practices.
Example persistency:(small version, large version)
Review dry matter intake, nutrient levels and nutrient balance of
your herd to spot nutritional weaknesses. Some DRPC's will
calculate a recommended protein level for your grain mixture,
amount of topdress protein supplement, and protein and energy
indexes (amount of nutrient fed divided by the amount of nutrient
needed expressed as a percentage) for groups, strings or the entire
herd. The amount of forage fed (usually expressed as a percentage
of body weight or pounds of dry matter per 100 pounds of body
weight) varies from 1.5 to 2.5 percent or pounds, depending on milk
yield, forage quality, grain intake and inventory. Values outside
this range should be checked. The milk-to-grain ratio is another
useful diagnostic tool. Guidelines (grain levels expressed on a 90
percent dry matter basis) are listed in Table 2.
TABLE 2. Milk to grain ratios for various breeds
and levels of milk yield.
Breed Milk Yield Milk:Grain
Holstein and Brown <40 lb 4:1
Swiss 40-70lb 3:1
>70lb 2-1/2:1
Guernsey, Ayrshire, <30lb 3:1
Jersey and Milking 30-60lb 2-1/2:1
Shorthorn >60lb 2:1
Grain Recommendations
Most DHI reports provide a grain recommendation for each cow or
group (Sample 3;small version, large version). First, determine how your
values are calculated by the DRPC for your region.
Example sample day data
Method One
Computing centers often use a standard grain mixture (for example,86 percent
Total Digestible Nutrients (TDN) on a 100 percent dry matter basis) and
calculate the amount needed based on milk and fat yield. Some DRPC's
calculate and print out a grain and concentrate allowance based on the
milk fat production of individual cows in the herd. The formula used is:
(Daily milk fat (lb) - 1) x 15 = daily grain (lb)
For example, a cow producing 2 pounds of milk fat daily would be
fed 15 pounds of grain-concentrates:
(2 lb milk fat - 1) x 15 lb grain
The formula assumes that the cow is eating enough forage to fulfill
her requirements for maintenance and the production of one pound of
milk fat daily (about 30 pounds of milk fat monthly). If forage
quality or intake are not sufficient to accomplish this, the number
subtracted in the above formula can be changed to reflect the
amount and quality of forage being fed. For example, if the forage
provides only enough nutrients for 0.8 pound of milk fat daily
(about 24 pounds monthly) above the maintenance requirement of the
cow, the recommendation for the above example would be 18 pounds of
grain-concentrates daily:
(2 lb milk fat - 0.8) x 15 = 18 lb grain
Similarly, the number subtracted in the formula could be increased
if excellent quality forage were being fed, resulting in a lower
grain and concentrate recommendation with this kind of forage. For
example, if the forage consumed provides enough nutrients for 1.2
pounds of milk fat daily (36 pounds per month), the recommendation
would be 12 pounds of grain-concentrate daily:
(2 lb milk fat - 1.2) x 15 = 12 lb grain
If it is desirable to reduce the amount of grain fed because of an
unfavorable milk price to feed price ratio, the reduction can be
accomplished by using a smaller multiplier than 15. If 10 is used
as the multiplier in the original equation above, the
recommendation would be 10 pounds of grain-concentrates daily:
(2 lb milk fat-1) x 10 = 10 lb grain
A dairy manager can modify the equation according to the forage
quality being fed and the economic conditions on the dairy farm.
The factors 1 and 15 are used automatically if the dairy producer
does not indicate a modification on his barnsheet each month.
Method Two
Other programs calculate grain recommendations based on reported
forage intake and fiber minimums, dry matter intake prediction
equations and reported nutrient levels in the grain mixture.
Individual protein topdressing guidelines for electronic feeders
and individually fed cows are available in some states. An option
available in some states is a comparison of actual grain fed and
recommended amounts calculated by the DRPC. A quick review of the
differences between the two figures reveals excesses or shortages
in grain fed and necessary feed changes. Be sure to consider the
phase of the lactation curve for each cow or group of cows since
milk yield may be still increasing (first 60 days after calving)
and a lead factor should be added. Observe body condition and use
fat test when fine-tuning grain levels.
Economic Aspects
The most common value calculated is income over feed cost per day
and for the lactation period. Producers should determine how
individual cow feed intake values are obtained (reported,
calculated, and/or adjusted value based on body weight, dry matter
edits or other factors) and that these values are correct. Daily
income over feed costs reflects profitability of a cow during the
lactation cycle and indicates a logical time to sell cull cows.
Producers can subtract all other costs (variable, capital, labor
and fixed costs) from income over feed costs on a lactation basis
to determine profitability of an individual cow and the dairy
enterprise. Another useful value is feed-cost-per-100 pounds of
milk, which reflects feed efficiency. Compare your value to similar
production levels and herd sizes. If your values are too high or
low, review your inputs. An example of midwest feed costs is given
in Table 3, but your cost should be compared with similar
operations within your geographic region. A 1984 study of 4,123
Holstein herds in New York shows the same trend of income over feed
costs as reported in Table 3.
Grouping Strategies
In larger herds, cows frequently are housed and fed in groups in
freestall barns or drylot corrals. Groups of cows are fed the same
ration rather than the individual cow feeding that is practiced in
tiestall barns. It is important that cows with similar nutrient
requirements be grouped together and fed a ration that fulfills the
requirements of the group. If milk production varies widely within
a group, the low producers often will be overfed and become fat,
and the high producers will be underfed and drop in milk production
after body fat reserves are depleted.
Some DRPC's provide optional monthly reports that include a listing
of cows ranked according to test day production. The best
productive evaluation for grouping cows for feeding is according to
fat-corrected-milk (FCM) because it takes into consideration both
the volume of milk produced and the greater nutrient requirements
for production of milk with a higher fat content. A report that
lists Test Day FCM can be used to allocate cows to groups for
feeding according to production. Adjustments for first calf heifers
should be considered also. Rations can be formulated then according
to the nutrient requirements of the group and fed in community feed
bunks or mangers. When a herd is divided into a sufficient number
of groups according to production level (three or more groups of
lactating cows plus dry cows) and balanced for a determined level
of production, milk production is similar to that achieved with
individual feeding of cows according to production.
TABLE 3. Feed costs in 1,137 Illinois DHIA herds, by production level.
Income
over Feed
Production Number of Feed cost feed cost cost per
level(lb) herds per day per day cwt
Under 9,000 6 1.57 0.73 5.81
9,000-10,999 71 1.56 2.21 5.67
11,000-12,999 202 1.64 2.7 5.14
13,000-14,999 412 1.78 3.4 4.63
15,000-16,999 343 2 3.95 4.5
17,000-18,999 95 2.15 4.45 4.38
18,999+ 8 2.31 5.3 4.09
All Herds 1137 1.85 3.43 4.83
Another option provided by DRPC's expands on the Test Day FCM
listing. If the dairy manager provides information on the number of
corrals available and the number of cows to be allocated to each
corral, the DHI report will include a listing of cows to go into
each corral based on their Test Day FCM production. The report can
be used by the dairy manager to ensure that cows are put into the
correct corral. This is especially helpful in large herds where
hired labor do much of the milking, feeding and day-to-day
operations on the dairy farm. Once the cows are allocated to
corrals, optimum rations can be formulated for each group of cows
based on the range of milk production within each corral and the
prices of available feedstuffs.
Feeding Inventory Control
DHI reports may summarize the amount of feed distributed to the
herd on a monthly and yearly basis (Sample 4; small version, large version).
This information allows the manager to determine if adequate amounts of
various feeds are available, to shift feed ingredients (for example,
substitute silage for hay), purchase feed when it is available or when it
is a "good" buy and purchase in bulk quantities. An accurate inventory
allows for forward planning if expansion or changes will occur. Monitoring
inventory and feeding changes along with production responses allows the
manager to evaluate the dairy operation from year to year.
Example feeding summary
Points to Remember
1. DHI reports vary from state to state. Each DRPC allows options
that will not be calculated unless requested.
2. Accurate feed inputs (feed test results, feed intake and
correct reporting) are needed if the resulting recommendations are
to be of value.
3. Understand how your feed results are computed so you can
adjust procedures to your needs and make the figures more accurate
and useful.
4. Use the feeding aspects of your DHI records to increase the
return on your investment.
תתתתתתתתתתתתתתתתתתתתThe National Dairy Database (1992)תתתתתתתתתתתתתתתתתתתת
תתתתתתתתתתתתתתתתתתתתתתת\NDB\DAIRY\TEXT\DA108800.TXTתתתתתתתתתתתתתתתתתתתתתתת
%f TITLE;USING DHI RECORDS FOR FEEDING DAIRY CATTLE
%f COLLECTION;DAIRY HERD IMPROVEMENT
%f ORIGIN;Illinois
%f DATE_INCLUDED;June 1992