• TABLE OF CONTENTS
HIDE
 Copyright
 Front Cover
 Table of Contents
 Review of literature
 Method of procedure
 Results and discussion
 Summary and conclusions
 Literature cited






Group Title: Bulletin - University of Florida. Agricultural Experiment Station - no. 742
Title: Maintenance feeding of different grades of steer calves
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027522/00001
 Material Information
Title: Maintenance feeding of different grades of steer calves
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 16 p. : ; 23 cm.
Language: English
Creator: Kirk, W. Gordon ( William Gordon ), 1898-1979
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1970
 Subjects
Subject: Beef cattle -- Feeding and feeds -- Florida   ( lcsh )
Calves -- Feeding and feeds -- Florida   ( lcsh )
Calves -- Feed utilization efficiency -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 15-16.
Statement of Responsibility: W.G. Kirk ... et al..
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station) ;
 Record Information
Bibliographic ID: UF00027522
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: aleph - 000929606
oclc - 18422765
notis - AEP0397

Table of Contents
    Copyright
        Copyright
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Review of literature
        Page 3
    Method of procedure
        Page 4
        Page 5
        Page 6
    Results and discussion
        Page 7
        Initial weight and grade groups
            Page 7
        Daily gain and feed conversion
            Page 8
            Page 9
            Page 10
        Live and carcass grades and dressing per cent
            Page 11
        Gains by individual calves
            Page 12
        Increase in weight by 70-day periods
            Page 12
            Page 13
    Summary and conclusions
        Page 14
    Literature cited
        Page 15
        Page 16
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida





























Maintenance Feeding of
Different Grades of
Steer Calves
HUrME- U3BRARY


W. G. Kirk, F. M. Peacock, A. Z. Palmer, J W. Carpenter Ond
Agricultural Experiment Stations --
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. W. Sites, Dean for Research
















CONTENTS


Page

Review of Literature .. .-.. 3

Method of Procedure ...........- -- 4

Results and Discussion .... ..-.. 7

Initial Weight and Grade Groups .. .....- 7

Daily Gain and Feed Conversion 8

Live and Carcass Grades and Dressing Per Cent 11

Gains by Individual Calves 12

Increase in Weight by 70-Day Periods 12

Summary and Conclusions .. 14

Literature Cited .. 15








Maintenance Feeding of Different
Grades of Steer Calves

W. G. Kirk, F. M. Peacock, A. Z. Palmer,
and J. W. Carpenter'
The number of steers and heifers fed in dry-lot has increased
rapidly in Florida during the past 15 years. Florida bred year-
ling and older cattle have responded to balanced rations and
good management practices resulting in rapid and economical
gains and high yielding carcasses. Little is known, however, of
the potential to gain rapidly and final carcass quality of younger
and lighter Florida cattle. Few data are available on the nutri-
tional requirements of different grades of feeder calves for op-
timum feedlot gains, and on efficient conversion of feed for either
maintaining or improving slaughter grade during the feeding
period.
The purpose of the study was to maintain initial slaughter
grade of calves by varying the proportion of roughage to con-
centrates in the ration and length of feeding period.

REVIEW OF LITERATURE
Kirk et al. (5)2 found that individually fed Shorthorn-
Brahman crossbred calves, averaging initially 538 pounds and
fed for 120 days, required 446 pounds total digestible nutrients
(TDN) per 100 pounds gain. Dressing percentage was 60.2,
and carcass grade averaged U.S. Good. Hentges et al. (3) in
a 70-day trial observed that the slaughter grade of 240-pound
calves improved from Low Standard to Low Good with an aver-
age daily gain of 2.01 pounds and 550 pounds feed per 100
pounds gain. In a series of four 140-day feeding trials, Peacock
and Kirk (8) showed that Choice % Shorthorn-1, Brahman,
Low Choice 1 Shorthorn-1/2 Brahman, Choice 3/1 Brahman-1/4
Shorthorn, and Low Choice Brahman feeder calves had car-
casses which graded Low Choice, High Good, Good and Low
Good, respectively. Carcass grade failed by one-third to one
grade per lot to equal the estimated feeder grade, showing that
1Dr. Kirk is Professor Emeritus (Animal Scientist Emeritus), and
Mr. Peacock is Associate Professor (Associate Animal Husbandman),
Range Cattle Station, Ona. Dr. Palmer is Professor (Meat Scientist) and
Dr. Carpenter is Associate Professor (Associate Meat Scientist), Agri-
cultural Experiment Station, Gainesville.
2 Numbers in parentheses refer to literature citations.








140-day feeding period did not allow sufficient time for the steer
calves to reach their carcass potential. Carpenter et al. (1)
found that as Shorthorn breeding increased, carcass and fat
content increased; and carcasses from steers with more Brah-
man breeding had a larger amount of lean tissue, and more
moisture and protein in the lean tissue.

METHOD OF PROCEDURE
The experimental design consisted of selecting weaned steer
calves according to initial slaughter grade for immediate slaugh-
ter and for feeding periods of 70, 140, and 210 days. Trial I
was conducted in 1956-57, Trial II in 1957-58, and Trial III in
1958-59. Initial slaughter grade for each calf was estimated by
a three member panel of staff members experienced in apprais-
ing calves.
A group of weaned steer calves, representing each grade,
was sent to Gainesville for slaughter at the beginning of each
trial. The remaining calves were weaned in pens for 8 to 10
days; then they were separated for feeding into groups ac-
cording to estimated slaughter grade. The breeding and number
of calves slaughtered when weaned and those full-fed 70, 140,
and 210 days are given in Table 1. The average initial weaned
slaughter grades of calves used in each of the three trials are
shown in Table 2.
Weaned calves divided into U.S. Choice, Good, and Standard
slaughter grades were fed in Trials I and II, while in Trial III
the only calves available were Good, Standard, and Utility
grades. All calves selected for feeding in each trial were sepa-
rated as to slaughter grade and fed the first 70 days. At this
time representative calves were removed from each grade group
for slaughter, and those that remained were fed for the next
70 days. After the selected calves fed 140 days were removed,
the remaining calves were fed for a further 70 days, 210 days
altogether. Evaluation of grade change was the difference be-
tween initial slaughter and carcass grade of each calf fed.
The 99 steer calves were raised at the Range Cattle Experi-
ment Station (RCES). They came from a cow-calf project
having three herds of the same breed composition: purebred
Shorthorn and Brahman and crosses of these two breeds (4).
The three herds were maintained on separate pastures to supply
low, medium, and high levels of nutrition. Steer calves grading
Utility and Standard came mostly from the herd maintained on
native pasture. The Good and Choice calves were from the herds









Table 1.-Number of calves in breeding and feeding groups.


Treatment Group

Slaughtered Feeding Period-Days
when weaned 70 140 210 Total
number of calves
3 1 1 5
3 3 6 4 16


6 9


Table 2.-Estimated


5 6 26
4 3 12
4 4 19
2 1 13


Breed Group


Shorthorn
V2 Sh- 1/2 Br
% Sh 1/4 Br
7/ Sh- %/8 Br
% Br- 1/4 Sh
% Br %/ Sh
Brahman
Total


Trial Estimated Grade*
Group Choice Good Standard Utility Total
number of calves
Slaughtered
when weaned:
Trial I (1956-57) 1 9 2 12
Trial II (1957-58) 2 3 4 3 12
Trial III (1958-59) 1 3 3 1 8

Fed:


Trial I (1956-57)
Trial II (1957-58)
Trial III (1958-59)


7 13
7 14
6


- 24


6 6 18


Total 18 48 23 10 99
*Determined by visual appraisal by a three-member panel.


kept on pasture which furnished medium and high levels of
nutrition.
The calves fed in drylot ranged in age from 175 to 281 days
with an initial average of 236 days. The Utility grade calves
had an average initial age of 242 days; Standard calves, 238
days; Good calves, 227 days; and Choice grade calves, 249 days.
The average mixed rations fed the four grade groups are
given in Table 3. Pangolagrass hay was fed in limited quantities


3
23 22 22



slaughter grades of calves.












Table 3.-Percentage ration composition.
Trial I (1956-57) Trial II (1957-58) Trial III (1958-59)
Stand- Stand- Stand-
Grade Group Choice Good ard Choice Good ard Good ard Utility


Ingredients:

Cottonseed
hulls, % 5 10
Cottonseed
meal (41%
protein), % 27.5 27.5 27.5
Citrus pulp, % 57.5 52.5 47.5
Corn meal, % 10 10 10
Alfalfa meal, % 5 5 5
Complete
mineral,* % -

TDN % 70 69 67
Crude protein % 16.4 16.2 16.1
Hay fed daily/
steer, lb 2.6 2.4 1.2
*All lots given free access to separate mineral even when


10 25


71 67 63
15.6 15.2 14.9


2.5 1.9
mixed in feed.


- 5 25


1 1 1

70 68 63
14.3 14.2 13.7

1.3 0.9 0.1








with larger amounts fed in the first weeks of each trial. All
rations contained more than adequate protein and sufficient
mineral and vitamin A for the nutritional needs of the calves.
All groups had free access to a complete mineral mixture (2)
which contained steamed bonemeal, defluorinated rock phos-
phate, common salt, red oxide of iron, copper sulfate, cobalt
chloride, cane molasses, and cottonseed meal. In Trial III each
concentrate feed contained 1% by weight of mineral mixture.
The ration formulas were prepared in an attempt to
maintain the initial weaned slaughter grade until calves were
slaughtered. On the 91st day of Trial II, 10 parts corn meal
replaced an equal weight of citrus pulp to increase the TDN in
the ration fed the Choice group, the only instance when the
composition of the concentrate ration was changed during a
trial. Calves were fed the daily allowance of hay and as much
of the mixed ration as would be consumed in a 24-hour period
at 8:00 a.m.
Calves were weighed individually when placed on feed and
at 14-day intervals. The representative calves in each grade
group selected for slaughter after each 70-day feeding period
were trucked 190 miles to the Meats Laboratory, University of
Florida, Gainesville. The steers were weighed individually,
given access to water overnight, and slaughtered the following
morning. The same procedure was followed with the calves
slaughtered at weaning. Dressing per cent for each calf was
based upon individual weight at slaughter plant and chilled car-
cass weight.

RESULTS AND DISCUSSION
Initial Weight and Grade Groups
The average initial weight of calf groups slaughtered at
weaning and those fed in the four grade groups in the three
trials are given in Table 4. The average weight of calves in
each group is their initial weight when slaughtered or placed
on feed. The fed calves consisted of 6 with an initial slaughter
grade of Utility, 14 Standard calves, 33 Good calves, and 14
Choice grade calves. The average grade was Low Good for the
32 calves slaughtered when weaned and Good for the 67 fed
calves.
There was a considerable difference in average weight of
calves slaughtered when weaned and a substantial weight in-
crease in the fed calves as weaned slaughter grade improved








with larger amounts fed in the first weeks of each trial. All
rations contained more than adequate protein and sufficient
mineral and vitamin A for the nutritional needs of the calves.
All groups had free access to a complete mineral mixture (2)
which contained steamed bonemeal, defluorinated rock phos-
phate, common salt, red oxide of iron, copper sulfate, cobalt
chloride, cane molasses, and cottonseed meal. In Trial III each
concentrate feed contained 1% by weight of mineral mixture.
The ration formulas were prepared in an attempt to
maintain the initial weaned slaughter grade until calves were
slaughtered. On the 91st day of Trial II, 10 parts corn meal
replaced an equal weight of citrus pulp to increase the TDN in
the ration fed the Choice group, the only instance when the
composition of the concentrate ration was changed during a
trial. Calves were fed the daily allowance of hay and as much
of the mixed ration as would be consumed in a 24-hour period
at 8:00 a.m.
Calves were weighed individually when placed on feed and
at 14-day intervals. The representative calves in each grade
group selected for slaughter after each 70-day feeding period
were trucked 190 miles to the Meats Laboratory, University of
Florida, Gainesville. The steers were weighed individually,
given access to water overnight, and slaughtered the following
morning. The same procedure was followed with the calves
slaughtered at weaning. Dressing per cent for each calf was
based upon individual weight at slaughter plant and chilled car-
cass weight.

RESULTS AND DISCUSSION
Initial Weight and Grade Groups
The average initial weight of calf groups slaughtered at
weaning and those fed in the four grade groups in the three
trials are given in Table 4. The average weight of calves in
each group is their initial weight when slaughtered or placed
on feed. The fed calves consisted of 6 with an initial slaughter
grade of Utility, 14 Standard calves, 33 Good calves, and 14
Choice grade calves. The average grade was Low Good for the
32 calves slaughtered when weaned and Good for the 67 fed
calves.
There was a considerable difference in average weight of
calves slaughtered when weaned and a substantial weight in-
crease in the fed calves as weaned slaughter grade improved








Table 4.-Initial grade and weight of calves.
Initial Grade and No. Average
Treatment Group Calves Weight, lb

Calves slaughtered when weaned:
Trial I (1956-57) 12 467
Trial II (1957-58) 12 388
Trial III (1958-59) 8 408
Total 32 423
Fed calves:
Utility grade
Trial III (1958-59) 6 373
Standard grade
Trial I (1956-57) 4 498
Trial II (1957-58) 4 346
Trial III (1958-59) 6 450
Total 14 434
Good grade
Trial I (1956-57) 13 522
Trial II (1957-58) 14 472
Trial III (1958-59) 6 472
Total 33 492
Choice grade
Trial I (1956-57) 7 627
Trial II (1957-58) 7 534
Total 14 580
Average weight of all calves 99 467
Average weight of fed calves 67 488



from Utility to Standard, Good and Choice. The greatest vari-
ation in average initial weight was for the Standard grade
calves, from 498 pounds in Trial I to 346 pounds in Trial II,
a difference of 152 pounds. Fed calves in Trial I were heavier
in all groups than those assigned to these groups in later trials.
Weather records at the RCES (6) show that 1956 was a more
favorable year for pasture growth than in 1957 and 1958, re-
sulting in more nutritious forage and heavier calf weaning
weights.

Daily Gain and Feed Conversion

The highest rate of gain with the Standard, Good, and
Choice groups was observed during the second 70-day feeding
period (Table 5); the smallest variation in daily gain for the
three periods was in the Standard group. The Utility calves
fed only in the third trial did not respond in the same manner









as the other grade groups. These calves, although lighter in
weight, were thrifty and had the potential to grade higher than
Utility when weaned, but, because of their poor condition, made
their greatest gain in the first 70-day period. This gain was
made with the mixed ration containing 25% cottonseed hulls
and the concentrate feed having 63% TDN (Table 3). The
Standard calves in the first 70 days gained slightly faster and
at only 10 pounds more TDN per hundred pounds of gain than
the Utility calves.
Less total feed per unit gain was required in the first 70
days than in second periods by Utility, Standard, and Choice
grade groups with essentially no difference in the Good grade
for the first two periods. The Utility, Standard, Good, and


Table 5.-Average daily gain and feed efficiency of fed steers.
Feed/100 Pounds
Gain, lb
Feeding Average Average
No. Period, Calves Initial Daily
Trials Days Fed Weight, lb Gain, lb Total TDN

Utility Grade:
1 70 6(2)* 373 1.96 768 473
1 140 4(2) 494 1.71 961 607
1 210 2(2) 573 1.89 918 581

Standard Grade:
3 70 14(4) 435 2.06 751 483
3 140 10(4) 579 2.14 836 532
3 210 6(6) 733 1.99 941 605

Good Grade:
3 70 33(12) 504 1.86 801 505
3 140 21(11) 628 2.27 799 528
3 210 10(10) 769 2.04 867 597

Choice Grade:
2 70 14(5) 581 1.90 765 505
2 140 9(5) 715 2.26 821 535
2 210 4(4) 901 1.56 1209 788
*Number of calves slaughtered at end of each period in brackets. Initial
weights, gains, and feed 100 lb) gain calculated on only the remaining
steers and for the subsequent 70-day feeding period.









Table 6.-Daily feed consumption


Feeding
Grade Period,
Group Days

Utility 70
140
210
Standard 70
140
210
Good 70
140
210


Choice 70 14
140 9


Average
Steers Weight
Fed Steer, lb *


by grade group and feeding period.
Average Daily Ration, lb

100 pounds Crude
Total liveweight TDN protein


6 442 15.2 3.4 9.3 2.1


554 16.4 3.0
639 17.5 2.7
505 15.1 3.0
659 17.9 2.7
801 19.2 2.4
565 14.5 2.5
692 17.8 2.6
853 18.9 2.2
649 14.7 2.3
896 18.0 2.3


10.4 2.3
11.0 2.6


9.6 2.2
12.1 2.6


210 4 956 18.7 2.0 12.3 2.6
*Not average initial or final weights, but the average steer weight during
the indicated 70-day feeding period.


Choice groups required 28%, 10%, 5%, and 6% more TDN per
unit gain, respectively, in the second 70 days and 23%, 25%,
18% and 56%, more TDN in the third than in the first 70-day
period. The Choice calves in the third 70-day period made the
lowest rate of gain because of their condition and consequently
required 47% more total feed and TDN per unit gain than in
the second 70-day period.
The average weight and daily ration for the four slaughter
grade calf groups by 70-day periods are shown in Table 6. Total
daily feed and TDN intake increased from period to period as
would be expected as steers gained in weight, while feed eaten
per 100 pounds live weight was reduced in all but the Good
group in the second 70-day period. The lighter weight Utility
steers ate the most feed per 100 pounds live weight in all three
periods compared to the higher grade groups, with a decrease
in feed eaten with longer feeding and as slaughter grade im-
proved in all groups.
The calculated daily TDN and crude protein intake for the
Utility, Standard, and Good grade groups in the three 70-day
periods met the nutritional requirements as outlined by National
Research Council (NRC) (7) for calves 400 to 800 pounds and









heavier, with the Choice grade group slightly below the recom-
mended level.

Live and Carcass Grades and Dressing Per Cent
Initial and final slaughter grades, carcass grades, and
dressing percentages are presented in Table 7. Initial slaughter
and carcass grades were used as a basis for determining grade
change during the three feeding periods. Utility calves improved
to Low Standard after 70 days on feed, Low Good after 140
days and from Low Utility to Good after 210 days on feed. The
ration full-fed Utility calves provided too high a level of TDN
to maintain their initial slaughter grade. These calves, being
healthy, thin in flesh, and thrifty, responded with a moderate
rate of gain and considerable improvement in carcass grade.


Table 7.-Live and carcass grades and dressing per cent.
Grades*
Feeding Steers
No. Period, Slaugh- Slaughter Dressing
Trials Days tered Initial Final Carcass Per Centt

Representative calves slaughtered when weaned:
3 32 8 8 8 58.2

Initial grades of fed calves:
Utility grade
1 70 2 4 6 6 57.8
1 140 2 4 10 9 60.0
1 210 2 3 10 10 60.8
Standard grade
3 70 4 7 8 8 59.1
3 140 4 8 11 9 62.5
3 210 6 8 12 12 62.5
Good grade
3 70 12 10 10 9 60.8
3 140 11 10 10 11 64.0
3 210 10 11 12 12 64.4
Choice grade
2 70 5 12 12 10 64.4
2 140 5 11 12 13 64.3
2 210 4 12 15 14 66.2
*Slaughter and carcass grades: 3, Low Utility; 4, Utility; 5, High Utility;
6, Low Standard; 7, Standard; 8, High Standard; 9, Low Good; 10, Good;
11, High Good; 12, Low Choice; 13, Choice; 14, High Choice; 15, Low Prime.
fBased on live weight after 190-mile haul and 48-hour chilled carcass
weight.








Standard grade calves improved 1/3 of a carcass grade in
the first and second 70-day periods, while those fed 210 days
improved 11/3 grades. Good grade animals lost 1/3 of a grade in
the first 70-day period and improved 1/ of a grade in both the
second and third 70-day feeding periods. Choice steers lost 2/%
of a grade in the first 70 days and improved 2/% of a grade in
both the second and third periods. These results indicate that
to maintain slaughter grade TDN should be reduced for Utility
grade calves in all three 70-day periods; for Standard and Good
grade calves, TDN should be reduced in second and third 70-
day periods; and for Choice calves, TDN should be increased
in first 70-day period and reduced in both second and third
periods.
Dressing per cent increased in all grade lots with longer
feeding and was correlated with carcass grade. The improve-
ment in dressing per cent from 70 days to 210 days on feed was
3.0%, 3.4%, 3.6%, and 1.8% for the Utility, Standard, Good,
and Choice grade steers, respectively.

Gains by Individual Calves
Range in average daily gain of individual calves by 70-day
feeding periods for the four grade groups are shown in Table
8. Variations of 1.07 and 1.0 pounds in average daily gain of
Good calves fed 140 and 70 days, respectively, and 1.04 pounds
by Utility calves fed 140 days are the extremes. The smallest
variation was 0.28 of a pound for Utility calves in the third
70-day period; however, the gain of these calves was low com-
pared to those in the other grade groups for the period.
It is to be expected that calves in thin flesh, with well de-
veloped skeletons and high feeder grade, have the capacity
to utilize feed nutrients for gain and grade improvement. In
contrast calves carrying excessive finish may lose flesh before
eating sufficient nutrients to maintain their initial slaughter
grade. Utility grade calves had the lowest initial weight in
each 70-day feeding period, and the Choice group was the
heaviest and in the highest flesh. Both conditions limited their
rate of gain compared to the Standard and Good grade groups.

Increase in Weight by 70-Day Periods
The per cent increase in weight by each of the four grade
groups of calves fed in the three 70-day periods is shown in
Table 9. Calves fed the third 70-day period and for 210 days








Standard grade calves improved 1/3 of a carcass grade in
the first and second 70-day periods, while those fed 210 days
improved 11/3 grades. Good grade animals lost 1/3 of a grade in
the first 70-day period and improved 1/ of a grade in both the
second and third 70-day feeding periods. Choice steers lost 2/%
of a grade in the first 70 days and improved 2/% of a grade in
both the second and third periods. These results indicate that
to maintain slaughter grade TDN should be reduced for Utility
grade calves in all three 70-day periods; for Standard and Good
grade calves, TDN should be reduced in second and third 70-
day periods; and for Choice calves, TDN should be increased
in first 70-day period and reduced in both second and third
periods.
Dressing per cent increased in all grade lots with longer
feeding and was correlated with carcass grade. The improve-
ment in dressing per cent from 70 days to 210 days on feed was
3.0%, 3.4%, 3.6%, and 1.8% for the Utility, Standard, Good,
and Choice grade steers, respectively.

Gains by Individual Calves
Range in average daily gain of individual calves by 70-day
feeding periods for the four grade groups are shown in Table
8. Variations of 1.07 and 1.0 pounds in average daily gain of
Good calves fed 140 and 70 days, respectively, and 1.04 pounds
by Utility calves fed 140 days are the extremes. The smallest
variation was 0.28 of a pound for Utility calves in the third
70-day period; however, the gain of these calves was low com-
pared to those in the other grade groups for the period.
It is to be expected that calves in thin flesh, with well de-
veloped skeletons and high feeder grade, have the capacity
to utilize feed nutrients for gain and grade improvement. In
contrast calves carrying excessive finish may lose flesh before
eating sufficient nutrients to maintain their initial slaughter
grade. Utility grade calves had the lowest initial weight in
each 70-day feeding period, and the Choice group was the
heaviest and in the highest flesh. Both conditions limited their
rate of gain compared to the Standard and Good grade groups.

Increase in Weight by 70-Day Periods
The per cent increase in weight by each of the four grade
groups of calves fed in the three 70-day periods is shown in
Table 9. Calves fed the third 70-day period and for 210 days









Table 8.-Variation in individual daily gain by grade groups and feeding periods.
Range in Daily Gain by Grade Groups, lb
Feeding
Period, Utility Standard Good Choice
Days Low High Low High Low High Low High

70 1.53 2.00 1.57 2.36 1.36 2.36 1.43 2.29
140 1.82 2.86 1.54 2.32 1.50 2.57 1.61 2.54
210 1.43 1.71 1.79 2.55 1.74 2.40 1.76 2.14

Table 9.-Per cent weight increase by 70-day periods.
Feeding Period
and Weight Grade Group
Increase Utility Standard Good Choice

First 70-day period
No. calves 6 14 33 14
% increase 37 33 26 21
Second 70-day period
No. calves 4 10 21 9
% increase 24 26 25 22
Third 70-day period
No. calves 2 6 10 4
% increase 23 19 19 12
Entire 210 days
No. calves 2 6 10 4
% increase 88 100 88 65


are the same animals, as they were the steers on feed through-
out the trials. Number of animals and average weight varied
with each period, as calves were removed after 70 and 140
days on feed. Weight increase in the first 70-day period ranged
from 37% for Utility to 21% for Choice calves. There was
little difference in per cent weight increase in the second pe-
riod between the four grade groups. The per cent weight in-
crease of Utility calves was the greatest in the third 70-day
period and the lowest for the Choice calves.
There were 22 calves on feed for 210 days-2 grading Util-
ity initially, 6 Standard, 10 Good, and 4 Choice. The Standard
animals fed 210 days doubled their weight. Utility and Good
calves had 88% weight increase and Choice steers 65% in the
same period. These comparisons are not typical because of
the variation in numbers in the four groups. They indicate,
however, that on the basis of initial weight, degree of finish,








and rate of gain factors Standard grade calves may be the most
desirable feeder animals, followed by Utility and Good with
Choice grade last. Utility grade calves were lighter in weight
and therefore required a longer feeding period to reach a live
weight of 850 pounds or more. The results indicate that Choice
calves may lose one-third to two-thirds in slaughter grade
before the feed eaten provides sufficient nutrients to main-
tain and improve grade. Choice calves because of their higher
fleshing required more nutrients per unit gain than animals
in the lower grades.

SUMMARY AND CONCLUSIONS
Ninety-nine calves which were Shorthorn-Brahman crosses
and a few purebred animals of each breed were used in three
trials to evaluate grade change as shown by initial slaughter
with carcass grades. Thirty-two calves were slaughtered when
weaned. Sixty-seven calves were allotted according to estimated
grade and fed for either 70, 140, or 210 days with representa-
tive animals from the grade groups removed for slaughter
at the end of each 70-day feeding period. Grade of steer calves
were: Utility, one trial; Standard and Good three trials; and
Choice, two trials. Each grade group was fed a ration esti-
mated to maintain the initial slaughter grade. Rations con-
tained sufficient protein, vitamin A, and minerals to meet the
needs of growing and finishing steers with roughage and con-
centrates varying according to grade of calves.
Daily gains were considered moderate for the weight of
calves fed. Utility grade calves responded to a well-balanced
ration by making their fastest gain the first 70 days on feed,
lowest in the second period, and moderate in the third 70-day
period. Standard and Good grade calves made comparable gains
when the three periods are considered. Choice calves made
their highest gain in period two, with much reduced rate of
gain in period three due to their high condition. Average daily
gain for the four groups was: Utility, 1.86 pounds; Standard,
2.06 pounds; Good, 2.01 pounds; and Choice, 1.97 pounds. The
live weight after 210 days on feed was Utility, 764 pounds;
Standard, 867 pounds; Good, 914 pounds; and Choice, 994
pounds.
Total feed intake increased as steers grew and put on flesh
with a corresponding decrease in feed eaten per 100 pounds live
weight. TDN requirements per 100 pounds gain were the low-








est in the first 70 days on feed for all four lots. Average car-
cass grade of the 32 steers slaughtered when weaned was High
Standard. Initial slaughter grade and carcass grades at the
end of the three 70-day successive feeding periods, were as fol-
lows: Utility-Low Standard, Low Good, and Good; Standard-
High Standard, Low Good, and Low Choice; Good Low Good,
High Good, and Low Choice; Choice Good, Choice, and High
Choice.
The 32 calves slaughtered when weaned dressed at 58.2%.
Average dressing per cent for steers slaughtered at the end
of the three 70-day periods was: Utility, 57.8 to 60.8; Standard,
59.1 to 62.5; Good, 60.8 to 64.4; and Choice, 64.4 to 66.2. The
higher the carcass grade the higher the dressing per cent.
Changes in grade in three successive 70-day periods show that
the ration fed Utility grade calves was too high in energy nu-
trients in all three periods to maintain initial slaughter grade.
Ration fed Standard calves was too high in nutrients in the
third 70-day period to maintain grade. Ration fed Good calves
was about right in all three periods, while the ration fed Choice
calves was too low in nutrients in first period and high in sec-
ond and third 70-day periods.

LITERATURE CITED
1. Carpenter, J. W., A. Z. Palmer, W. G. Kirk, F. M. Peacock,
and Marvin Koger. 1964. Slaughter and carcass charac-
teristics of Brahman and Brahman-Shorthorn steers. Fla.
Agr. Exp. Sta. Bull. 680.
2. Cunha, T. J., R. L. Shirley, H. L. Chapman, Jr., C. B. Am-
merman, G. K. Davis, W. G. Kirk, and J. F. Hentges, Jr.
1964. Minerals for beef cattle in Florida. Fla. Agr. Exp.
Sta. Bull. 683.
3. Hentges, J. F. Jr., W. D. Fletcher, and T. J. Cunha. 1958.
The winter feeding of Standard, Utility, and Cull summer
beef calves for slaughter. Fla. Agr. Exp. Sta. Circ. S-106.
4. Kirk, W. G., E. M. Hodges, F. M. Peacock, and M. Koger.
1963. Nutrition and weaning performance of Brahman-Short-
horn crossbreds. Crossbreeding beef cattle. Univ. of Florida
Press, Gainesville. pp. 142-147.
5. Kirk, W. G., F. M. Peacock, E. M. Hodges, and D. W. Jones.
1958. Urea and cottonseed meal in the ration of fattening
cattle. Fla. Agr. Exp. Sta. Bull. 603.








6. McCaleb, J. E., and E. M. Hodges. 1960. Climatological
Records at the Range Cattle Experiment Station, 1942-
1958. Fla. Agr. Exp. Sta. Circ. S-124.
7. Nutrient requirements f beef cattle. 1963. National Re-
search Coundil Publ. 1173. Washington, D. C.
8. Peacock, Fentress M., and W. G. Kirk. 1963. Feedlot per-
formance and carcass grades of Brahman and Brahman-
Shorthorn steers. Fla. Agr. Exp. Sta. Bull. 597.




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