xt7k0p0wrh5s https://exploreuk.uky.edu/dips/xt7k0p0wrh5s/data/mets.xml   Kentucky Agricultural Experiment Station. 1964 journals 138 English Lexington : Agricultural Experiment Station, University of Kentucky Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Progress report (Kentucky Agricultural Experiment Station) n.138 text Progress report (Kentucky Agricultural Experiment Station) n.138 1964 2014 true xt7k0p0wrh5s section xt7k0p0wrh5s  °        I »’’’ »   I I   ' - I
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· ‘ I Q July 1964
UNIVERSITY OF KENTUCKY • AGRICULTURAL ExI>EIuMzN·r STATION

 PROGRAM FOR I964 ANNUAL LIVESTOCK FIELD DAY V (
LEXINGTON PRINCETON
July I5, I964 July l7, I964
Morning Morning _
Chairman " C. Frank Buck Chairman “ Paul P. Appel
Coldstream Farm ·· Conducted tours Livestock Farm West Kentucky
showing beef, sheep and swine Substation. Conducted tours *
research will start at regular showing beef, sheep and swine
intervals, beginning at 9 a.m. research will start at regular
(EST). Last tour starts at intervals beginning at 9 a.m.
IO a.m . (CST). Last tour starts at
IO a .m .
Noon Noon .
Lunch Lunch l
Courtesy of G. W. Gardner, Bluegrass Courtesy of Farmers Elevators, Inc. h
Stockyards, Lexington and Field Packing Com"
pany, Owensboro
Afternoon
Chairman " W. P. Garrigus 4
l:l5 Address ·· "Livestock Production in J. A. Hoefer, Professor of
a Changing Economy." Animal Science,Michigan State
University
(Cover Illustration: The IBM punch cards, intended for computer processing,
symbolize some of the newer techniques used in animal science research.)

 KENTUCKY
ANIMAL SCIENCE RESEARCH REPORTS
1964
PROGRESS REPORT 138
(Filing Code 2)
]uIy 1964
UNIVERSITY OF KENTUCKY
AGRICULTURAL EXPERIMENT STATION

 V
CONTENTS
Page
BEEF CATTLE SECTION
Volatile Fatty Acid Production and Performance of Steers Fed
Different Levels and Physical Forms of Hay and Corn 5 {
Tylosin for Beef Steers on Pasture 7
Effect of Ciodrin-Treated Backrubbers and Rid-Ezy (Ronnel)
Fed Free Choice on Fly Control, Grub Control and Rate
of Gain 10 _
Slaughter Beef From Grain and Grass - 1963 Results 13
Evaluation Forage Crops for Beef Production 17
Utilization by Beef Steers of Pelleted or Chopped Dehydrated
Sudax Harvested at Two Stages of Maturity 20
A Comparison of Corn Silage-Soybean Meal and Corn Cob-Corn-
Soybean Meal Rations for Wintering Steer Calves 24 "
Supplementation of Ground Ear Corn for Fattening Beef Steers
in Drylot 25
Feedlot Adaptation and Gains of Feeder Steers Treated with
Tranimal, Vitamin A and Sulfadimethoxine 29
Measurement and Selection of Economically Important Traits
in Beef Cattle 33
ANIMAL NUTRITION SECTION
Utilization of Casein and Gelatin by Wethers When Given Orally
or Into the Abomasum 35
In Vitro Technique for Measuring Starch Digestion by Rumen
Microorganisms 36
Apparent Pre—intestinal Destruction of Vitamin A From Different
Sources 37
Vitamin A Supplementation of Steers on Pasture 38
Concentrations of Thiamine, Riboflavin and Biotin in Ruminal
Fluid of Steers Fed Different Levels and Forms of Hay and Grain 41

 ANIMAL NUTRITION SECTION (continued) Page
Butyrate Uptake In Vitro by Epithelial Tissue from the Rumen of Steers
Fed Different Levels and Forms of Hay and Grain 42
Plasma Levels of Acetate and Propionate in Sheep Following
Ruminal or Abomasal Administration 44
SHEEP SECTION
Creep Rations for Lambs Suckling Ewes Fed Corn or Alfalfa Silage 46
Performance of Ewes on Corn and Alfalfa Silages and Two Levels of
Grain Feeding 47
Early Weaning of Spring Lambs 48
Southdown, Hampshire, and Southdown-Hampshire Crossbred Rams
as Sires of Spring Lambs 50
Western Crossbred Ewes Mated to Slow, Medium and Rapid Gaining
Hampshire Rams 51
GENETICS SECTION
Progesterone and 6-Methyl-17-Acetoxyprogesterone as Inhibitors
of Spermatogenesis in Rams 52
Development of the Reproductive Organs and Growth Rate of Ram
Lambs Injected with Progestogens 53
Effects of Short Periods of Heat Stress Upon Fertility and Early
Embryo Survival in Ewes 54
Selecting for Earlier Lambing Date in Purebred Southdown Sheep 55
Semen Characteristics of Yearling Southdown Rams 56
MEATS SECTION
Partial Pumping of Hams 58
Comparison and Relationship of Beef Carcass Characteristics 59
The Effects of Pancreatic Lipase and Papain on Palatability, Ten-
derness and Rancidity Development of Quick—aged Country-
. style Hams G1

 MEATS SECTION (Continued) Page
Physical Composition of Pork Cuts and Relative Cutout Per-
centages of Pork Carcasses from Three Different Weight
Groups of Hampshire Barrow and Gilt Littermates 64
Carcass Evaluation of Lambs from Selected Sires 69
4
SWINE SECTION
A Study of the Vitamin A Requirement of the Gestating and
Lactating Sow 71
The Calcium Requirement of the Gestating Gilt 74 ·
The Effects of Various Chelates and Protein Sources on the
Incidence of Parakeratosis 78
A Comparison of the Response of SPE and Non—SPF Pigs to
Antibiotics and Sulfonamides 80
Effect of Maltol on Creep Ration Utilization by Early Weaned Pigs 83

 -5-
BEEF CATTLE SECTION
VOLATILE FATTY ACID PRODUCTION AND PERFORMANCE
OF STEERS FED DIFFERENT LEVELS AND PHYSICAL FORMS OF HAY AND CORN
James T. Thompson, N. W. Bradley and C. O. Little
University of Kentucky
Beef cattle have long been known to utilize high-grain rations for meat production
less efficiently than simple-stomach animals. During the past few decades much work
has been conducted to improve the efficiency of beef production. It has been found that
carbohydrates are broken down to volatile fatty acids (VFA) by the rumen microorganisms
and the acids are utilized as energy sources. Acetate and propionate are the two acids
found in highest concentration in rumen fluid. Acetate is usually the more prevalent
of the two, but propionate is believed to be utilized more efficiently under certain condi-
tions. A shift in the production from acetate to propionate has been proposed as a means
of increasing the efficiency of gains by ruminants.
Several factors have been found to shift the acetate—propionate ratio to favor a
greater percent of propionate, including grinding, pelleting, or decreasing the roughage,
increasing the concentrates in the ration, treating the feed with heat, and flaking of the
grain portion of the ration.
This experiment was designed to study the VFA ratios in rumen fluid and feedlot
performance of cattle consuming rations containing no hay, long hay, or ground hay with
flaked corn or ground corn.
Forty-eight Angus steers of medium flesh, averaging 750 pounds each, were allotted
to six different treatments with eightsteers on each. They were as follows:
Ration 1 - No hay and flaked corn Ration 4 - Long hay and ground corn
Ration 2 — No hay and ground corn Ration 5 - Ground hay and flaked corn
Ration 3 ·· Long hay and flaked corn Ration 6 — Ground hay and ground corn
All rations were supplemented to meet NRC requirements for crude protein, calcium and
phosphorus. A complete trace mineral mix and 450 I. U. of vitamin A per pound of ration
were also added.
At the beginning of the experiment each steer received a 24 mg implant of stilbes-
- trol. The rations were self-fed, and grotuid alfalfa hay was mixed with the feed, whereas,
the long alfalfa hay was hand fed, both at the rate of 4 pounds per head per day. After a
10-day preliminary period, the steers were fed for lll days in lots of two steers each,
during which time data on gains and feed consumption were collected. Rumen samples
were taken by stomach tube at 0, 14, 28, 56, 84 and lll days during the trial. Measure-
ments of pH were made, and the samples were analyzed for VFA by use of gas chromato-
graphy. At the end of the trial the animals were slaughtered and data on carcass measure-
ments were collected. Summaries of the results are given in Table l.
Steers receiving ground hay and long hay gained an average of 0.7 and 0. 5 lb more
per head daily, respectively, than steers receiving no hay. During the first 56 days of the
trial, the steers fed no hay gained 0. 8 lb. per day less than did those on long or ground
hay. There were no significant differences in ADG during the last 55 days of experiment.
There were significant differences in feed consumption but not feed efficiency due to hay

 -6-
Table 1 - Feedlot Performance, Carcass Measurements and Rumen Sample Data of
Steers Fed No Hay, Long Hay or Ground Hay with Flaked or Ground Corn
No hay No hay Long hay Long hay G hay G hay
F corn G corn F corn G corn F corn G corn
Feedlot Data .
No. steers 8 8 8 8 8 8
Initial wt, lb 751 749 741 741 748 752
Final wt, lb 983 969 1008 1036 1068 1038
ADG (0-56 day), lb 1.96 1.77 2.65 2.65 2.76 2.64
ADG (56-111 day), lb 2. 48 2. 32 2.15 2. 66 3.01 2. 50
ADG (0-111 day), lb 2.03 1.98 2.40 2.65 2.88 2.57
Feed cons. , lb 16. 2 17.0 20. 6 22.1 21. 9 21. 6 4
Feed/cwt gain, lb 813. 6 867.3 809. 8 756.7 764.7 848.9
Average ration
Corn, lb 13.8 14.5 15.1 16.5 16.5 16.2
Supplement, lb 2. 4 2. 5 1. 5 1. 6 1. 5 1. 6
Hay, lb —- -— 4.0 4.0 3.9 3.8
Carcass Data
Dressing % 60. 5 60. 9 62. 2 63. 4 62. 7 61. 5
U.S. Grade 2* b 11.6 11.1 13.4 12.8 12.6 11.9
Marbling score 5. 25 4. 88 6. 63 6. 00 5. 88 5. 38
Dual grade C 3.00 2.75 3.00 3.00 3.25 3.38 t
Loin eye area, sq in. 11.0 10.9 11.0 11.7 11.4 11.4
Loin eye/cwt body wt 1.13 1.13 1.10 1. 13 1. 07 1. 10
Fat over eye, in. 0.58 0.50 0.67 0.72 0.68 0.58
Kidney fat, % 2. 63 2. 88 2. 94 3. 25 3.13 3. 06 `
Rumen pH
Av pH (0-56 day) 5. 99 5. 69 6. 40 6. 25 6. 06 6. 00
Av pH (56-111 day) 5.51 5.53 6.25 6.36 6.09 5.60
Av pH (0-111 day) 5.81 5.61 6.34 6.29 6.07 5.81
VFA Concentration - (Average 0-111 Days)
C2 (molar %) 39. 5 38. 3 46.0 45. 1 41.1 41. 6
C3 (molar %) 41.0 39.7 34.4 36.3 41.2 39.7
C4 (molar %) 11.5 13.4 13.0 11.2 11.0 12.0
i - C5 (molar%) 2.6 2.9 3.1 3.1 2.6 3.2
n - C5 (molar %) 5.4 5.8 3.5 4.4 4.1 3.6
C2/C3 1.02 1.04 1.37 1.30 1.01 1.05 (
C3/C4 3.70 3.37 2.78 3.46 3.68 3.37
C;3/C4 3.57 3.11 3.63 4.18 4.00 3.53
Total VFA (micromoles/ml)141. 9 169. 6 118. 6 134. 4 137.0 170. 4
si 11 : high good, 12 = low choice, 13 = av choice
b —l = slight, 5 = small, 6 = modest
c The lower the dual grade the higher the percent of carcass wt that is lean cuts.
F = flaked; G Z ground

 -7..
treatment. The physical form of corn did not significantly effect feedlot performance.
Dressing percentage and carcass grade of steers fed no hay were significantly less than
steers receiving ground hay. Dual grade was significantly higher on steers fed ground
hay than those fed no hay or long hay.
Steers receiving long hay had a significantly higher molar percentage of acetate
with a correspondingly lower percentage of propionate (C2/C3 = 1. 34) than steers fed no
hay (1. 02) or ground hay (1. O3). They also had a significantly lower total VFA concen-
tration (126. 5 micromoles/ml) than steers fed no hay (155. 7) or ground hay (153. 7).
Rumen fluid of steers fed flaked corn contained significantly less total VFA (132. 5 micro-
moles/ ml) than steers on ground corn rations (158. 1). Arithmetic averages of ruminal
pH were significantly affected by hay treatments. They were: no hay - 5. 7, long hay —
6. 3 and ground hay - 5.9.
Changes in the acetate-propionate ratio due to removing or grinding the roughage
were similar to shifts reported by other investigators; however, contrary to most re-
ported results there was no difference in the ratio produced from flaked compared with
ground corn. The decreased ADG of steers fed no hay during the first 56 days of the ex-
periment deserves further study.
TYLOSIN FOR BEEF STEERS ON PASTURE
Dennis Herd, N. W. Bradley and David McKechnie
University of Kentucky
Cattlemen are constantly alert for ways of improving the performance of steers
used in grazing programs. The value of stilbestrol in such programs is well established.
The values of antibiotics and various means of administering them are not so well es-
tablished. Data reported by this Station last year suggested that the antibiotic tylosin,
when administered in a sustained release bolus to grazing steers implanted with stil-
bestrol, would increase steer gains over those obtained with stilbestrol alone. The pur-
pose of this experiment was to obtain further information on the response of grazing
steers to tylosin boluses.
Forty 600-pound yearling Angus steers of medium flesh were allotted to four groups
for the following treatments:
1. Control
` 2. STEP bolus
3. Tylosin bolus at 14-day intervals
4. Tylosin bolus at 42-day intervals
Each STEP bolus contained a total of 6 grams of antibiotic activity composed of 7
parts streptomycin, 7 parts tylosin, 7 parts erythromycin, and 4 parts penicillin. Steers
on the STEP treatment received one STEP bolus each at the beginning of the experiment.
Each tylosin bolus contained 6 grams of tylosin activity. All steers receiving tylosin
were bolused with one bolus each at the beginning of the experiment. One group was then
rebolused at 14-day intervals, and the other group was rebolused at 42-day intervals.
All steers were implanted with 24 mg of stilbestrol and grazed together on two 25-
acre bluegrass—wh1te clover pastures which were rotated as pasture conditions dictated
during the 154-day trial.

 -8-
The steers were held off feed with access to water over night before each weighing.
Weights were taken at 14-day intervals throughout the trial. Initial and final weights were
the average of two weighings taken the same morning.
The results of this experiment are summarized in Table 1. No increase in .
average daily gain was obtained from using STEP boluses. Use of tylosin boluses at 14-
and 42-day intervals resulted in increased daily gains of 0. 20 and 0. 26 lb per head daily,
Table 1 - Effect of Antibiotics on Grazing Steer Performance ‘
a/ Tylosin §/ Tylosin £/
Control STEP — 14—days 42-days
Number of steers 10 10 10 10 _
Initial weight, lb 600 596 599 601
Final weight, lb 768 771 797 808
Total gain, lb 168 175 198 207
Total A. D. G. , lb 1. 09 1. 14 1. 29 1. 35
A. D. G. Q/by Periods
0-14 days 1. 53 .94 1. 11 1. 60
14-28 days 1. 39 1. 50 2.00 1. 61
28-42 days 1. 54 2.14 2.14 1. 86
42-56 days 1. 07 1. 32 1. 25 1.89
56-70 days - .43 - .43 .18 - .21 .
70-84 days - . 14 . 29 - . 04 . 50
84-98 days 1.71 1.50 1.71 1.82
98-112 days 1.61 1.36 1.75 1.96
112-126 days 1.36 1.21 1.61 1.54 -
126-140 days 1. 93 2. 39 2. 36 2. 36
140-154 days . 40 . 29 .06 - . O9
2/ STEP boluses were given at the beginning of the experiment only
M Tylosin boluses were administered at the beginning and repeated at 14-day in-
tervals.
g/ Tylosin boluses were administered at the beginning and repeated at 42-day in-
tervals.
Q/ Average daily gain.
respectively. These differences were not statistically significant because of the large
within-treatment variation that existed. Bolusing with tylosin at 42-day intervals was
just as effective as bolusing at 14-day intervals. This would seem to indicate that the ‘
effective level of tylosin was being supplied for the 42-day period by one bolus and that
additional tylosin supplied by bolusing at 14-day intervals was of little value. This is in
contrast to results reported last year which suggested the effective life of the bolus was
only two weeks.
In this experiment different period gain patterns were found for the 42-day ty-
losin treatment than were reported for a similar treatment last year. Gain by periods

 ..9-
after bolusing is summarized in Table 2 for steers which received tylosin at 42-day in-
tervals. In this experiment, bolusing with tylosin every 42 days produced substantial in-
creases in gain the first and third two—week periods after bolusing and only a small in-
crease in gain during the second two—week period. This lack of response to tylosin during
the second two—week period after bolusing can be accounted for entirely by the negative
gain of tylosin-treated steers during the last two weeks of the grazing season. It can be
seen in Table 2 that this is a different gain pattern than that reported last year for a
similar treatment whe re a substantial increase in gain was obtained only during the first
two weeks after bolusing. Last year's response to tylosin during the first two weeks after
bolusing and little or no response from 14 to 42 days after bolusing would indicate that the
tylosin time—release bolus was effective only during the first two weeks. However, the
results this year show as much response from 28 to 42 days after bolusing as for any of
the other periods. This would indicate that the effective life of the bolus was at least 42
days and possibly longer.
Table 2 - Average Daily Gain of Steers at Different Times After Bolusing
Time After Bolusing
0 - 14 days 14 - 28 days 28 — 42 days
o -5 T 9/ o Ei T W o -**3 T M
First Bolus, lb 1. 53 1. 60 1. 39 1. 61 1. 54 1. 86
Second Bolus, lb 1. 07 1. 89 -0. 43 -0. 21 -0. 14 0.50
Third Bolus, lb 1. 71 1. 82 1. 61 1. 96 1. 36 1. 54
Ninth Bolus, lb 1. 93 2. 36 0. 40 -0. 09
Average of this ex-
periment, lb 1.56 1.92 0.74 0.82 0.92 1.30
Average reported
last year, lb 1.01 1.39 1.44 1.52 1.31 1.23
_a_/ Control
]2/ Tylosin at 42-day intervals
The reason for the difference in gain patterns obtained for the two different years
is not fully understood. Work is now in progress on a more intensive type of study which
may provide answers to some of the questions which have arisen.

 -10-
EFFECT OF CIODRIN-TREATED BACKRUBBERS AND RID—E ZY (RONNE L)
FED FREE CHOICE ON FLY CONTROL, GRUB CONTROL AND RATE OF GAIN
(Department of Entomology and Botany and Department of Animal Science
Cooperative Project)
F. W. Knapp, N. W. Bradley and W. C. Templeton ,
University of Kentucky
In recent years considerable progress has been made in developing new and more
effective insecticides for horn fly and grub control. Considerable effort has been ex-
pended in studying different methods of applying these insecticides to animals. Back-
rubbers treated with certain insecticides have proven to be very effective in controlling
horn flies on cattle. Either oral administration or "pour on" application of other insecti- .
cides has very effectively controlled grubs. It would be highly desirable to find an in-
secticide and a simple method of application which would control flies during the sum-
mer and also prevent the occurrence of grabs in the backs of cattle the following spring.
During the past three or four years face flies have caused considerable discomfort
to cattle in northern and central Kentucky. Any method of controlling this recent pest
would certainly be welcomed. This experiment was conducted to study the effect of
Ciodrin-treated backrubbers and Rid-—Ezy (ronnel incorporated into a mineral block) fed
free choice on horn fly control, face fly control, grub control and rate of gain of yearling
steers. I
Forty—eight lightweight yearling Angus steers were used in this study. The steers »
were randomly divided into two groups of 24 each. One group was provided access to a
Ciodrin-treated backrubber, whereas the other group was given the Rid—Ezy blocks free
choice. The group receiving Rid—Ezy blocks did not receive any other supplemental
minerals. Plain loose salt, steamed bonemeal, and ground limestone were provided ‘
free choice to the other group. The burlap backrubbers were treated with 1 percent
Ciodrin EC in No. 2 fuel oil. Each backrubber was saturated with about 1 gallon of the
solution to every 20 linear feet at weekly intervals. The steers were divided and handled
in such a way that forage quality and quantity were considered to be comparable for the
two treatment groups. All animals had previously been treated for flies before this test
started.
The experiment started on August 23. During the first 84 days the steers were on
pasture, and during the last 103 days they were on a fattening ration in drylot. During
the drylot phase of this study all steers were fed together without regard to previous
treatment.
During the pasture phase face fly and horn fly counts were made at weekly intervals
from August 23, 1963 to October 24, 1963. Grub counts were made on March 5, 1964.
Table 1 shows the results of face fly and horn fly counts made during the pasture
phase. Little difference was noted between the treatments for face fly control. It should
be pointed out that Ciodrin did gradually reduce face flies, whereas the numbers of face
flies on cattle treated with Rid—Ezy were more erratic. Good horn fly control was achieved
with both methods. As would be expected, it took Rid-Ezy longer to control flies since
control is achieved through death of larvae in droppings whereas Ciodrin causes death
of the adult fly upon contact with the treated animal.

 -11-
Table 1 - Average Flies Per Animal at Weekly Intervals
Date 8-23-; 8-30 9-6 9-20 9-24 10-4 10-11 10-18 10-24
Face Flies
Ciodrin 4 3 3 2 1 1 1 1 1
Rid-Ezy 4 3 3 3 2 5 5 2 1
Horn Flies
Ciodrin 0 1 1 0 0 0 0 0 0
Rid—Ezy 4 4 2 1 0 3 1 0 0
*9*/ Pretreatment counts
, Table 2 gives results of grub counts made on March 5, 1964. Ciodrin would not
be expected to have any effect on grubs since it is not a systemic insecticide. There-
fore, the group treated with Ciodrin during the summer served as a control for this
comparison of the effectiveness of ronnel in controlling grubs. There were no grubs
in cattle treated with ronnel, but an average of 20. 5 grubs were counted in the control
cattle.
Table 2 - Incidence of Grubs in Control and Ronnel—treated Steers
Rid-Ezy (Ronnel) Ciodrin-Treated
Blocks Backrubbers
Animal No . Animal N o . Anim al No . Animal No .
No. of Grubs No. of Grubs No. of Grubs No. of Grubs
17 0 36 0 3 14 16 41
20 O 37 (died) — 21 11 32 36
26 0 39 0 22 17 35 23
29 0 40 0 28 6 56 47
41 0 1 0 30 4 2 17
42 0 8 0 47 31 6 11
43 0 19 0 54 23 11 9
9 0 27 0 60 39 15 23
18 0 38 0 5 14 25 5
14 0 51 0 10 29 33 0
24 0 52 0 12 47 34 15
31 0 23 0 13 31 7 0
36 0
 
Total Animals - 24 Av Grubs - 0 Total Animals -24 Av Grubs 20. 5
 
Table 3 gives rate of gain data for both the summer and winter phases of this ex-
periment. There was a slight but nonsignificant trend for Ciodrin-treated cattle to gain
faster during both phases. Obviously the absence of grubs in cattle treated with ronnel
did not cause the cattle to gain faster during the 103-day feedlot period.

 -12-
The results of this experiment indicate that good horn fly control and reasonably
good face fly control can be achieved with either of the methods used in this comparison.
Feeding the blocks containing ronnel for an 84-day period beginning the latter part of
August, also resulted in excellent grub control.
Table 3 — Steer Performance
 
Rid-Ezy (Ronnel) Ciodrin-Treated 4
Blocks Backrubbers
 
Pasture Phase — 84 days
No. of Animals treated 24 24
Average initial weight, lb 646 619
Average weight off pasture, lb 691 670 _
Average gain on pasture, lb 45 51
A. D. G. on pasture, lb 0.53 0. 61
Block, lb/head daily §/ . 12 --—
Feedlot Phase — 103 days
Average final weight, lb 889 880
Average feedlot gain 198 210
A. D. G. in drylot 1. 92 2. 04
Combined Pasture Phase and Feedlot Phase — 187 days
Total gain 243 261 .
A. D. G. 1.30 1.40
2/ 2. 94 gm of actual ronnel per head daily .

 -13-
SLAUGHTER BEEF FROM GRAIN AND GRASS — 1963 RESULTS
Dennis Herd, N. W. Bradley, David McKechnie and J. Ralph Overfield
University of Kentucky
This station has previously demonstrated that deferred feeding of grain to steers on
pasture is a suitable system for making maximum use of pastures and producing the type
of slaughter beef the market demands. It was the purpose of this experiment to confirm
that high good and low choice slaughter beef could be produced by this program. A
secondary objective was to study the value of supplemental protein and mineral feeding
during the grain-grass phase of the program.
. One of the comparisons made during the summer of 1963 was at the U. K. Cold-
stream Farm on bluegrass-white clover pasture. Two groups of 20 yearling Angus
steers were used to compare ground shelled corn versus ground shelled corn plus 2
pounds of soybean meal per steer per day.
All steers were implanted with 24 mg of stilbestrol at the beginning of the experi-
ment and grazed together from May 9 to July 4 during the pasture phase. At this time
the steers were split into two groups, using a predetermined allotment, and placed in two
20—acre bluegrass white clover pastures with self feeders containing the appropriate
rations. To equalize pasture quality and quantity, the two groups of steers were rotated
on the two pastures at 14-day intervals. To reduce the possibility of founder, a mixture
of 60% ground shelled corn and 40% ground corn cobs was self fed during the first week
the cattle were on grain. The second week the ratio was changed to 80:20 corn to cob and
after than ground shelled corn was fed. Once again this method of starting the steers on
feed proved to be satisfactory.
The results of this comparison are given in Table 1. During the first 56 days of the
experiment, daily gains for the two groups were quite different even though all of the cattle
were treated alike up to this time. During the last 112 days the group receiving corn and
supplement outgained the group receiving only corn, but for the entire 168 days there was
very little difference in the daily gains of the two groups of steers. Although the steers
receiving corn and supplement had a higher selling price per steer, this increase was off-
set by the added expense of the protein supplement which resulted in both groups of steers
returning the same amount to pasture, labor and investment. It thus appears that ground
shelled corn is sufficient in this program when pastures are properly managed and contain
from 40 to 60% legumes.
A second experiment was conducted at the West Kentucky Substation at Princeton com-
paring free choice versus force feeding of minerals during the grain-grass phase of the de-
ferred feeding program. Thirty-six yearling Angus steers were divided into two groups of
18 steers each for this trial. Nine steers of each group were implanted with 24 mg of
stilbestrol, while the other nine were implanted with 36 mg. Both groups of steers were
grazed together from April 10 to July 3 during the grass phase, which was approximately
. a month longer than the grass phase at Lexington. Pastures used were predominately
fescue. The amount of trace mineral salt force fed was about 14 times as much as that
consumed by the group offered salt free choice. The amount of bonemeal force fed was
about 12 times higher than the amount consumed free choice. The ygtigng fed during the grain-
grass phase were as follows:
Minerals Free Choice Minerals Force Fed
1, 800 lb ground shelled corn 1, 775 lb ground shelled corn
200 lb 44% soybean meal 200 lb 44% soybean meal
Trace mineral salt and bone meal 20. 75 lb trace mineral salt
were fed free choice 4. 25 lb bone meal

 -14-
Table 1 - A Comparison of Steers Fed Corn and Steers Fed Corn and Supplement in a
Deferred Feeding Program on Bluegrass-White Clover Pasture
 
Corn Corn & Supplement
 
First 56 days
Number of steers 20 20 _
Beginning weight, lb 683 684
56-day weight, lb 802 781
56-day gain, lb 119 97
56-day A. D. G. , lb 2. 12 1. 73
Last 112 days
56 to 168-day gain, lb 245 280
56 to 168-day A. D. G. , lb 2. 19 2. 50 ‘
Corn/steer, bu 37.4 35. 1
Soybean meal/steer, lb —- 225
Entire 168 days
Final weight, lb 1047 1061
Total gain, lb 364 377
Total A. D. G. lb 2. 17 2. 24
Carcass and Slaughter data
Weight at packing plant, lb 1013 1025
Dressing percent 618 62. 8
Carcass grade 11. 1 (Good+) 11. 2 (Good +)
Fat thickness over rib, in. 0. 66 0. 62
Cost and return per steer .
Initial steer cost at $26/cwt $177. 58 $177. 84
Corn cost §/ b/ 45. 23 42. 44 ‘
Soybean meal cost- ····· 9. 00
Selling price/cwt C/ 23. 30 23. 66
Selling price/steer · 236. 03 242. 52
Returns to pasture,
labor, & investment 13. 22 13. 24
 
2/ Includes cost of corncobs. Corn at $1. 20/bushel.
M Soybean meal at $80/ton.
Q Based on delivery weight at packing plant.
A. D. G. = average daily gain.
Results of this comparison are given in Table 2. There was little difference in the
daily gains of the two groups of steers at any time throughout the experiment. The steers
that were force fed minerals ate 1. 6 lb more feed per day each and weighed slightly more
when sold, but they graded slightly less and brought less per 100 pounds when sold. The
steers that were force fed minerals returned less to pasture, labor and investment mainly
because of the increased expense acquired by the larger amount of feed eatenand the in-
crease in minerals consumed. Feeding minerals free choice appears to be sufficient in
this deferred feeding program.

 -15-
Table 2 - A Comparison of Steers Force Fed Minerals and Steers Fed Minerals Free
Choice in a Deferred Feeding Program
Minerals Free Choice Minerals Force Fed
First 84 days
Number of steers 18 18
Beginning weight, lb 706 706
84-day weight, lb 722 784
84-day gain, lb 66 78
84-day A. D. G. 0. 78 0. 93
Last 112 days
84- to 196-day gain, lb 287 285
84- to 196-day A. D. G. 2. 56 2. 54
Feed/steer/day, lb 19. 8 21. 4
Corn/steer, bu 35. 6 38
Soybean meal/ steer, lb 222 240
Trace mineral salt/steer, lb 1. 83 24. 9
Bone meal/steer, lb 0.43 5. 1
Entire 196 days
Final weight, lb 1059 1069
Total gain, lb 353 363
Total A. D. G. 1. 80 1. 85
Carcass and slaughter data
Weight at the packing plant, lb 1009 1022
Dressing % 63 62. 6
Carcass grade 12. 2 (Ch-) 11.4 (Good +)
Fat thickness over rib, in. 0.71 0. 77
Cost and returns per steer
Initial steer cost at $26/cwt $183. 56 $183. 56
Supplemental feed cost, $2/ 51. 67 56. 08
Selling price/cwt, $ b/ 24. 06 23. 65
Selling price/steer, $ · 242. 77 241. 70
Returns to pasture,
labor and investment, $ 7. 54 2. 06
·%/ Corn at $1. 20/bushel, soybean meal at $80/ton, bone meal at $100/ton and trace
mineral salt at $50/ton.
E/ Based on delivery weight at the packing plant.
Table 3 gives the results of implanting with either 24 or 36 mg of stilbestrol. There
were no significant differences in any of the performance or slaughter data for stilbestrol
treatment. In view of these results as well as previous ones it still seems advisable to
implant grazing steers with 24 mg. of stilbestrol.

 A ` J <
-l6-
Table 3 - A Comparison of Two Levels of Stilbestrol Implants for Grazing Steers Re-
ceiving a Deferred Feed of Grain
 
24 Mg 36 Mg
 
Number of steers 18 18
Grass phase initial weight, lb 709 703
84-day weight, lb 782 773
84-day gain, lb 73 70
84-day A. D. G. , lb 0. 87 0. 84
Grain-grass phase
84-196 day gain, lb 285 287
84-196 day A. D. G. , lb 2. 54 2. 56
Combined phases
Final weight, lb 1067 1060 4
Total gain, lb 358 357
Total A. D. G. , lb 1. 83 1. 82
Slaughter data
Carcass grade 12.1 (ch-) 11. 8 (ch-)
Carcass conformation grade 12. 8 (ch) 12. 6 (ch)
Dressing % 63. 0 62. 5
Rib eye area, sq. in. 11. 6 11. 8
Rib eye area/cwt chilled
carcass, sq. in. 1. 8 1. 8
Fat thickness over rib, in. O. 7 O. 7
Marbling 5. 2 (small) 5. O (small) v
Percent kidney fat, % 3. 2 3. O
Color fat 2. 0 (creamy white) 2. 0 (creamy white)
Color lean 3. 5 (normal) 3. 6 (normal) _
Hot carcass weight, lb 654 650
Cold carcass weight, lb 642 638
Carcass cooler shrink, lb 12 12. 5
In transit shrink, lb 50 46
 
The results of both of these experiments confirm the results of last year which
showed that desirable slaughter beef can be produced economically by this "grain or
grass" program.

 \
-17-
EVALUATING FORAGE CROPS FOR BEEF PRODUCTION
(Department of Agronomy and Department of Animal Science Cooperative Proj ect)
W. C. Templeton, Jr. , C. F. Buck, N. W. Bradley, and D. McKechnie
This project was initiated in 1962 to study the effects of several kinds of plants
and certain mixtures on steer gains and on time and amount of feed production.
The treatments were: (1) 16 acres of Kentucky bluegrass-Ladino clover; (2) 8
acres of Kentucky bluegrass-Ladino clover, 4 acres of Piper sudangrass, and 4 acres
of Korean lespedeza, and (3) 8 acres of renovated Kentucky bluegrass-Narragansett
alfalfa, 4 acres of Piper sudangrass, and 4 acres of Korean lespedeza. Each treat-
ment consisted of two replications of 8 acres each.
All pastures were limed at the rate of 2 tons per acre. During early spring the _
bluegrass-clover pastures were reseeded with 1