Table Of Content.'.''cl't-
IMPACT OF THREE DIFFERENT FEEDINGREGIMENS ON PERFORMANCE,
MICROBIOLOGY, SENSORY, AND OBJECTIVE CHARACTERISTICS OF
FLORIDA BRANGUS BEEF CATTLE
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KEAWIN CARON SARJEANT
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A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTL^iL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
2006
J'i
Copyright 2006
by
Keawin Caron Sarjeant
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ACKNOWLEDGMENTS
I wish to express my gratitude to Dr. Sally K. Williams, associate professor and
supervisory committee chairperson, forher guidance, patience, and supportthroughout
the Doctor ofPhilosophy program. I thank her forbeing all that she is to me and
believing in me. Appreciation is extended to Dr. Ray Mobley for all ofhis guidance and
words ofencouragement. Thanks are also extended to Dr. Gary Rodrick, Dr. D.D.
Johnson, and Dr. Adegbola Adesogan. I want to thank myparents, Luidsey and Veronica
Saijeant, and my brother, Kevin Sarjeant, fortheir love, patience, caring, and support
throughout my pursuit ofmy Ph.D. degree. Throughout the good andthe bad theyhave
been there for me givingme unconditional love, support, and guidance. Without all of
them I would not be where I am today andbethe person I amtoday. I want to make all of
themjust as proud ofme as I am ofthem. I thankNatashaNicole Sarjeant. Without her I
am nothing. I want to thank my sons, my oldest Keiron Lindsey Sarjeant and my
youngest Kaden Emory Sarjeant for loving daddy no matter what and for being who they
are. They bothare mypride andjoy and everythingthat I do, I do it forthem. I wantto
thank my best friend, Johnny Davis, foreverythinghe has done forme from getting me
here to getting me out ofhere. I also thankJohnny forkeeping me sane throughoutthe
stressful times and always beingthere for me, helping me every step ofthe way. Finally I
wantto thankNoufoh Djeri forall ofher support, patience, and motherly advice.
m
TABLE OF CONTENTS
page
ACKNOWLEDGMENTS ••••••• '"
LIST OF TABLES vi
ABSTRACT ..;.... x
INTRODUCTION •' 1
LITERATURE REVIEW 6
Performance 6
Pasture and Forages 11
Concentrates and Supplements 23
30
Feed Additives
Microbiology ^^
Microorganisms ofConcern in BeefCattle Food Safety 37
Characteristics ofEscherichia coli 37
Fecal coliforms "^3
Characteristics ofSalmonella 44
45
Parasites
Sensory Characteristics ofBeef 50
Objective Characteristics 53
MATERIALS AND METHODS 58
Animals 58
Animal Diets and Feeding Procedure 59
Weight. Fecal, and Blood Collection 60
Microbiological Analysis 61
Parasite Analysis 63
Environmental Samples 63
Animal Slaughter and Carcass Characteristics 65
66
Sensory Analysis
Objective Color Analysis 68
Warner Bratzler Shear Analysis 68
pH 69
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Data Analysis 69
RESULTS AND DISCUSSION
71
Experiment One: Performance, Microbiology, Sensory and Objective Analyses for
17 Month Old Brangus Cattle and Environmental Sample Analyses 71
Experiment Two: Performance, Microbiology, Sensory and Objective Analyses for
10 Month Old Brangus Cattle and Environmental Sample Analyses 97
Cost Analysis for Experiment One 118
Cost Analysis for Experiment Two 121
SUMMARY AND CONCLUSIONS
125
APPENDIX MEAN WEIGHT OF BRANGUS STEERS DURING EXPERIMENT
ONE AND TWO
131
LIST OF REFERENCES 134
BIOGRAPHICAL SKETCH
153
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LIST OF TABLES
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Table
Average daily weight gain values ofBrangus steers fed different commercially
1
available feed concentrates, and allowed to graze on bahiagrass or allowed to graze
only for four months: Experiment One 72
2 Average daily weight gain values ofBrangus steers that were initially fed Super 12,
or B-80 and allowed to graze, or allowed to graze only and then placed onto Super
12 concentrate: Experiment One 74
3 Mean total aerobic bacteria counts ofsteer fecal samples. Steers were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only: Experiment One 76
4 Mean generic Escherichia coli counts ofsteer fecal samples. Steers were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only: Experiment One 77
5 Mean total aerobic bacterial counts ofbahiagrass that was grazed by all three
groups ofsteers for Experiment One 80
6 Mean total aerobic bacteria counts, Escherichia coli, and Fecal coliform counts for
the animal drinking water for Experiment One 80
7 Mean total aerobic bacterial counts ofthe two commercially available animal feeds
given to the steers for Experiment One 81
8 Mean parasitic eggs isolated from feces ofsteers given two different commercially
available feeds and allowed to graze on bahiagrass or allowed to graze only:
Experiment One 82
9 Mean proximate analysis values and pH for bahiagrass samples collected from
pastures for Experiment One 83
Mean blood values ofaspartate amino transferase and gamma glutamyl
1
transpeptidase in the blood ofsteers given two different commercially available
VI
feeds and allowed to graze on bahiagrass or allowed to graze only for Experiment
84
One
11 Mean blood values for calcium, magnesium, chloride and potassium in the blood of
steers given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment One 85
12 Mean blood values for anion gap, glucose, and carbon dioxide in the blood ofsteers
given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment One 89
13 Carcass characteristics and standard error ofmeans from steers that were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment One 90
14 Mean objective color values ofBrangus steer steaks cut from the short loin portion
ofsteers given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment One 92
15 Mean pH values ofBrangus steer steaks cut from the short loin portion of steers
given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment One 93
16 Mean thaw loss and cooking loss ofBrangus steer steaks cut from the short loin
portion ofsteers given two different commercially available feeds and allowed to
graze on bahiagrass or allowed to graze only for Experiment One 94
17 Mean trained sensory panel scores ofBrangus steer steaks cut from the short loin
portion ofsteers given two different commercially available feeds and allowed to
graze on bahiagrass or allowed to graze only for Experiment One 95
18 Mean Wamer-Bratzler Shear force values ofBrangus steer steaks cut from the short
loin portion ofsteers given two different commercially available feeds and allowed
to graze on bahiagrass or allowed to graze only for Experiment One 96
19 Average daily weight gain values ofBrangus steers fed different commercially
available feed concentrates, and allowed to graze on bahiagrass or allowed to graze
only for seven months: Experiment Two 98
20 Average daily weight gain values ofBrangus steers that were initially fed Super 12,
or B-80 and allowed to graze, or allowed to graze only and then placed onto Super
12 concentrate: Experiment Two 100
vu
1
21 Mean total aerobic bacteria counts, ofsteer fecal samples. Steers were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 101
22 Mean generic Escherichia coli counts, ofsteer fecal samples. Steers were given
two different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 103
23 Mean Fecal coliforms counts, ofsteer fecal samples. Steers were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 104
24 Mean total aerobic bacteria counts, Escherichia coli. and Fecal coliform counts of
bahiagrass that was grazed by all three groups ofsteers only for Experiment
Two 105
25 Mean total aerobic bacterial counts, Escherichia coli, and Fecal cohform counts of
the animal drinking water ofsteers given two different commercially available
feeds and allowed to graze on bahiagrass or allowed to graze only for Experiment
Two 106
26 Mean total aerobic bacterial counts. E. coli. and fecal coliforms ofthe two
commercially available animal feeds given to the steers only for Experiment
Two 107
27 Mean coccidia parasitic eggs isolated from feces ofsteers given two different
commercially available feeds and allowed to graze on bahiagrass or allowed to
graze only for Experiment Two 108
28 Mean parasitic eggs, isolated from feces ofsteers given two different commercially
available feeds and allowed to graze on bahiagrass or allowed to graze only for
Experiment Two 108
29 Mean proximate analysis values and pH for bahiagrass samples collected from
pastures for Experiment Two 109
30 Mean blood for chloride, sodium, potassium and phosphorous for steers given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 110
3 Carcass characteristics and standard error ofmeans for steers that were given two
different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 112
Vlll
32 Mean objective color values ofsteaks cut from the short loin portion ofsteers given
two different commercially available feeds and allowed to graze on bahiagrass or
allowed to graze only for Experiment Two 1^4
Mean pH values ofsteaks cut from the short loin portion steers given two different
commercially available feeds and allowed to graze on bahiagrass or allowed to
graze only for Experiment Two ^ ^5
34 Mean thaw loss and cooking loss for steaks cut from the short loin portion ofsteers
given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment Two 115
.35 Mean trained sensory panel scores ofsteaks cut from the short loin portion steers
given two different commercially available feeds and allowed to graze on
bahiagrass or allowed to graze only for Experiment Two 116
36 Mean Wamer-Bratzler Shear force (WBS) values ofsteaks cut from the short loin
portion steers given two different commercially available feeds and allowed to
graze on bahiagrass or allowed to graze only for Experiment Two 117
37 Commercial feed cost summary for Experiment One 119
38 Commercial feed cost summary for Experiment Two 122
39 Mean weight ofBrangus steers fed different commercially available feed
concentrates, and allowed to graze on bahiagrass or allowed to graze only for four
months: Experiment One I-'1
40 Mean weight ofBrangus steers that were initially fed Super 12. or B-80 and
allowed to graze, or allowed to graze only and then placed onto Super 12
concentrate: Experiment One l-'^
41 Mean weight ofBrangus steers fed different commercially available feed
concentrates, and allowed to graze on bahiagrass or allowed to graze only for ten
months: Experiment Two l-^-^
m
Abstract ofDissertation Presented to the Graduate School
ofthe University ofFlorida in Partial Fulfillment ofthe
Requirements forthe Degree ofDoctor ofPhilosophy
IMPACT OF THREE DIFFERENT FEEDING REGIMENS ON PERFORMANCE,
MICROBIOLOGY, SENSORY, AND OBJECTIVE CHARACTERISTICS OF
FLORIDA BRANGUS BEEF CATTLE
By
Keawin Caron Sarjeant
May 2006
Chair: Sally K. Williams
Major Department: Animal Sciences
Two experiments were conducted to evaluate three typical commercially available
feeding regimens and their effects on average daily weight gain, prevalence ofE. coli
0157:H7, generic E. coli, fecal coliforms, total aerobic bacteria, and parasites in beef
cattle. This study also focused on blood chemistry ofthe animals, theproximate
composition ofthe grass on which animals grazed, animal drinking water, animal feed,
the resulting carcass characteristics, pH, objective colorcharacteristics and sensory
attributes ofsteaks collected fi-om the short loin ofthe carcasses. Sixty Florida Brangus
steers, where 30 steers with an average age of 17 months were used forExperiment One,
and 30 steers with an average age of9 months were used in Experiment Two. Steers in
both experiments were assigned randomly to one ofthree feeding regimens: 1) Super 12,
a non medicated concentrate, plus bahiagrass, 2) B-80, a medicated concentrate
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