Exam 3 Flashcards
(113 cards)
1
Q
Warner-Bratzel Shear Force
A
- a system to predict meat tenderness
2
Q
B-AR agonists
A
- act through adrenergic receptors
- repartitioning agents (repartition nutrients away from fat deposition and toward lean deposition)
- increase protein synthesis and stimulate lipolysis
- > MUSCLE GROWTH
3
Q
Anabolic Implants
A
- Promote growth through increased gain and efficiency
- Typically administered at initial feedlot placement and possibility a reimplant during the middle of the feeding period
ex: Revalor
4
Q
ACTOGAIN and OPTAFLEXX
A
- for FINISHING CATTLE
- increase weight gain, inc feed efficiency, inc carcass leanness
- feed during last 28-42 days on feed
5
Q
Proper site for placing growth promoting implants in beef cattle
A
- under the skin on the back subcutaneous middle one-third of the ear
6
Q
Result of feeding B-AR agonists
A
- increased skeletal muscle mass
- > increase protein synthesis
- > decrease protein degradation - decrease adipose tissue mass
- > decrease lipogenesis (fat synthesis)
- > increase lipolysis (fat breakdown) - Inc lean muscle
7
Q
Dietary energy and lysine levels
A
- ractopamine may be included in swine diets containing 16% CP
- feed with lysine to improve feed efficiency
- integrated swine operations typically feed diets with approximately 3.4 Mcal of ME/kg
- > increases WBS and lower IMF (tougher and less marbling, not good to sell for quality)
8
Q
Effects of Beta adrenergic agonists on cattle
- zilpaterol vs ractopamine
A
- responses differ by b-agonist
- > zilpaterol (b2) > ractopamine (b1)
- > zilpaterol is more aggressive in cattle
- both inc ADG (Ract > zilp)
- both inc HCW (zilp > ract)
- inc feed efficiency
- both inc ribeye area (zilp > ract)
- both Inc WBS = dec tenderness and inc toughness
- Zilp dec REA and Ractopamine inc REA
- both reduce fat thickness (zilp > ract)
- > zilpaterol REALLY high (concern for palatability)
- both inc FG fiber area = extreme muscle hypertrophy
9
Q
Synovex-H
A
- an implant for heifers
- 400 lbs or more
10
Q
Implant Matrices
A
- hormones are embedded in a matrix
- hormones are released consistently and over a long period of time
- pay out is dependent on the implantation technique
- > will reduce the number of re-implants
- > compressed pellet, 60-120 d
- > silastic rubber, 150-200 d
11
Q
Affect of anabolic implants on stocker calves
A
- given in stocker phase increase ADG over non-implanted control
- a 22-35 lbs increase in weight gain after a 150 d stocker period (10-16% inc)
- an additional increase of $25-40/head for a $1.29-1.38 initial investment
- inc in ADG over non-imp and in weight after 150 d stocker period
1. Synovex-S = .15 lb/d and 22.5 lbs
2. Ralgro (Z) = .20 lb/d and 30 lbs
3. Revalor-G = .23 lb/d and 34.5 lbs
12
Q
Zilmax
A
- for FINISHING CATTLE only
- feed for last 20 days on sole ration of feed
- 3 day withdrawal period
13
Q
Animal welfare and beta-agonists
A
- in 2013, Tyson Fresh Meats suspended PURCHASE OF CATTLE FED ZILMAX (zilpaterol hydrochloride), citing concerns that it might be causing AMBULATORY PROBLEMS IN CATTLE
- Merck Animal Health, maker of Zilmax, voluntarily and temporarily SUSPENDED SALES of the feed additive in the US and Canada to address these concerns
- > 5-step plan for responsible beef
14
Q
EU Ban on Implanted Beef
A
- 1989 banned imports of beef treated with growth-promoting hormones
- US does not fit the 11.500 metric ton quota for high-quality, non-hormone treated beef
- to become eligible to export non-treated beef, producers must obtain certification from NHTC (non-hormone treated cattle) program
- under this program ensures that cattle “have never been fed or treated with hormonal growth promotants”
- only 16 farms registered as of 2002
15
Q
Beta-agonists
A
- Repartitioning agents that stimulate lean growth instead of fat deposition at the end of the feeding period
- Used last 20-40 of finishing
16
Q
Actogain function
A
- increase gain without compromising efficiency
- LW inc 17 lb
- feed efficiency inc 15%
- carcass weight inc 11 lb
17
Q
What is important in the beef cattle industry
A
- southeast farms avg 100 cows or less
- consistent profit
- makes the COW-CALF industry most important!!
- Stocker industry -> someone who has calves that are under weight for sale
18
Q
Synovex One Grass
A
- used for weight gain and operational flexibility from 200 days of uninterrupted growth (pay out up to 200 days)
- stocker steers and heifers to inc gain and help stretch out performance when forage available for grazing beyond 140 d
- good for the stocker industry for cows fed on grass alone
- newer, more aggressive and expensive
- 10:1 ratio of TBA:E2
- STEERS 17.2% improvement in gain over non-implanted steers
- HEIFERS 11.3% inc in average daily gain (ADG)
19
Q
B-andrenergic receptors (B-AR)
A
- consists of over 400 amino acids
- 7 hydrophobic transmembrane domains
- 3 extracellular segments associated with the N-terminus
- 3 intracellular loops with the C-terminus
20
Q
How much beef would a male have to consume to exceed FDA rule?
A
- 342 3oz servings (64 lb/d) of implanted beef per day to exceed 1% of normal estrogen production
- 477 3oz servings (90 lb/d) of non-implanted beef per day to exceed 1% of normal estrogen production
- zero chance this occurs
21
Q
Synovex-C
A
- an implant for sucking calves
- 45 d or older
- up to 400 lbs
22
Q
Influence of implant on feedlot cattle with ADG, feed/gain, HCW, LMA, REA
A
- ADG
- inc .47-.57 lb/d - Feed to gain
- dec .19-.42 lb/lb - HCW
- inc 22-52 lb - LMA
- .39-1.07 in^2 - REA
- .34-1.09 in^2
23
Q
Combination Implants for FINISHING cattle
A
- Revalor-G
- G stands for grass
- mild implant
- lower ratio of TBA : estradiol
- implant for WEANED pasture cattle, steers and heifers
- for YOUNGER, growing cattle
- about $1 - Revalor-S
- implant for FEEDLOT steers
- hormone amount increased bc it is a larger animal
- cost more as well because need a larger amount of hormone
- about $3
24
Q
Environmental and economic impact of removing growth enhancing technologies
A
- removing growth enhancing technologies would have a significant negative consequence
- increase resource use
- increase waste/manure output (greenhouse gases)
- increase carbon emissions
- increase production cost per pound of beef
- increase cattle numbers
- increase feedstuff and land use
25
Affect of anabolic implants on suckling beef calves
- increase in ADG over non-implant
- > .11-.13 lb/day
- additional weight gain of 23-27 lb
- increase in profit by $30-37 for a 1.25-1.37 initial investment
26
Synthetic b-AR agonists
- active with oral administration
- bind to B-AR
- > activates Gs protein
- > then activates cAMP, a major intracellular signaling molecule for response in the body
- > increases muscle synthesis, dec muscle degredation, reduce lipogenesis, inc lipolysis
27
Revalor + Zilmax additive response on WBS on day 14
- WBS inc 1.67 (toughness inc)
| - additive response
28
Repartitioning agents
- compounds that shift nutrients from adipose tissue and toward muscle
- energy is directed to lean muscle growth and less fat
29
Synovex-C (C)
- works as a growth promoting implant for cow-calf operations
- INC RATE OF WEIGHT GAIN in suckling steer or heifer calves
- use when 45 d or older, up to 400 lbs
- initial implant followed by Synovex S 70 days later
- increased weight of gain rate in feedlot steers over 400 lbs
- one implant has 4 pellets
- use a lower dose
- DO NOT USE IN VEAL CALVES
- 100 mg progesterone and 10 mg estradiol benzoate (EB)
30
Marbling and Implants
- Relationship between INCREASED LMA (longissimus muscle area) and REDUCED MARBLING SCORES
- Appears to be a dilution of intramuscular fat rather than a direct effect on lipogenesis
31
Natural Organizations Beliefs
- they do not use growth hormones
- they are organic and all naturally raised
- BUT all hormones are NATURAL, they only make growth occur faster
32
PAYLEAN 9
- for FINISHING SWINE only
- premix that goes into feed
- contains at least 16% of CP
- for the LAST 45 TO 90LBs of gain before slaughter
- ONLY FOR LATE FINISHING PERIOD
33
Combination of Implants
- most implants contain both estrogenic and androgenic anabolic implants
- additive responses
34
Affects of Ractopamine aka paylean in finishing swine
- repartitions nutrients from fat deposition toward increased protein synthesis
- muscle protein accretion without impacting pork quality
- inc ADG
- inc feed efficiency
- inc LMA
- dec fat thickness at the 10th rib
- inc fat free carcass lean
35
How much beef would a female have to consume to exceed FDA rule?
- female (non-pregnant) would have to consume 4275 3oz. servings of implanted beef per day
- pregnant females would have to consume 16,333 3oz. servings of implanted beef per day
- zero chance this occurs
36
How much does Ralgro(Z) and Synovex-C cost
- ralgro Z is 1.37 per dose
| - synovex-C is 1.25 per dose
37
Ralgro Z/Ralgro Z Combination inc in ADG
- .13
38
Antibiotic concerns
- resistance
- > bacterial resistance to antibiotics and human health
- > FDA establishes minimum time intervals between last use of feeds containing antibiotics and slaughter of the animal, which allows for the elimination of antibiotics
- > monitor for residues
39
How do we produce more beef to feed a growing world
- increase number of animals
| - produce more beef meat per animal
40
Antibiotics
- sub-therapeutic levels
- > prevent disease, improve growth, and enhance feed efficiency
- > no changes in carcass quality
41
Phytoestrogens
- phenolic and non-steroid compounds that have similar structure and biological activity as human estrogens
- plant secondary metabolites found in over 300 plant species
- used for estrogen replacement therapy for women in menopause
- > isoflavons stimulates osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent excessive bone mass loss in mice and rats with removed ovaries
- antioxidants to protect against harmful effects of free radicals
- > flavonoids
- bind to both estrogen receptors, ERalpha and ERbeta
42
Growth Promotants (3 Major)
- anabolic compounds that are exogenously administered to promote growth
- all growth promotants are regulated by the FDA
ex:
- Anabolic Implants
- beta agonists
- ionophores
43
Implants with Local Antibacterial
- every implant has a Tylan pellet, a localized antibacterial, it will dissolve and quickly releases the antibacterial throughout the implant site
- the implant procedure causes an inflammatory response in all animals, this can increase abscess rates (especially in dirty or wet conditions)
- good implanting procedures paired with the Tylan pellet will reduce the number of abscesses and improve health/performance of the implant and site
44
Implant Products on the Market
- Center for Veterinary Medicine(CVM) Approved Cattle Drugs
- all approved by the FDA for use in CATTLE based on sex, weight and program
- ZERO DAY WITHDRAWAL (can implant and slaughter whenever, it is safe)
- the label of each brand specifies what type of cattle to use for
- 38 implant products available for the use in cattle
1. 8 implants with estrogenic activity (E)
2. 2 implants with androgenic activity (A)
3. 28 implants with combination of estrogenic and androgenic activity (C, additive response)
45
What % of feedlot cattle have been implanted at least once and what % uses combination implant
- 97.2% of feedlot cattle have been implanted at least once
| - 78% use combination implant (when both an estrogenic and androgenic implant is used)
46
Synovex-Choice
- the most versatile potency implant for feedlot steers and heifers
47
Two types of Adrenergic Receptors
1. alpha-adrenergic receptors (a-AR)
2. beta-adrenergic receptors (B-AR)
- > present in most all tissues in the body, but in differing amounts depending on tissue type
- > are members of the G protein-coupled receptors (GPCR)
48
JECFA
- international scientific expert committee focusing on the residues of veterinary drugs in food
- Joint Expert Committee on Food Additives (Food and Agricultural Organization-FAO/World Health Organization-WHO)
- used by the Codex Alimentarius Commission to establish standards
- ADI (acceptable daily intake) for ractopamine
- MRL (maximum residue limit) in cattle and pig tissues
- defined ractopamine as "synthetic substance that is used as a veterinary drug in animal feed to promote muscle growth in approved food animal species, namely pigs and cattle and, to a limited extent heavy turkeys"
49
History of Anabolic Implants
1. 1954- oral DES approved for CATTLE
- DES: anabolic compound with estrogenic activity
2. *1956- Estradiol Benzoate (EB)/progesterone implants approved for STEERS
3. 1958- EB/Testosterone approved for HEIFERS
3. 1968- oral MGA approved for heifers
4. 1969- ZERANOL implants approved for cattle and lambs
5. 1987- Trenbolone Acetate (TBA) approved for cattle
50
DES use in humans
- DES was used in humans during the first trimester of pregnancy to prevent miscarriages
- the daughters of these mothers who used DES developed adenocarcinogens
- in 1979 all use of DES was BANNED by the FDA
51
Other countries
- China: zero tolerance policy for ractopamine residues in meat imports since 2009
- Russia: banned imports of US meat containing ractopamine, loss of $500 million in sales per year
- Canada: ractopamine free pork certification program
- USDA: allows labels for meat productions, "never fed beta-agonists"
52
Summary of antibiotics and ionophores
- antibiotics
- > VMD eliminates use of antibiotics for growth promotion
- ionophores
- > improve feed efficiency
- > no changes in carcass quality or composition
53
Ionophores
- first approved in 1971 as a coccidiostat for poultry
- 90+% of feedlot cattle are fed an ionophore in a finishing diet
- antimicrobial compounds
- > alter the ability of sensitive cells to transport nutrients and end-products through the cell membrane which forces them to expend additional energy, which reduces their survival
54
FDA approval with estrogen
- intake from residues in meat < 1% of daily production of estrogen
- the amount of extra hormone(E2) in MEAT MUST NOT EXCEED 1% of the average amount of that hormone produced by a person in the most sensitive segment of the human population
- prepubertal boy has the lowest levels of estrogen
- pregnant female has the highest levels of estrogen
55
Increase in value if implant both suckling and stocker beef calves with anabolic implants
- weight increase = 45.5-61.5 lb/hd(head)
| - additional profit = $56.54-75.91
56
Mechanism of action when bind to B-AR
- activates Gs protein
- > a-subunit of the Gs protein. then activates adenylyl cyclase, the enzyme that produces cyclic AMP (cAMP)
- cAMP is a major intracellular signaling molecule
- > bind regulatory subunit of protein kinase A to release the catalytic subunit that then PHOSPHORYLATES a number of intracellular proteins
- > can prod lipase enzyme or deactivate long-chain fatty acid synthesis
57
Synovex-S
- steers over 400 lbs
58
Suckling Beef Cattle
- calves below 7 months of age and not 400-500 lbs yet
- use ralgro w zeranol (1 mos of age and older)
- use Synovex-C (45 d of age and older)
- implant products available for suckling calves
- easy management, implant subcutaneously in the ear (lasts 40-60 days)
- an increased rate of weight gain (weaned at a heavier weight)
- not used in bull calves or weaning heifers intended for reproduction, dairy cows, or cows processed for veal
59
Reimplantation
1. Pay-out
- 60 to 120 days
2. Reimplant
- 60 to 120 days after first implant
- depends on the total days on feed
60
Desensitization of Ractopamine
- improves feed efficiency by 20% when fed for 27 d
- after 27 d of feeding paylean, the advantage in feed efficiency dec 7%
- optimal response is 20-27 d of feeding (tissues responsiveness to paylean is v short)
61
DES history
- Iowa State College filed for a patient in 1953 for use of oral DES in cattle
- By the end of 1955, it was estimated that 6 million cattle were fed DES (80-95% of fed cattle)
- there was a 15% improvement in gain and feed efficiency
- no residues in meat
62
Skeletal Maturity
- Implants can advance skeletal maturity
- > estrogens
- Number of implants used important
- > If each implant advances maturity by 10 points, then this can add up when using multiple implants and depending on time-on-feed
- Concerns
- > can effect marbling, quality grade, tenderness
63
Benefits from implanting
- INCREASED RATE OF WEIGHT GAIN
| - IMPROVED FEED EFFICIENCY
64
When should anabolic implants be used?
- at calves(suckling) and stocker phase
65
Implants and ionophores
- 22% increase in beef production without increasing level of supplementation or pasture land
- utilizing both ionophores and implants together decreased cost of gain by 26%
- net return increased by $30-$54 USD over control
- inc ADG .46 lb/d
66
B-agonists in swine
- increased performance
- inc ADG and gain:feed by 25-28%
- increase fat-free lean
- > increase muscle mass(26%), dec fat mass(13%)
- dietary energy and protein levels important
- > maximizing muscle growth may impact marbling and tenderness
- greatest improvements first 20-27 d
- NO IMPLANTS FOR PIGS(not FDA approved), ONLY CATTLE
67
How do implants in beef production work
- increase lean muscle growth
- increase IGF-1
- Increase satellite cell proliferation
- estrogens increase protein synthesis
- androgens decrease protein degradation
- additive responses with combination implants
68
Two B-AR products approved for use in the USA
1. ractopamine hydrochloride
- b1 adrenergic agonist (called diff things 4 diff species)
- paylean (pigs)
- optaflex (cattle)
- topmax9 (turkey)
- actogain (cattle)
2. zilpaterol hydrochloride
- b2 adrenergic agonist
- zilmax (cattle)
- 3 d withdrawal period prior to slaughter
69
Adrenergic receptors (AR)
- define, prevalence, mechanism of action
- different receptor subtypes
- > allow differential effects
- subtypes differ between tissues and species
- > have a preference of which to bind to
70
Implant Problems
- abscessed (biggest issue, 22%)
- bunched
- crushed
- missing
- pellets missing
- walled off
- in cartilage
- improper site
71
Advantages of anabolic implants
1. Larger calves at weaning
- get larger bc there is an increase in avg daily gain
2. More lbs = more $$$$$
3. Increase in Ribeye area
- important bc this is where the $$$$ comes from
4. larger cows leaving stocker programs
72
Concerns with Implanting and Meat Quality
- marbling
- quality grade
- tenderness
73
Meta-analysis for ractopamine in swine
- inc 11.8% ADG
- inc 16.7 G:F (feed efficiency)
- 3% inc HCW
- Dressing percent inc 1.2%
- LMA inc 12.6%
- fat free lean inc 4.7%
74
Implant products are available for?
for suckling calves, grazing cattle and finishing cattle
75
SYNOVEX-Zoetis Implant
- part of a broad portfolio of implants in every production phase
76
Differences between AR types
- B-AR: Gs-protein stimulated cAMP-mediated events
| - a-AR: coupled to inhibitory Gi protein (turns off)
77
Synovex-PLUS
- the most potent implant for feedlot steers and heifers
78
Maximum residue limit (MRL) in ractopamine and zilpaterol
1. 2010-Ractopamine
- MRL for muscle, liver, fat, 150 ug/kg
- MRL for kidneys, 200 ug/kg
2. 2012-Zilpaterol
- not enough data to establish MRL
79
Alternatives to antibiotics
- antimicrobial peptides
- clay minerals
- egg yolk antibiotics
- essential oils
- eucalyptus oil-medium chain fatty acids
- rare earth elements
- recombinant enzymes
80
Hormonal Growth Promotants Components for beef cattle
1. Estrogens
2. Androgens
3. Progesterones (MGA and progesterone)
- all growth promotants technologies are regulated by the food and drug administration (FDA)
- causes an increase in growth hormone that produces muscle growth
81
All-natural beef
- produced without the use of growth promoting implants
| - USDA Non-Hormone Treated Cattle Program for certification
82
Percents of finished cattle that come from feedlot operation and pasture operation
- 95% feedlot
| - 5% pasture
83
Endocrine Disruptors in Environment
endocrine disruptors
- > mimic the actions of estrogens and inhibit the effect of androgens
- tea tree oil and lavender oil
- > causing gynecomastia in prepubertal boys (development of breasts)
- after removal of these products, gynecomastia resolved after several months
84
Why shouldn't beta adrenergic agonists be fed for long term periods?
- constant exposure to B-AA desensitizes or inactivates receptor-mediated signaling
- waste of money to continuously use it bc it will stop working
85
Safety of beta-agonists for human consumption
- approved by FDA
- ractopamine used in more than 20 countries
- zilpaterol only used in 5 countries
- EU European Union banned use of beta-agonists in farm animals in 1996
86
Ralgro (Z) Z=Zenerol
- 36 mg Zenerol
- anabolic agent that INC RATE OF WEIGHT GAIN
- improves conversion of weaned beef calves, growing beef cattle, feedlot steers and feedlot heifers
- increases rate of weight gain in SUCKLING beef calves
- DO NOT USE IN VEAL CALVES
- do not use in calves under 1 mos of age or in heifers intended for reproduction
87
Synovex-S
- an implant for steers
| - 400 lbs or more
88
Safety of Anabolic Implants
- USA has used for over 60 years
- 1956 first EB/progesterone implant approved for steers
- all anabolic implants are FDA approved
- have ZERO DAY SLAUGHTER WITHDRAWAL
89
Androgenic Anabolic Implants
- testosterone propionate (TP)
- trenbolone acetate (TA)
- > 3-5 fold greater androgenic activity and 8-10 fold greater anabolic activity than testosterone
90
Dominant adrenergic receptor (AR) in the cattle
- over 90% B2 in adipose tissue
| - over 99% B2 in skeletal muscle
91
Cattle: B-agonists
1. zilpaterol (zilmax)
- b2 adrenergic agonist
2. clenbuterol
- b2 adrenergic agonist
- not approved for use in US commercially
- experimental lab use only
3. ractopamine (optaflexx and actogain)
- > b1 adrenergic agonist
92
Veterinary Feed Directive (VFD) Final Rule
- purpose is to revise FDA's VFD regulations to improve the efficiency of the VFD program while continuing to protect public health (human and animal health)
- In 1996, Congress enacted the Animal Drug Availability Act (ADAA) to facilitate the approval and marketing of new animal drugs and medicated feeds
- new regulatory category for certain animal drugs used in or on animal food (animal feed) called veterinary feed directive drugs (or VFD drugs).
- VFD drugs are new animal drugs intended for use in or on animal feed which are limited to use under the professional supervision of a licensed veterinarian.
- Any animal feed containing a VFD drug can only be fed to animals based upon an order, called a veterinary feed directive (VFD), issued by a licensed veterinarian in the course of the veterinarian's professional practice
- in short, all antimicrobial drugs used for food-production purposes must be approved and distributed by a licensed vet
93
Anabolic Implants and Beta-agonists additive responses
- increase gain and HCW
- reduction in marbling and tenderness (tougher)
- will increase pounds in beef and lower cost
- in 2002 70-80% of US cattle fed Zilmax or Optaflexx
94
Phytoestrogens are divided into two groups
1. Isoflavonoids
a. isoflavones
- isoflavones
- soybean and red clover
b. coumestans
- also found in soybean and red clovers
- MOST PRONOUNCED ESTROGENIC AFFECTS
- coumestrol
2. Lignans
- flaxseed, sesame seed, cabbages, cereals
95
Epinepherine (adrenaline) and norepinephrine
- released when stimulated by nerve fibers
- response to stress
- bind both alpha-AR and b-AR
- > induce significant metabolic effects on various tissue
- > epinepherine is more potent than norepinepherine for a-AR
96
Stocker calves
- stocker phase = after weaning (over 400 lbs) and before finishing in feedlot
- typically on forages/pasture systems
- use Ralgro, Synovex-S, Revalor-G or Synovex One Grass
- > all approved to increase weight gain
97
What implant is used in Suckling Beef cattle
- Ralgro with Zenerol (given at 1 month of age)
- synthetic estrogen made from corn mold
- Synovex-C (45 days of age)
98
Meta-analysis results of optaflexx
- HCW inc 13.6 lbs
- marbling score dec by 5.1
- WBS inc .2 (inc toughness)
99
Synovex-CONE
- aggressive feedlot implant, really stimulate growth
| - has a negative impact on marbling
100
Combinations: ionophore and BAA
- 90+% of feedlot cattle are fed an ionophore
- 85% of feedlot cattle are fed B-AA
- fed in combination
- > currently laidlomycin propionate (cattlyst) lacks combination approval (monensin has approval)
- > this study was conducted to evaluate the combination
101
β-Adrenergic Agonists
- Another Growth promoting technology
- Approved for use in ONLY FINISHING swine, cattle, turkeys
- Used to increase skeletal muscle growth and decrease lipid/adiposity(dec fat production) content
- Repartitioning agent
- Energy is directed to lean muscle growth and less fat
- Increase lean yield
- commercially available compounds for use in meat animals
- typically growth responses
- constant exposure to B-AA
102
Simpson and Edisto Rec Cattle Research
- Steers (160) were used from two locations in SC (Simpson Beef Station and Edisto Rec Center)
- two groups at each location implant group and a no implant (control group)
- Ralgro(Z) implant at 4 mos of age, re-implant using Revalor-G implant
- they used a real time ultrasound to see ribeye area and fat thickness
RESULTS
- inc in weight gain and ADG
- dec in fat thickness
- inc in ribeye area
103
Beef production w implant influence
- use of growth promotant technologies INC BEEF PRODUCTION (inc pounds of beef) and REDUCES INPUTS (less feed per pound of gain)
- INC SUSTAINABILITY: more beef for less, efficiency increases, less feed per lb of gain
- Since the population is increasing rapidly there will be a 70% increase in demand for meat, milk and eggs (growth promotants will help)
104
Estrogenic Anabolic Implants
- estradiol 17-Beta (E2)
- estradiol benzoate (EB)
- zeranol (Non-steroid compound from corn infected with fungus. Fusarium that has estrogenic activity)
105
Meta-analysis results of zilmax
- meta analysis is when you take all prior studies on the topic, reanalyze and get avg of results
- HCW inc 33.22 lb
- REA inc 1.24 in^2
- marbling score dec by 23
- WBS aka shear force inc by .84 kg (inc toughness)
106
Implant and ionophore affect with cattle on pasture
- implant inc .31 lb/d
- ionophore inc .15 lb/d
- both .46 lb/d
- > $30-54 inc
- > 22% inc in beef prod
107
Implant Timing
- early implant has largest choice
108
Synovex-H
- heifers over 400 lbs
109
Beef Consumption does not trigger early onset of Estrus (Puberty)
- earlier onset of puberty in young American girls has led researchers to question if a casual relation exists between dietary sources of estrogenic compounds and precocious puberty
- PREPUBERTAL GILTS as an animal model were fed:
1. cooked ground beef from non-implanted beef
2. cooked ground beef from implanted beef
3. cooked tofu patty
- gain, muscle, fat deposition and number of days to estrus
- concluded that daily consumption from a very early stage in physiologic development DOES NOT LEAD to precocious puberty
110
Antibiotic mode of action
1. metabolic effect
- directly affect rate or pattern of metabolic processes
2. nutrient sparing effect
- reduce dietary requirement for one or more essential nutrients
3. disease control effect
- suppress organisms that produce toxins or limit their capacity to produce toxins which adversely affect performance of the animals
111
Physiological B-AR agonists
- epinepherine (adrenaline) and norepinephrine
- > fight or flight response to stress
- synthetic b-AR agonists
112
Synovex One Feedlot
- an extended duration (up to 200 days) implant for feedlot steers and heifers
113
B-AA summary
- they are synthetic compounds that bind to B-AR
- cAMP stimulates phosphorylation of certain enzymes that regulate metabolism
- short-term effects to alter growth
- > constant exposure to B-AA desensitizes or inactivates receptor-mediated signaling
