Exam 2 Flashcards
(163 cards)
1
Q
Conclusions of Ruminant Protein Req from diet study
A
- 50% of Soybean Meal Diet(SBM) can be replaced with a cheaper source of crude protein (ex: urea) without compromising feedlot performance or carcass quality
- rumen protected amino acid supplementation did not enhance carcass quality, or performance. Therefore, the diets were not lacking in these amino acids
2
Q
Net Energy of Gain (NEg)
A
- amount of energy in a feed available for protein and lipid accretion
3
Q
TBA and protein degradation
A
- TBA reduces protein degradation
4
Q
Hypertrophy occurs when
A
- muscle synthesis is greater than muscle breakdown (degradation)
5
Q
Real Time Ultrasound
A
- used to determine traits of:
1. Ribeye Area
2. Intramuscular Fat
3. Fat Thickness
4. Rump Fat
6
Q
Current US beef average for choice carcass
A
- 83%
7
Q
What happens if inadequate levels of protein in monogastrics?
A
- Less muscle growth and inc in fat deposition
2. Lower carcass price and value
8
Q
USDA Grade (Pork)
A
- expected combined yield of 4 lean cuts
Grade= (4*last rib Fat Thickening) - muscle score - U.S 1, 2, 3, 4
9
Q
Calculate carcass price ($/lb) and carcass value ($/carcass)
A
Calculate carcass price ($/lb) in BEEF
1. Find base price for that weight
2. Find premium/discount for QG/YG
- Both Given in $/100 lb so must convert to PER POUND
3. Add/subtract both numbers together and divide by 100
4. answer is now in $/lb
Calculate carcass price ($/lb) in LAMB
- find live weight price and divide by .5 dressing %
- then divide by 100
Calculate carcass price ($/lb) in PORK
- find back fat and loin eye area
- divide by 100
Calculate Carcass Value ($/carcass)
1. Multiply carcass price by weight provided
2. answer is in $/carcass
10
Q
Estrogens
A
- ovary is a source of 3 estrogens
1. estrone
2. estriol
3. estradiol
11
Q
Estrogen and IGF-1 mRNA levels
A
- E2 increases IGF-1 mRNA in bovine satellite cells
12
Q
Blood glucose in the diet
A
- Monogastrics
- absorb glucose in the diet - ruminants
- absorb VFAs from diet and rely on gluconeogenesis
13
Q
Net Energy of Lactation (NEI)
A
- amount of energy in a feed available for milk production and body maintenance
14
Q
Nutrient restriction in beef
A
- at d 120-150 (early 2nd trimester)
1. native range (NR; 65% CP)
2. improved pasture (IP; 1.1% CP) - Steer calves were finished on high concentrate diet
15
Q
Empty Body Weight
A
- the body weight minus the weight of the gut fill contents
- take the weight of the digestive tract(remove gut fill) after flushing out the contents, then add that to the weight of the empty carcass
- helps get rid of the “fill” issue when weighing
16
Q
PREDICTING carcass composition
A
- usually done by eyesight on a packing plant
1. Specific Gravity
2. 9-10-11th rib sections
3. VIA
4. DEXA
17
Q
9-10-11th Rib Section
A
- considered the best representation of the carcass as a whole
- used to determine lean to fat ration
- proximate analysis done on that one section vs doing one on the carcass as a whole
18
Q
At the same chronological age, what is the difference between late maturing animals and early maturing animals?
A
- late maturing animals will be leaner, physiologically younger and heavier than early maturing animals
19
Q
Estrogen (E2) or TBA on proliferation of satellite cells (SC)
A
- E2 and TBA increases proliferation of satellite cells
20
Q
Fetal Brain Sparring
A
- asymmetrical fetal growth
- brain is larger than body weight bc brain priority
- due to uteroplacental insufficiency
- will shunt blood flow to vital organs such as brain, adrenal gland and heart
- mechanism to maintain survival of fetus, at the expense of overall growth
21
Q
PORK Wholesale cuts % of Carcass weight
A
- Leg - 22% (largest)
- Loin - 16%
- Boston Butt - 9%
- Picnic Shoulder - 9%
total - 565
—–>^ 4 lean cuts - other-> belly - 13%
22
Q
What is wrong with measuring live weight?
A
- GUT FILL
- fill is the amount of weight remaining in the digestive tract
- monogastrics have 1 chamber stomachs
- ruminants have 4 chamber stomachs
23
Q
Critical transitions in growth at weaning
A
- removed from their mother
- experience post-weaning lag:
1. decreased rate of growth
2. loss of fat stores
3. loss of muscle mass if severe
24
Q
GH and muscle growth
A
- mediated by IGF-1
- increases rates of muscle protein synthesis and decreases protein degradation
25
Insulin and Glucose
- response to fasting and feeding to maintain blood glucose levels
- feeding (inc insulin and glucose)
- fasting (dec insulin and glucose)
- stimulation of insulin with propionate and butyrate
- > direct response not dependent on alternations in blood glucose
- > gluconeogenic
26
Rumen Protein Sources
1. Rumen Degradable Protein
2. Bypass Protein (Rumen Escape Protein)
- can escape rumen without being digested and utilized
27
Beef frame scoring system
- used to predict weight at which animal is finished
28
Quality in Pork
- acceptable or unacceptable
Minimum for acceptability:
- will be slightly firm, be slightly marbled and will be grayish to moderately dark red in color
- belly must have .6in thickness at any point
If Acceptable: eligible for U.S 1, 2, 3, 4
If Unacceptable: eligible for U.S Utility
29
To increase Growth
1. Increase total energy
| 2. Reduce maintenance energy cost
30
Areas of Yield Grade in BEEF
1. Hot Carcass Weight
2. Ribeye Area, 12/13th rib
- area of longissimus muscle
3. Fat Thickening, 12/13th rib
- measured at the 3/4 point of the lateral length of the ribeye muscle from the split chine bone
4. Heart, Pelvic and Kidney Fat
- percent of the carcass weight as internal fat
31
Ribbing of BEEF
- cutting between the 12/13th rib to expose the longissimus muscle
32
Net Energy- Production
- animal output and production functions
1. Growth
2. Milk
3. Eggs
33
Protein Accretion Formula
- Accretion = synthesis - degradation
| - accretion is growth or increase
34
Endocrine
- hormone secreted by cells and transmitted via bloodstream (usually at low concentrations) to act on distant target cells
35
Barker Hypothesis, Fetal Origins of Adult Disease(FOAD), or thrifty hypothesis
- The simplest form of the hypothesis is that undernutrition impairs fetal growth
- The association between fetal growth and long-term disease outcomes is likely to be confounded by a direct
association between undernutrition and disease
1. Undernutrition in pregnancy leads to:
a. fetal growth retardation and low birth weight
b. disease in adult life
36
Energy Systems
- fecal energy losses are a major component in the variability of the availability of energy in feed
- > measure energy concentration using DE(dig energy) and TDN(total dig nut)
- In ruminants, losses of energy in gas(methane), urine and heat are significant in describing the productive value of feeds
- as a result, the common energy system in North America for growing to finishing beef cattle is measured based on NE (Net Energy)
37
Net Energy- Maintenance (NEm)
- the minimum energy expended by an animal under specific conditions such as fasting, resting and thermo-neutrality
- the minimum net energy needs
1. Service Functions (organs)
2. Cell "maintenance"
38
GH mechanism
1. GH binds GH-receptor (GHR)
- GHR expressed in liver, skeletal muscle, fat, mammary gland in cattle
- greatest level in liver
2. activates signaling pathway JAK2-STAT5
3. stimulates IGF-1 gene transcription
- IGF-1 affects protein synthesis and muscle growth
39
Lamb Wholesale cuts % of Carcass weight
1. Leg - 34% (largest)
2. Loin - 11%
3. Rack- 10% (smallest)
4. Shoulder- 26%
- total 81%
40
Insulin Actions
1. promotes storage of glucose as glycogen
2. promotes storage of fatty acids as triglycerides
3. promotes storage of amino acids as proteins
4. stimulates cellular uptake of nutrients (glucose, amino acids, lipids)
5. stimulates lipogenesis, glycogenesis, and protein synthesis
41
Fescue Toxicosis
1. Reduced cattle gains
2. Reduced fertility
- alters sperm morphology
- lower pregnancy rates
3. Vasoconstriction
- fescue foot
- rough hair coat
4. Mares
- inc gestation length
42
Anabolic compounds with progestin activity
- melengesterol acetate (MGA)
| - commonly used in feedlot heifers
43
Limiting Amino Acids for poultry in corn diet
1. Methionine
2. Lysine
3. Tryptophan
44
Paracrine
- hormone from one cell is conveyed to an adjacent cell of different type over short distances via interstitial fluid
45
Third Trimester
- most rapid time of growth and development
| - focus is fetal WEIGHT
46
Maternal undernutrition lifetime consequences on offspring
1. Organ Growth
2. primary and secondary fiber formation
3. muscle hypertrophy
4. fetal size at birth, weaning and finishing
5. postnatal growth rates
6. Increase adiposity
7. Tenderness
47
Leanness in gender
- male leanest > castrate > female
- exception is gilt (adult female swine), will stay leaner than castrate, but typically males are leaner
- at a given age, an intact male will be heavier, leaner and physiologically younger than a castrated female or male
- at a given age, a castrated male will be heavier, leaner and physiologically younger than female (except a gilt)
48
Progestin growth actions
- suppression of estrus
| - increased expression of adipogenic genes
49
Video Image Analysis (VIA)
- more utilized in swine
- don't have to cut
- estimates fat percent
- does not specify which is intramuscular fat
50
Order of nutrient partitioning priority for tissues
1. Skeletal
2. Muscle
3. Adipose
51
Ruminants- Empty Body Weight
1. Sheep and goats
- typical diet is forage (makes them more efficient)
- fill is about 5-10% of live weight
- dressing percent 54%
2. Steer
- finishing diet is high concentrate diet
- fill is about 145 lbs
- makes up 10% of live weight
- dressing percent= 58-62%
52
Anabolic compounds with androgenic activity
1. testosterone propionate (TP)
| 2. trenbolone acetate (TBA)
53
IGF-1 evidence
- milk IGF-1 concentrations vary according to stage of lactation, season and milk SCC
- dietary intake of milk IGF-1 is negligible when compared with daily whole-body production of IGF-1 in saliva and digestive secretions in humans
- no evidence that orally consumed IGF-1 is absorbed in human
54
Order of nutrient partitioning priority for various systems:
1. Nervous
2. Circulatory
3. Respiratory
4. Digestive
5. Reproduction
55
Two types of androgens
1. Testicular androgens
- testosterone
- androstenone
2. Adrenal Androgens
- 17 keto steroids
56
Market Lamb Targets and US current Avgs
- 95% choice
- 75% YG (1-3)
- ***choice*** and prime w/ YG 1-3 (desirable)
- Higher quality (no problem) and leaner carcasses
- carcass wt about 45-83 lbs
- lighter weight = higher prices
- prices highest around easter
57
What is growth influenced by?
1. Gut Fill (ruminant vs non-ruminant)
2. Diet (high forage vs high concentrate)
3. Accuracy/Precision of the scales
4. Weighing group of animals or single animal
5. Weather
58
Large framed animals vs Small framed animals maturity
- larger framed animals are leaner and physiologically less mature at same chronological age
- smaller framed animals are fatter and physiologically older at the same chronological age
59
Limiting Amino Acids for pigs in corn diet
1. Lysine
2. Tryptophan
3. Threonine
60
Progestins
- progesterone
61
Specific Gravity
- water displacement method
- weighs air and water
- uses carcass density to estimate the percent of bone, fat and lean
62
Energy in monogastrics problems
- depending on the type of fat added can affect
1. the softness of the pork fat
2. Iodine Value
- must optimize levels of added fat to minimize impacts on pork quality!
63
Weaning stress: early weaning of cattle
- sometimes used in times of drought and low forage availability
- sometimes used for first-calf heifers as a management tool
64
Metabolizable Energy (ME)
- dietary energy available for metabolism after the losses of urine and gas(methane) energy are subtracted from DE
- LIMITATIONS:
- > Urine and gas energy losses are relatively predictable from DE, therefore DE and ME are highly correlated
- ME is often used in pork and poultry ration formulas
65
Does overfeeding protein promote increased muscle growth?
- NO!
- overfeeding protein does not promote increased muscle growth bc will be metabolized for energy or excreted
- BUT IT DOES COST MORE TO THE PRODUCER AND ANIMAL
66
Issues of rbST
- possible increased use of antibiotics to treat mastitis in cows
- potential effects of rbST on expression of certain viruses in cattle
- possibility that exposure of human neonates and young children to milk from rbST-treated cows increases health risks (type-II diabetes)
67
Anabolic Implants
- combination of estrogenic and androgenic compounds
68
For meat that packers do not want in beef:
- discounts are applied to carcasses for things that the meat packer does not want
- low YG 4-5
- standard
- select (choice-select spread varies throughout the year)
69
Summary of Androgens
1. increase IGF-1
2. Increase satellite cell proliferation
3. Decreased protein degredation (linear response)
70
Two types of hormones
1. steroids
| 2. polypeptides/proteins
71
Interuterine growth restriction (IUGR)
- reduced maternal blood flow to uterus
| - limits blood flow and nutrients to the fetus
72
Safety of recombinant bST (Polisac) and pST
- have been used to increase milk production in dairy cows and lean growth in pigs
- it is considered safe, but consumer acceptance is a problem
73
Maturity in LAMBS
Age
1. Lamb - 2-12 mos
2. Yearling Mutton - 12-24 mos
3. Mutton - < 24 mos
Maturity- based on skeletal and lean maturity
1. Break Joint
- growth plate not yet ossified and breaks, red in color with intact ridges
2. Spool Joint
- growth plate is ossified and will not break
74
Energy Partitioning in Monogastrics
1. Gross Energy
- fecal energy lost
2. Digestible energy
- urine and gas energy lost
3. Metabolizable energy
- used for maintenance and production
- releases product and heat increment
75
What happens if diet has sufficient energy, but insufficient protein?
- will result in an increase of fat deposition
76
Anabolic compounds with estrogenic activity
1. estradiol 17-beta (E2)
2. estradiol benzoate (EB; 71% E2)
3. zeranol
77
Additive Response
- benefit of adding estrogen and androgen together
78
Finishing Ruminant Protein Requirements
1. Quantity and Quality are less critical
| 2. Can utilize rumen microbial protein to supplement some amino acids
79
When should a producer ESTIMATE carcass composition?
- in a live animal, so the producer is more aware of when the animal is ready for production
- use a real-time ultrasound
80
Amino Acids
- the building blocks of protein
| - 10 essential amino acids and 20 common
81
Third Trimester undernutrition affects
1. Fetal size
| 2. Muscle fiber hypertrophy
82
Insulin resistance (IR)
- physiological condition in which body tissues have a lower response to insulin
- insulin responsiveness (insulin:glucose)
- insulin sensitivity (response of tissues to insulin, takes more and more insulin to get a response)
Associated with:
- obesity
- intramuscular fat deposition, ketosis, and other metabolic disorders
- IR of the mother associated with low birth weight
83
Estrogen and protein degradation
- E2 decreases protein degradation rates at high doses
84
Gross Energy (GE)
- heat released (heat of combustion) when an organic substance is completely oxidized to carbon and water
- at water value
- > FAT highest
85
Energy intake
- is a primary determinant of productivity in all livestock species
- estimates of the availability of energy in feeds are essential to systems for describing nutrient requirements
86
BEEF Wholesale cuts % of Carcass weight
1. Round - 23%
2. Loin - 17%
3. Rib - 10% (smallest)
4. Chuck - 27% (largest)
Total- 77%
87
Second Trimester undernutrition affects
1. Secondary muscle fiber number
88
Recombinant ST (rbST)
- rbST, also known as Posilac (Monsanto), is a biosynthetic version of the naturally occurring pituitary hormone in cows
- stimulates lactation
- inc IGF-1
- need to give daily injections of protein hormone bc if consume body will digest it
- daily gain inc and huge improvement on efficiency (feed:gain lower, adipose tissue dec, bone and skin inc)
89
Gluconeogenesis
- direct net conversion to glucose, including most amino acids and propionate
- products of metabolism of glucose in tissues
90
GH and adipose growth
- increases lipolysis
| - decreases lipogenesis
91
What percent of energy ingested is used to replace muscle protein that is degraded?
- 15 to 25%
92
What percent of protein in skeletal muscle is broken down and replaced per day?
- 20 to 25%
| - especially in early life
93
Skeletal Muscle mass makes up what percent of carcass weight?
- 60%
94
First trimester undernutrition affects
1. Organ growth
| 2. Primary muscle fiber number
95
BEEF targets for marketing
- discounts >>>> premium
| - high quality grade and low yield grade number!
96
Second Trimester
- continued growth and development
| - focus is fetal LENGTH
97
Two pathways for IGF-1
1. MEK/ERIK pathway
- stimulates cell proliferation and protein stimulates protein synthesis
2. PI3K/AKT pathway
- stimulates protein synthesis (direct) and inhibits protein degradation (indirect)
- more muscle growth
98
Energy Partitioning in RUMINANTS
- energetic losses involved in digestive and metabolic processes in ruminants
1. Gross energy (GE)
- fecal energy
2. Digestible Energy (DE)
- urine energy
- methane (gas) energy
3. Metabolizable Energy (ME)
- heat increment
4 and 5.
4. Net Energy- Maintenance
5. Net Energy- Production
99
First trimester
- period of organogenesis which is MOST CRITICAL for fetal development and growth
100
Digestible Energy (DE)
- gross energy minus the fecal energy losses
- "digestible"
- LIMITATIONS:
- > overestimates the available energy in low digestible high-fiber feedstuffs (straw, hay), relative to highly digestible low fiber feedstuffs (grains)
101
Growth hormone (GH)
- somatotropin
- protein hormone
- produced by anterior pituitary
- acts in an endocrine manner to affect a number of different tissues in the body
- must be injected for activity
- increases IGF-1 to increase growth and milk production
- reduces lipogenesis and stimulates lipolysis
102
Type-II diabetes evidence
- no change in macro- or microcomposition of milk with rbST
- given very low concentration of IGF-1 in milk that little to no IGF-1 is absorbed
- > IGF-1 in milk would not cause hypoglycemia effects
103
Grades of pork carcasses
- grades of gilt and barrow based on 2 factors
1. Quality
2. Expected yield of 4 lean cuts
* ribbed at 10/11th rib
104
GH functions
- stimulates growth, lipolysis, milk production, and expression of IGF-1 gene
- recombinant bST and pST have been used to increase milk production in dairy cows and lean growth in pigs
- mechanism not fully understood
- role of locally produced IGF-1 and liver-derived circulating IGF-1
- believe that both play a role in GH stimulated tissue growth
105
What is Growth?
- an animal getting larger
- change in live weight
- measured with scales
106
Glucagon Actions
1. mobilizes glucose by increasing glycogenolysis
2. mobilizes fatty acids by increasing lipolysis
3. increases amino acid catabolism
107
Carcass Composition
1. Chemical Composition
- proximate chemical composition is proteins, lipids, water and fats
- can use chemical composition to give us an idea of the percent of muscle vs fat
2. Physical Composition
- muscle, bone and fat
- specific primal and sub-primal cuts
- can take specific muscle and fat depots weights
108
Net energy systems in ruminants
- maintenance and growth
- protein turnover is very important in maintenance and growth
- to get growth and body weight gain need more energy than maintenance (cost)
109
How does your body use amino acids as building blocks?
- amino acids -> peptides -> proteins
110
Heat stress effect on energy in monogastrics(pigs)
- reduce energy intake
- reduce body weight gain and growth performance
- Management of heat stress:
- > increase energy density of the ration by adding fat to maintain the energy intake (inc BW gain)
111
Growth curve
- sigmoidal curve
- before and after birth is slow growth
- rapid, increase very efficient growth period
- levels off as reaches maturity
112
Factors Determining fat-free lean (Pork)
1. Hot Carcass Weight
2. 10th Loin eye area (LEA)
3. 10th Rib Fat Thickness (FT)
113
Autocrine
- hormone from one cell acts on itself or on neighboring cells of the same type
114
Compensatory growth
- high rates of growth after a period of nutrient restriction
- "catch-up growth"
- body weights may catch up to others whose growth was never compromised
- go from restricted feeding back to ad libidum to inc growth rate faster
115
Crude protein levels for growing animals
- higher requirement for younger animals with larger skeletal muscle growth
116
Market Values
1. Steer-highest
2. Lamb
3. Hog -cheapest
117
Estrogen actions on growth
- stimulates epiphyseal closure via influences on chondrocyte proliferation and bone formation
- stimulates muscle growth
1. increases proliferation on satellite cells
2. increases protein synthesis
3. decreases protein degradation (at high levels)
- increases IGF-1 levels
118
Monogastric- Empty Body Weight
- pigs are monogastric (non-ruminant)
- finishing diet is typically corn and soybeans
- fill is about 7.6 lbs, which is 2.6% of live weight
- dressing percent 74%
119
Major Points along growth curve
1. Conception
2. Birth
3. Self-accelerating
4. Inflection point or puberty
5. Self-retarding phase
6. Maturity
120
What happens if diet has excess protein?
- protein will be metabolized to energy or excreted
121
How can we fix gut fill influence when weighing animals live weight?
1. Fasted State
- fast animal overnight and take weight before feeding
- take two weight two consecutive days and average the two weights
2. Take Empty Stomach Body Weight
122
Fetal programming
- Receiving a lot of attention now in Animal Science
| - Much to learn about how maternal nutrition alters subsequent growth of the animal
123
Neurocrine
- hormone is synthesized in a cell body of a neuron but secreted into bloodstream to act on relatively distant target cells
124
Maturity in BEEF
- estimate the chronological age of an animal
| - assess the physiological stage of maturity of the skeletal and lean in carcass
125
Glycogenolysis
- breakdown of glycogen for glucose
126
Quality Grade in BEEF
- indicator of eating quality
| - Prime, Choice, Select, Standard, Commercial, Utility, Cutter, Canner (8)
127
What was the significance of the Dutch Hunger winter/Dutch Famine
- unplanned human health experiment
- discovered what affects malnutrition of mother can have on fetal growth
- the children born to these mothers experienced significant problems
1. Low birth weight for gestational age
2. Died at a higher rate, than people born before or after this time
- 10% inc in mortality after 68 years
3. Metabolic Diseases
128
Skeletal Muscle Composition
1. Protein
2. Water (75%)
3. Lipid
129
9 Degrees of Marbling from Highest to Lowest
1. Abundant
2. Moderately Abundant
3. Slightly Abundant
4. Moderate
5. Modest
* 6. Small = choice
* 7. Slight = select
8. Traces
9. Practically Devoid
130
Restricted feeding
- feed intake is restricted to 85-95% of ad libidum intake
- can reduce excess fat deposition without altering muscle growth
- major restriction on intakes (<75%) reduces both muscle and fat growth
131
For meat that packers do want in beef
- sell at premium prices
- prime
- CAB
- choice
- YG of 1-2
132
Estrogen and protein synthesis
- E2 increases protein synthesis
133
GH and bone growth
- mediated by IGF-1
- increases chondrocyte proliferation and osteoblast activity
- increases bone length
134
Summary of estrogens
1. increase IGF-1
2. Increase satellite cell proliferation
3. increased protein synthesis (linear response)
135
Beef Quality Grade
1. Sex Class Determination
- steer, heifer, bullock, bull and cow
2. Maturity
- skeletal and lean maturity
3. Marbling
- distribution and accommodation of intramuscular fat within the longissimus muscle
4. Lean Firmness, Color, and Texture
- absence of dark cutting condition
136
Net Energy (NE)
- net quantity of energy recovered in an animal product
- 2 Major Advantages
1. Animal requirements stated as net energy are INDEPENDENT of diet
2. Feed requirements for maintenance are estimated separately from feed needed for productive functions
137
Critical transitions in postnatal growth after birth
- during late stages of gestation, glycogen and triglycerides are deposited in the fetus
- increased metabolism for survival
- utilization of brown fat for heat production
- utilization of glycogen in liver and muscle
138
Nutrients in the bloodstream distribution
- most important for mother brain and CNS to get nutrients, as well as the placenta/fetus
- if nutrient deficient, mother will sacrifice distribution of nutrients to bone, muscle and fat to protect these two functions first
- does this in order to survive and keep pregnancy
139
TBA and protein synthesis
- TBA increases protein synthesis rates at higher doses
140
How do we measure weight with the carcass?
1. Hot Carcass weight(HCW)
- weight taken while the carcass is hot (before it is chilled)
2. Cold Carcass Weight
- weight taken after the carcass has cooled
- usually see a shrink in about 3-5% bc water evaporates in the first 24hrs
3. Dressing Percent= (HCW/LW) x 100
141
Increasing energy in Ruminants
- adjust roughage (forage) and concentrate diet ratios
- Feedlot finishing steers need
1. low roughage diets
2. high concentrates to increase energy content
142
Buttons
- cartilaginous ends of thoracic vertebrae
- with age ossifies, from center of the bone out
- evaluate the top 3 buttons anterior to the 12th rib
143
Market Hog Target
- 74% dressing percentage
| - want lean and heavy muscled carcasses
144
Thyroid hormones
- thyroxine (T4) and triiodothyronine (T3)
- synthesized by follicular cells of the thyroid and stored in their lumens
- regulate metabolism, growth, and development
- potentiate insulin action on carbohydrate metabolism
- T4 and T3 decrease w restriction, but then returned to normal levels
145
The thrifty phenotype hypothesis
- Exposure of the developing organism to a low plane of nutrition promotes metabolic thrift in order to
ensure survival, live off small amounts of food
- In a postnatal environment in which nutrients are in short supply this metabolic thrift continues to be a survival trait
- but if nutrients are present in excess (nutrient-rich) the thrifty trait will promote the metabolic syndrome and obesity bc helps save adipose fat
146
Growth in terms of energy Formula
- Growth = (total energy - maintenance)
| - maintenance is a cost bc replacing turnover each day
147
Duel-energy x-ray absorptiometry (DEXA)
- uses 2 x-ray beams at different energy levels to determine total body fat, bone mass and total muscle in the body
- can scan a carcass under 2 minutes
- tells us total body fat, but does not clarify what is SQ and what is intramuscular fat!
- MAGGIE (TA) did a study with this
148
What happened during the Dutch Famine
- also called the Dutch Hunger Winter
- German occupied a part of the Netherlands after WW2
- Germans placed embargo on all food transports to western netherlands
- even after the ban was lifted, could not get food supply in bc winter came early and was harsh
- the canal had froze over
- Food rations declined steadily over
the course of several months
- In April, Germans gave permission for Allied planes to
drop food
- Affected approximately 4.5 million people and killed
upwards of 22,000
149
Overall for ruminants, what is important in terms of protein regulation during growth?
- CP levels are lower
| - microbial protein and can utilize NPN sources
150
TBA and growth
1. increases satellite cell proliferation
2. reduced protein degradation rate
- linear response
3. increases protein synthesis rates
- high doses
151
Importance of coordination of insulin and glucagon
- key to integration of metabolism
152
Energy Level of the diet alters growth rate
1. Higher plane of energy = faster growth
2. Energy Restriction = decrease protein growth
3. Increased energy density = increased growth, greater fat deposition
153
Energy requirements in Monogastrics
- increase energy density of the ration by adding fat!
- inc efficiency
- especially during time of heat stress!
154
Choice-Select Spread
- differential between choice and select quality grades
- if choice carcasses are abundant, spread is low
- if choice carcasses are low, spread is abundant
- changes on a daily basis, it is based on the supply of choice carcasses in the marketplace
155
Monogastrics Protein Requirements
- quality and quantity are very important
1. Meet amount of amino acids for that specific type and stage of growth
2. Meet amount of protein requirement
3. Need higher levels of protein in younger animals with higher skeletal muscle growth
156
Ruminant Protein requirements
1. Quantity and quality is less important
2. Can utilize rumen microbial protein to satisfy some amino acids
3. Can Utilize Non-protein Nitrogen Sources (NPN)
- 1 and 2 for finishing ruminants
157
Nutrient restriction (NR) in sheep
- 50% of nutrient restriction from d 28 to 78 of gestation (2nd trimester)
- controls get 100% of NRC requirements
- showed a major reduction in the secondary fiber development
158
Lamb Grading
1. Quality Grade
- sex determination
- maturity
- flank streaking (nine degrees of marbling)
- conformation (expression of muscle)
2. Yield Grade
- fat thickness
* ribbed btw 12/13th rib
159
Program feeding
- use net energy equations to calculate quantity of feed needed to achieve a specific rate of gain
Benefits
1. Improve feed efficiency
2. May reduce excess backfat deposition
Negatives
- quality grade lower than ad libidum fed animals
160
Common example of a maternal undernutrition
- runt pig
- will be sig lower in body weight than litter mates bc did not get a sufficient share of nutrients
- all body organs will be smaller, except the brain
161
Overall for monogastrics, what is important in terms of protein regulation during growth?
- both quantity and quality
| - CP and amino acid levels must be at required levels for muscle growth
162
Yield Grade in BEEF
- predictor of carcass cutability
- numerical score from 1-5 that represents the percent of boneless, closely trimmed cuts from the 4 wholesale cuts
- highest cutability 1 and lowest is 5
163
Amino Acid requirements in growing pigs
- first limiting amino acid in corn-soybean meal diet is Lysine
- must supplement synthetically or adjust protein level in diet to meet requirement
