Chapter 16: Beef Cattle Flashcards
1
Q
Class
A
Mammalia
2
Q
Order
A
Artiodactyla
3
Q
Family
A
Bovidae
4
Q
Subfamily
A
Bovinae
5
Q
Genus
A
Bos
6
Q
Species
A
Bos indicus and Bos taurus
7
Q
Bos indicus
A
- heat resistant
- droopy ears, thin skin w/ folds to release heat
- parasite resistant
- hump on back
- origins from Indian subcontinent and Africa
- Zebu, Brahman
8
Q
Bos taurus
A
- cooler climates; European breeds
- Black Angus, Limousin, Charolais, Belgian Blue, Hereford, Longhorns
- 70 breeds of cattle?
9
Q
Black Baldy
A
- hybrid
- Bos taurus x Bos taurus
- Angus x Hereford
10
Q
Braford
A
- Bos indicus x Bos taurus
- Brahman x Hereford
11
Q
Brangus
A
- Bos indicus x Bos taurus
- Brahman x Angus
- mostly classified as Bos taurus bcs Bos indicus in him is very diluted; greater percentage of Bos taurus blood
12
Q
Crossbred Advantages
A
- heat and parasite resistant
- muscled, more milk production, growth
- hybrid vigor: extra boost in performance in mixed breeds
13
Q
Number of Chromosomes
A
- 60 chromosomes (30 pairs)
14
Q
Cattle Domestication
A
- 6500 BC
- domesticated in Asia and Europe
15
Q
Bull
A
- male bovine
16
Q
Cow
A
- mature female bovine
17
Q
Castrated Male
A
- steer (pre-puberty castration), stag (post-puberty castration)
18
Q
Heifer
A
- young female before first calving
19
Q
Calf
A
- bovine < 1yr old
20
Q
Springer
A
- pregnant female
21
Q
Parturition (Calving)
A
- process of giving birth
22
Q
Beef Cattle Production
A
- China: largest cattle producer
- Brazil and India: 2nd largest, tho India not as much for beef
- US: 90M heads of beef
- US: 20% global beef supply
- US: avg person consumes 20 kg beef/yr
- Hong Kong: 50 kg/person/yr
- consumption linked to changing economic conditions
- US has 10M cattle in feedlots at any time (half in TX, some in NE, some in KS
- 33M cow-calf ops: 5M in TX, 2.5M in CA, 2M in MO
- US exports to lots of countries (like Japan, who doesn’t have a lot of ag)
23
Q
Cattle Dentition Formula
A
- 0/4, 0/0, 3/3, 3/3
- same as sheep
- they have dental pads too
24
Q
Timing Between Each Incisor Pair
A
- one year apart
- 1st pair at 1.5-2 years
- 4th pair at 4.5 years
- by 5th year, full mouth
- by 6 years, 1st pair starts to deteriorate, and so on until 9th year
- a lot of cows live until 20, so they keep teeth
25
Dentition Uses
- to estimate age
- to make sure they have healthy dentition for pasture/grazing/feed they'll be on
26
Puberty
- more dependent on bodyweight than age (for any animal; could also be seasonal, but not for cows)
- 300 kg
- 8-18 mo
27
Cotyledonary Placenta
- just like sheep
- caruncle on mom's side and cotyledon on fetus's side
28
Polyestrous
- will cycle throughout the year
- we want them to calve in the spring for more available food (like sheep)
29
Freemartin
- refers to female in twin calves (one male, one female)
- female is infertile (reproductive tract not fully developed, udder not fully developed)
- caused by male releasing testosterone into circulation, which causes sister to be masculinized
- externally normal, but cannot reproduce
- distance between vulva and anus is distorted, and if inserting into the vulva, dead end reached
30
Gestation Period
- 283 days (almost 9 mo)
- longer than sheep (5 mo)
- longer generational length than sheep
- takes longer to shift phenotype through selection w/ animals w/ longer gestation
31
AI Advantages
- can selectively breed w/ semen from bulls around the world
- brings in outside genetics for gene pool diversity to avoid inbreeding
- management control over selective breeding and when the event happens
- safety for humans from bull
- disease control in terms of preventing bull from infecting cows w/ STDs especially
- can get sexed semen to choose for female (especially in dairy, not as much in beef) --> done by weighing spermatozoa for different weight of Y chromosome
- 1 bull can give hundreds or thousands of straws of ejaculate vs. only being able to service 30-50 in person
- can have long-term storage of semen
- not all farms need to pay for bull upkeep
32
AI Disadvantages
- relies on humans to tell when cow is in heat/when heat began
- natural breeding/service has more success at impregnating cows
33
Clean-Up Bull
- females that aren't impregnated by AI come back into heat
- cleanup bulls provide natural service and impregnate females to avoid loss of money in that production facility
- females that aren't pregnant are losing money
34
Dystocia
- difficult birth
- especially with crossbreeding
- Brahman x Angus
- Brahman calves are much bigger than Angus calves
- results in greater risk of calf and mother death
- need to supervise births more in cases where this is predicted
34
Estrous Cycle
- 21 days
35
Newborn Calf
- 35 kg
- born on a range w/out humans or w/ supervision
- cows generally do fine giving birth without human assistance
- average 1 calf per cow
36
Colostrum
- first milk accumulated in mammary gland in last weeks before birth
- full of antibodies that give immunity against pathogens, viruses, and bacteria
- ruminants especially depend on antibodies from mom to get their own immunity, and these have to come from colostrum
37
Colostrum Inside the Calf
- bypasses rumen via reticular/esophageal groove
- goes into abomasum then small intestine
- small intestine is leaky and allows antibodies to enter blood supply of newborn
- these antibodies are there for the rest of the animal's life
- small intestine seals up 24 hours after birth, so colostrum MUST be given to newborn ASAP after birth
- otherwise, antibodies won't enter newborn's blood supply
38
Passive Transfer/Immunity
- antibodies from mum to newborn through colostrum
- antibodies that come from mum are especially important because they reflect the same environment that calf is born into
- calf is exposed to same pathogens, viruses, bacteria that mum has immunity against
39
Wallaroo
- mix between kangaroo and wallaby that can kill you or dogs
40
Beef Calves
- 35 kg
- raised w/ moms and milk for 6 mo
- weaning weight of 200 kg
- cow-calf op --> stocker --> feedlot
41
Seedstock Breeder
- nucleus population
- females and bulls w/ best genetics
- F1 offspring/population/progeny go into feedlot operation from stocker (grass) operation
42
Sire
- father
43
Dam
- mother
44
Cow-Calf Operations
- in CA and MO
- places w/ good rangeland and feed that can match lactation cycles to raise calves
45
Feedlot Locations
- TX, OK, NB (Nebraska)
46
Feedlot
- animals in confinement
- also called CAFO: confined animal feeding operation
- optimal feed for maximum ADG
- specific diets based on what goal you need them to achieve, based on sex, based on body composition
47
Feedlot Advantages
- optimize, maximize, specialize feed diets
- close observation
- easier access to utilities and feedstuffs (one of the main inputs into these ops is feed)
- high stocking density (number of animals per unit land); more efficient
- consistency, balanced inputs (keeping similar-sized animals together; all steers together, etc.)
48
Hormonal Growth Promotants (HGP)
- slow-release hormones that promote growth
- progesterone and estrogen to steers
- testosterone, MGA to heifers
- makes animals more efficient per pound of feed
- Europe is strict about HGPs, so stuff from US has to be HGP-free before being exported to Europe
- public and government concerns about health and safety, but hormone traces are gone by the time the animals are slaughtered; no residual HGPs in the meat
- also, needs to be small amounts of hormones so that disruptive mounting behaviors etc. are not exhibited and interrupt feeding
49
MGA
- given to heifers as one of the HGPs
- suppresses estrous cycle
- no lordosis, focus on eating, which enhances animal growth
50
Time Spent in Feedlot Op
- 120 days
- ADG of multiple kgs per day
51
Feed Efficiency
- amount of gain relative to the amount fed (G:F)
- feed efficiency = (kg of bodyweight) / (kg of feed)
52
Veal
- beef raised on milk diet
- calves will be kept back, intensively raised, and fed milk
- lower iron in the diet results in paler meat
- considered a delicacy, but not super common to produce in the US
53
Feeding
- match body composition to feed
54
Rumen Development in Calves
- rumen development as transition occurs from milk to plant-based diet
- calves go for/are fed roughage, which stimulates development of rumen papillae
- developed papillae are needed for the rumen walls to be able to transport VFAs into circulation of calf
55
Skeletal/Bone Development of Calf
- requires a lot of energy, calcium, and phosphorus
- milk is high in Ca and P
- milk is designed to meet reqs for bone growth
- also need a lot of proteins
56
Muscle Development in Calves
- muscle is particularly rich in protein
- "microbial protein" when microbes die and are digested by abomasum; those AAs are used to make new muscle
57
Fat in Feedlot Stage
- need to deposit adipose/fat in feedlot stage
- higher level of energy: corn, soybeans, high-quality alfalfa
58
Ad Libitum in Feedlot Stage
- unlimited access to food in feedlots
59
Feed Conversion Ratio (FCR)
- efficiency
- (kg of gain) / (kg of feed)
60
Rumen Modifiers
- can use chemicals to change chemistry of rumen/species of microbes
61
Monensin
- chemical that kills protozoa in the rumen, which are not as efficient as bacteria in making VFAs
62
Methane Inhibitors
- introduce feedstuffs and/or chemicals that target methane production
- types of seaweed have been found to inhibit methane production
63
Feeding More Grain in Feedlots
- run the risk of making rumen too acidic
- grain is really fermentable
- acetate increases when there's a high level of hay/grass
- propionate increases when there's a high level of grain
- causes a drop in the pH and an excessively acidic environment
64
Acidosis
- excessively acidic environment in the rumen
- to prevent/stop acidosis, you need to feed a buffer substance to avoid pH changes
- normal rumen pH is roughly neutral
65
Feedlot
- modifying body composition
- muscle (main component), fat, bone, and connective tissues are in meat
66
Connective Tissues
- cell types that keep things together
- the cells that connect muscle to bone; cartilage
67
Muscle
- 70% water
- 15-20% protein
- 2-12% fat
- < 1% ash/minerals
68
Ash
- minerals
- when meat is dried to DM, then DM is burned, the other elements leave as carbon dioxide or water vapor
- ash that remains is the mineral content of the meat/muscle
69
Myocyte
- muscle cell
- myocytes have myofilaments
- myofilaments have a structure of molecules that are like little zippers
- these are the main proteins in muscles: myosin and actin
- myosin and actin move across each other and let muscle fiber contract or not
70
Muscle is High in Protein
- when we eat meat, we're consuming myosin and actin at molecular level
- they're made up of AAs that came from the animal's feed or from the microbial protein in the animal that make new myosin and actin in the muscle
71
Myology
- study of muscle biology
72
Belgian Blue
- appearance caused by 2x as much myosin as a regular animal
