Chapter 16: Beef Cattle Flashcards

Question

Dentition Uses

Answer 1

- to estimate age - to make sure they have healthy dentition for pasture/grazing/feed they'll be on

Answer 2

- more dependent on bodyweight than age (for any animal; could also be seasonal, but not for cows) - 300 kg - 8-18 mo

Answer 3

- just like sheep - caruncle on mom's side and cotyledon on fetus's side

Answer 4

- will cycle throughout the year - we want them to calve in the spring for more available food (like sheep)

Answer 5

- 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

Answer 6

- 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

Answer 7

- 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

Answer 8

- relies on humans to tell when cow is in heat/when heat began - natural breeding/service has more success at impregnating cows

Answer 9

- 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

Answer 10

- 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

Answer 11

- 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

Answer 12

- 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

Answer 13

- 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

Answer 14

- 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

Answer 15

- mix between kangaroo and wallaby that can kill you or dogs

Answer 16

- 35 kg - raised w/ moms and milk for 6 mo - weaning weight of 200 kg - cow-calf op --> stocker --> feedlot

Answer 17

- nucleus population - females and bulls w/ best genetics - F1 offspring/population/progeny go into feedlot operation from stocker (grass) operation

Answer 18

- in CA and MO - places w/ good rangeland and feed that can match lactation cycles to raise calves

Answer 19

- TX, OK, NB (Nebraska)

Answer 20

- 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

Answer 21

- 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.)

Answer 22

- 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

Answer 23

- given to heifers as one of the HGPs - suppresses estrous cycle - no lordosis, focus on eating, which enhances animal growth

Answer 24

- 120 days - ADG of multiple kgs per day

Answer 25

- amount of gain relative to the amount fed (G:F) - feed efficiency = (kg of bodyweight) / (kg of feed)

Answer 26

- 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

Answer 27

- match body composition to feed

Answer 28

- 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

Answer 29

- 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

Answer 30

- muscle is particularly rich in protein - "microbial protein" when microbes die and are digested by abomasum; those AAs are used to make new muscle

Answer 31

- need to deposit adipose/fat in feedlot stage - higher level of energy: corn, soybeans, high-quality alfalfa

Answer 32

- unlimited access to food in feedlots

Answer 33

- efficiency - (kg of gain) / (kg of feed)

Answer 34

- can use chemicals to change chemistry of rumen/species of microbes

Answer 35

- chemical that kills protozoa in the rumen, which are not as efficient as bacteria in making VFAs

Answer 36

- introduce feedstuffs and/or chemicals that target methane production - types of seaweed have been found to inhibit methane production

Answer 37

- 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

Answer 38

- 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

Answer 39

- modifying body composition - muscle (main component), fat, bone, and connective tissues are in meat

Answer 40

- cell types that keep things together - the cells that connect muscle to bone; cartilage

Answer 41

- 70% water - 15-20% protein - 2-12% fat - < 1% ash/minerals

Answer 42

- 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

Answer 43

- 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

Answer 44

- 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

Answer 45

- study of muscle biology

Answer 46

- appearance caused by 2x as much myosin as a regular animal

Chapter 16: Beef Cattle Flashcards

(73 cards)