ANSC 240 Exam 1

what are the grand challenges of animal agriculture/production?

Environment

Well-being

Climate

Disease

Limited resources

Competing uses

how have the quantities of most meat animals changed over time?

remained approximately the same

how has the quantity of broiler chickens changed over time?

massive increase

why the massive increase in number of broiler chickens?

they are cheap

how has egg production changed over time?

65% increase

why the large increase in egg production?

the demand is higher; people used to not have to buy as many eggs because they had their own chickens

how has the poultry pounds to meat ratio changed over time?

increased

what is F:G?

feed to gain ratio

what is ADG?

average daily gain

do you want a high or low ADG?

high

do you want a high or low F:G?

low

how has the ratio of animals to product changes over time?

lower inventory of animals, higher output in pounds

which species have experienced a less drastic change in the ratio of animals to product?

lamb and beef

which species have experienced the massive change in the ratio of animals to product?

poultry, pork, and milk

what is consolidation?

Fewer operations with more animals

what have housing system innovations led to?

Greater control of animal environment and less disease challenged=body puts resources towards growth

what species is vertical integration not very effective/successful?

beef and sheep

what industry structure has been very effective/successful in most productions?

vertical integration

what is horizontal integration?

each step is done by a separate company(approximately)

what is the downside to horizontal integration?

each step has to be paid

what is vertical integration?

whole process done by one company(approximately)

what is the benefit of vertical integration?

there only has to be overall profit, not each step

how are we getting these greater efficiencies from the animals themselves?

genetics

how are we getting these greater efficiencies from inputs?

environments, modified and new feed sources, preventative and enhancing pharmaceuticals

how are we getting these greater efficiencies from the outputs?

higher demand from consumers, policy makers, and international markets

how has the diversity of products changed over time?

Used to be just chicken parts, now there are chicken strips, nuggets, rolls, etc. convenience items!

why don’t we have things like beef nuggets?

Beef and pork physiology doesn’t lend itself to products like chicken does

what species are allowed hormones?

only cattle

is the image of the skinny to fat chickens false?

no, the images are correct but the reasoning is often false

what is the most common kind of growth curve?

cumulative

how is the cumulative growth curve broken up?

into tissue growth curves(muscle, fat, bone)

what are the three tissue growth curves?

muscle, fat, and bone

what is majority of an animal’s weight made up of?

muscle, particularly skeletal

what is a frame score?

how much space an animal’s skeleton takes up

what happens to the tissue growth curves once the frame score is established?

the bone curve flattens out

what is the law of developmental direction?

tissue is deposited in an anterior to posterior pattern

where is more fat found in an animal: near head or tail?

head

what measurements of body composition can be measured with a tape measure?

length, height, girth, volume

is weight the same as size?

no

how many phases of growth are there usually?

four

Length of each growth phase and what the end phase is varies greatly by what?

species

is early developed fat important?

very, even though it is limited

what phase of growth has the steepest slope?

two

when is phase 1?

Shortly after birth until early weaning

what growth phase is characterized by growth of head, neck, and legs(skeletal growth and organ growth)?

one

how much total growth is complete at the end of phase one?

15-20%

how much total growth is complete at the end of phase two?

75%

how much total growth is complete at the end of phase three?

80-90%

how much total growth is complete at the end of phase four?

90-95%

what growth phase does this look like?

organs=very active

Bone and muscle=active

fat=very limited

one

what growth phase does this look like?

organs=approaching maturity

bone=begins to slow

muscle=very active

fat=begins to increase

two

what growth phase does this look like?

organs=mature

bone=mature

muscle=very active

fat=very active

three

what growth phase does this look like?

muscle=slows

fat=active

four

what growth phase results in an increase in body length?

two

what is phase two also called?

growing phase

what is phase three also called?

finishing phase

what phase is characterized by deepening and thickening of body?

three

what is the depth of the body?

distance from back to belly

what species are done after phase three?

poultry and sheep

what kind of animal is not done after phase three?

breeding

what is a phase four animal called?

finished or brood

what phase of growth is characterized by increase in loin, hindquarters, depth, and thickness?

four

which phase is characterized by a major increase in fat weight?

four

what phase is the least efficient phase?

four

what impacts the growth curves of an animal?

genetics and environment

what aspects of genetics impact an animal’s growth curve?

individual animal variation, breeds(terminal vs maternal), and specific genes

what aspects of environment impact an animal’s growth curve?

housing, nutrition, and management

what are terminal breeds selected for?

growth rates(ADG, F:G), and carcass composition(muscle, fat)

what are maternal breeds selected for?

reproduction/breeding(conception rate, small birth weights, parturition ease), weaning weight(want high), and litter size/survivability

what is the first step in the cycle of breeding programs?

Defining breeding goals

what is an example of a breeding goal in the cycle of breeding programs?

early 2000s didn’t want ‘fat’

what is the second step in the cycle of breeding programs?

identify animals with desirable traits

how do you identify animals with desirable traits for a breeding program?

choose the animals at the far right of a bell curve

what is the third step in the cycle of breeding programs?

utilize selected animals

what is the fourth step in the cycle of breeding programs?

evaluate offspring for response

why may the offspring not always portray a response to a breeding program?

Some selection traits are more heritable than others

what happens after evaluating the offspring of a breeding program?

repeat the cycle

what are the three categories for defining breeding goals?

reproduction, health, and production traits

what kind of traits are the most heritable?

carcass

why are F:G and ADG not as easy to evaluate heritability?

different feed compositions

what species is immunocompetence a breeding goal focus?

pigs

what are EPDs?

expected progeny differences

what species are EPDs still used lots?

beef

what is performance data in EPDs?

data od the animal itself

what is progeny data in EPDs?

data of offspring

what are the kinds of data in EPDs?

performance, progeny, and pedigree

what are pedigree relationships in EPDs?

data of relatives

what are the downsides to EPDs?

can only compare within a breed, accuracy is skewed by animal’s age, and slower

what does this EPD mean?

BW=2.2

on average, offspring from that bull will have a birth weight 2.2 pounds heavier than the average from that breed

what does this EPD mean?

Marb= -0.21

means calves from that bull will have 0.21 less marbling than others

what are GE-EPDs?

genomic-enhanced EPDs

where are GE-EPDs used more?

dairy

what are the major factors of genomic selection?

accuracy of selection, selection intensity, genetic variation, and generation interval

is genomic selection more or less reliable than parent averages?

more

how quickly are genomically tested cattle sires ready?

a year

how quickly are EPD tested cattle sires ready?

4-5 years

what is the smallest tier of the genetic animal stock pyramid?

elite stock/seed stock

what is the largest tier of the genetic animal stock pyramid?

commercial stock

what are the tiers of the genetic animal stock pyramid from largest to smallest?

commercial, parent, grand parent, grade grand parent, elite/seed

definition: Mathematical average of all terms everywhere

mean/true mean