(1) appraisal of market animals

what knowledge do we use to evaluate market animals?

relative merit and market situation

what is market situation?

population of cattle (supply), import availability, drought (forces to sell cattle when u don’t wanna, decreases $)

what is relative merit determined by?

age, weight, sex, fatness, and muscling

what factor affects relative merit?

age

what happens to tenderness as animals age?

they become less tender due to collagen

what happens to flavor as animals age?

they become more flavorful (stronger/deeper flavor)

what happens to lean color as animals age?

they become darker in lean color due to myoglobin, less affinity for O2 to bind

what happens to fat color as animals age?

it becomes yellow, which could be associated with grass-fed animals

what happens to animals health as they age?

they are more likely to be diseased with weaker auto-immune systems

as animals age increases they become fatter or skinnier?

fatter

not all species are affected…

equally

comparative effects of age on market value by species is what ratio?

old:young ratio

effects of age formula

old young value/young animal value x 100

what animals are the least impacted in terms of old:young ratios?

swine

what animals are the most impacted in terms of old:young ratios?

sheep due to negative effects of increasing age on the value of older animals

what are problems associated with beef regarding old:young ratio?

less tender, more intense in flavor, darker lean color, and yellow fat color

what are problems associated with swine regarding old:young ratio?

fatterr

what are problems associated with sheep regarding old:young ratio?

undesirable flavor and higher condemnation rate due to higher incidence of disease

as animals increase in weight carcasses become…

fatter

as animals increase in weight retail cuts become…

larger

why do discounts exist for heavy beef carcasses?

consumers object to both fatness and excessively large (too costly/unit serving) cuts

sexes differ in:

dressing percentages, carcass proportions, cutability, palatability, and acceptability

sexes differ in those things because of ?

age at marketing vs age at puberty

beef age at marketing

18 months

beef age at puberty

12 months

swine age at marketing

7 months

swine age at puberty

7 months

sheep age at marketing

8 months (spring lamb) 14 months (old crop lamb)

sheep age at puberty

8 months

T/F: heifers have higher dressing percentages than steers bc they’re fatter

F

beef dressing percentage

decrease 4-10%. heifers due to pregnancy; bulls due to heavier hides and heads and less fat

beef carcass proportions

chuck +2% in bulls due to crest development; flank +2% in heifers due to udder fat deposition

beef cutability ranking

bullock (less fat bc of testosterone) > steer > heifer; due to hormonal differences

beef palatability

bullock (tenderness problem)

swine dressing percentage, carcass proportions, and acceptability

no effect

swine cutability ranking

boar > gilt > barrow; due to puberty

swine palatability

boar (flavor problem— boar odor)

sheep dressing percentage

decrease 4-10% in old crop lambs. same general reasons as for beef

sheep carcass proportions

shoulder +3% in old crop rams due to development of secondary sexual characteristics

sheep cutability ranking

ram > wether > ewe

sheep palatability

ram (flavor problem)

sheep acceptability

ewes may have class designation of “Yearling Mutton” bc of earlier maturity

what’s the net effects of intact males and females vs castrated males of species?

intact males and females are usually priced lower

fatness contributes:

firmness & appearance to cuts, retards cooler shrink, retards cooking shrink, and contributes palatability

fat is deposited in what sequence?

mesenteric, kidney, intermuscular, subcutaneous, intramuscular

mesenteric, kidney and intermuscular, contribute little to…

firmness and appearance, retarding shrink and palatability, but subcutaneous and intramuscular fat do

correlation of subcutaneous fat to marbling is

.24 explaining abt 58% of the variation

bc of relationship bw red (Type I) vs white (Type IIB) muscle fibers and fatness-muscling, it’s difficult to select for?

very muscular animals that marble

breeds w/superior ability to deposit marbling

Duroc, Southdown, and Angus

breeds with inferior ability to deposit marbling

Yorkshire, Merino, and Limousin

predominantly red (Type I) fibers

Angus, Jersey, Longhorn, Shorthorn

predominantly white (Type IIB) fibers

Charolais, Limousin, Maine Anjou, Gelbvieh

what does marbling play an important role in?

price of beef

a large portion of price of beef deals with what?

supply and demand

small changes in what can have a great impact on the price of beef subprimals?

intramuscular fat

growth gradients for muscling

starts at extremities (forelimbs and hindlimbs), moves upward (chuck and round), progresses forward from rump and backward from withers, meets at rib-loin juncture

what is the 1st theory of 3 regarding muscling and responses?

with increased length of loin and rib sections, the flank and plate sections are longer too; no net effect from a percentage standpoint

what is the 2nd theory of 3 regarding muscling and responses?

muscles grow in concert, so as you select for increased muscle in the round, muscles in the chuck will also increase

expensive muscle group makes up what percent of total muscle weight of cattle of very diff shapes and appearance?

56%

what is the 3rd theory of 3 regarding muscling and responses?

muscle is always present in constant ratio and proportion to bone (false)

thinly muscled muscle:bone ratio

2.5:1

normally muscled muscle:bone ratio

3.5:1

thickly muscled muscle:bone ratio

4.5:1

double muscled muscle:bone ratio

5.5 to 8.5:1

leanness

ratio of total muscle to total fat

muscling

ratio of total muscle to total bone

meatiness

ratio of total muscle plus “acceptable” fat to total bone plus “trimmable” fat