Carcass quality, leather and wool quality Flashcards
What is carcass quality?
It’s not the same as meat quality
Assesment of different traits of a carcass right before or after slaughter
Payment to producers is based on carcass quality and not meat quality
What are measures of carcass quality?
Category
Cattle: age, gender
pigs: ready-to-slaughter, sows
Carcass weight
Warm, weighed max. 60 min postmortem
Fatness
Subjective (cattle/sheep) and objective (pigs) measurements
Dressing percentage
Carcass weight as % of live weight
Lean proportion
Subjective (cattle/sheep) and objective (pigs) measurements
CH-TAX, EUROP categorization for cattle
Dressing percentage
Carcass weight as % of live weight
Dressing percentage
Carcass weight as % of live weight
Not so important for payment or carcass quality but useful information for the farmer
Example: high fiber diet for pigs led to a greater weight of intestines -> lower carcass weight
Lean proportion
Subjective classification in cattle & lambs
- based on CH-TAX in Switzerland
- EUROP system in EU
- “Neutral judging”
Objective classification in pigs using Autofom
Measurements of fatness
p. 19
Scale from 1 to 5 where one is no fat covering and 5 is overall fat cover
ca. 3 is optimal
Lean proportion - effect of genetics
Number of muscle fibers -> meat yield
- Number of cells determined before birth (genetically)
- Fusion from precursor cells
- Genetic selection criteria based on total number of fibers
Large number of cells in muscle
- Slaughter age: only enlargment of cuts
- Breed/line/origin
- Less abnrmalities in meat quality
- high muscle and meat retention potentail
Fatness - effect of genetics
Number of fat cells -> level of fatness, not fully independent from lean proportion
Numbers of cells increases at the start of animal growth
Gender: femalse ahve greater fatness than males, castrates in pigs get fatter and leander in cattle compared with female
in later stages mostly increase of cell size
- explains part of fatness which is determined by genetics
- with increasing slaughter age fatness increases
What is “Doppellender” or double muscling?
Mutation in myostatin gene leads to hyperplasia
s. 31
Positive aspects of double muscling
higher carcass wuality
higher proportion of meat
lower proportion of fat and bone
good sensory quality
negative aspects of double muscling
more susceptible to respiratory disease, urolithiasis, lameness, nutritional stress, heat and dystocia
birth problems - high birthweight
Lean proportion - effect of feeding
level of increase limited by the fixed genetic protein retention potential
declines with energy deficiency
declines with metabolic protein deficiency
- deficient protein supply
- imbalances in protein: energy ration, AA imbalance
Antinutritional factors
Antinutritional factors
Saponins
Tannins
Protease inhibitors
Alkaloids
Non protein amino acids
Lectins
Fatness - effect of feeding
Increasing feeding itensity -> increasing fatness w/o additional meat formation
Lebel of energy supply
- deficiency and excess have similar effect
Metabolic protein deficiency results indirectly in an increased carcass fatness
Excessive N in poultry and pigs somewhat reduced carcass fatness
slides 42 - 49
Effect of husbandry on carcass quality
Cold:
Carcasses leaner at the same energy supply
Carcasses fatter when same daily gains are achieved
Heat:
Somewhat increased carcass fatness and lower daily gains
What are the sections of the skin (cattle)
p. 56
Hair
Epidermis (top skin)
Papillary layer of the leather section
Reticulary layer of the leather section
Subcutis
Products of hide and hair
Leather: from the leathery skin of tame (leather or wild animals (buckskin)
Fell: Skin with atteched hairs (calf, small ruminants)
Fur: fell which is processed to a piece of cloth
Wool: Fibers from specific wool hairs of sheep, goat and camelids
Down: distinct feathers of geese and eider ducks
Criteria of leather quality
Rendement
Skin thickness
Structure: intensive collagenzation, well ordered, homogenous thickness
Appealing appearance of the surface
Proportion of undamaged skin, size of undamaged parts
Factors affecting leather quality
Genetic determination:
Breed-skin thickness (cattle thicker when used to higher altitude, small size e.g. Angus)
Nutrition:
Deficiency of any kind imparis skin quality (thinner, less well structured)
High feeding intensity: greater skin proportion, lower rendement and lower quality (structure)
Damage by photo sensitivity (Certain feeds and antibiotics)
Husbandry:
Increasing age: more skin damage, less compact, less well structured
Chilly environment: thicker skin, better structured
Husbandry measures: damages by inapropriate housing and treating animals
Criteria of wool quality
Rendement:
Recovery; % of pure wool of total dirty wool weight
Dirt
Wool hair properties
Properties determining the use as clothes
Faulty wool
Properties determining the use as clothes
Stability against tearing
Elasticity
Forming suitability
Inclination to wrinkle
Water binding capacity
Heat isolation
Faulty wool
Yarny wool
Felted wool
Varying thickness
Meagre wool
Wool contaminated with feed residues
Wool hair properties
Fineness
Length
Degree of bending
Homogeneity within and between hairs
Resistance to tearing
Proportion of awn hairs (cannot be dyed and are not well flexible)
Prickle factor
Pigmentation
Factors affecting wool quality
Genetic determination
- heritabilities
- genetic correlation
- breed
- body part
Nutrition
- breakability
- incomplete creatinisation
pigmentation
Husbandry
- time of wool harvest, length of the wool fibers
- climate: chilly slightly worse? humid: unfavorable microclimate within the wool -> discoloration, fiber hardness higher through microbial acitivity
- diseases: mainly high breakability, gathering, faulty colour
Highly priced specialty wools
Angora wool
Cashmere
