Lecture 5 Flashcards
(17 cards)
What is crossbreeding
Generally refers to mating different animals species, breeds, strains and liens
What is the genetic concept of cross breeding
Increases the frequency of heterozygosity by reducing homozygosity
What does cross breeding combine
Both additive (estimated breeding value) and non-additive (gene recombination value) genes to create hybrid
What is the crossbred formula
P=u + EBV + GCV + E
What are requirements of cross breeding
- Crossbreeding between species delicate
- Must belong to same taxonomic genera
- Must have same number of chromosomes
- Most progeny die early or sterile as adult
Why do you cross breed pigs
To increase leanness, eye loin area and to reduce backfat thickness
What does heterozygosity increase
Fitness and enables more choices in physiological response to environmental challenges
What are some goals of a pasture production system(4)
- Low investment in building
- Requires large pasture availability to be able to rotate the pigs in a bid to reduce diseases
- Farrowing takes place only once or twice a year
- Number of sows farrowing per year is small
What are some goals of a confined management system (6)
- Use of little high-priced land space
- High investment in buildings and equipment
- High level of mechanisation, low labour costs
- Large sow not raised multiple farrowings/year
- Stringent, better control of diseases and parasites
- High level of management skills required
What are feeder pigs
Maintaining a breeding herd of sows and reading the piglets until weaned. The weaned piglets are then sold to feeders who in turn feed them to market weight
What are finisher pigs
Operator buys feeder pigs and raises them to market weight
What is complete sow and litter production
Based on maintaining a breeding herd of sows, farrowing them and caring for the pigs until they are weaned and fed to market weight
What determines the carcass quality of pork
- Colour
- Marbling
- Firmness
- Water holding capacity
- pH
- Tenderness
- Taste
How to determine the water-holding capacity of meat
Kauffman filter paper method measures amount of moisture on the cut loin surface
How to determine the pH of meat
Measured 25 hours after slaughter, you insert a pH probe into the muscle
What are the features of meat with a higher pH
Darker colour, low drip loss, more firmness and increased tenderness
How is tenderness measured
The instron tenderness star probe puts pressure on the meat and the less the pressure the more tender the meat is
