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Swine Production Exam 1 > Selection of Breeding Stock > Flashcards

Flashcards in Selection of Breeding Stock Deck (24)
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1
Q

Producers need to evaluate several breeding stock factors.

A

Genetics
Expected Genetic Potential
Phenotype

2
Q

When 1 or both testicles are retained in body cavity

-When both retained, boar is sterile

A

Cryptorchidism

3
Q

Mostly seen in Yorkshire and Landrace, occasionally occurs in large litters as a result of uterine crowding

  • Most are genetic female
  • Portions of male sex organs and tipped vulvas
A

Hermaphrodites

4
Q
  • Failure of nipples to protrude from udder surface
  • Milk flow is prevented
  • Should look at boar teats too, can genetically pass on to daughters
A

Inverted nipples

5
Q
  • Result of weakness of musculature surrounding inguinal canal
  • Intestines to drop into the scrotum
A

Scrotal hernia

6
Q
  • Weakened muscle in the naval area causes intestines to protrude through belly wall
  • Some pigs die during growth due to strangulation of the intestine
A

Umbilical hernia

7
Q
  • Most common leg disorder
  • Mainly affects rear legs
  • Incomplete development of muscle fibers in front and rear legs
  • Affected pigs can be treated somewhat successfully
A

Splay leg/Spraddle legs

8
Q
  • Carrier of this dominant gene
    • lower muscle pH
    • pale meat color
    • lower water holding capacity
    • greater cooking loss
  • Seen in hampshires and hampshire x’s
  • Dominant have elevated glycogen storage in muscles, ^ lactate prod., reduces ultimate pH at harvest
A

Napole Gene (RN)

9
Q

Best estimate/indicator of a sire or dam’s genetic potential

  • It is actual difference a producer could expect from future offspring
  • # can be (+) or (-)
A

Expected Progeny Difference (EPD)

10
Q

6 common terminal traits evaluated (what we want)

A
  1. ) Backfat (low)
  2. ) LEA (high)
  3. ) Days to 250 (low)
  4. ) Lbs of lean (high)
  5. ) Avg. daily gain (high)
  6. ) Feed efficiency - lb feed/ lb gain (low)
11
Q

4 common maternal traits evaluated (what we want)

A

1.) # born alive (high)
2.) # weaned (high)
3.) Litter weaning weight (high)
4.) Wean-to-estrus interval (low)
-How many days from weaning for a sow to go
back into heat

12
Q

Allow for simultaneous selection of multiple traits

  • Weighs EPDs relative to their economic value
  • 3 types
A

Swine Indexes

- Terminal Sire Index
- Maternal Line Index
- Sow Productivity Index
13
Q

Terminal Sire Index

A

Designed to select boars to be used as sires in crossbreeding programs

14
Q

The TSI combines (3):

A

Days to 250
lb of lean
Backfat

15
Q

Average for TSI is…

A

100

> 100 is most desirable

16
Q

Maternal Line Index

A

Indicates economic value of the progeny produced

17
Q

With MLI, there is 2X as much emphasis on _____ traits as on _____ traits.

A

Reproductive… Post-weaning

18
Q

The MLI combines (5):

A
Backfat
Days to 250
Lb of lean
# born alive
Litter wt
19
Q

MLIs will be used for…

A

Boars to be used for breeding

20
Q

Sow Productivity Index

A

Indicator for a sow’s reproductive traits

21
Q

The SPI combines (3):

A

born alive
Litter weaning wt
-Also includes, lifetime # born alive and litter weaning weight

22
Q

Female selection underline:

A

Minimum of 6 or more functional teats

23
Q

Reproductive soundness (5)

A
Feet and legs
Growth
Muscle
Capacity (depth of body)
Leanness
24
Q

Leanness is visually evaluated on gilt’s fat depots (6)

A
  1. ) Jowl
  2. ) Blades
  3. ) Elbow pocket
  4. ) Belly
  5. ) Loin edge
  6. ) Seam of ham