A19: . Breeding goals and traits of sheep production, types, usage and products.

Question 1

List the uses of shee

Answer 1

Use of Sheep:
-> Wool
-> Meat: Mutton + Lamb
‣ New crop lamb (15 kg)
‣ Light lamb (25 kg)
‣ Heavy lamb (40 kg)
-> Sheepskin
◦ Clothes
◦ Footwear
◦ Rugs, Etc.
-> By products
◦ Tallow → candle and soap making
◦ Gelatin

Question 2

What are the results of trait-based selection influenced by?

Answer 2

Inheritance (heritability, repeatabilty) of characteristics.
Correlations btw characteristics.

Question 3

What maternal effects carry over?

Answer 3

pregnancy,
twins,
multiple births,
birth weight,
viability,
milk-suckling

Question 4

live weights:
birth weight of lambs?
weaning weight?
weight at 6 months?
fully mature weight?

Answer 4

Birth weight of lambs (2-4kg),
Weaning weight (30-day weight: 14-17kg),
Weight at 6, 9 months, yearling, mature adult (30-40 kg, 60-130kg, ram 30-40% more)

Question 5

What is the daily weight gain?

Answer 5

100-600g/day,
ram 15-20% more

Question 6

What is the specific feed conversion of sheep?

Answer 6

Rate of gain/ unit feed consumed (specific feed conversion): 3.2-3.7kg/kg.
rams are better.

Question 7

What are traits of the carcass?

Answer 7

• Carcass weight
• Carcass quality (colour, tenderness, flavour, palatability).
• Degree of fatness; -Back fat thickness over loin eye (23%).
• Fat around kidneys.
• Tallow (fat), bone, lean %.
• Valuable ratio (primal cuts):
  o Shoulder o Rack o Loin o Legs
• Loin (and back) ratio (wide, muscular loin, loin eye area, body length, marbled intramusc. Fat).
• Carcass: neck, fore shank, shoulder, breast, rack, loin, flank, legs(extreme muscling, muscular hypertrophy, CLPG).

Question 8

What are the traits of fine wool and fur?

Answer 8

• Grease (fleece weight): 4 - 8kg
• Wool (clean fleece weight)
• Wool thickness
• S/P ratio = secondary: primary follicle ratio)
• Fineness → length & diameter of fiber (20 - 33 microns).
• Medullation of fiber
• Crimps
• Staple (combing fiber) 5 - 15cm
• Curl type and size.
• Cashmere & angora goats: Mohair, pashmina.
  wrinkles or skin folds.
  fibre length and diameter: 40 - 60 microns, coarse and carpet wool.

Question 9

What are the milk production traits in sheep?

Answer 9

• Milk yield
• Lactation performance:
  o Sheep 80-300 (600) L
  o Length of lactation 150-200 days
• Daily milk yield
• Milk fat % -high
• Milk protein % -high
• Ease of milking (milking machine), dairy sheep: machine milking
• Udder size & form