C16: Milk type and prolific sheep breeds (prolificacy genes)

Question 1

what are the milk production traits of sheep breeds

Answer 1

• 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

Question 2

what are the most common methods of selection for milk production breeding?

Answer 2

progeny testing of rams and group selection of best ewes are the most common methods

Question 3

what is the difference between pure dairy breeds and dual purpose breeds?

Answer 3

-> Dual purpose breeds that may primarily be meat or wool sheep are often used secondarily as milking animals.
-> There are few breeds predominantly used for milking.
-> These sheep do produce a higher quantity of milk and have slightly longer lactation curves.
-> The quality of milk, fat and protein content percentages of dairy sheep vary from non-dairy breeds but lactose content doesn’t.

Question 4

what is the length of lactation in performance groups of dairy sheep

Answer 4

150 - 200 days

Question 5

what is the average milk yield of HIGH potential milk sheep breeds?
Mention some breeds

Answer 5

avg. milk yield:200-500kg
Friesland,
British Milksheep (East Friesian/Texel),
Awassi (Israel),
Chios (Greece),
Lacaune (France),
Sarda (Italy)

Question 6

what is the average milk yield of AVERAGE/ GOOD potential milk sheep breeds?
Mention some breeds

Answer 6

avg. milk yield: 90-200kg

Beglika(Bulgaria),
Bergamasca (Italy)
Churra (Spain),
Comisana (Italy),
Kymi/Skopelos (Greece),
Lacha (Spain),
Langhe (Italy),
Stara Zagora(Bulgaria),
Zlatoucha(Bulgaria)

Question 7

what is the average milk yield of LOW potential milk sheep breeds?
Mention some breeds

Answer 7

average milk yield: 50-90kg

Awassi(Turkey/Middle East countries) Barbary(Tunisia/Libya),
Bordaleiro(Portugal),
Kivircik(Turkey)
Manchega(Spain),
Manech(France),
Mytileni(Greece),
Serra de Esrela(Portugal),
Serres(Greece),
Sopravissana(Italy), Tsigaia(Hungary/Serbia/Bulgaria),
Vlahiko(Greece)

Question 8

Name a prolific sheep breed and why they are prolific breeds

Answer 8

• Booroola strain of the Merino sheep breed has a high rate of multiple births.
• Booroola’s prolificacy = The Booroola strain has a high rate of multiple births.
• It was studied extensively in New Zealand by researchers who provided one of the 1st examples of the practical application of gene mapping in sheep → by mapping the Booroola gene to chromosome 6.