B4: Breeding goals and characteristics (valuable traits) of dairy cattle, milk properties

Question 1

Animal production cycle

Answer 1

breeding goal —> valuable trait —> BVE —> selection —> mating —> production of offspring —> breeding goal……….

Question 2

what is the breeding value of an animal?

Answer 2

-> the deviation of the individual genetic merit from the mean genetic merit of a reference population.
(BVi = GMi - GM pop)
-> The individual breeding value is of altering degree, and changes according to the value (genetic merit) of the reference population or of mating partners.

Question 3

what is the aggregated breeding value (or breeding index)?

Answer 3

-> it is a complex type of breeding value established
for more traits simultaneously
-> it is achieved upon the base of a linear combination of the valuable traits.

Question 4

Most important performance traits used in dairy cattle selection: chemical composition of milk includes?

Answer 4

Chemical composition:
o Fat content (%)
o Protein content (%)
o PFR – Protein to fat ration
o FPD – Fat protein difference
o Lactose content (%)
o SCC (somatic cell count)

Question 5

What are the primary traits of milk producing cattle?

Answer 5

• Milk producing ability
• Milk yield, kg
• Relative milk yield, kg
• Milk composition, (see extra point)
• Milking ability
• Other

Question 6

What are secondary traits of milk producing cattle?

Answer 6

• Conformation (shape or structure of a horse & it can impact a horse’s athletic ability)
• Reproduction
• Feed intake, - conversion ratio
• Adaptation (e.g. industrialized environment)
• Health
• Resistance
• Others

Question 7

What are milk properties?

Answer 7

Use points fror milk performance and chemical composition.

Question 8

What is milk pay-out?

Answer 8

milk payment prices, refers to a kg of milk with 4% fat and 3.4% protein, which dairy farmers receive from the milk industry.

Question 9

What is milk pay-out determined by?

Answer 9

payment farmer receives from milk industry for the product he supplied.

1) quantity delivered
2) bacterial count
3) somatic cell count
4) residuals
5) freezing point
6) price level on world market.

Question 10

What are the components of milk?

Answer 10

water: 87 - 88%
dry matter: 12 - 13%
fat content: 3 - 4.5%
sugar content: 4.8 - 4.9%
protein content: 3.5 - 4%
minerals: 0.7%

lactation length: 240 - 340 days