Factors Affecting yield & Composition of Milk (Part 1)

Question 1

A cow yielding ….. per day

Answer 1

40 kg milk

Question 2

Some factors-are under the control of the farmer

Answer 2

frequency of milking
They can alter them to increase improve its composition

Question 3

Some factors-are outside the farmer’s control, e.g.

Answer 3

Stage of lactation , pregnancy and estrus

Question 4

Genetics :
Large among breed differences due to differences in …

Answer 4

gene frequencies

Question 5

Differences among …. are greater than differences among breeds

Answer 5

individuals within a breed

Question 6

……… are heritable traits

Answer 6

Milk yield and milk components

Question 7

Milk yield is … correlated with fat and protein percentage.

Answer 7

Negatively

Question 8

Most variable in milk

Answer 8

Fat

Question 9

Least variable in milk

Answer 9

Ash , lactose

Question 10

The diameter of the fat globule as example of differences

Answer 10

Guernseys have the largest and Holsteins and Ayrshires the smallest fat globules

Question 11

….. and ….. cow convert much less carotene to vitamin A than other breeds

Answer 11

Guernsey and Jersey

Question 12

Why Guernsey cows “Golden Guernsey” are becoming less
popular ?

Answer 12

convert much less carotene to vitamin A than other breeds
Yellow milk

Question 13

fast (easy) milking cows

Answer 13

Less RM (more milk will be removed before the myoepithelial is relax)

Higher fat content (more of the last milk is obtained)

Question 14

Slow (hard) milking cows are

Answer 14

incompletely milked

Question 15

Rate of milking is a …. trait

Answer 15

heritable

Question 16

….. have the highest milking speed among the major dairy breeds.

Answer 16

Holsteins

Question 17

Milking speed is related to

Answer 17

• The strength of the sphincter muscle
• surrounding the streak canal
• The diameter of the teat opening
• Vacuum level , pulsation rate and pulsation ratio

Question 18

Why easy milking cows with wider teat opening are more susceptible to mastitis

Answer 18

One function of the streak canal is to prevent bacteria from gaining entrance into the teat

Question 19

Mature cow reach peak yield in …

Answer 19

40 - 60 day

Question 20

………. and ……… define the shape of the lactation curve

Answer 20

Peak milk
Persistency

Question 21

PY Is the highest daily milk production in the cow’s first ..

Answer 21

150 days in milking

Question 22

First lactation animals reach peak yield in …

Answer 22

70 DIM

Question 23

The timing and level depend on

Answer 23

1) the cow’s genetic potential
2) BC at calving (Most important)
3) Feeding level

Question 24

Higher producing cow tend to peak … than low producing ones

Answer 24

later

Question 25

305 day yeild

Answer 25

Daily yield at peak X (200 to 250)

Question 26

Peaky yield has a direct effect on ….

Answer 26

Total yield of the year