Question

QUESTION 3

(A) In dairy production, what do you understand by the term ‘lactation cycle’? (1 Mark)

(B) Mention the four (04) phases of the lactation cycle and highlight the specific time periods when these phases occur in dairy cows (4 Marks)

(C) Explain how milk production varies in the different phases of the lactation cycle (4 Marks)

(D) Relate the milk production to the feed intake and body weight of the dairy cow during the four phases of the lactation cycle (8 Marks)

(E) Briefly explain the term ‘negative energy balance’ and when does this normally happen in dairy cows (2 Marks)

(F) What is the recommended time of servicing the dairy cow during her lactation cycle?

Answer 1

Question

A. Lactation period is the duration during which a cow produces milk. This period begin after the birth of calf and last for approximately 305 days.

B. The four phases of lactation cycle are:

I. Early period: this period last for 120 days.

II. Mid-period:this period last for 120 days.

III. Late lactation period: this period last for 120 days.

IV. Dry lactation period: this period last for 60 days.

C. The milk production varies in the lactation period in the following way:

I. Early period: during this period the cow start to lactate and start lactating milk.

II. Mid-lactation period: this is the period of maximum lactation

III. Late-lactation period:in this period milk production start decreasing .

IV. Dry-lactation period: this period is the least milk production period.

D. Milk production in cow is dependent on the feed intake and body weight of the cow. During early period of lactation, the body reserve of the cow are used to produce milk. During mid-lactation period live weight is constant and after that body reserve is regain for next lactation period.

E. Negative energy balance take place in cow when daily requirement of the cow is unable to fulfilled by the daily food intake of cow. This occurred after calving in the cow.

F. The recommended time of servicing the dairy cow is between 40 to 90 days after calving.