4.3 Artificial insemination (AI) improves the conception rate in cows. To achieve the expected objective, the farmer needs to observe the signs of oestrus to detect heat.

4.3.1 Name the phase of the oestrus cycle during which artificial insemination could be performed. (1)

4.3.2 State TWO methods that dairy farmers could use to detect heat in cows. (2)

4.3.3 State TWO characteristics of good quality semen. (2)

4.3.4 State TWO disadvantages of artificial insemination. (2)

4.4 Cattle breeders can increase the number of offspring by artificially bringing all the cows into estrus at about the same time.

4.4.1 Identify the process in the scenario above. (1)

4.4.2 Name TWO techniques or methods used in the process identified in QUESTION 4.4.1. (2)

4.4.3 Name TWO disadvantages of the process identified in QUESTION 4.4.1. (2)

4.5 Arrange the statements about the stages of mating below in order. Write down ONLY the letters (A - E).

A. Penetration of the vagina (1)

B. Bull jumps off (1)

C. Bull shows interest in cows due to increased pheromone levels (1)

D. Bull stands on his hind legs and rests his chest on the female animal's back (1)

E. Bull releases sperm cells (1)

4.3.1 The phase of the oestrus cycle during which artificial insemination could be performed is the estrus phase. During this phase, the cow is in heat and is most receptive to breeding.

4.3.2 Two methods that dairy farmers could use to detect heat in cows are:

Observation of behavioral signs: Farmers can observe changes such as increased activity, restlessness, and standing heat, where a cow will allow others to mount her.
Heat detection aids: Tools like tail paint, mount detectors, or electronic sensors can be used to identify when a cow is in heat.

4.3.3 Two characteristics of good quality semen are:

High sperm motility: The sperm should be active and capable of moving efficiently to fertilize an egg.
High sperm concentration: There should be a high number of sperm cells per unit volume of semen to increase the chances of successful fertilization.

4.3.4 Two disadvantages of artificial insemination are:

Requires skilled labor: Performing AI requires trained personnel to ensure success and reduce risks to the animals.
Management challenges: AI requires careful timing and observation of the estrus cycle, which can be labor-intensive and may not always align with natural cycles.

4.4.1 The process in the scenario above is identified as estrus synchronization. This process allows cattle breeders to bring all cows into estrus at the same time, increasing breeding efficiency.

4.4.2 Two techniques or methods used in estrus synchronization are:

Use of prostaglandins: These are hormones used to manipulate the reproductive cycle to induce estrus.
Progestagen treatment: This involves administering synthetic progesterone to regulate the reproductive cycle.

4.4.3 Two disadvantages of estrus synchronization are:

Cost: It can be expensive due to the need for hormones and additional labor.
Stress on animals: The process may stress the animals if not managed correctly.

4.5 Arrange the statements about the stages of mating:

C. Bull shows interest in cows due to increased pheromone levels.
D. Bull stands on his hind legs and rests his chest on the female animal's cross.
A. Penetration of the vagina.
E. Bull releases sperm cells.
B. Bull jumps off.