Minimum Breeds in Rotational Crossing

Correct Answer: Two

From the notes: The minimum number of breeds in rotational crossing is two (2-way rotational cross / Criss-cross). In a 2-breed rotational cross, two breeds are crossed alternately.

Types of Rotational Crossing

• 2-way rotational cross (Criss-cross): Two breeds crossed alternately. System in which 2 breeds are crossed alternatively.
• 3-way rotational cross: Three breeds crossed in rotation. System in which 3 breeds are crossed in a rotational manner.

Hybrid Vigour in Rotational Crossing

Maintenance of hybrid vigour in a cattle herd is done by rotational crossing. It maintains 67% (2-breed) or 86% (3-breed) of maximum possible heterosis across generations without the need to produce new F1 hybrids each generation.