What type of blood is used in blood agar plates for better production of beta-hemolysis of Haemophilus?

The correct choice is horse blood for use in blood agar plates to promote the expression of beta-hemolysis by Haemophilus species. Horse blood is particularly beneficial because it contains higher concentrations of certain nutrients and growth factors that are conducive to the growth of fastidious organisms like Haemophilus. This type of blood also supports better hemolytic reactions, which are crucial for differentiating between types of bacterial hemolysis.

In the context of laboratory practices, using horse blood in blood agar creates an environment where these bacteria can thrive and exhibit robust beta-hemolytic activity. This contrasts with other blood types, such as sheep or rabbit blood, which may not provide the same optimal conditions for Haemophilus growth. While sheep blood is commonly used in many standard blood agar formulations, it does not enhance beta-hemolysis to the same extent as horse blood does for this particular genus.