What effect does the repetition of the phrase "straight from the horse's mouth" have in Brave New World?

Animal imagery plays a nuanced role in Brave New World, and the repetition of "straight from the horse's mouth" plays into the function of animal motifs throughout the book. There is a strong current of irony which runs through Brave New World. The society of the characters values technological and material progress above all else; they've done away with the "primitive" and inefficient sentimentality of days gone by. However, by reducing their citizens by sorting them into a series of categories which revolve entirely around their labor, the society essentially treats its members like animals, like cattle. From Alphas to Epsilons, all people embody their social classes and nothing more. There are no individuals or families. Each person is not really a person at all, but a living piece of property—much like an animal.
This concept becomes crystal clear in Chapter 1, when the Director is giving a tour of the Central London Hatchery and Conditioning Centre to a group of young students. Multiple times we are told each student "carried a notebook, in which, whenever the great man spoke, he desperately scribbled. Straight from the horse's mouth." We are meant to understand that the Director is an absolute authority figure, regarded as a paragon of knowledge and truth by the students. But, by placing the image of a horse in our minds, the author also wants us to acknowledge this man and his "truths" as part of a larger, grotesque outlook on this society. Several paragraphs later, when the Director explains how the society has accelerated human development, he asks the students to "[c]onsider the horse." It is clear that even the Director himself is a mere biological unit in a large societal machine of identical units; this society regards its own members as mere cattle.
As "straight from the horse's mouth" is repeated numerous more times, this meaning gains impact. The repetition endows the reader with an eerie sense that something is profoundly warped within this society.