"An old black ram is tupping your white ewe"

Iago’s warning to Brabantio that “an old black ram/ is tupping your white ewe” is found in Act I, Scene 1, lines 87-8 of Othello.
Some Related Themes:
• Racial language: Although not specifically named as “the Moor” race is indirectly mentioned through the introduction of the “black” ram versus the “white” ewe.
• Animal Imagery: This statement compares Othello to an old black ram—which introduces both animal imagery and the racial connotation of black versus white. In reducing Othello to a ram, Iago demotes him to a beast, which is a position below that of humanity in the Great Chain of Being.
• Gender: The specificity of gender is direct in the language of “ram” versus “ewe”. Furthermore, the inclusion of “tupping” (a bawdy term for copulation of sheep) points to gender dynamics. One should also take note that Desdemona is referred to as “your” white ewe—which demonstrates the hierarchal order of man over women (and women as objects or property) in the society.
• Word choice: “Tupping” is an impolite term, and points toward Iago’s immense knowledge of both high and low language, and his versatility, as he can use low language while also employing the educated technique of metaphor/imagery. Also “ewe,” in the auditory performance, has a possible second interpretation as “you”—meaning that Othello is damaging Brabantio’s "white" or spotless reputation.