Most people in the UK, at least those over a certain age, know that it means 'What did you study?'. But it is outdated/ overly formal. Nobody would ever use 'read' in this sense in everyday conversation. We don't even say 'study' most of the time : "do" is the usual collocation with a subject e.g. "He did maths at Cambridge". I think it's still used in the intros on University Challenge, and as the prompt for lame jokey responses such as 'Comics'.

My answer to the question would be the subject that I studied, but inwardly I would probably be asking myself 'why have you phrased the question like that?' I know what it means but I am in agreement with Su.Ki. that it is outdated. Incidentally, your question reminds of my first week at university and a story one of my friends told me about the first time he met his tutor. My friend studied maths and he and his fellow students met the college fellow at a meet and greet in the first week of term, the point of which was to give the tutor the opportunity to explain to the students the specifics of the course and what exactly was expected from them. My friend said the tutor began by saying 'so, you lot are here to study mathematics, then?' To which they replied in the affirmative. The tutor then shook his head and said, 'No you are not, you are here to READ mathematics.' That story always makes me smile because one, it shows the importance that some people place upon their own subject (the fellow was in his 60s and was what you might describe as a typical Oxford academic). He obviously considered 'reading' a subject to be more involved than simply 'studying.' And the second reason is that my friend began that story by saying, 'So my new tutor is a bit of a ****.' He thought it sounded bit pretentious.

i read agric seience

In the U.S., we don't "read" at a university. We "study". I'd ask, "what did you study in college?" or "What did you study in school?" I studied business in graduate school after studying math in college.

Generally useful Elements of style - William Strunk Jr & Elwyn Brooks White Bergsons Writings - Henry Bergson Against Method - Paul Feyerabend Academic Reconstruction - Ari Tervashonka Intuition Unleashed - Asta Raami Qualitative research Validity in Interpretation - Eric Donald Hirsch Qualitative Research Practice - Clive Seale, Giampietro Gobo, Jaber F. Gubrium & David Silverman General System Theory - Ludwig Bertalanffy Basics of qualitative research - Anselm Strauss & Juliet Corbin Related philosophy of science Interpretation theory - Paul Rocoeur Reconstruction in Philosophy - John Dewey Deconstruction in a nutshell - Jacques Derrida Cartesian Meditations - Edmund Husserl The Logic of Scientific Discovery - Karl Popper Hermeneutics and Criticism - Friedrich Schleiermacher Hans-Georg Gadamer - Philosophical Hermeneutics