I think all cultures have been tainted by bestiality, definitely not limited to India. But anyway, looks like I was right about the website being legitimate, although I grant you, it may have misinterpreted the Sanskrit although I'm more convinced that it didn't.
It does not appear to be anti-Hindu propaganda http://india30.tripod.com/index.html appears to be a legitimate scholarly website, "Hinduism - Indology - Indian history - Indic languages", articles taken from Indopaedia at http://www.geocities.com/Athens/Ithaca/1335/, "The largest and best collection of encyclopedias on India anywhere un the internet. India is one of the least understood regions of the world. This site dispells some of the mythology and folklore taught about India. It is a standard reference for both laymen and learned scholars. Some of the hyperpedias located here contain more than 100 references each. The design of the hyperpedias is such that the layman need only concern himdelf with the uppermost portions of each page, while the scholar can continue to the more difficult parts further down the page. Several mistakes made in standard textbooks are corrected.
However, the site is still under severe construction. There are several volumes of Lexica Indica; not all are yet available"
but at any rate, I checked Princeton University Press website and they do have: Goldman, Robert P. The Ramayana of Valmiki: an Epic of Ancient India. Balakanda (vol. 1). Pub.: Princeton University Press. ISBN 0-691-06561-6. listed.
I also read http://www.valmikiramayan.net/bala/sarga14/bala_14_frame.htm
Translation says: Queen Kousalya encircled that horse around in reverence and great joy, and killed it with three knives. [1-14-33]
Queen Kousalya lived with that [slain] horse for one night for [achieving the ritual] results, with a firm and virtuous mind. [1-14-34]
I looked up "avasat" in Sanskrit dictionary, found Sanskrit to French where it says:
vas_1 v. [‍1‍] pr. (vasati) impft. (avasat) pft. (uvāsa) pp. (uṣita) abs. (uṣitvā, -uṣya) pf. (adhi, upa, ni, pra, vi, saṃ) habiter, demeurer | passer, séjourner; rester — ca. (vāsayati) loger, héberger, abriter || all. Wesen; ang. was"
(Maybe, maybe not although IMO it looks like the implied meaning is "slept with")
See second paragraph of a paper written by Lowell Edmunds, Professor of Classics at Rutgers University since 1988 where he states: "It turns out that in the as’vamedha the mahisî or chief queen cohabited with the stallion that was the centerpiece of the ritual (161); the sexual element is lacking in the Roman ritual; in the Celtic ritual, the king mates with a mare."
(Just another confirmatio that religions are shams. There are no holy men, only an Holy God.)