1-nichi Nyuugyuu Taiken: Oishii Milk ga Dekiru made

It's a story about a man who, for some reason, comes to a farm to experience milking cows, and is made to undergo TS, and then stays that way... Although it's not long on the pages, it is very well-expressed, and I enjoyed it, as it shows the TS protagonist being made to feel good, having his huge breasts squeezed, and being inseminated. There is, however, a bit more that happens afterwards, so that's also something to look forward to.

Note: Released at Comiket 99