Note:
(a) "成功受精的母猪会被饲养在 '分娩舍' 一起等待生产。 * * * 约于预产期的前一周，母猪会被带到产房。产房的设置可以避免母猪因产后不便而把小猪压死"
(i) gestation crate https://en.wikipedia.org/wiki/Gestation_crate
("A few days before giving birth, sows are moved to farrowing crates, which are slightly wider so they can lie down to nurse. Crates have 18-in. (46-cm) "troughs" on each side where the piglets can safely lie without being in danger of sow overlay (when the sow lies down on top of a piglet)" )
(ii) farrow (n, v) https://www.merriam-webster.com/dictionary/farrow
(b) "大约六周便可达到屠宰标准—120公斤"
It is a typo -- not six weeks, but six months.
(c) The description here, about raising pigs in Germany, are the same in most factory farming. See
Anna K Johnson and JN Marchant-Forde, Welfare of Pigs in the Farrowing Environment. Iowa State Univesity, 2009 https://lib.dr.iastate.edu/cgi/v ... mp;context=ans_pubs
(the entire abstract: "In the USA, housing for the lactating sow and her piglets can be divided into five main areas. Total confinement, defined as the farrowing crate, houses the highest number of at 83.4 plus or minus 4.0%. Remaining operations house fewer sows with open buildings that have outside access at 12.4 plus or minus 4.1%, open building with no outside access, 2.9 plus or minus 0.5%, lot with hut or no building, 0.6 plus or minus 0.2% and pasture with hut or no building the lowest at 0.7 plus or minus 0.3% (. In the UK, it is estimated that around 70% of sows farrow in crates, 27% farrow outdoors in farrowing arks and only 3% farrow in loose-housed indoor systems")