乳清 is read as にゅうせい (nyuusei) and means whey.
にゅうせい
nyuusei
うば
wet nurse
ちち
breast
ちうじ
dairy cow
ちくび
nipple
にゅうじ
infant (below 1 year old)
にゅうようじ
infants
にゅうぎょう
dairy industry
にゅうとう
(mammary) nipple
にゅうえき
latex (milky fluid found in plants)
にゅうかじゅうごう
emulsion polymerization
にゅうこけいぶん
milk solid
にゅうようしゅ
dairy cattle