"乳牛场的女工" can be translated into English as "female dairy farm workers" or more specifically, "female dairy workers" (if the context clearly implies a dairy farm).
Here are some examples of usage:
The female dairy farm workers work hard every day to take care of the cows. （乳牛场的女工们每天辛勤工作，照顾奶牛。）
She is a female dairy worker who has been working on the farm for many years. （她是一名在农场工作多年的乳牛场女工。）