For broilers: an increase in feed consumption and in body weight gain; and an improvement in feed conversion and in meat quality.
For layers: an increase in feed consumption and in body weight gain; and an improvement in feed conversion, egg production, the duration of the laying period, number of eggs, egg weight, egg shell stability and the colour of the yolk.
For turkeys: an increase in feed consumption and in body weight gain; and an improvement of feed conversion and in meat quality.
For piglets and pigs: an increase in feed consumption and in body weight gain; and an improvement in feed conversion and in nitrogen retention. Particularly with pigs, its use allows an improvement of the meat quality (e.g. an improvement of the protein content of the muscle "longissimus dorsi").
Finally for dairy cows: it allows an improvement in feed conversion, ruminal fermentation process, protein utilization efficacy, milk production and the content of milk constituents, protein and fat. Note that the three last improvements are due to the stimulation of the bacterial growth.
In addition, there are synthetic steroid drugs such as anti-inflammatory agents (prednisone, dexamethasone), steroid drugs that promote protein synthesis, and oral contraceptives. Anabolic steroids are similar to synthetic male sex hormones. They are a class of chemically synthesized derivatives similar in structure and activity to the human male hormone testosterone. On October 27, 2017, the World Health Organization’s International Agency for Research on Cancer published a preliminary list of carcinogens, androgen (anabolic) steroids are in the list of category 2A carcinogens. Steroids are a general term for a large class of cyclopentane-condensed fully hydrogenated phenanthrene derivatives widely distributed in the biological world.