Use of melengestrol acetate in feed for contraception in herds of captive ungulates

Herds of blackbuck antelope ( Antilopa cervicapra ) and barasingha ( Cervus duvauceli ), axis ( Cervus axis ), sambar ( Cervus unicolor ), and Formosan sika ( Cervus nippon taiwanaus ) deer at the Wildlife Conservation Society/Bronx Zoo (WCS/BZ) were fed melengestrol acetate (MGA) at a concentration of 0.000154% in pelleted feed for various periods of times during 1991–2001. The target dose per animal of MGA was 1–2 mg per day. Contraceptive rates during treatment were 100% for blackbuck antelope and barasingha, sambar, and sika deer, and approximately 93% for axis deer. There were no observed adverse effects from MGA treatment on gestation. Post‐treatment reproductive rates were lower than pretreatment rates. Zoo Biol 22:455–463, 2003. © 2003 Wiley‐Liss, Inc.