This study compares four sigmoidal models using 770 weekly body weights data of Cihateup duck male n=14 and Cihateup Female n=21 collected over 22 weeks. Four sigmoidal models, Richards, Gompetz, Logistic and Morgan-Mercer-Flodin (MMF) were fitted to determine the best model curve. R 2 and SE values were used for model determination. The R 2 values for these models were; 0.9956, 0.9956, 0.9955 and 0.9928 respectively in males, and 0.9982, 0.9964, 0.9979 and 0.9970 for females respectively. The SE values for the respective models were 41.0852, 41.0852, 40.3999 and 52.4300 in males while 23.0558, 31.7047, 24.3066 and 29.9865 in females. Richards function was suitable for the Cihateup breed better than the other three models based on higest R 2 and lowest SEvalues

Keywords : Sigmoidal Models, Body Weights, Cihateup Duck, Richards.