A FEEDING EXPERIMENT ON LABORATORY-BRED M ALE CYNOMOLGUS MONKEYS .1. MORPHOMETRICAL STUDY

Effects of restricted feeding on the growth of laboratory-bred male cy nomolgus monkeys (Macaca fascicularis) aged between one year and four years were studied morphometrically. A series of 11 variables represen ting physical elements were measured. Before 2.5 years of age, the amo unt of commercial diet (Type AS, 382kcal/100g and 28.1% of crude prote in, Oriental Yeast Co. Ltd.) per day was restricted to 50g (group A) , 30g (group B) or 20g (group C) and increased to 100g (group A), 50g ( group B) or 40g (group C) respectively at 2.5 years old. Throughout th e experimental period ca 100g of apples and oranges per day were provi ded. Significant differences in body weight between group A and C were detected excepting the early period of the experiment. Although the s light suppression in weight gain was observed in group B during the se cond trimester of the experiment, body weight increased gradually afte r increasing the amount of food and no significant difference from A w as observed at four years of age. The minimum requirement of diets is judged to be 30g/day before two years old and 50g/day over two years o ld in the laboratory-bred male cynomolgus monkey. Moreover, the suppre ssive effects of restricted feeding were most significant on the growt h of the limbs and, secondarily, on the growth of the trunk. Practical ly no effect on the growth of the head was observed.