Artificial nursing of new-born cynomolgus monkeys as a model of the human infant and development of abnormal behavior (author's transl)

Abstract

New-born cynomolgus monkeys were sucessfully reared by artificial nursing that was started just afterbirth with a 12% solution of a commercially prepared powdered-milk (Yukijirushi, P 7a) containing 13.3g of protein per 100g. Marked growth-retardation was observed in baby cynomolgus monkeys fed on a 12% solution of the modified P 7a milk containing only 6.6g of protein per 100g to which lactose was supplemented to give a baby monkey the same caloric value as that of the original P 7a milk. These artificially reared cynomolgus monkeys manifested various kinds of abnormal behavior such as self-clasping, autism-like self mouthing, huddling, stereotype rocking, head-knocking, autoerotism, fear, aggression, etc.. Generally, development of these abnormal behaviors was more noticeable in the monkeys nursed with a milk bottle fixed to the side of a cage without human contact than in the monkeys nursed by a care-taker with bodily touching. These qualitative observational results indicate that the new-born cynomolgus monkey can be used as a model of the human baby for research into the relationship between malnutrition and abnormal physical and mental growth.