Physical growth of cebus monkeys, Cebus albifrons, during protein or calorie deficiency.

Infant cebus monkey (Cebus albifrons) on experimental diets providing low-protein (2.8% of calories) or low-calorie (67% of ad libitum intake) levels for 20 weeks beginning at 8 weeks of age showed marked changes in their patterns of physical growth. Significant size differences between the malnourished animals and the control group appeared within 4 weeks. Although rates of growth were significantly reduced in all measurements, all of the malnourished monkeys, including low-protein animals showing zero weight gain, continued skeletal growth (except in skull measurements) at low levels for the duration of experiment. Both the protein- and calorie-restricted animals developed a thin, emaciated appearance often associated with marasmus, not by the continuous loss of tissue byt by the redistribution of the tissue over a slowly expanding skeleton. For many skeletal proportions, the pattern and shape development in the malnourished animals differed from that of the control animals. Growth during malnutrition was most affected in those parts of the skeleton which were more advanced in relative size.