Nutrient requirements of monkeys were first considered by the National Research Council’s Committee on Animal Nutrition in a section of Nutrient Requirements of Laboratory Animals (National Research Council, 1972). The information was updated and expanded in Nutrient Requirements of Nonhuman Primates (National Research Council, 1978). The present publication is a second revised edition of the 1978 report that constitutes a further updating and expansion of the topic.
This report is distinctive among most other publications in the Committee on Animal Nutrition series of reports on animal nutrient requirements. Many of the reports in this series deal with a particular species of domestic animal for which there is a significant amount of peer-reviewed research and an abundance of studies that examine specific nutrient requirements for various life stages. This revision is unlike those other reports for several reasons. First, it attempts to address the needs of over 250 species. Second, there are few data on which to draw conclusions and make recommendations for most species. Third, the animals addressed here are not domestic animals raised and bred for maximum efficiency in growth and production, but rather they encompass research animals, educational animals, and rare, endangered, and threatened animals that are maintained in various institutions for conservation purposes. Given the nature and importance of the animals that are the topic of this report and recognizing that the users of this report will span a wide range of professional expertise and practical knowledge of nutrition, the Committee used extreme care in evaluating and summarizing the available information. We chose not to go beyond what the data allow and we have grounded our recommendations firmly in scientific fact. To deviate from this approach, to venture beyond the scientific evidence, or to attempt to provide equations and estimates that cannot be validated— as they are validated in domestic food-producing animals— could potentially do more harm than good to the approximately half million primates currently maintained in biomedical and conservation institutions throughout the world.
Definition of the nutrient requirements of a single primate species at all life stages is difficult because little research specifically aimed at determination of nutrient requirements has been conducted. Definition of the nutrient requirements of each of some 250 primate species is virtually impossible with our current knowledge. Energy requirements of fewer than 20 species have been studied, and protein, mineral, and vitamin requirements of fewer than 10. Although there may be much dissimilarity among primate species in behavior and in the presence of fermentation compartments within the gastrointestinal system, similarities in the other aspects of physiology that influence nutrient requirements tend to be greater than the differences. Some extrapolation from one species to another is possible; this allows the formulation of diets that will usually meet requirements for adult maintenance, reproduction, and growth, even though specific quantitative needs have not been experimentally established. Although much more information is needed in those instances where specialized features of the gastrointestinal tract dictate a comparably specialized diet, research findings are beginning to fill the knowledge gap.
With few exceptions, captive species can be sustained in good health for periods equal to or greater than their life spans in the wild. That does not mean that all institutions housing primates are equally successful, but such an outcome is probable if rational and research-based dietary practices are consistently followed. This document is meant to help those who are struggling with this challenge.
When defining nutrient requirements, it is common to search for minimal dietary concentrations that will support maximal responses in important endpoints, such as growth rate of the young. It would be ideal if the same nutrient concentration produced a maximal response in all important endpoints, but that is seldom the case. For example, vitamin E has little effect on growth rate but is exceedingly important in protecting cellular membranes against the peroxidative damage associated with the stress of capture and handling. Furthermore, the degree of protection appears to be positively related to the dose until tissues
are fully saturated; to complicate the matter, tissues of some organs become fully saturated with vitamin E before tissues of others. Thus, as satisfying as it would be to have a single minimal dietary concentration that met the requirements of the whole animal, minimal required concentrations vary with the sensitivity of the endpoint selected. Because nutrient-requirement research in primates is so sparse, we have seldom had the option of identifying a need for more than one endpoint. When such information was available, we tried to relate the minimal requirement to it.
Chapter 1 is a new feature of this revision that was not provided in the previous edition. This chapter is provided to give the reader an understanding of variations in feeding ecology and digestive strategies among primates, which is critical knowledge needed to make informed decisions on feeding primates. The discussion is concerned with foraging strategies in natural ecosystems, species differences in gastrointestinal morphology and physiology, and the significance of these factors in development of appropriate systems of dietary husbandry for captive primates. Because the usefulness of data gathered in field studies of feeding ecology varies with the method used, we discuss the strengths and weaknesses of the methods. Relevant field-study data are tabulated by species, and we illustrate the various gastrointestinal types found among nonhuman primates.
Chapter 2 is a detailed review of energy terms, methods used to determine energy requirements, and energy requirements of nonhuman primates for adult maintenance, growth of young, and pregnancy and lactation. Tables include data on body weight, measured energy expenditures, and estimates of daily metabolizable-energy requirements as multiples of basal metabolic rate.
Chapter 3 discusses first the classification of carbohydrates, their characteristics, digestion, metabolism, and analysis and then discusses analytic systems for fiber, the role of dietary fiber in primate gastrointestinal health, and potentially beneficial dietary fiber concentrations.
Chapter 4 covers proteins, protein sources, and methods of assessing protein quality and requirements. Information on protein-calorie malnutrition and on protein deficiencies and excesses is included. Although quantitative requirements of nonhuman primates for specific amino acids could not be defined, evidence of the essentiality of methionine, lysine, phenylalanine, tryptophan, and taurine is presented. Protein requirements, based on high-quality reference proteins and various criteria, are given in tabular form.
Chapter 5 addresses fats and fatty acids, including classification, nomenclature, digestion, absorption, and metabolism. It describes essential fatty acids and presents estimated requirements for n-3 and n-6 fatty acids. Fatty acid composition of primate milks, potentially harmful fatty acids, cholesterol metabolism, and use of nonhuman primates as models for study of cardiovascular disease are discussed.
Perhaps the most greatly expanded chapter in this revision is Chapter 6, which is a review of mineral nutrition and metabolism, including functions and signs of mineral deficiencies and excesses. In the first edition of this report, which was published in 1978, there was no discussion of sulfur, copper, cobalt, or molybdenum needs of nonhuman primates. In Chapter 6 of this second edition, we are able to provide the first recommendations on mineral requirements for copper and selenium based on a comprehensive review of the scientific literature. Similarly, Chapter 6 provides the first review and discussion of sulfur and cobalt in primate nutrition by the National Research Council Committee on Animal Nutrition. Mineral requirements of several primate species at various ages are given.
Chapter 7 is a discussion of fat- and water-soluble vitamins, including form, function, metabolism, and signs of deficiency and toxicity. Estimates of quantitative requirements of nonhuman primates are provided.
Chapter 8 deals with water as a component of the primate body and with the influence of activity and various environmental factors on the proportion of body water. Water sources, water quality, water turnover, water requirements, and important considerations in providing water for nonhuman primates are discussed.
Chapter 9 presents information on a number of pathophysiologic and life-stage considerations that are relevant to nonhuman-primate nutrition. It includes values of body mass (weight) and body composition, studies of the nutritional needs of neonates, effects of aging on nutritional needs, and relationships of nutrition to aging, obesity, and diabetes. Special considerations for hand-rearing of orphaned or abandoned young animals are covered and recommendations for simulating the composition of milk produced by the mother in normal lactation and the mother’s normal nursing schedule are provided as well as introducing solid food into the diet as the young progress toward weaning.
Chapter 10 discusses primate-diet formulation, effects of feed processing on nutrient loss, factors that influence food intake, and some general suggestions for dietary husbandry. Plants that have been safely used as browse offerings in captivity are listed.
Providing much more detailed and focused recommendations than the general recommendations provided in the previous edition, Chapter 11 tabulates estimated nutrient requirements of model nonhuman primates in six categories (suborder Strepsirrhini; families Hominidae and Pongidae, Cercopithecidae, Cebidae, and Callitrichidae; and subfamily Colobinae). These requirements were estimated on the basis of a thorough review of the world’s scientific literature, input from numerous scientific sources, and the Committee’s best judgment. The requirements apply most satisfactorily to purified diets with high nutrient bioavailability and without substantial adverse interactions among nutrients. The estimates represent minimal requirements without safety allowances.
Also provided in this chapter is a table (Table 11-2) of dietary nutrient concentrations proposed as a guide for formulation of diets containing natural ingredients and intended for post-weaning primates. These have been
expressed per unit of dietary dry matter, assuming an energy density of 4 kcal ME·DMg-1. It should be noted that these nutrient concentrations are intended only as guides, have not been directly tested as a group with any primate, and may not be appropriate for all species or all post-weaning physiologic stages.
Chapter 12 provides tables of the compositions of feeds commonly used in nonhuman-primate diets.
Chapter 13 is a new area of discussion that was not included in the previous edition. This chapter discusses food as a component of environmental enhancement, an application arising from concern for the psychologic well-being of nonhuman primates in captivity. Various food choices and means of presentation are suggested.
The Appendix contains a scheme of taxonomic relationships within the Primate Order, including scientific and common names, plus tables of weight equivalents and weight-unit conversion factors.
The Committee has concluded that appropriately formulated nutritionally complete diets best serve the health and welfare needs of most captive primates. These diets are available in various forms including dry extruded, canned, and gelled. Potential impacts on oral health are among the many factors that must be considered when selecting the form of a diet to be fed.
If fed as size-appropriate, ground, mixed, dry extrusions, oral health will not be compromised. It initially might be necessary to entice some animals to accept dry extrusions by softening them with water, mashed fruit, fruit juices, or nectars. Other foods can be used for behavioral enrichment, but care must be exercised to ensure that their composition and amounts consumed do not distort nutrient concentrations and ratios in total dietary dry matter beyond required minimums and maximums. In general, alternative foods that are high in moisture are least likely to have such effects.
National Research Council. 1972. Nutrient Requirements of Laboratory Animals. Washington, DC: National Academy of Sciences.
National Research Council. 1978. Nutrient Requirements of Nonhuman Primates. Washington, DC: National Academy of Sciences.