Marmoset Metabolism, Nutrition, and Obesity

Abstract

The use of marmosets as nonhuman primate models of human disease has undergone rapid expansion in the United States in the last decade, with an emphasis in the field of neuroscience. With this expanding need, there has been an increase in the formation of small marmoset colonies. The standardization in care and husbandry techniques for marmosets has historically lagged behind other established nonhuman primate models, resulting in a great deal of variation in practices between colonies. There remains a lack of consensus and evidence-based recommendations regarding best standards for nutrition, enrichment, weight management, and diagnostics for clinical metabolic disease. Marmoset base diets vary broadly in their nutritional value, and therefore the physiological responses to these diets also vary broadly. In this review, we briefly outline what is known about nutrition for captive marmosets and highlight what is known regarding metabolic dysfunction and obesity.

Comparing different strategies to reduce hepatocellular damage in obese common marmosets (Callithrix jacchus)

“…However, recent focus has shifted to obesity in common marmosets 4 . Prevalence of marmoset obesity ranges from 20% to 40% in published reports from multiple captive colonies 5,6 . At our institution, approximately 35% of marmosets 2 years of age or older are overweight.…”

“…9 There is no standardized body weight guideline for what constitutes an obese marmoset, and institutions vary widely in their definition of obesity. 6 At our institution, any animal with a body weight of 450 g or greater is considered obese. However, body condition score is also utilized to determine obesity as age, body size, and body composition also factor into obesity.…”

“…4 Prevalence of marmoset obesity ranges from 20% to 40% in published reports from multiple captive colonies. 5,6 At our institution, approximately 35% of marmosets 2 years of age or older are overweight. One proposed explanation for the high prevalence of obesity in captive marmoset colonies is lack of standardization of diet composition.…”

“…Institutions often feed a "cafeteria-style diet" to their marmosets, with only 75% of an animal's daily calories coming from the base diet and the other 25% coming from edible enrichment. 6 The result is a large variation in animals' caloric and nutritional intake that can lead to fluctuation in body weight and body condition in captive colonies. Previous studies have also shown that individual marmosets have different levels of dry matter digestibility, adding another variable to the amount of nutrients each animal receives from their diet.…”

The Common Marmoset—Biomedical Research Animal Model Applications and Common Spontaneous Diseases

“…32 In contrast to weight loss, obesity can be a problem in some colonies. 112 A 500-g marmoset is considered obese. There may be a relationship between obesity and prenatal factors such as litter sizes and birth weights, but mechanisms have not been explored.…”