Effect of living conditions on biochemical and hematological parameters of the cynomolgus monkey

Abstract

The cynomolgus monkey (Macaca fascicularis) has been increasingly used in biomedical research. Although living conditions affect behavioral and physiological characteristics in macaques, little data is available on how living conditions influence blood-based parameters in the cynomolgus monkey. We hypothesize that there are significant differences in serum biochemical and hematological parameters in single-caged versus socially housed cynomolgus monkeys, and that age and sex influence the effect of living conditions on these parameters. Sixty single-caged and 60 socially housed cynomolgus monkeys were segregated by age group (juvenile, adult) and sex. The effects of living condition, age, sex, and the interactions between these factors on commonly reported serum biochemical and hematological parameters were analyzed by a three-way analysis of variance (ANOVA). Then, the differences between single-caged and socially housed subjects were tested in each parameter by Student's t-test. Creatinine, glucose, triglyceride, alanine aminotransferase, red blood cell volume distribution width (SD, CV), median fluorescence reticulocyte percentage, white blood cell and basophil counts, and monocyte (count, %) were lower in single-caged subjects. Blood urea nitrogen and globulin were lower in single-caged juveniles and adults, respectively. Red blood cell count, hemoglobin, hematocrit, and neutrophil (count, %) were higher, and reticulocyte and lymphocyte (counts, %) were lower, in single-caged juveniles. Mean corpuscular hemoglobin concentration was higher in single-caged subjects (but more pronounced in adults). Total protein was higher in single-caged juvenile males and lower in single-caged adult females. Alkaline phosphatase was lower in single-caged juvenile females. Mean corpuscular hemoglobin was higher, and high fluorescence reticulocyte percentage was lower, in single-caged adult males. In conclusion, living conditions significantly affect several serum biochemical and hematological parameters in the cynomolgus monkey, and these effects vary by age and sex. As this macaque is commonly housed under different living conditions, these findings should aid researchers in avoiding inaccurate conclusions concerning this species.

Post‐weaning environmental enrichment improves BDNF response of adult male rats

“…Enriched animals showed higher hematocrit value relative to SC rats. While some studies have found no effect of housing condition on hematocrit value (Tsai et al, 2002;Watson, 1993), the others have reported lower hematocrit value in subordinate animals (Wehle et al, 1978;Xie et al, 2014). Being subordinated would result in social stress (Fiore et al, 2003).…”

Laboratory rhesus macaque social housing and social changes: Implications for research

“…Outdoor and social group housing, either harem or multi‐male/multi‐female groups is the gold standard for housing macaques because it replicates, as closely as possible, the normal social environment of macaques [Bernstein, ]. This results in the healthiest and most normal macaques, both behaviorally and biologically, and thus optimal welfare [Capitanio et al, ; Fontenot et al, ; Karere et al, ; O'Neill et al, ; Vandeleest et al, ; Westergaard et al, ; Xie et al, ]. Social life is so critical that captive rhesus macaques in environments with no or limited social interaction frequently develop abnormal behavior and physiology [Anderson & Chamove, ; Capitanio, ; Eaton et al, ; Gottlieb et al, ; Harlow et al, ; Lutz et al, , ; Novak, ; Rommeck et al, ; Suomi et al, ; Vandeleest et al, ].…”

“…Exceptions to social housing requirements occur, however, when scientifically justified and approved by an institutional oversight committee (Institutional Animal Care and Use Committee or IACUC in the US) for a project or when efforts to socially house an animal are not successful. Accumulating evidence suggests that not all types of social housing provide the same benefits, and further, that changes to animals’ social housing can alter behavior and physiology in ways that indicate reduced welfare and quality as a research model [Capitanio & Cole, ; Clarke et al, ; DiVincenti & Wyatt, ; Gilbert & Baker, ; Gust et al, ; Xie et al, ]. Therefore, accomplishing social housing in a way that both benefits animal welfare and is compatible with research goals can be a challenge.…”

Socialization of adult owl monkeys (Aotus sp.) in Captivity

“…Given the benefits documented for socializing same‐sex pairs in primates (e.g. Baker et al, []; Becker et al []; DiVincenti et al []; Duarte et al []; Lee et al []; and Xie et al []) these results suggest that giving the owl monkeys the opportunity to live with another conspecific is a viable option when developing a housing plan for owl monkeys. Though there is some risk in forming non‐species typical pairs, the animals are under constant observation during the pairing process, and provides a potentially high benefit to the animals.…”