A Collaborative, Multi-Institutional Growth Standard for Dam-Reared Infant Rhesus and Pigtail Macaques (Macaca...

Area of Science:

• Primate research
• Comparative biology
• Veterinary medicine

Background:

• Existing macaque growth curves are institution-specific and assume linear growth.
• Limited applicability of previous growth standards across diverse research settings.
• Need for updated, unified growth references for infant macaques.

Purpose of the Study:

• To generate novel weight-for-age growth standards for infant rhesus and pigtail macaques.
• To establish a reliable benchmark for assessing healthy development in research colonies.
• To challenge the assumption of linear growth in infant macaques.

Main Methods:

• Multicenter data collection from seven US research institutions.
• Comparison of linear and Box-Cox Power Exponential (BCPE) distribution models.
• Utilized generalized Akaike's information criterion for model selection.

Main Results:

• Multiparameter models with BCPE distribution demonstrated a superior fit to the data compared to linear models.
• Findings indicate that infant macaque growth rates are non-linear within the first year of life.
• Developed weight percentiles and growth velocity charts from the best-fit model.

Conclusions:

• The new growth standards provide a unified, physiologically representative reference for infant macaques (birth to one year).
• These standards are integrated into user-friendly tools (centile charts, MS Excel application).
• Offers crucial guidance for assessing macaque infant health and development across research breeding colonies.