Defining predictive factors for reproductive output in captive common marmosets (Callithrix jacchus)

Area of Science:

• Primate reproductive biology
• Animal science
• Veterinary medicine

Background:

• Reproductive output in common marmosets (Callithrix jacchus) varies significantly.
• Factors influencing litter size in captive marmosets require further investigation.

Purpose of the Study:

• To identify key factors determining litter size in common marmosets.
• To explore the influence of maternal and paternal characteristics on marmoset litter size.

Main Methods:

• Retrospective analysis of clinical records from a captive breeding colony over 9 years.
• Involved 26 dams and 22 sires, with data on 115 litters.
• Multivariate statistical modeling was employed to analyze the data.

Main Results:

• Marmosets born in smaller litters (≤2 offspring) tended to produce smaller litters themselves.
• Maternal body weight at conception significantly impacted subsequent litter size.
• Litter size was influenced by parturition number, with increased odds of triplets after the second parturition.
• Maternal age, interbirth interval, and season of birth did not significantly affect litter size.
• Paternal factors had a negligible effect on litter size.

Conclusions:

• Dam's original litter size, maternal body weight at conception, and parturition number are primary determinants of marmoset litter size.
• Maternal litter size is a novel factor identified as a significant determinant of offspring litter size in marmosets.
• Further research into the role of maternal litter size in marmoset breeding is recommended.