Home > Our Research > Projects: Sumatran Rhino Report

Managed Sumatran rhino breeding in absence of ultrasound or progesterone assay

Without ultrasound or progesterone assay as tools for reproductive management of Sumatran rhinos, daily introductions are necessary in order to avoid missing the short period of female receptivity characteristic of these induced ovulators. Based on discussions with Steve Romo, we feel strongly that this strategy of forced daily introductions of captive Sumatran rhino with the hopes of eventually finding the day of receptivity and breeding may be counterproductive for the following reasons:

• Increased risks associated with male injuring female

• Potential detrimental and possibly long-term behavioral modifications to subject rhinos secondary to the repeated aggression of forced introductions

• Lost time and effort that could be directed in more productive ways

• Inadvertent missed breedings secondary to staff shortages, male overuse, etc.

• Not consistent with the biology or ecology of this highly solitary and seclusive forest mammal

 

Prediction of preovulatory follicle for purpose of timed breeding,

Based on previous cyclic pattern (ie. 21 day cyclic period) or use of current serum progesterone assay, ovarian function should be examined via ultrasound in the late diestrus period (day 16-18) in preparation of upcoming female estrus. The preovulatory follicle will enlarge to the size of 22 to 26 mm immediately prior to the period of female receptivity. The follicle diameter will quickly become a highly accurate and quick measure of female receptivity.

Documentation of ovulation and luteal formation

In corroboration with serum progesterone assay, the documentation of ovulation and subsequent luteal formation is essential information to assure normal female reproductive function. This information also allows documentation of ovulation timing, knowledge fundamental to any future advanced reproductive techniques in Sumatran rhino. more »

page 31