International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
The gradual change-over from feeding milk replacer formulas to feeding a total fish diet is<br />
called “weaning”. More research needs to be conducted to determine the most optimal age to<br />
start a slow gradual weaning process. The information available indicates that a giant otter cub<br />
should be around at least 2 ½ to 4 months old when fish is first introduced into its diet <strong>and</strong> the<br />
weaning process is begun. The age at which each cub will first accept fish will vary from<br />
individual to individual, although it seems that milk formula should be given to fulfill 100% of<br />
the giant otter cub’s nutritional needs until it reaches around at least 2 ½ months of age. Not<br />
fulfilling 100% of the cub’s nutritional needs with a milk formula before this age or waiting too<br />
long to begin the weaning process may cause health problems. When the weaning process was<br />
started with cubs that were around approx. 2 ½ <strong>and</strong> 3 or 4 months old, those cubs were<br />
successfully reared. Many wild-born orphaned cubs reared at the institutions that used this<br />
method have been successfully reared (Lazzarini 1998 pers. comm.; McTurk/Duplaix pers.<br />
comm. 2004). Note: the ages of the wild-born animals were estimated. At Hagenbecks<br />
Tierpark (Germany) giant otter cubs, at approximately 8 weeks old, mouthed <strong>and</strong> played with<br />
fish that the mother brought to them; although they only first started swallowing solid fish at 70<br />
days of age (10 weeks old) (Hagenbeck <strong>and</strong> Wünnemann 1992). Later reports explain that two<br />
captive-born h<strong>and</strong>reared cubs at Hagenbecks ingested solid food at 3 months old, although it<br />
was found that they could not digest the fish properly when they were this age. “The feces<br />
contained a lot of undigested fat <strong>and</strong> protein <strong>and</strong> the enzyme level of chymotrypsin was much<br />
lower than in adult animals” (Wünnemann 1995 b ). <strong>Giant</strong> otter cubs are dependent on the<br />
mother’s milk for at least the first 4 months of life (Wünnemann 1995). The cubs continued<br />
nursing mother’s milk when they were around 6 1/2 months old, although only insignificant<br />
amounts were obtained <strong>and</strong> it provided little nutritional value. The weaning process can occur<br />
over a varying time period until the cubs choose to reject the milk formula (Duplaix/McTurk &<br />
Wünnemann pers. comms. 2004). Cubs may choose to reject milk formula from one, a couple,<br />
a few, or even several months after accepting fish within their diet for the first time (pers.<br />
comms. of the h<strong>and</strong>rearers listed within this manual). Sometimes they may also reject milk<br />
formula from 2 to 3 weeks after they start to eat fish within their diet. Caution must be taken<br />
although, as the offering of milk formula should not be eliminated or reduced in amount too<br />
soon or problems may result. See Chapter 5 Section 12 for details.<br />
Reports indicate that giant otters do not require milk to meet their basic nutritional needs when<br />
they are at the age of around 6 ½ months <strong>and</strong> older (note: this does not mean that their needs can<br />
not be met at an earlier age; see the paragraph above). At one institution, some h<strong>and</strong>reared<br />
otters although have been reported to drink some supplemental milk formula (i.e. in addition to<br />
their fish diet), even up to 10 months of age <strong>and</strong> they were reported to be successfully reared<br />
(Duplaix/McTurk, pers. comm. 2004). H<strong>and</strong>rearers should although take care that otters wean<br />
themselves fully of all milk formula within a reasonable time period. It seems that by at least 6<br />
½ months of age, <strong>and</strong> up to an age that does not exceed approx. 10 months [based on the<br />
outcome of the h<strong>and</strong>reared otters just mentioned above], the cub should be eating a total fish<br />
diet <strong>and</strong> should no longer be drinking any milk formula (Duplaix/McTurk & Wünnemann pers.<br />
comms. 2004). Scientific research on the meeting of nutritional needs of h<strong>and</strong>reared giant otters<br />
at various ages should be conducted to establish scientific guidelines for the weaning process.<br />
The physical <strong>and</strong> behavioral development of each wild orphaned <strong>and</strong> captive-born individual<br />
h<strong>and</strong>reared should be thoroughly documented <strong>and</strong> studied. Field researchers are currently<br />
requesting information on cub body weight, body length, <strong>and</strong> age correlation <strong>and</strong> behavioral <strong>and</strong><br />
physical ability development in order to use as a reference source for wild populations. A<br />
complete age - weight - length growth curve needs to be developed for h<strong>and</strong>reared giant otters.<br />
I.e. measurements should be taken from the earliest age to the latest age that is possible. (See<br />
62