Macaca fascicularls (Cynomolgus or Long-Tail Macaque) 
Utilization 
This macaque is second only to the rhesus in the numbers used for medical 
purposes in the United States. Approximately 6,000 were required in 
1977. As is the rhesus, this species is also considered to be a general- 
purpose primate, and for many uses, it is substituted for that species. 
Moreover, for some purposes it is considered preferable, because it 
is more tractable and is slightly smaller. It is likely that the trend 
of substituting the cynomolgus for the rhesus has accelerated as the 
supplies of rhesus have become more and more restricted. However, a major 
field of use in which the cynomolgus has not yet been accepted as a 
substitute for the rhesus is in the safety testing of vaccines, especially 
poliomyelitis vaccine. 
Foreign Sources 
This primate is available from Southeast Aslan countries where it remains 
relatively plentiful. However, the destruction of the habitat and other 
competition from man are causing a continuous reduction in the population 
of this animal in its native countries, and wild populations will certainly 
continue to diminish. Thailand has recently prohibited their export; the 
other source countries for the United States are Indonesia, Malaysia, 
and the Philippines. 
Production in United States 
A few cynomolgus macaques are bred by research institutions for their 
own use. In 1976, the Division of Research Resources, National Institutes 
of Health, awarded a contract to produce 150 of these animals per year 
for the scientific community in general. That goal should be attained 
by 1980. 
Recommendations 
The supply of the wild-caught long-tail macaque will probably remain about 
the same for the next few years. The relative abundance and the widespread 
geographic distribution of this species make it less likely that foreign 
supplies will be totally eliminated in the foreseeable future. However, 
the lack of breeding stock to rapidly expand our rhesus production colonies, 
and the Increasing use of the cynomolgus makes it necessary to place more 
emphasis on the establishment of large colonies of this macaque. The 
United States should have sufficient breeding capacity to meet at least 
half of the nation’s needs for M. fascicularls . Based upon the estimated 1977 
requirements, an ultimate production goal of 6,000 cynomolgus per year 
is proposed. It is recommended that at least four colonies be established 
as soon as possible for an annual production for 1982 of 3,000 and a po¬ 
tential for expansion to 6,000. 
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