There was also significant production and studies in Japan and Korea in the middle of the 20 th Century. Currently, most of the mulberry research for sericulture takes place in China and India, with several institutions actively involved in both countries. For fruit and for silk production, studies are carried out in the Central Asian Republics of the ex-Soviet Union, for example in Uzbekistan, Turkmenistan, Tadjikstan and Kyrgystan. Studies on mulberry as animal feed are or have been conducted in Japan, India, Tanzania, Kenya, Costa Rica, Colombia, Mexico, San Salvador, Guatemala, Brazil and Cuba. The most active research on mulberry for animal feeding is currently taking place in Cuba.
Research includes agronomic aspects, harvesting modalities, forage preservation and animal trials.
It is not by chance that mulberry germplasm is causing so much interest as an alternative high quality feed for farm animals. Over several hundred, and perhaps thousands, of years, mulberry species and varieties have been selected and improved to feed the silkworm, which is nutritionally very demanding. Although, in general terms, the principles of mulberry cultivation for sericulture purposes should apply to its cultivation as forage for feeding farm animals, there are certain important differences. Frequency of harvesting and in particular planting density, can be intensified if the goal is to feed ruminants, since the quality is already high enough and the main purpose would be to increase overall biomass yields. Individual leaf picking, as is commonly practiced for silkworm feeding, could be only justified for small scale or family units of mini-livestock, e.g. snails, guinea pigs or rabbits.