Can rabbits eat soybean meal and if so how much?
Looking on GOOGLE I found information on feeding Soymeal to rabbits. WabbitWiki Shows a long list of rabbit food choices and their content. At least half show soy as an ingredient in the form of hulls, oil, beans and meal. I found only 1 suggestion that soymeal may have a negative effect on breeding does because of natural estrogenic qualities on a site named MannaPro, but I could not find any further information on estrogenic effects.
For the amount to feed at different ages take a look at WabbitPro/ Diet for a comprehensive breakdown with suggestions.
According to Feedipedia on GOOGLE, Soymeal is an important source of proteins for rabbits. Toasted soybean meal is a reference feedstuff for rabbits, and it is generally included at a 15-20% level in their diets (Lebas, 2004). Soybean meal is a very consistent product and one of the least variable protein sources for animal nutrition (Smith, 1986). It also is subject to variables which can change its effectiveness. The potential health issues of genetically-modified soybean and other GM foods have been the matter of considerable debate. While most studies have failed to show deleterious side-effects to GM soybean use (EFSA GMO Panel, 2008), these varieties remain controversial and subject to legal authorisation in some countries.
Lebas, F., 2004. Reflections on rabbit nutrition with a special emphasis on feed ingredients utilization. Proceedings of the 8th World Rabbit Congress, September 7-10, 2004, Puebla, Mexico 2004
Heuzé V., Tran G., Kaushik S., 2015. Soybean meal. Feedipedia, a program by INRA, CIRAD, AFZ and FAO. http://www.feedipedia.org/node/674 Last updated on October 8, 2015, 14:36
Smith, K., 1986. Advances in feeding soybean products. In: World Conference on emerging technologies in the fats and oils industry. Ed: Baldwin A.R., American Oil Chemists’ society
EFSA GMO Panel, 2008. Safety and nutritional assessment of GM plants and derived food and feed: the role of animal feeding trials. Food Chem. Toxicol., 46 (Suppl 1): S2-70