Evaluación proteínica y energética de semillas tratadas de Canavalia empleadas como alimento para aves en el trópico

Legumes are a very important protein resource in tropical areas both for human and animal consumption. Among them, Canavalia ensiformis is used widely in many parts of the world. The most important inconvenience of the use of Canavalia is the content of anti-nutritional factors such as phytates, cyanogenic glycosides and tannins among others. Various treatments using heat are available to eliminate toxicity, but high temperature reduces protein digestibility and energy concentration. Treatments using low heat in combination with salting or the separation of the protein fraction from the rest of the constituents of the grain, may be alternative methods to eliminate toxic elements. The objective of these trials was to reduce the antinutritional factors and to determine the possible change in protein digestibility and TME content of Canavalia ensiformis after detoxification using low heat combined with salting-in or obtaining a protein concentrate, in order to incorporate it into poultry diets. Beans were grinded and submitted to two different experimental treatments and control: Detoxification using an acidified saline solution with low heat (ASOL-H); and an extraction of its protein concentrate (PC); raw Canavalia was used as Control. The following toxic compounds were analyzed: phytates, cyanogenic glycosides, tannins, trypsin inhibitors, lectins and canavanine, as well as protein digestibility and true metabolic energy. Means and standard deviation were calculated and data was also analyzed using the General Lineal Model (GLM) procedure to detect effects of treatments. Results showed a sharp reduction of antinutritional factors due to treatments (P>0.05). PC reduced more efficiently all toxic substances. Protein digestibility and TME were not affected by the use of either method of detoxification. Therefore the use of both treatments, but specially PC, may be advantageous to eliminate toxicity preserving the protein and energy value of Canavalia to be used in poultry diets.