In Europe, several antinutritionnal factors (AF) limit the use of animal feeding, of different plant products rich in proteins. Main problems are with:
- glucosinolates of rape seed
- saponines of lucerne
- alcaloids of lupins
- vicine and convicine in fababean.
In order to reduce these factors by the genetic tool, and complicated by the fact the genetic determinism of these factors content is not always monogenic, plant breeders need fast and cheep ways to screen among a large number of accessions. For this purpose, a physical test (near infrared reflectance spectroscopy: NIRS) and/or a biological test with small animals (growth performances of Tenebrio molitor L.) have been tested or adapted to these different A F.
Rapid screening methods have been developed for the detection and evaluation of antinutritional factors in protein producing crops. The use of near infrared (NIR) techniques appear to give reliable correlations for glucosinolates in rapeseed and to a lesser extent for saponins in lucerne.
Correlations were better in tests whith larvae of the mealworm (Tenebrio molitor). Feeding experiments on cockerels and chickens confirmed the susceptibility of these animals to the substances mentioned; the effect of saponins in lucerne could be depressed by cholesterol supplementations.
The experiments gave unsatisfactory results for accurate determinations of alkaloids in white lupins and for glucosides of faba bean, the latter inducing haemolytic anaemia in animals.
For most products except alcaloids of lupins, reference technique of extraction by HPLC was available and consequently was applied to a large number of genotypes of each species. In the case of Vicia faba it had to be simplified. A representation sample of the genetic variability for AF content available has been defined. On this set of genotypes, using a Technicon "IA500", calibration of near infrared reflectance spectroscopy has been searched. Introducing genotypes of rapeseed and lucerne of known AF content in diets, growth parameters of Tenebrio molitor and chicken have been measured.