Investigations in growing pigs on the feeding value of a new cultivar of field beans (Vicia faba L.) supplemented with DL-methionine or DL-methionine-hydroxyanalogue

A basal control mixture of barley, soy bean meal and soy bean oil was replaced by 25% of the new field bean-cultivar 'Divine' and the 'resulting two mixtures were supplemented with minerals, trace elements, vitamins and amino acids according to the ideal protein concept. The control diet was adjusted with DL-methionine (DL-Met), the field bean mixture either with DL-Met or DL-methionine-hydroxyanalogue (DL-MHA) assuming biological equivalence on a molar basis for both supplements. The three experimental diets were fed to growing pigs (35-40 kg bwt.). Spontaneous urine samples were analysed separately for determining parameters that characterize the acid-base status of the pigs. There were no significant differences between experimental groups in nutrient digestibilities. The level of bacterially fermentable substances was increased in the diets containing field beans. The field beans contained 14 mg ME/kg DM. There were no significant (p < 0,05) differences in N- and mineral-retentions (Ca, P, Na, K) between the treatments. The stronger alkalinity found in urine after feeding the field bean mixtures resulted from a higher electrolyte balance of the diet.