Variations in nutritional and antinutritional contents among faba bean cultivars and effects on growth performance of weaner pigs

A total of 84 faba bean samples, 11 of color-flowered and 5 of white-flowered cultivars, were used to investigate variations in nutritional and antinutritional components among faba beans. There were no effects of flower color, but significant effects (P < 0.05) of cultivar within flower color were observed for starch, crude protein (CP), and neutral detergent fiber. The color-flowered cultivars had a greater content of condensed tannins (CT) and the white-flowered cultivars a greater content of vicine and convicine. Within the color-flowered cultivars, Alexia had the greatest (7.68 g/kg DM) and Julia the smallest (6.05 g/kg DM) CT content. The enzymatic in vitro digestibility of DM, OM, CP, and calculated standardized ileal digestibility of CP was greater (P < 0.05) in white flowered than color-flowered cultivars. However, on a yield per hectare basis, color-flowered cultivars yielded more (P < 0.05) standardized ileal digestible (SID) CP and starch than white-flowered cultivars. Based on these results, 3 cultivars were selected for a growth study with weaner pigs. Gloria (a white-flowered cultivar) and Fuego and Julia (both color-flowered) were selected for deviating content of SID CP, where Julia had more SID CP than Fuego. The control diet contained soybean meal and potato protein as the main protein sources, whereas the experimental diets contained 10 and 20% Julia or Fuego (Julia10, Julia20, Fuego10, Fuego20) and 20% Gloria (Gloria), with a total of 6 experimental diets. The diets were fed to 300 pigs in a randomized complete block design with 5 groups of pigs over time (blocks), with each block comprising 6 pens of 10 piglets. The pigs were weaned at 5 weeks of age and received the experimental diets ad libitum for 27 days, starting immediately after weaning. For the total experimental period, pigs fed Julia10 and Julia20 had the greatest average daily body weight gain (P < 0.05) and pigs fed the control and Fuego20 had the smallest. Average daily feed intake was greater (P < 0.05) in pigs fed Julia10 and smaller in pigs fed Fuego20 (P < 0.05) than in pigs fed the other diets. Feed efficiency was greatest in pigs fed Julia20 and smallest in pigs fed the control. In conclusion, faba bean is a viable protein source in well-balanced diets to weaner pigs, with cultivar rather than flower color determining the nutritional value.