Effects of the Partial Substitution of Soybean with Faba Bean(Vicia faba) in the Concentrate on Beef Cattle Performances

The aim of this study was to study the effect of the partial substitution of soybean with faba bean in fattening concentrate for beef cattle. Fifteen Pie-Noire Holstein breed beef cattle (average age and initial liveweight: 5 months and 170 kg, respectively) were used and divided into 3 equal groups receiving a basal diet composed of oat-vetch hay. Animals were supplemented with 3 types of fattening concentrate composed of barley, wheat barn, corn, minerals and vitamins supplements and including, respectively 0 (D1), 16 (D16) and 23% (D3) of faba bean, substituting partially soybean. The three types of concentrate (C0, C16, C23) are almost iso-energetic and iso-nitrogenous. The trial lasted 6 months and animals were weighted twice a month. Intake was determined at 4 times at equal intervals, among all the experimental period. Chemical composition of feeds and characteristics of their in vitro fermentation using cumulative gas production technique, dry matter intake (DMI), live weight gain (LWG) and feed conversion ratio (FCR) were determined. The obtained results showed no significant differences in in vitro gaz production Parameters, in vitro organic matter digestibility (IVOMD) and metabolisable energy (ME) between C0, C16 and C23. The incorporation of faba bean in the fattening concentrate of beef cattle did not induce a significant variation in daily LWG (averaged 1400 g day 1). The differences in DMI were not significant between the three groups and DMI of hay varied from 3.3-5.5 kg day 1. The same trend was noted for FCR (averaged 5.5). It was concluded that substituting soybean with faba bean until a rate of 23% of fattening concentrate allowed the obtaining of the same performances as the conventional concentrate based on soybean representing the main protein source. The economical interest of this substitution may depend on the comparative cost of faba bean.