The objective of the present work is to develop and evaluate fodder beet chopping machine to obtain beet sizes suitable for small ruminants feeding and to avoid clogging during chopping process. Experiments were carried out at Sakha Agriculture Research Center during winter season of 2009 / 2010 using fodder beet crop (Monovert variety ) to assess the effect of rotor speeds, beet feed rates and beet moisture content on chopper performance (machine productivity, chopping sizes, power requirement and energy consumed and chopping cost ). Results indicated that, the optimum operation condition was obtained at rotor speed of 350 rpm, beet feed rate of 9.9 Mg/h and beet moisture content of 84.15% (w.b). Whereas, the minimum values of energy consumed of 1.411 and 0.748 kW.h/Mg were obtained under these conditions for original and modified machine, respectively. Also, an acceptable beet sizes of 25 and 56 % for < 2 cm however, they were 23 and 21 % for > 2 – 4 cm for the two proposed machines. Meanwhile, machine productivity of 6.278 and 9.165 Mg/h were occurred under the same conditions. Moreover, the cost calculations indicated that the original chopping machine costs about 1.46 times the modified machine.