Abstract:
Fourty-eight male and female crossbred rabbits (NZW x Thai Native) with average initial weight at 1,000 grams were used in the experiment. Rabbits were divided equally in sex and number to 8 groups. Each group received the diets base on two different sources of protein (fish meal-FM and rubber seed meal-RSM) and four levels of cassava root meal (CRM), residual from pelleting process. 0, 50, 75 and 100% to substitute broken rice. Growth performances, and the concentrations of thiocyanate thyroxin in the serum were measured. Growth characteristics and the concentration of thyroxin in serum were not affected by the levels of CRM. Increasing the quantity of CRM significantly coincided with an increase in the level of thiocyanate in the serum (P<.01). FM showed lower feed intake, and better feed conversion ratio than RSM, Level of thiocyanate in rabbits serum was obtained from RSM higher than FM (P<.01) and caused the reduction in serum thyroxin levels (P<.05. Used of FM-CRM rations showed a tendency to give better production performances than RSM-CRM. CRM at the levels of 50% to substitue broken rice (20% in the ration) gave the best results in both protein sources.
