Abstract
To estimate the value of metabolizable energy (ME) of soybean curd residue (SCR) (experiment 1), a semi-purified diet was substituted by SCR at 0 (CP; 18.4%, ME; 3.39kcal/g, Gross energy (GE); 4.16kcal/g), 10 (CP; 21.0%, GE; 4.35kcal/g) and 20% (CP; 23.9%, GE; 4.48kcal/g) levels. Chromic oxide was mixed with each SCR diet at a 0.3% level to measure digestibility. A total of 4 Single Comb White Leghorn cockerels of each group were given water and each diet ad libitum for 6 days preliminary adaptation period, then feces from each bird were collected 2 times a day for 4 days. According to the glucose substitution method, ME values of SCR was estimated from the difference between ME of SCR containing diet and ME of reference diet. From this method, ME of SCR was determined as 2.70kcal/g DM.
To investigate the effects of dietary SCR on feed intake and body weight gain in broiler chicks (experiment 2), all the diets were formulated to contain same amount of nitrogen (CP; 21.0%) and energy (ME; 3.00kcal/g). SCR was included at 0, 5, 10 and 15% levels in mash and pellet forms. Five broiler chicks were given each experimental diet and water ad libitum from 7 to 28-d-old. Five trials with same protocol were carried out using a total of 200 birds. In mash diets, the feed intake showed a tendency to decrease, but the body weight gain tended to increase with increasing the SCR levels, resulting in improved feed conversion ratio. However, in pellet diets, both feed intake and body weight tended to decrease due to inclusion of SCR, resulting in the impairment of feed conversion ratio. Although feed intakes were higher in each pellet diet than those of mash diets, the body weight gain did not show a definite increase. These results suggest that SCR could be incorporated into broiler chick diets up to 15% in mash form.
