Nutritional Value Evaluation Of Fermented Rapeseed Meal And Its Effects On Growth And Development Of Broilers

The three tests of this research is to determine the nutritional characteristics of rapeseed meal (RSM) before and after fermentation, to measure metabolizable energy, energy utilization and nutrient utilization of RSM, soybean meal (SBM) and fermentated rapeseed meal (FRSM), and to discuss effects of FRSM on growth performance, immune indicators, antioxidant capacity, blood biochemical parameters and intestinal morphology in broilers.Experiment1:Effects of microbial fermentation on nutritional value of rapeseed meal.Common rapeseed meal was used as raw materials and Bacillus subtilis, Candida utilis and Enterococcus faecalis were selected to study the nutritional characteristics of FRSM. The results showed that crude protein, crude fat, true protein, water-soluble protein and small peptides in FRSM respectively increased by5.98%(P＜0.05),95.30%(P＜0.05),3.99%(P＜0.05),102.32%(P＜0.05) and88.76%(P＜0.05) compared to those in RSM. However, crude fiber contents in FRSM were24.68%(P＜0.05) lower than that in RSM. Total amino acids and total essential amino acid in FRSM respectively increased by12.20%and12.45%compared to those in RSM. In addition, the neutral protease and amylase activity were208.70U/g and227.85U/g respectively after fermentation. The lactobacilli, bacilli and saccharomycete counts increased rapidly and maintained at about8.57,8.93and8.21log CFU/g for the remainder of the fermentation period. Total amino acids in FRSM increased by12.20%(P＜0.05) compared to that in RSM. Most of amino acids contents were significantly increased after fermentation. Oxazolidinethione (OZT) in FRSM was almost undetected.Compared to RSM, glucosinolate, isothiocyanate (ITC), tannin, and phytic acid in FRSM were reduced by96.20%,83.13%,36.36%and19.13%respectively.Experiment2:Study on metabolizable energy, energy utilization and nutrient utilization of fermentated rapeseed meal, rapeseed meal and soybean meal.16healthy rooster were randomly allocated into4dietary treatments with4replicates of1bird per group. Metabolizable energy, acid mino and energy apparent and true utilization of FRSM, RSM and SBM were determined by the method of "TME". The results showed that the apparent and true metabolizable energy of FRSM were11.24and12.30MJ/Kg higher than that of RSM (P＜0.05). The apparent metabolic rate of FRSM was5.11%(P＜0.05) higher than that of RSM, but 6.16%(P＜0.05) lower than that of SBM. In addition, the true metabolic rate of FRSM was6.24%(P＜0.05) lower than that of SBM. The apparent and true utilization of crude protein of FRSM were17.28%(P＜0.05) and17.22%(P＜0.05) higher than that of RSM. The apparent and true utilization of crude fat and crude fiber of FRSM were17.12%(P＜0.05),17.09%(P＜0.05),13.27%(P＜0.05) and12.07%(P＜0.05) higher than those of RSM, and29.35%(P＜0.05),26.43%(P＜0.05),6.52%(P＜0.05) and6.29%(P<0.05) higher than that of SBM. The apparent and true utilization of total amino acid and total essential amino acid on FRSM were the highest comparing to those of RSM and SBM.Experiment3:Effects of fermented rapeseed meal on growth and development of broilers.A total of300, healthy, male Arbor Acres broiler chicks were obtained from a commercial hatchery on day of hatch. Chicks were randomly allocated into5dietary treatments with6replicates of10birds per group. The control birds (Control group) were fed by a corn-soybean based diet, as well as four experimental diets in which part of SBM was supplemented with25%RSM (Group A) or FRSM (Group C) by equal nitrogen. RSM instead of25%SBM protein of based diet plus antibiotics by equal nitrogen used as Group B. And then, FRSM instead of50%SBM protein of based diet by equal nitrogen used as Group D. The results indicated that the average daily gain (ADG) of broilers fed FRSM were superior (P＜0.05) to that of broilers fed RSM over the entire experimental period (d1-42). On day21, spleen index of group C for broilers was significantly higher (P＜0.05) than that of group A and D. The levels of serum T-AOC and T-SOD of group B and D were higher (P＜0.05) for broilers than those of group A. The levels of serum TP, ALB and GLU of group C were significantly higher (P＜0.05) than those of group A. The levels of total protease, amylase and lipase activity in duodenum, jejunum, ileum and cecum of group C on broilers were superior (P＜0.05) to those of the control group. Duodenal and jejunum villus height, and villus height-to-crypt depth ratio of broilers in group C were significantly higher (P＜0.05) than those of the control groups. Jejunum, ileum and cecum crypt depth were significantly lower (P＜0.05) for broilers in group C than the control group. Duodenal bowel wall thickness were significantly decreased (P＜0.05) in broilers in group C compared just with the group A. After42days, bursa index of broilers was increased by group A and D compared with the group D (P＜0.05). The levels of serum T-SOD of group C were higher (P＜0.05) for broilers than those group B. The levels of serum ALB of group B and C were significantly higher (P＜0.05) than those of group A and D. Furthermore, group C had lower (P＜0.05) levels of serum BUN than that of the group A. The levels of total protease, amylase and lipase activity in duodenum, jejunum, ileum and cecum of group B and C on broilers were superior (P＜0.05) to those of the control group. Ileum and cecum villus height, and villus height-to-crypt depth ratio of broilers in group C were significantly higher (P＜0.05) than those of the control groups. While ileum and cecum jejunum crypt depth in group C were significantly poorer (P＜0.05) than that of the control group. And then, duodenal, jejunum, ileum and cecum bowel wall thickness were significantly decreased (P＜0.05) on broilers in group C when compared with group A.In conclusion, the nutritional value, metabolizable energy, and energy, nutrient and amino acid utilization of RSM have improved apparently by the mixed composite microbial fermentation of Bacillus subtilis, Candida utilis and Enterococcus faecalis. FRSM instead of25%SBM protein of based diet by equal nitrogen improve the growth performance, immune function, digestive enzyme activity and intestinal morphology of broilers.