Amino Acid Digestibility Of Rapeseed Meals By Broilers

The objective of this study is to assess the variability in amino acid digestibilityof rapeseed meals for broilers, and the effect of a multiple enzyme product on aminoacid utilization by broilers. The study included three experiments described as below.Experiment1. Variation in amino acid content of rapeseedmeals from different regionsTotal70rapeseed meal samples,50kg per sample, were sourced from differentlocations. These samples were from different processes, but were met the China feedstandard. Samples were analysed for all amino acids contents. The results showed theaverage content for ASP, SER, GLU, GLY, ALA, TYR, PRO, and CYS were2.64%,1.52%,6.96%、1.88%,1.72%,0.93%,2.27%and0.87%, respectively. The averagecontent for THR, VAL, MET, ILE, LEU, PHE, LYS, HIS, ARG, and TRP were1.63%,1.90%,0.63%,1.48%,2.60%,1.45%,2.03%,0.96%,2.18%and0.21%；Except for ASP, SER, MET and TRP, the variability in amino acid content was lessthan10%for70samples。Experiment2. Amino acid digestibility of rapeseed mealsfor broilersTen rapeseed meals were selected based on their amino acid profile and NIRspectrum. Total528Cobb broilers were allocated into11treatments at day24of age,with8replicates per treatment and6birds per replicate. Semi-purified diet was usedto test the endogenous amino acid loss. The result showed no difference in bothapparent ileal and true ileal digestibility of amino acids between male and femalebirds. There was a significant difference in both apparent ileal and true ilealdigestibility of amino acids among the10rapeseed meal samples (P<0.05). Sample6from Wuwei had a higher digestibility than other rapeseed meal samples.Experiment3. Effect of multiple enzymes on thedigestibility of amino acids by broilersTotal432Cobb broilers of24days of age were selected to assess the effect of amultiple enzyme products on the digestibility of amino acids of4rapeseed meals withvariable quality. Birds were allocated into9treatments (4treatment without enzyme, 4treatment with enzyme,1treatment as semi-purified diet), with8replicates/treatment and6birds per replicate. The result revealed that adding enzymeimproved apparent and true ileal protein digestibility by4.7%and3.8%, respectively.The application of multiple enzyme also increased the digestibility of amino acids inrapeseed meals by4-7%(P<0.05).