| Two trials of ideal amino acids balanced ration and addition of phytase in phosphorus -lowered soybean-corn ration were conducted to investigate their effects on layers' productive performance, utilization and excretion of nitrogen and phosphorus, using one-factor entire randomization design.Firstly, 180 35-week-old layers were selected and randomly divided into 2 groups of control and trial, each with 90 birds and with respectively 3 repeats of 30 birds in cages. The control group used conventional diet while the trial group treated with ideal AA balanced diet. At the completion of the test, 4 birds were randomly selected from each repeat for metabolic tests, which showed that although no significant differences were found between these 2 groups in regard to laying rate, egg production, egg weight and FC (P>0.05), the trial group revealed some improvements with significant increase of apparent N and P utility 6.46% (P<0.05) and 9.31% (P<0.05), significant deducing of N excretion (11.93%, P<0.05) and insignificant TP excretion (2.20%, P>0.05), compared with the control.Secondly, by the same group-divided method as above, using 46-week-old layers, the control group was fed with basic diet, and the other was supplemented with phytase. As usual, 4 randomly chosen hens' metabolic tests demonstrated that there were very significant improvements in N and TP apparent utility, i.e. 7.62% (P<0.05) and 44.24% (P<0.01) while their excretion deduced significantly by 13.41% (P<0.05) and 12.07% (P<0.05).This shows that ideal diet with balanced amino acids and addition of phytase in phosphorus -lowered soybean-corn diet for layers could increase N and TP utility and meanwhile decrease their excretion to alleviate environmental pollution by rational technology for nutrition control. |
